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Early development of Betta splendens under stereomicroscopy and scanning electron microscopy
Abstract
Betta splendens
is a very important ornamental species. The current paper describes the embryonic and larval development of
B. splendens
under stereomicroscopy and scanning electron microscopy. Eggs and larvae from natural spawning were collected at different developmental stages at previously established intervals and analysed. The eggs of
B. splendens
are yellowish, clear, spherical, demersal, translucent and telolecithal with a large amount of yolk. Between 0–2 h post-initial collection (hpIC), the eggs were at the egg cell, first cleavage and morula stages. The blastula stage was identified at 2–3 hpIC and the early gastrula phase was observed at 3–4 hpIC with 20% epiboly, which was finalized after 13–18 hpIC. When the pre-larvae were ready to hatch, the appearance of somites and the free tail were observed, at 23–25 hpIC. At 29 hpIC, the majority of larvae had already hatched at an average temperature of 28.4 ± 0.2°C. The newly hatched larvae measured 2.47 ± 0.044 mm total length. The mouth opened at 23 h post-hatching (hPH) and the yolk sac was totally absorbed at 73 hPH. After 156 hPH, the heart was pumping blood throughout the entire larval body. The caudal fin, operculum and eyes were well developed at 264 hPH. When metamorphosis was complete at 768 hPH, the larvae became juveniles. The current study presents the first results about early development of
B. splendens
and provides relevant information for its reproduction, rearing and biology.
... Berdasarkan data pada Tabel 1 dapat dilihat bahwa lama waktu pengeraman telur di dalam mulut induk jantan dari mulai memijah sampai menetas adalah enam hari. Waktu penetasannya cukup lama, berbeda dengan B. imbellis yang memerlukan waktu sekitar 29 jam 04 menit (Cindelaras et al., 2015), 35 jam (Narwati, 2012), dan pada B. splendens sekitar 38 jam (Duarte et al., 2012;Valentin et al., 2013;Annur et al., 2016). ...
... Selain pergerakan aktivitas enzim juga berperan dalam pelunakan chorion sehingga mudah untuk dipecahkan oleh embrio (Blaxter, 1969). Pada ikan B. imbellis, larva cupang menetas setelah mengalami perkembangan selama 29 jam 04 menit (Cindelaras et al., 2015), hal yang sama seperti pada B. splendens menetas selama 29 jam (Valentin et al., 2013). ...
... Periode perkembangan larva berlangsung sampai umur 39 hari. Periode ini berlangsung lebih lama dibandingkan dengan periode perkembangan larva B. imbellis yang berlangsung sampai umur 23 hari pada suhu ruang (Rahmawati & Kusrini, 2013) dan 32 hari pada B. splendens (Valentin et al., 2013 Sehari setelah menetas, larva mempunyai kuning telur yang cukup besar dengan diameter 1,07 mm; sudah ada pigmentasi, bintik mata sudah terlihat namun belum berfungsi, mulut belum membuka, organ pencernaan belum terbentuk, dan sirip belum terbentuk (Gambar 1a); dan pada hari kedua setelah menetas, sirip ekor larva mulai berkembang dan pigmentasi sudah lebih jelas (Gambar 1b). Larva berwarna transparan agak kekuningan terutama pada kuning telur, pembuluh darah terlihat jelas terutama di bagian depan kuning telur. ...
Salah satu jenis ikan cupang alam yang menarik perhatian adalah cupang Betta rubra Perugia, 1893; yang merupakan jenis endemik dari perairan Banda Aceh. Status B. rubra di habitat aslinya sudah mulai sulit diperoleh sedangkan budidayanya belum berkembang. Oleh karena itu, informasi tentang embriogenesis dan perkembangan stadia awal ikan B. rubra sangat diperlukan untuk mendukung keberhasilan pengembangbiakannya. Penelitian ini bertujuan untuk mengetahui embriogenesis dan perkembangan larva ikan B. rubra. Telur dan larva yang digunakan berupa hasil pemijahan alami B. rubra di Balai Riset Budidaya Ikan Hias, Depok. Parameter yang diamati yaitu fase embriogenesis, perkembangan larva, dan benih ikan B. rubra. Pengamatan embriologi di mulai setelah ikan memijah sampai telur menetas, sedangkan perkembangan larva di mulai dari larva menetas sampai menjadi benih atau perkembangan telah sempurna. Pengamatan dilakukan setiap hari di bawah mikroskop binokuler Olympus SZX9 perbesaran 8-25 kali. Hasil penelitian menunjukkan bahwa perkembangan embrio telur B. rubra terjadi selama enam hari atau 144 jam hingga menetas menjadi larva pada suhu 27°C-28°C. Perkembangan embriogenesisnya yaitu hari pertama setelah memijah di mulai dengan pembelahan awal; hari kedua: blastula; hari ketiga: gastrula; hari keempat: pembentukan bakal kepala dan ekor; hari kelima: pembentukan ovtic vesicle dan notochorda; hari keenam: menetas. Perkembangan larva H-3—H-4 setelah menetas mata dan mulut mulai membuka; H-5—H-6: terbentuk anus dan kuning telur habis; H-7: peralihan pakan (indogeneous ke exsogeneous) dan metamorfosis terjadi 39 hari atau 936 jam setelah menetas.Betta rubra Perugia, 1983 is an endemic ornamental fish found in the swamp areas of Banda Aceh. Due to its appealing physical appearance, B. rubra wild population has been heavily exploited. Current aquaculture technology of the species is not yet available which implies an imminent threat to the conservation of this species. Therefore, the domestication the fish species is the first important step toward developing the aquaculture technology of the species which requires specific information on embryogenesis and the development of the early stadia B. rubra. This study aimed to determine embryogenesis and larval development of B. rubra. The eggs and larvae used from the natural spawning of B. rubra wild parents reared in the facility of the Ornamental Fish Cultivation Research Center, Depok, Indonesia. The parameters observed were the embryogenesis and early stages development of the fish from larvae to juvenile. Observation of embryogenesis started from eggs fertilization until hatching. The development of larvae was observed from post hatching until fully developed as fish juvenile. Embryonic and larval development were monitored daily using an Olympus SZX9 binocular microscope with 8x-25x magnification. The results showed that the embryogenesis of B. rubra lasted for six days or 144 hours until it hatched. The development stages of the embryogenesis after fertilization are as follow: division phase on the first day; blastula on the second day; gastrula on the third day; formation of heads and tails on the fourth day; formation of ovtic vesicles and notochordas on the fifth day; hatch on the sixth day. Larval development consists of: eyes and mouth begin to open at three to four days after hatching; anus is formed and the yolk is gone between the fifth and sixth days; intermediate feed (indogeneous to exsogeneous) at seventh day and metamorphosis at 39 days or 936 hours after hatching.
... Establishing genetic tools in betta will advance their use as a powerful experimental system to study developmental processes and behavioral traits. Genetic manipulation of betta is facilitated by their reproductive biology: betta fertilize externally and produce clutches of 250 eggs, each with a relatively large diameter of 1 mm (Valentin et al., 2015;Lichak et al., 2022). This enables the microinjection of zygotes in a similar manner to methods for genetic manipulation of zebrafish (Danio rerio) and medaka (Oryzias latipes). ...
... This enables the microinjection of zygotes in a similar manner to methods for genetic manipulation of zebrafish (Danio rerio) and medaka (Oryzias latipes). Nevertheless, the asynchronous egg fertilization resulting from a protracted mating process that can last many hours, coupled with a short interval between fertilization and cell division, as well as a thick chorion, constitute significant challenges for genetic manipulation (Valentin et al., 2015;Lichak FIGURE 1 CRISPR/Cas9-mediated knockout in betta (A) Experimental scheme for generating knockout betta. (B) Efficiency of knockout generation in P0, as determined by a T7EI assay. ...
Betta splendens, also known as Siamese fighting fish or “betta,” is a freshwater fish species renowned for its astonishing morphological diversity and extreme aggressive behavior. Despite recent advances in our understanding of the genetics and neurobiology of betta, the lack of tools to manipulate their genome has hindered progress at functional and mechanistic levels. In this study, we outline the use of three genetic manipulation technologies, which we have optimized for use in betta: CRISPR/Cas9-mediated knockout, CRISPR/Cas9-mediated knockin, and Tol2-mediated transgenesis. We knocked out three genes: alkal2l, bco1l, and mitfa, and analyzed their effects on viability and pigmentation. Furthermore, we knocked in a fluorescent protein into the mitfa locus, a proof-of-principle experiment of this powerful technology in betta. Finally, we used Tol2-mediated transgenesis to create fish with ubiquitous expression of GFP, and then developed a bicistronic plasmid with heart-specific expression of a red fluorescent protein to serve as a visible marker of successful transgenesis. Our work highlights the potential for the genetic manipulation of betta, providing valuable resources for the effective use of genetic tools in this animal model.
... With regard to reproduction, the male constructs a bubble nest in which he attaches the eggs and the embryos develop under his care [4,38,44]. The hatching takes place between 29-and 38-h-post-fertilization (hpf) at 28 • C, according to different authors [12,47]. ...
... B. splendens is native for South East Asia and was domesticated for centuries [38]. Its selective breeding aims fighting and ornamental purposes like looking constantly for new color patterns and fin shapes [32,47]. This last aspect is very important due to the keeping of ornamental fishes is one of the most popular hobbies around the world [50]. ...
The Siamese fighting fish (Betta splendens) has great importance as an ornamental aquarium fish as well as laboratory model species. Due to its rapid development, a cooling-embryo protocol could provide some advantages in their transportation, embryonic synchronization, and optimization of hatcheries. In this context, this work aimed to develop a protocol to storage B. splendens embryos at two temperatures (5 and 14 °C), testing three cryoprotective solutions (S1: 0.5 M sucrose, 1.5 M methanol; S2: 0.25 M sucrose, 0.75 M methanol; and S3: 0.125 M sucrose, 0.375 M methanol) and evaluating the quality of the larvae obtained. Moreover, a method to isolate the embryos from the bubble nest constructed by the male and to incubate them without parental care was applied in this study. The cooling assays were done using embryos of 24-hours-post-fertilization at 26 °C and the results demonstrated that it is possible to store these embryos deprived of cryoprotectants at 5 °C for at least 6-hours without negative effects. Meanwhile, S2 and S3 were the most suitable solutions for its storage for 9-hours at 5 °C or 24-hours at 14 °C, obtaining 77% hatching and 52% normal larvae in the first case or 88% hatching and 81% larvae with mild abnormalities in the second one. Indeed, type and frequency of larval abnormalities were evaluated and, remarkably, a partial recovery was described on malformed larvae from embryo cooled at 14 °C. Finally, this work is the first report about the cooling of B. splendens embryos and establishes the conditions for further studies on this field with this species.
... For male Siamese fighting fish, Betta splendens, territories are a key resource because they provide space to build bubble-nests for their offspring, which plays a significant role in reproductive success [27][28][29][30]. The high fitness value of territory for males looking to build nests, and the even higher value for males protecting existing nests, underlies much of the B. splendens well-defined agonistic repertoire, including their display, attack and use of visual cues from opponents to assess their ability (RHP) and compare it to their own [31][32][33][34][35][36]. ...
... Bars indicate the standard error and effect sizes are indicated by Cohen's d where appropriate [**P ≤ 0.01] exceeds resource and contest costs. This relies on the contribution of bubble nests to reproductive success by preparing fish for mating and constituting investment in parental care [27][28][29][30]. The effects of nest presence on contest motivation are in line with previous evidence showing that the defence of territory with nests is a paternal priority for male Siamese fighting fish [28,31] and that bubble-nest holders exhibit elevated defensive aggressiveness against other males [32,33]. ...
Background
Competition is considered to rely on the value attributed to resources by animals, but the influence of extrinsic stressors on this value remains unexplored. Although natural or anthropogenic environmental stress often drives decreased competition, assumptions that this relies on resource devaluation are without formal evidence. According to theory, physiological or perceptual effects may influence contest behaviour directly, but motivational changes due to resource value are expected to manifest as behavioural adjustments only in interaction with attainment costs and resource benefits. Thus, we hypothesise that stressor-induced resource devaluations will impose greater effects when attainment costs are high, but not when resource benefits are higher. Noise may elicit such effects because it impacts the acoustic environment and imposes physiological and behavioural costs to animals. Therefore, we manipulated the acoustic environment using playbacks of artificial noise to test our hypotheses in the territorial male Siamese fighting fish, Betta splendens.
Results
Compared to a no-playback control, noise reduced defense motivation only when territory owners faced comparatively bigger opponents that impose greater injury costs, but not when territories also contained bubble nests that offer reproductive benefits. In turn, nest-size decreases were noted only after contests under noise treatment, but temporal nest-size changes relied on cross-contest variation in noise and comparative opponent size. Thus, the combined effects of noise are conditional on added attainment costs and offset by exceeding resource benefits.
Conclusion
Our findings provide support for the hypothesised modulation of resource value under extrinsic stress and suggest implications for competition under increasing anthropogenic activity.
... scalare) start to swim actively within 3-4 days (Çelik, Çelik, Gürkan, & Şahin, 2014). Similarly, Betta splendes (Valentin et al., 2013), Colisa fasciatus (Barman, Vikash, Kumar, Bhattacharjee, & Datta, 2013) and ...
... In most freshwater ornamental species, the larval development was completed within 30-35 days after hatching and the larvae were transformed into juveniles (Araujo-Lima, 1994; Barman et al., 2013;Çelik, 2010;Çelik et al., 2014;Hossen et al., 2014;Park et al., 2015Park et al., , 2014Valentin et al., 2013;Vilasrao, 2013). Histomorphological findings indicated that the larval development stage of serpae tetra larvae was completed in 30 days after hatching. ...
In this study, the embryonic and larval development stages of one of the most important ornamental fish serpae tetra (Hyphessobrycon eques) are described. The early life stage is documented from fertilization until the beginning of the juvenile period. The fertilized eggs (the average diameter = 938.55 ± 35.20 µm) were incubated at a water temperature of 26 ± 0.5°C. The cleavage finished in 1:10 hr (=h) and the early blastula stage occurred at 1:26 hr post fertilization (hpf). The gastrulation started at 3:05 hpf, and 50% epiboly was observed at 3:25 hpf. Segmentation stage was monitored at 7:26 hpf. Embryonic developmental stage was completed and hatching occurred 20–21 hpf. The total length (TL) of newly hatched larvae was 2.64 ± 0.21 mm. The larval development of serpae tetra was divided into four different periods: Yolk‐sac larva (1–4 DAH, TL = 2.77 ± 0.09 mm ‐ 3.85 ± 0.11 mm), preflexion larva (5–12 DAH), flexion larva (13–15 DAH, TL = 5.78 ± 0.46 mm on the 15th day) and post‐flexion larva (16–30 DAH, TL = 10.7 ± 0.27 mm on the 28th–30th days). The mouth and anus are closed at 1 DAH. The mouth and anus opened at 4 DAH. Exogenous feeding started on the 4th day. The first gulping of the swim bladder was on days 3. The larva begins to swim freely, and the yolk sac was completely consumed at 4 DAH. Histological structures of the eye and brain of new hatched larva were clearly identified at 1 day after hatching (DAH). According to histological findings, the digestive system (stomach, intestine) started to develop and the liver could be seen on the ventral side of the swim bladder at 5 DAH. No histological difference was observed between the anterior intestine and the posterior intestine at 15–16 DAH. The larval metamorphosis was completed, and the larvae transformed into juveniles at 28–30 DAH.
... The B. orbignyanus eggs had a wide perivitelline space, which was also observed in other species of teleost fish (Sampaio et al., 2015;Marques et al., 2017). However, Valentin et al. (2015) and Santos et al. (2016) reported that Betta splendens and Astyanax altiparanae eggs hydrate very little, while presenting a small perivitelline space. The size of perivitelline space depends on the reproductive characteristics of each species (Paes et al., 2014), the environment in which the eggs develop and the functions attributed to it such as mechanical protection, osmotic regulation, nutrition and prevention to polyspermia (Laale, 1980). ...
... The size of perivitelline space depends on the reproductive characteristics of each species (Paes et al., 2014), the environment in which the eggs develop and the functions attributed to it such as mechanical protection, osmotic regulation, nutrition and prevention to polyspermia (Laale, 1980). Embryogenesis extends from fertilization to hatching and, for teaching purposes, is usually divided into stages such as cleavage, blastula, gastrula and segmentation (Valentin et al., 2015;Santos et al., 2016;Marques et al., 2017). In B. orbignyanus, the first cleavage divided the egg cell into two same size blastomeres that appeared indistinguishable, similar to Danio rerio (Kimmel et al., 1995) and Zungaru jahu (Marques et al., 2017). ...
Brycon orbignyanus is an important large teleost that is currently on the list of endangered species, therefore studies on its reproductive biology and embryology are fundamental to help species conservation and recovery. The objective of this research was to characterize the events that occur during extrusion, fertilization and embryonic development of the species. The samples were collected at predetermined times, fixed and processed for light microscopy and scanning electron microscopy. The greenish oocytes were spherical, had translucent chorion and a mean diameter of 1.3±0.11 mm. The eggs had well defined animal and vegetative poles approximately 18 min post-fertilization. Stages from 2 to 128 blastomeres occurred between 20 min and 3 h post-fertilization (hPF), when the morula was characterized. The blastula stage was observed between 2 and 3 hPF, and the gastrula between 3 and 7 hPF, when the embryonic shield emerged and the cellular migration with the consequent formation of epiblast and hypoblast. At 8 hPF, the formation of the neural tube, above the notochord and the encephalic region, was observed, delimiting the forebrain, mesencephalon and rhombencephalon regions. From 11 hPF onward, the optic vesicle was formed close to the forebrain and the embryo tail was well developed. The optic vesicle was observed from 12 hPF onward, and the tail showed an intense movement that culminated with the rupture of the chorion and consequent hatching of the larva at 13 hPF and 27°C.
... The retina of Betta splendens was formed (with seven layers) within 4 days and similar reports were observed on zebrafish (Danio rerio) (Gahtan et al., 2005) and catfish (Pangasianodon hypophthalmus) (Mukai et al., 2010). While, Oliveira and Sa (2012) have reported that the eye of B. splendens is strongly pigmented at hatching, other study claim that at this stage the eyes of B. splendens are undifferentiated and only slightly pigmented (Valentin et al., 2013). ...
... Furthermore, these species have highly developed eyes at hatching, as observed in Brycon cephalus (Romagosa et al., 2001). B. splendens, on the other hand, is a species with parental care (Valentin et al., 2013) and slow development rates when compared to other ornamental fish (Anjos and Anjos, 2006;Celik et al., 2011;Paes et al., 2011). Therefore, it is expected to display very different visual development rates to the species mentioned above. ...
Basic studies on early morphology and behaviour are necessary to support applied research on larval rearing. Thus, the aim of this study was to analyze the initial feeding behaviour, eye structure and the influence of different background colours (red, blue and clear) on prey capture rates (Artemia sp.) of Betta splendens larvae. The retina was formed by 90 h post-fertilization and consisted of seven layers. The feeding behaviour of the larvae changed with ocular development and thus, prey were captured more efficiently with time. No significant difference (p>0.05) was observed between the different background colours on prey capture rates under the experimental conditions tested (10 min of exposure). In conclusion, B. splendens larvae displayed a typical feeding behaviour, which changed with larval development and was dependent on visual ontogeny. Even though the different background colours did not significantly affect feeding behaviour, our findings provide important insights for future studies on this field.
... Ornamental fish are commercialized globally until the present day, and the demand for ornamental fish has been rising over the years [1]. Out of over 5300 freshwater ornamental species traded, Betta sp. which is an altricial species [2], is one of the most famous ornamental fish due to its interesting and luring colour and shape, especially the male species [3]. The beautiful colour wrapping the whole body and its fin make it very highly demanded which can be highly produced with no doubt in the market trade [4]. ...
Betta sp., also known as Siamese fighting fish, is renowned in the ornamental fish trade for its captivating colours and unique shapes, particularly among male specimens. Despite extensive research, challenges persist in meeting market demand for this species due to high mortality rates during production. Therefore, this study focused on determining the water quality properties (pH, dissolved oxygen, temperature), survival rates and blood profile of the Betta sp. by applying different concentrations of Terminalia catappa leaves (TCL) extracts: 0 (Control treatment), 480 (Treatment 1), 960 (Treatment 2), 1440 (Treatment 3) and 1920 (Treatment 4) ppm on three months old Betta splendens for 30 days. The experiment employed a completely randomized design (CRD) with three replications for each treatment. Results indicated that temperature and dissolved oxygen remained unaffected by varying concentrations of TCL, while pH exhibited a significant decrease with increasing concentration, ranging from 7.07 to 5.88. Notably, treatment 2 (pH 6.73) demonstrated a significant improvement in survival rate, achieving 100 % survival compared to the control (pH 7.07) with 46.67 % survival. Moreover, treatment 2 exhibited a significantly higher specific growth rate (0.85 % per day) compared to the control (0.04 % per day). Red blood cell (RBC) content also exhibited significant differences, with the highest RBC content (1.269 x 10^6 µL) observed at the highest TCL concentration (treatment 4, 1920 ppm). Therefore, the study concludes that the most optimal concentration of TCL, as determined from the research, was 960 ppm with a pH of 6.73. This concentration yielded the highest survival rate and growth performance for 3-month-old Betta splendens.
... Rotifers are the most dominant zooplankton in all freshwater aquatic ecosystems (Tingson & Zafaralla, 2018;Mendoza et al., 2019) and considered as valuable live food for the culture of larvae of most fish species due to its small size ranging in 105-160 μm in width (Udit et al., 2020). Their slow swimming motion makes them easy prey to fish larvae which usually have underdeveloped locomotory organs (Valentin et al., 2013). They also reproduce rapidly and can be cultured in high density, making them available in large quantities within a relatively short period. ...
The lack of size-suitable live food for small-gaped fish larvae is a major impediment to their growth and survival. Rotifers are viable live food that can bridge the gap between the dependence of such fish larvae from their endogenous yolk to larger-sized live feeds. The present study focused on developing Filinia longiseta, a very small local rotifer, as an important live food for fish larviculture. The study specifically investigated the effects of four different supplements (yeast, commercial fish fry booster, rice bran and fish waste) in the microalgae (Chlorella vulgaris) diet of Filinia longiseta to its population growth and individual growth. Yeast, fry booster and fish waste significantly (p<0.05) improved the population growth of F. longiseta better than rice bran and Chlorella only diet after 6 days of culture. Individual growth did not significantly vary among different diet treatments and control (p>0.05). Performance of these different supplements have been investigated in the past and showed that their effectivity in improving rotifer population and growth parameters were attributed to proper preparation, their digestibility, efficient absorption and interaction with microflora in the culture media.
... However, morphological taxonomy on fish eggs and larvae still remains challenging due to their small size, limited morphological development, scarcity of comparative material of known origin, and reliance on few characteristics such as egg diameter and presence of oil globules for species determination (Ahlstrom and Moser 1980;Moser 1996;Richards 2006;Richardson et al. 2007). Furthermore, some of the embryonic characters, such as pigmentations on the embryo, are only applicable in late stages of the egg development making earlier species determination difficult or impossible (Taylor et al. 2002;Valentin et al. 2013). In some cases, this have led to errors in the identification of commercially important fish species with consequences for management (Fox et al. 2005;Fox et al. 2008). ...
Increased and updated knowledge of reproductive strategies of fish is crucial to optimize the temporal and spatial planning for conducting seismic surveys; in order to reduce its potential negative ecosystems impacts. The overarching goal of this study is to investigate the current spawning times and locations for the North Sea fish stocks. Molecular barcode and traditional visual taxonomic analyses were performed on eggs and larvae, systematically collected with plankton nets along a south to north axis in the North Sea. This report describes the establishments of methodology employed and preliminary results based on samples collected during August 2017 to September 2018. In total, 129 samples have been analysed from which 22 different fish taxa are identified. Based on historic data and published literature, our results agree with the expected number of the most prevalent fish species breeding in the North Sea. Both the taxonomic and molecular methods used, demonstrate similar results in the identification of taxonomic groups. The results further demonstrate that the molecular taxonomic approach is more appropriate for identification to species levels for some taxonomic groups, whilst the identification of egg and larvae developmental stages can only be performed using the visual taxonomic method. The two techniques complement each other to provide a detailed description of the annual fish spawning cycle for the main North Sea species. There are already emerging patterns evident in the results on the timing for breeding in some species at certain areas. However, improvements of the sampling methodology are still required, and an increased number of samples collected systematically over an extended time-period must be accomplished in order to provide appropriate data as basis for advice in timing of seismic surveys.
... Traditional morphometric and meristic methods and visual observation are not discriminatory for many larval species (Matarese & Sandknop, 1984;Watson et al., 1998;Victor et al., 2009;Ko et al., 2013;Kwun, 2018). Furthermore, the pigmentation pattern of eggs and larvae changes in the later stages of development, making the species identification very challenging (Taylor et al., 2002;Valentin et al., 2015). Additionally, the succession of changes in eggs and larvae is very quick, and it leads to incorrect identification of early stages of commercially important fish species (Fox et al., 2005;Fox et al., 2008). ...
Identifying the breeding grounds of fishes is crucial for the sustainable management of fisheries resources. The present study is aimed at identifying the potential breeding ground of Mugil cephalus along the estuary of the North Mumbai coast. A total of 1197 specimens of M. cephalus, including 546 eggs, 271 larvae, 235 juveniles, and 235 adults, were collected from four sampling stations in the Karanja estuary between January to October 2022. Water quality parameters, plankton dynamics in the estuary, and the reproductive and feeding biology of M. cephalus were also examined. The eggs, larvae, juveniles, and adults were identified using traditional morpho-meristic and DNA barcoding techniques. The results revealed a potential spawning ground of M. cephalus in the Karanja estuary. The results of reproductive biology also confirmed the occurrence of matured fishes during May–July. The abundance of eggs and larvae at the estuary’s mouth and the presence of juveniles and mature individuals of M. cephalus dominantly in the Karanja estuary from May to July infer the presence of a spawning site. It is also recorded that M. cephalus spawn in higher salinity (35 ppt) and seawater temperature (33 °C) where the hatching of offspring takes place successfully. This study emphasizes the significance of DNA barcoding in guiding routine monitoring surveys and demonstrates its usefulness when combined with these techniques in identifying fish spawning grounds. The study findings will serve as baseline information to develop effective conservation and management strategies and protect the ideal spawning stock.
... Moreover, morphological taxonomy of fish species is challenging and can provide erroneous identification status that would be deterrent towards the management of commercially important fish species (Fox et al., 2008). For instance, the morphological taxonomy of fish eggs and larvae have been in practice for the identification of spawning fish species (Harada et al., 2015), however, due to limited morphological development at this stage, the morphological taxonomic keys have been found mostly irrelevant in correct identification of fish specimens (Valentin et al., 2015). Thus, to complement the traditional morphology-based taxonomic identification, alternative techniques as molecular barcoding has been advocated (Ahern et al., 2018). ...
Aim: In this study we characterized the fish Cynoglossus lingua collected from Chandipur Coast of Odisha using the mtDNA markers cytochrome c oxidase I (COI) and cytochrome b (Cyt-b) genes. Methodology: Samples of flat fish were collected from Balaramgadi fish landing center, Chandipur sea beach, Odisha coast. The collected specimens were initially identified based on the morphology using standard taxonomic keys. Molecular characterization was accomplished through PCR amplification of COI and Cyt-b genes. The sequences were subjected to BLAST analysis and aligned using Clustal W for homology mapping. Phylogenetic status was inferred by the neighbor-joining method using MEGA v7.0. Results: The taxonomic keys and the COI and Cyt-b gene sequences identified the specimens as C. lingua. The COI and Cyt-b gene sequences showed 98% and 99% sequence similarity with C. lingua isolate FMU.CIFRI.FF-7 COI gene (GenBank accession: MN889532.1) and the C. lingua isolate FM.CIFRI.CYTB.FF-7 Cyt-b gene (GenBank accession MT362541.1), respectively. Interpretation: The study supports the reliability of combining classical taxonomic approaches with molecular analysis using COI and Cyt-b genes for the identification of C. lingua. Key words: Cynoglossus lingua, COI gene, Cytochrome b gene, DNA barcoding, Molecular taxonomy
... Kematian ikan tidak ditemukan setelah umur 60 hari setelah menetas (hsm) (Gambar 5). Hal ini diduga berkaitan dengan perkembangan ikan cupang yang mencapai stadia juvenil pada umur 32 hsm (Valentin et al. 2013) dan 40 hsm (Poungcharean & Limpivadhana 2022). Karena itu setelah umur 60 hsm ikan lebih kuat dan diduga organ labirin juga telah berfungsi dengan baik. ...
Betta splendens males have colours and shapes that are popular in the ornamental fish market compared to females. Because of that, betta cultivation can be done through male production using sex reversal technology in directing the sex development of fish to become male (masculinization). The natural ingredient that has been used to masculinize fish is honey. So the research objective was to examine the use of honey by immersing the embryo to masculinize betta. Analyzed masculinization success through characteristics of honey, percentage of male fish, egg hatching rate, mortality every 15 days, and survival at the end of rearing. The embryos used were 20 hours post-fertilization. The research treatment was immersion of betta embryos in honey solution (mL L-1) 5, 10, 15, 20, and 25. Soaking was carried out for 7 hours. The results showed that the honey used had 0.31% potassium and a pH of 4. In this study, the administration of honey did not affect the number of male betta. Giving honey 25 mL L-1 water produced 56.98 ± 4.58% of males, egg hatching rate 99.17 ± 1.67%, and survival at 90 days after hatching 79.89 ± 4.50%. Mortality occurs at the start of larval rearing. After the age of 60 days after hatching, there is no death in betta. The high values of egg hatching and survival rates indicate that honey is a natural material safe for masculinizing fish in mono-sex aquaculture.
... This lab space is lighted for roughly 12 h per day (from around 7:00-19:00) with white and yellow LEDs, and has windows to the outside of the building. Larval fish begin hatching between 29 and 44 h after fertilization 19,30,75 and begin swimming by 72 h after fertilization. 30 We use a glass transfer pipet daily to remove unfertilized eggs or embryos that are not developing or that are clearly malformed. ...
Betta splendens, also called Siamese fighting fish or 'betta,' are a popular species in the fishkeeping hobby. Native to Southeast Asia, betta have been selectively bred for their fighting ability for hundreds of years, which has resulted in the species' characteristic male aggression. More recently, betta have been bred for a number of ornamental traits such as coloration, fin morphology, and body size. Betta have unique characteristics and an evolutionary history that make them a useful model for studies in the fields of behavior, endocrinology, neurobiology, genetics, development, and evolution. However, standard laboratory procedures for raising and keeping these fish are not well established, which has limited their use. Here, we briefly review the past and present use of betta in research, with a focus on their utility in behavioral, neurobiological, and evolutionary studies. We then describe effective husbandry practices for maintaining betta as a research colony.
... However, morphological taxonomy on fish eggs and larvae still remains challenging due to their small size, limited morphological development, scarcity of comparative material of known origin, and reliance on few characteristics such as egg diameter and presence of oil globules for species determination (Ahlstrom and Moser 1980;Moser 1996;Richards 2006;Richardson et al. 2007). Furthermore, some of the embryonic characters, such as pigmentations on the embryo, are only applicable in late stages of the egg development making earlier species determination difficult or impossible (Taylor et al. 2002;Valentin et al. 2013). In some cases, this have led to errors in the identification of commercially important fish species with consequences for management (Fox et al. 2005;Fox et al. 2008). ...
The North Sea is an important spawning and nursery ground for many demersal and pelagic fishes whose spawning areas are largely overlapping in time and space. This makes ichthyoplankton visual identification from the various species particularly challenging. Despite historically intensive research in the area, detailed information on spawning sites and times for many taxa, are incomplete. To update and detail the mapping of fish spawning performance and distribution in the central and northern regions of the North Sea, the performance of a visual method and a molecular taxonomic approach used for taxonomic classification of ichthyoplankton was evaluated. Samples of fish eggs and larvae were collected regularly and in parallel at different latitudinal locations from the central to the northern North Sea, including a sample with 78 larvae used for direct comparison between both methods. A total of 5332 individuals were inspected and 36 different species were identified. The visual processing identified 89% of the collected larvae to species level, however, for the eggs the taxonomic resolution was lower with only 5% identified to species level. In comparison to visual identification , molecular barcoding gave higher precision of identification for larvae and especially for the eggs. For the larvae, 98% were assigned to species level, and for the eggs 94% were assigned to species level. We find that molecular barcoding is more effective and precise in taxonomic identification of both eggs and larvae to species level. However, visual identification is still needed to provide information on the developmental stages.
... Golongan ikan lain yang membuat sarang seperti ikan cupang adalah ikan gurami dan juga kesamaan dalam tingkah laku untuk reproduksi (Liengpornpan et al., 2007). Larva ikan cupang yang baru ditetaskan berukuran rata-rata 2 mm, mulut tertutup, kantong kuning telur dan terdapat sedikit pigmen pada matanya (Valentine et al., 2013). ...
The purpose of this study was to find out the survival rates of betta fish larvae (cupang) that were given life feed Alona sp., boiled egg yolk and commercial feed for 21 days. Data analysis was performed by one-way ANOVA, and continued with BNJ (Tukey) test. The result of the survival rate is as follow treatment with life feed Alona sp. 56%, treatment with boiled egg yolk 26%, and treatment with commercial feed 0%. The results of statistical tests show there are significant differences. Significant value p <.0002 (<.05). Water quality parameter measured during the study was temperature of 26 ºC.Keywords: betta fish larvae, life feed, Alona sp., survival rateABSTRAKTujuan penelitian ini adalah untuk mendapatkan laju kelangsungan hidup larva ikan betta (cupang) yang dibeerikan pakan alami Alona sp., rebusan kuning telur dan pakan komersil selama 21 hari. Analisis data dilakukan dengan ANOVA one way, dan dilanjutkan dengan uji BNJ (Tukey). Hasil laju kelangsungan hidup adalah sebagai berikut, perlakuan dengan pakan alami Alona sp. 56%, perlakuan dengan rebusan kuning telur 26%, dan perlakuan dengan pakan komersil 0%. Hasil uji statistik menunjukan adanya perbedaan yang nyata. Nilai signifikan p <.0002 (<.05). Parameter kualitas air yang diukur selama penelitian adalah suhu 26ºC.Keywords: larva ikan betta, pakan alami, Alona sp., kelangsungan hidup
... With regard to zootechnical performance, Artemia treatment produced the best results with the higher water depth, possibly due to higher feed availability throughout the column which increased the visual stimuli that are important to predation behaviour (Valentin et al., 2013). The improvement in larval growth with Artemia feed at a 5-cm water depth was also verified by Kim (2007). ...
Panagrellus redivivus is a nematode with a high protein content and low‐cost production. It is successfully used in the larviculture of shrimp, however, it has not yet been evaluated as feed for Betta splendens larvae. Thus, the objective of this study was to evaluate P. redivivus as feed for betta larvae maintained at different depths of water. The experiment was based on a completely randomized 3 × 2 factorial design, represented by two feed types and one alternating feeding regime plus two water depths (2.5 and 5.0 cm). The Artemia feed promoted the highest weight gain, followed by the alternating feeding regime. The single use of the nematode as live feed produced the poorest weight gain. The water depth and the feeding method influenced the specific growth rate (SGR). At a depth of 2.5 cm, the alternating feeding promoted similar SGR compared to fish fed with Artemia only. Furthermore, at the greater water depth an improvement in SGR was observed in fish fed Artemia only, but the similarity to alternating feeding regime remains. Thus, the inclusion of nematode is an appropriate and lower cost feed strategy for the betta larviculture independent of water depths.
Hatching corresponds to the moment an individual leaves its egg envelope. Yet, hatching has scarcely aroused the interest of biologists, and the question posed here, ‘why do larvae hatch when they do?’ appears to have been rarely asked. In this proof-of-concept study, we tested the hypothesis that fish larvae hatch when a specific ratio between egg surface area (ESA) and larval surface area (LSA) is reached, irrespective of egg diameter and abiotic factors. An estimated mean ratio of 1: 1.52 (CI = 1.39–1.63) was obtained from the eggs of 33 species of teleosts, with diameters ranging from 0.63 to 5.7 mm. We assume that this ratio has a value beyond which the oxygen supply through the egg surface cannot cope with the oxygen requirements of the embryo. The detailed ecological consequences are unknown but can be expected to impact fisheries and aquaculture negatively.
The fighting fish Betta splendens is a freshwater species from Thailand and other Southeast Asian countries. This fish has been domesticated for 1000 years and bred for fighting, various colours, body size and fin types for 600 years. It is one of the most important fish species cultured for the world ornamental fish market. This fish is easy to culture, highly fecund and displays great morphological diversity. Its biology has been studied for over 100 years. Recently, its compact genome and transcriptomes have been sequenced. Genome editing with CRISPR/cas9 has been applied to knock out genes in this fish. Its diverse phenotypes, including colours, colour patterns, fin types, and aggressive behaviour, are complementary to those of other model animals. Therefore, this fish could be the next important model organism for studying phenotypic variation and aggressive behaviour. In this paper, we synthesized knowledge about its aquaculture, biology, genetics, genomic tools, phenotypes and novel insights on phenotypic variation, sex determination and aggression. We hope that the information described in this paper will facilitate genetic studies on phenotypic variations in aquaculture and aggressive behaviour in other species, including humans.
Vertebrate pigmentation provides an ideal system for studying the intersections between evolution, genetics, and developmental biology. Teleost fish, with their accessible developmental stages and intense and diverse colours produced by chromatophores, are an ideal group for study. We set out to test whether Betta splendens is a good model organism for studying the evolution and development of diverse pigmentation. Our results demonstrate that B. splendens can be bred to produce large numbers of offspring with easily visualized pigment cells. Depending on the colour of the parents, there was variation in larval pigmentation patterns both within and between breeding events. In juveniles the developing adult pigmentation patterns showed even greater variation. These results suggest that B. splendens has great potential as a model organism for pigmentation studies.
Paracheirodon axelrodi, ou cardinal tetra, é um peixe ornamental cuja ocorrência natural está restrita í Bacia dos Rios Negro e Orinoco. É encontrado principalmente em igarapés de água preta e ácida com baixa velocidade de fluxo, e sua biologia reprodutiva é ainda pouco estudada. Neste trabalho são apresentados dados relativos a reprodução e desenvolvimento embrionário e larval em laboratório. A manipulação do nível da água (chuva artificial), pH e condutividade elétrica favoreceram a desova de Paracheirodon axelrodi. A espécie possui desova parcelada e os ovos são adesivos. Análises de oito fêmeas de cardinal tetra revelam fecundidade de 154 a 562 ovócitos, positivamente relacionada com o tamanho do peixe. O desenvolvimento dos ovócitos é do tipo sincrônico em mais de dois grupos, isto é, inúmeros ovócitos em diferentes fases de desenvolvimento são liberados em grupos. í€ temperatura média de 26,0 ± 1,0°C, o desenvolvimento do ovo apresentou diferenciação embrionária rápida e período larval longo. As larvas eclodiram, aproximadamente, 19 a 20 horas após a fertilização, com 2,9 ± 0,2 mm de comprimento total e corpo não pigmentado. No 5o dia de vida, as larvas apresentavam, em média, 4,1 ± 0,2 mm de comprimento total e nadadeiras em desenvolvimento. No 12 o dia de vida foram observados os primeiros pigmentos vermelhos na base da nadadeira anal, e uma faixa azul metálica lentamente formando-se e expandindo-se até a base da nadadeira adiposa. No 22o dia de vida, todas as nadadeiras estavam formadas, e os juvenis se assemelhavam aos adultos, com média de 11,0 ± 1,0 mm de comprimento total.
Hoplias malabaricus, ou traíra é um peixe predador com ampla
distribuição na América do Sul. Ε encontrado com frequência na Amazônia, porém sua
biologia ainda é pouco estudada na região. Nesta nota apresentamos dados relativos a sua
reprodução e ao início do seu desenvolvimento larval na várzea do rio Solimões. A traíra
se reproduz durante todo o ano. As fêmeas têm fecundidade relativamente baixa, que varia
conforme o tamanho do peixe. Os ovócitos maduros são grandes (média = 1,5 mm). Ovos
fecundados foram encontrados em posturas nas margens dos lagos de várzea. As larvas
eclodiram com 4,7 cm de comprimento e detalhes sobre seu desenvolvimento embrionário são
apresentados.
The embryonic and larval development of black skirt tetra, Gymnocorymbus ternetzi, are described under controlled laboratory conditions. In addition, major histomorphological changes and the allometric growth patterns during larval development have been described. The laboratory-reared broodstock, that is 1 year of age, were spawned. Hatching occurred 20–21 h after spawning at 24 ± 0.5°C. The cleavage was finished in 2 h and the early blastula stage occurred at 2:04 hours after spawning. The gastrulation started at 3:20 hours and 30% epiboly was observed at 3:34 hours after spawning. Eight-somite stage was observed at 08:33 hours. And embryonic developmental stage was completed at 21 h after spawning. The newly hatched larvae were 1442 ± 14.3 μm in mean total length (TL). The mouth opened at 3 days after hatching (DAH). The yolk sac had been totally absorbed and the larvae started to swim actively within 3–4 days. Notochord flexion began at 11 DAH. The metamorphosis was completed and the larvae transformed into juveniles at 32 DAH. In this paper, the full developmental sequence from egg to juvenile of G. ternetzi is described for the first time.
The objective of this work was to study the morphologic development and the swimming and feeding behaviors of piracanjuba larvae, Brycon orbignyanus Valenciennes (1849) (Characiformes, Characidae, Bryconinae), during the period from zero to 172 hours after hatching (standard length = 3.62 - 11.94 mm). The morphological analyses were accomplished by using a trinocular stereo microscope, while the behavioral analyses were performed through periodic observations. In 28 hours after hatching, the larvae (standard length = 6.25 ± 0.13 mm) showed the following structural and behavioral characteristics that made them become active predators able to overcome a larval critical phase, the beginning of exogenous feeding: presence of pigmented eyes, terminal and wide mouth, developed oral dentition, developing digestive tube, yolk sac reduction, fins and swim bladder formation, horizontal swimming, cannibalism, and predation. Intense cannibalism among larvae was verified from 26 to 72 hours. At the end of the metamorphosis - 172 hours after hatching - the larvae measuring 11.94 + 0.80 mm in standard length presented a flexed notochord, caudal fin bifurcation, dorsal and anal fin formation, synchronized movements, and formation of shoals, characteristics that together allow enhanced perception and locomotio in exploration of the environment, determining the best moment for transfering to the fishponds. New studies can contribute to commercial fish farming by improving feeding management, performance, survival, and productivity of this species.
The effect of incubation temperature (2, 4, 6, 8 and 10°C) on haddock Melanogrammus aeglefinus development and growth during the embryonic period and in subsequent ontogeny in a common post-hatch thermal environment (6°C) was investigated. Hatching times were inversely proportional to incubation temperature and ranged from 20.3 days at 2°C to 9.1 days at 10°C. Growth rates were directly proportional to incubation temperature during both the embryonic and larval periods. There was a significant decline in growth rates following hatch in all temperature groups. Compared to the endogenously feeding embryos, growth rates in the exogenous period declined by 4.4-fold at 4°C to 3.9-fold at 8°C, indicative of the demarcation between the endogenous and exogenous feeding periods. Yolk utilization varied from 17 days at 2°C to 6 days at 10°C and followed a three-stage sigmoidal pattern with the initial lag period inversely proportional to incubation temperature. Time to 50% yolk depletion varied inversely with temperature but occurred 1-1.5 days post-hatch at all temperatures. Additionally, the period between 10 and 90% yolk depletion also decreased with increased temperature. Overall developmental rate was sequential with and directly proportional (2.3-fold increase) to incubation temperature while the time spent in each developmental stage was inversely proportional to temperature. Larger embryos tended to be produced at lower temperatures but this pattern reversed following hatch, as larvae from higher temperature groups grew more rapidly than those from other temperature groups. Larvae from all temperatures achieved a similar length (c.total length 4.5 mm) upon complete yolk absorption. The study demonstrated the significant impact that temperature has upon developmental and growth rates in both endogenous and exogenous feeding periods. It also illustrated that temperature changes during embryogenesis had significant and persistent effects on growth in subsequent ontogeny.
The full developmental sequence from egg to juvenile of Gobius paganellus under controlled conditions is described. Embryonic development lasted 9–10 days at 18·5–20·0°C and 10–11 days at 15·0–16·5°C. Newly hatched larvae measured 3·90 mm, had the mouth and anus opened, pigmented eyes and almost no yolk. They first settled 25 days after hatching (10·0–10·5 mm total length [TL]) and showed juvenile behaviour and body form 36 days after hatching (14·0 mm TL). However, they only showed full juvenile pigmentation patterns 15 days later (17·0 mm TL) (16·0–16·5°C). In addition, a preliminary differentiation between the newly hatched larvae of the most common Gobius species of south-western European shores is presented.
The Siamese fighting fish, of which Betta splendens is representative, is gaining popularity as judged by increasing export values and demands for novel types worldwide, especially the ornamental ones. However, relatively little is known about the bettas scientifically. In this review we cover what is known about the desired morphology and pigments, genetics, aquaculture, diseases and feeds involved in breeding bettas. We also propose breeding the bettas for domestic enjoyment and export by exploiting current knowledge of gene technology and molecular developmental biology in addition to the use hitherto of only classical genetics. Other aspects of fish culture such as feeds, disease prevention and water quality should also be scientifically studied and improved upon. Because of dwindling and worsening habitats in Thailand, more studies on biodiversity and work towards species conservation of the wild types are needed.
There is a vast literature on the reproductive behaviour of cichlid fishes, most of which describes spawning strategies and parental care. However, descriptive information on the early development of cichlids is scarce. In this study, embryos and larvae of laboratory-reared Cichlasoma dimerus are described. The early ontogeny is documented from oocyte activation until the beginning of the juvenile period. At a water temperature of 25 ± 0.5 °C and a 12:12 h photoperiod, cleavage is finished in 10 h and the first somites appear at 26 h of development. The larvae hatch during the beginning of the third day and are deposited by both parents in a pit they have dug out in advance. Yolk-sac larvae present three pairs of adhesive glands over the head, these transient larval organs being characteristic of substrate-brooding cichlids. After another 5 days, the fry swim freely and begin to feed exogenously. Since the yolk-sac is not completely reabsorbed until 2 or 3 days later, there is a period of combined endogenous and exogenous food supply. The juvenile stage is reached on the 42nd day from spawning.
We used metadata on nine reproductive traits of 67 species of Brazilian iteroparous, oviparous, teleost freshwater fishes
to test phenotypes associations to discriminate species that only spawn in large rivers (lotic fishes) from those capable
to spawn in lentic habitats (lentic fishes). We tested the hypothesis that lotic fishes present spawning migration, shorter
spawning season, single spawning, no parental care, free eggs, higher relative fecundity, faster embryogenesis, and larger
size, while lentic fishes present no spawning migration, longer spawning season, multiple spawning, parental care, adhesive
eggs, lower relative fecundity, slower embryogenesis, and smaller size. Our analyses supported the hypothesis but not all
phenotypic associations satisfied it, specifically with regard to lentic fishes or to pairs of phenotypes typical of lentic
fishes. We also concluded that spawning in large rivers is a better predictor of bionomic characters than spawning in lentic
habitats, and lotic fishes are specialists compared to lentic fishes.
This study presents, for the first time, information on the eggs and early development of Franciscodoras marmoratus, fish of São Francisco river, Brazil. To analyse the egg ultrastructure and morphological events of embryogenesis, a total of 36 F. marmoratus specimens (18 males and 18 females) were captured and subjected to spawning induction. Gametes were collected by manual extrusion, and fertilization was conducted using the dry method. After fertilization, eggs were kept in incubators with water temperature of 24°C. The embryonic development was monitored using a stereomicroscope until hatching. There was a 67% positive response to hypophysation by the females and the fertilization rate was 73.8 ± 6.2%. The oocytes are discoid, yellow, adhesive and covered by a thick jelly coat. Under the electron scanning microscope, the oocytes presented a surface with pore canals and funnel-shaped micropyle with a smooth vestibule. Recently extruded oocytes had a mean diameter of 1.27 ± 0.4 mm and after hydration was 1.91 ± 0.05 mm. The jelly coat was 0.34 ± 0.03 mm thickness, and the perivitelline space was 0.19 ± 0.04 mm. Eight phases of the embryonic development were identified, and embryogenesis was completed at 47 h after fertilization, at 24°C water temperature. The recently hatched larvae had 2.76 ± 0.57 mm of total length. These results provide useful information for the successful breeding and reproductive strategies of fishes.
The male Siamese fighting fish, Betta splendens, builds a bubble nest on the water surface to care for offspring during the reproductive period. To our knowledge, this study is the first to determine the composition of the bubble nest and to compare the pharyngeal organs of male and female Siamese fighting fish to determine the relationship between the pharyngeal organ and the ability to make bubble nests. Dot blots of the bubble nest probed with periodic acid-Schiff's (PAS) staining and Ponceau S solution revealed that the contents of the nest are glycoprotein rich. Dissection of the heads of Siamese fighting fish showed that the pharyngeal organ is located in the position through which inhaled air passes. The epithelial structure of the pharyngeal organ of the Siamese fighting fish, like that of other teleosts, has numerous wrinkles and papillae. Mucous goblet cells were observed on the epithelium of pharyngeal organs in male and female fish. The pharyngeal organ was found to be larger in male than in female fish. In addition, the epithelium of the pharyngeal organ in male fish has a greater number of mucous goblet cells than that in female fish. In Siamese fighting fish, this sexual dimorphism of the pharyngeal organ suggests that the male fish secretes more glycoprotein-rich mucus to build the bubble nest. Future work will focus on the type of mucous cells found in the epithelium of the pharyngeal organ that contributes to bubble formation and will determine the components of the mucus in the bubble nest.
The black armoured catfish Rhinelepis aspera is an important commercial species found in the São Francisco River (Brazil) that has great potential for pisciculture. This paper presents, for the first time, information on the embryogenesis and larval development of this species. The breeder fish were subjected to spawning induction with crude carp pituitary extract. Eggs were kept in incubators at 24 degrees C and embryogenesis was observed with a stereomicroscope until hatching. Ovary fragments, samples of recently extruded oocytes and larvae were fixed in Bouin's solution and subjected to routine histology techniques. Recently extruded oocytes were also analyzed with a scanning electron microscope (SEM). Females (80%) had a positive response to hypophysation. Oocyte extrusion was performed at 8 h and 30 min after the second hormone injection and the fertilization rate achieved 72.4 +/- 8.8%. Recently extruded oocytes had a mean diameter of 1360.80 +/- 40.87 microm and presented a conspicuous jelly coat covering the zona pellucida. Histochemical reactions indicated the presence of neutral glycoproteins in the yolk globules and in the zona pellucida. These reactions also indicated the presence of neutral glycoproteins and carboxylated acid glycoconjugates in the follicular cells and the jelly coat. These compounds form mucosubstances that can be related to the adhesiveness of the eggs. Under the SEM the oocytes presented a micropyle disc and a thick jelly coat over their surface. The closure of the blastopore occurred 9 h and 40 min after fertilization and embryogenesis was completed at 45 h and 50 min after fertilization, when the embryos were incubated at 24 degrees C. The total absorption of the yolk sac occurred during the fifth day indicating the need for an exogenous food supply. These results provide essential information for the successful breeding and management of the promising R. aspera.
The developmental stages of Oreochromis niloticus are similar to those described in other mouth-breeding tilapias except that, as in zebrafish, no cavity was found in the blastula. Variation in the rate of development of the embryo and larva of O. niloticus was found within a clutch of eggs as well as between clutches. Hatching glands are described for the first time in tilapias. They are widely distributed within the ectoderm covering the head, body, tail, and surface of the yolk sac near its attachment to the embryo. Timing of larval development is similar to that in other mouthbrooding tilapias, but is slower than that found in substrate-spawning tilapias. A pneumatic duct connects the swimbladder to the digestive tract and swimbladder inflation and initiation of feeding occurs at about the same time. The digestive tract of the larva 8 and 9 days after fertilization is similar to that found in the adult, except that there are no digestive glands. An endocrine pancreatic islet was first seen 76 h after fertilization. A prominent thymus gland is present at 100 h. Hematopoietic tissue develops in the vicinity of the pronephros during early larval development. A spleen develops later, 7 days after fertilization.
This survey was performed to characterize the embryogenesis of Prochilodus lineatus. Seven stages of embryo development were identified--zygote, cleavage, blastula, gastrula, segmentation, larval and hatching--after a period of incubation of 22 h (24 degrees C) or 14 h (28 degrees C). The following cleavage pattern was identified: the first plane was vertical (2 blastomeres); the second was vertical and perpendicular to the first (4 blastomeres); the third was vertical and parallel to the first (4 x 2); the fourth cleavage was vertical and parallel to the second (4 x 4); the fifth was vertical and parallel to the first (4 x 8); and the sixth cleavage was horizontal (64 blastomeres). At the blastula stage (3.0-4.0 h (24 degrees C); 1.66-2.0 h (28 degrees C)) irregular spaces were detected and periblast structuring was initiated. At the gastrula stage (4.0-8.0 h (24 degrees C); 3.0-6.0 h (28 degrees C)) the epiboly, convergence and cell movements, as well as the formation of embryonic layers, had begun. The segmentation stage (10.0-15.0 h (24 degrees C); 7.0-10.0 h (28 degrees C)) was characterized by a rudimentary formation of organs and systems (somites, optic vesicle and intestinal delimitation). The embryo at the larval stage (16.0-21.0 h (24 degrees C); 11.0-13.0 h (28 degrees C)) showed a free tail, more than 25 somites, an optic vesicle and a ready-to-hatch larval shape. The blastomeres at cleavage stage had disorganized nuclei indicating high mitotic activity. At gastrula, the blastomeres and the periblast had euchromatic nuclei and a large number of mitochondria and vesicles. The yolk was organized into globose sacs, which were dispersed into small pieces prior to absorption.
1 Introduction.- 2 The egg.- 3. Yolk (vitellus).- 4. Cortex and its alveoli.- 5. Egg envelope.- 6. Accessory structures of egg envelope.- 7. Micropyle.- 8. Sperm.- 9. Fertilization.- 10 Cleavage and formation of periblast.- 11 Gastrulation.- 12. Neurulation.- 13. Fate-maps.- 14. Kupffer's vesicle.- 15. Ectodermal derivatives.- 16. Hatching.- 17. Development of the eye.- 18. Mesodermal derivatives.- 19. Entoderm and its derivatives.- 20. Viviparity.- 21. Synthesis.- References.- Species Index.
At the end of gastrulation the outer layer of the embryo and yolksac consists of ectoderm1. In teleosts it is often referred to as ‘epiblast’ (to contrast it with the inner layer, the ‘hypoblast’). The ectoderm covering the embryonic shield is greatly thickened compared with the extraembryonic area and it undergoes neurulation as described in Chapter 12. Eventually the whole embryo and the yolksac become covered by the one-layered epidermis topped by a flattened layer, the EVL or periderm (Chapter 11).
Embryology (now called developmental biology) of teleosts was intensively analyzed from the beginning of the 19th century onwards. It is, therefore, most intriguing if not to say incomprehensible, that there are textbooks and even atlases of the development of amphibia, birds and various mammals widely available, but so far none on teleost fish. This was the compelling reason for the writing of this book.
Eggs of 23 Characiformes and eight Siluriformes, belonging to nine families with diverse reproductive behaviour, were ultrastructurally analysed. The migratory species exhibited non-adhesive eggs, whereas, most of the sedentary species presented some degree of egg adhesiveness. Among the Characiformes, non-adhesive eggs showed zona radiata with pore-canals or a fibrillar net at the surface; weakly adhesive eggs presented only zona radiata with pore-canals while adhesive eggs exhibited zona radiata with apparatus like globules, filaments, villi or honeycomb-like pores depending on the systematic group. The ' jelly ' coat is strongly related to the Siluriformes eggs apparently without relationship with adhesiveness. A micropylar disc was present in adhesive eggs of a few species of both Characiformes and Siluriformes. Some patterns were characteristic of the animal pole, others of the vegetal pole, and others were common to both poles. The radial ridges converging to the micropyle in Astyanax bimaculatus lacustris appear to be related to fertilization. In general, egg surface structures in the Characiformes varied according to the genus, whereas all Siluriformes showed a similar egg surface pattern, regardless of the group analysed. Multivariate analysis allowed the identification of eight clusters among the Characiformes and three among the Siluriformes showing relationships between reproductive style and egg characteristics. It is suggested that egg surface and adhesiveness may be related to reproductive patterns and to phylogenesis.
A phenomenon that has attracted a substantial theoretical and empirical interest is the positive relationship between egg size and the extent of parental care in fishes. Interestingly, despite the effort put into solving the causality behind this relationship over the past two decades it remains largely unsolved. Moreover, how general the positive relationship between egg size and parental care is among fishes is also poorly understood. In order to stimulate research exploring egg size and parental care variation in fishes, the potential selective forces from both natural and sexual selection on egg size and parental care are discussed. Recent empirical findings on how oxygen requirements and developmental times may differ between differently sized eggs are incorporated into a critical view of the current theory of this field. Furthermore, it is suggested that the up to now neglected effects of sexual selection, through both mate choice and sexual conflict, can have strong effects on the relationship between egg size and parental care in fishes. In light of the recent developments of comparative and experimental methods, future approaches that may improve the understanding of the relationship between egg size and care in fishes are suggested.
Many fish species require that their embryos (eggs) incubate and hatch in open water. Eggs are broadcast in the water column and either float or sink; adhesive eggs may attach to plants or hard substrates (rock or gravel). Eggs from other fish are laid in a nest, and parent(s) provide a constant water flow by fanning their fins. Some fish also incubate eggs in their mouths where movement of the gill plates provides both gentle tumbling and water circulation. Artificial incubation and hatching of fish embryos simulate these natural processes. In the wild, eggs (or egg masses) are susceptible to predation, and are easily damaged by the continual change of the natural environment. The advantage of man-made hatcheries is that the environment can be controlled and manipulated. Developing embryos and newly-hatched larvae (fry) are the most sensitive and delicate of the stages in the life history of a fish. Therefore, great care must be taken to provide them with the proper incubating and hatching environment. Water temperature, light, water quality, water flow, shock prevention, and type and size of the egg are very important considerations. Artificial incubation of fish eggs is a hatchery practice that will increase the economic efficiency of a commercial fish culture operation. Hatching rates and survival will be increased using artificial incubation. Also, removal of the eggs from the parents may increase egg production by shortening the time for another spawning to occur.
Eggs of 23 Characiformes and eight Siluriformes, belonging to nine families with diverse reproductive behaviour, were ultrastructurally analysed. The migratory species exhibited non-adhesive eggs, whereas, most of the sedentary species presented some degree of egg adhesiveness. Among the Characiformes, non-adhesive eggs showed zona radiata with pore-canals or a fibrillar net at the surface; weakly adhesive eggs presented only zona radiata with pore-canals while adhesive eggs exhibited zona radiata with apparatus like globules, filaments, villi or honeycomb-like pores depending on the systematic group. The ‘jelly’ coat is strongly related to the Siluriformes eggs apparently without relationship with adhesiveness. A micropylar disc was present in adhesive eggs of a few species of both Characiformes and Siluriformes. Some patterns were characteristic of the animal pole, others of the vegetal pole, and others were common to both poles. The radial ridges converging to the micropyle in Astyanax bimaculatus lacustris appear to be related to fertilization. In general, egg surface structures in the Characiformes varied according to the genus, whereas all Siluriformes showed a similar egg surface pattern, regardless of the group analysed. Multivariate analysis allowed the identification of eight clusters among the Characiformes and three among the Siluriformes showing relationships between reproductive style and egg characteristics. It is suggested that egg surface and adhesiveness may be related to reproductive patterns and to phylogenesis.
Data are presented on the embryonic and larval development of Gobius cobitis (Pisces: Gobiidae). Embryonic development lasts from 15 days at 15°C to 17 days at 18°C. Larval development takes 37–44 days. Larvae begin to settle on the bottom at 1·3–1·4 cm total length. After five and a half months juveniles are about 5·5 cm total length.
Factors affecting egg quality are determined by the intrinsic properties of the egg itself and the environment in which the egg is fertilized and subsequently incubated. Egg quality in fish is very variable. Some of the factors affecting egg quality in fish are known, but many (probably most) are unknown. Components that do affect egg quality include the endocrine status of the female during the growth of the oocyte in the ovary, the diet of the broodfish, the complement of nutrients deposited into the oocyte, and the physiochemical conditions of the water in which the eggs are subsequently incubated. In captive broodfish, the husbandry practices to which fish are subjected are probably a major contributory factor affecting egg quality. Our knowledge of the genetic influences on egg quality is very limited indeed. We know that parental genes strongly influence both fecundity and egg quality, but almost nothing is known about gene expression and/or mRNA translation in fish oocytes/embryos. This is surprising because the products synthesized in ovoand the mechanisms controlling their expression are likely to play a central role in determining egg quality. The genetic mechanisms underpinning oocyte and embryo growth and development are a priority for research
The onset of exogenous feeding in fish larvae can be considered as the period from which the ingestion is possible up to the moment when larval growth is detected. The main characteristic of this phase is that the source of nutrient and energy necessary to continue the larval development changes from the yolk reserves to the ingested food. To achieve this transition with success it is necessary that all structures and organs related with food uptake, digestion and assimilation are ready in due time and that the appropriate food is available. This review will focus on the most relevant processes during this short period of early life history of marine fish: gut anatomy, digestive capacities, feeding behaviour and metabolism.At the opening of the mouth and anus the yolk is completely or almost exhausted. The gut is a simple tube histologically differentiated in foregut, midgut and hindgut. The pancreas, liver and gall bladder are functional. From the first moment of feeding the larvae are able to ingest, digest and assimilate food particles. The digestion starts in an alkaline environment with the contribution of pancreatic enzymes as well as cytosolic enzymes. The main limitations at the beginning of exogenous feeding are mouth gape, restricting the particle size and larval length, restricting swimming capacity and hunting success. After the opening of the mouth, the organogenesis continues. A quick growth and differentiation of the digestive tract is necessary to reinforce digestion and nutrients absorption. A few days later the larval length and jaw size have increased enough to allow a more effective predation.
Astronotus ocellatus, popularly known as Oscar, is a cichlid fish from the Amazon basin (Brazil) with a great potential for fish farming. The aim of this research is to describe the morphology of eggs and larvae of A. ocellatus under stereomicroscopy and scanning electron microscopy. Eggs from natural spawnings were taken to hatcheries, collected at previously established time periods and then analysed. Oscar's eggs are demersal, adhesive and fragile to touch, with a slightly oval shape. The fertile eggs are yellowish in colour and when unfertilized are a white opaque colour. In the initial collection (IC), the majority of eggs were found to be at the gastrula phase with 30% epiboly. At 12 h after the IC, the formation of the embrionary axis and somites was observed, followed by differentiation of the tail and of the head. Fifteen hours after the IC, the emergence of the optic and otic vesicles, and of adhesive glands and the yolk pigmentation was observed. Larval hatching took place between 46 and 58 h after the first collection, at an average temperature of 27.45 ± 2.13°C. The larval stage was characterized by the development of the heart, fins, branchial apparatus, neuromasts, taste buds and adhesive glands on the head. Larval development to yolk absorption took a period of 257 h. These results provide important information for reproduction, rearing and preservation of A. ocellatus.
Brycon gouldingi is an endemic species from Tocantins-Araguaia basin, used as a food source by riverine communities and relevant to aquaculture. Information about the initial morphology of B. gouldingi, a recently described species, is absent. In the present study, we analysed the fertilization and the embryonic development of this species based on light and scanning electron microscopy. After collection of adult specimens in Mortes River - Mato Grosso, Brazil, adaptation to captivity and induced spawning at Buriti Fishculture, Nova Mutum - Mato Grosso, Brazil, in December 2007 and January 2008, samples were collected at pre-defined periods from egg extrusion up to larval hatching, which occurred at 13.9 ± 0.06 h post-fertilization (hpf) in average. At the moment of extrusion, the eggs were slightly ovoid bearing a single micropyle per oocyte with a funnel-shaped micropyle canal and vestibule covered with longitudinal folds, typical of the genus Brycon. The embryonic development of B. gouldingi was characterized by six stages with distinct features: zygote (from fertilization up to formation of egg-cell); cleavage (cell divisions resulting in blastomeres, including the morula phase); blastula (several embryonic cells in a cup shape, without distinction of cell boundaries); gastrula (cell movement); histogenesis/organogenesis (formation of tissues and organs); and hatching (larval chorion rupture). Right after hatching, the larvae presented neither swimming abilities nor visual accuracy, and the digestive trait was undifferentiated. The present study is the first report on biological features of embryogenesis in B. gouldingi, providing relevant information to several approaches, mainly related to taxonomy, ecology, conservation and captive rearing of this new Brycon species.
We describe the major events in the retinogenesis in an altricial fish species, the Senegalese sole. The major developmental events in the sole retina occurred early after hatching (posthatching day 0, P0). Thus, (1) plexiform layers became recognizable at P1. (2) Proliferative activity disappeared from the central retina at P1, and, as development progressed, became restricted to cells located in the circumferential germinal zone, and to sparse cells dispersed throughout the inner nuclear layer and the outer nuclear layer. (3) Apoptotic cells were sparsely observed, randomly localized in all three nuclear layers of the early posthatching retina from P0 to P4. (4) The first synaptic vesicles were detected at P0 in early postmitotic ganglion cells. However, their appearance in the plexiform layers was delayed until P2. (5) The neurochemical development of most major retinal cell classes occurred between P0 and P5. Thus, although Isl1 immunoreactive ganglion cells were the first to become postmitotic in the vitreal surface of the central retina at P0, the first glutamine synthetase-expressing Müller cells appeared in the central retina by P5. The onset of expression for other retinal markers, such as rod opsin, calretinin, parvalbumin, alpha-tyrosine hydroxylase, and alpha-protein kinase C, occurred between P2 and P4. Our results suggest that the most relevant processes involved in Senegalese sole retinogenesis occur during the prolarval and early larval stages (P0-P5). Furthermore, we conclude that altricial fish species may constitute a convenient model organism to address the relationship between the structural and functional development of sensory organs with the acquisition of behavioral repertoires. J. Exp. Zool. (Mol. Dev. Evol.) 314B, 2010. (c) 2010 Wiley-Liss, Inc.
INTRODUCTION
Axis and germ-layer formations are central issues in vertebrate embryology that can be examined in the zebrafish, Xenopus , chick, and mouse. An intriguing question is how the mechanisms that existed in an ancestral vertebrate have been modified during vertebrate evolution. A major stream of vertebrates (Osteichthyes) evolved in two monophyletic lineages: the Sarcopterygii and Actinopterygii. The zebrafish is a well-known and well-studied teleost fish highly derived in the actinopterygian lineage, ray-finned fishes. The early cleavage pattern of teleosts is meroblastic, in contrast to the holoblastic cleavage seen in amphibians, which diverged early in the sarcopterygian lineage. There are many differences in the molecular and cellular mechanisms of embryogenesis between teleosts and amphibians or actinopterygians and sarcopterygians, including the differences in bauplan (body plan). However, the lineage leading to the teleost fishes has undergone a whole-genome duplication before their radiation, which may have also caused changes in molecular usage independent of the teleost bauplan. Polypterus diverged from all other actinopterygians ~400 million years ago (Mya) during the Devonian period, soon after the divarication of an ancestral bony fish into Actinopterygii and Sarcopterygii. Polypterus is thus uniquely well suited for studies assessing the ancestral state or bauplan of Osteichthyes and Actinopterygii, as well as the divergence of embryogenetic processes in teleosts and amphibians.
Remodelling of fish larvae during metamorphosis involves different growth rates of parts of their body with respect to length and weight. The hypothesis that different growth rates, in the size range between 5 and 20 mm, are required to meet the changing demands of swimming, feeding and respiration are tested using data obtained from high speed movies and studies of larval morphology. Changing growth rates appear to reflect closely the size and feeding ecology dependent functional requirements.
The hybrid fish Pseudoplatystoma spp. has been raised on a large scale by several fish farmers, despite the fact that little is known about its biology. This is because it presents a number of zootechnical advantages over the parental species. In order to provide information about the early morphology of this important species, we analyzed the fertilization and embryonic development of the hybrid between spotted females and barred males of sorubim specimens by light microscopy and by scanning (SEM) and transmission electron microscopy (TEM) after induced spawning. Samples were collected at pre-established moments up to larval hatching. Seven distinct stages of hybrid embryonic development were identified: zygote, cleavage, morula, blastula, gastrula, histogenesis and organogenesis, and hatching. Under SEM, we observed spermatozoa at the micropyle entrance, the formation of a fertilization cone in the eggs, the differentiation of cephalic and caudal regions, the neural tube and embryo growth along the cephalo-caudal axis, as well as rudimentary optic vesicle and barbels. Under light microscopy, cytoplasmic movement was apparent with the consequent formation of animal and vegetative poles in eggs, in addition to epiboly movements and a small notochord portion. Under TEM, the oocyte chorion and eggs presented a sieve-like aspect in transversal cuts, coupled with the rupture of cortical alveoli and chorion elevation, thus enlarging the perivitelline space. Several mitochondria in the cortical cytoplasm were detected in both oocytes and eggs. Overall, we observed that the larvae hatched without visible morphological alterations, and seemed to be as viable in captive systems as they are in the natural environment.
The zebrafish has become an important vertebrate model in developmental neuroscience because it is a useful model for embryology, developmental biology, and genetic analysis. The similarities of its visual system to that of other vertebrates also make this animal a valuable model in vision science. The anatomical, physiological, and behavioral components of zebrafish visual processing have been studied in adult and in developing zebrafish. Its retinal anatomy continues to develop following hatching, providing an opportunity to correlate the development of retinal structure with visual physiology and behavior. In addition, a number of genetic mutations have been developed which are used to examine the contributions of genetics to visual development and function. This article will provide an overview of studies of zebrafish anatomical, physiological and behavioral processing, and the effects if genetic and environmental manipulations on visual development.
Simple, effective protocols for cryopreserving milt of five Brazilian migratory characids (Brycon
orbignyanus, Prochilodus lineatus, Piaractus mesopotamicus, Salminus maxillosus and Leporinus
elongatus) and one Brazilian migratory catfish (Pseudoplatystoma corruscans) are described. Milt
was frozen and stored in dry shippers immediately after collection, making the procedure practical
for use in the field. A diluent of 5% glucose, 10% dimethyl sulphoxide and 10% egg yolk was
effective for all of the characid species, and a diluent of 10% methanol and 15% powdered milk
was effective for P. corruscans.Milt was thawed in an ambient temperature water bath (28–30� C).
Activation of thawed milt was effective with either saline (0�9 or 0�45% NaCl) or bicarbonate (1%
NaHCO3). Fertilization rates with frozen milt varied between 49 and 300% of the control.
Application of the technology for increasing genetic diversity in hatchery programmes for
enhancement, mitigation or conservation breeding is discussed, as is its application in aquaculture.
Inappropriate use of the technology can threaten wild biodiversity and appropriate legislation and
education may be required for its responsible use.
Vertebrate embryogenesis entails an exquisitely coordinated combination of cell proliferation, fate specification and movement. After induction of the germ layers, the blastula is transformed by gastrulation movements into a multilayered embryo with head, trunk and tail rudiments. Gastrulation is heralded by formation of a blastopore, an opening in the blastula. The axial side of the blastopore is marked by the organizer, a signaling center that patterns the germ layers and regulates gastrulation movements. During internalization, endoderm and mesoderm cells move via the blastopore beneath the ectoderm. Epiboly movements expand and thin the nascent germ layers. Convergence movements narrow the germ layers from lateral to medial while extension movements elongate them from head to tail. Despite different morphology, parallels emerge with respect to the cellular and genetic mechanisms of gastrulation in different vertebrate groups. Patterns of gastrulation cell movements relative to the blastopore and the organizer are similar from fish to mammals, and conserved molecular pathways mediate gastrulation movements.
Pseudoplatystoma coruscans is a very popular species for tropical fish culture as it has boneless meat of delicate taste and firm texture. Few studies on fish reproductive biology refer to the morphological features of eggs. The goal, therefore, of this present work was to perform a structural and ultrastructural analysis of fertilization and embryonic development in P. coruscans. The incubation period, from fertilization to hatching, lasts 13 h at 28/29 degrees C and 18 h at 27 degrees C. The oocytes had a mean diameter of 0.95 mm and hatched larvae were 2.55 mm in diameter. Analysing their development, we observed round, yellow oocytes that bore a double chorion membrane and a single micropyle. At 10 s after fertilization, several spermatozoa were detected attached to the oocyte surface. After 1 min of development, a fertilization cone that obstructed the micropyle could be observed. Segmentation started between 20 and 30 min after fertilization, when the egg cell was then formed. The first cleavage occurred between 30 and 45 min after fertilization, prior to reaching the morula stage (75 and 90 min after fertilization). The epiboly movement started at 120 and 180 min after fertilization and ended at 360 and 480 min after fertilization. Differentiation between cephalic and caudal region was detected after 420 and 600 min after fertilization and larvae hatched between 780 and 1080 min after fertilization. Seven main embryonic development stages were identified: egg cell, cleavage, morula, blastula, gastrula, segmentation with differentiation between cephalic and caudal regions, and hatching.
Desarrollo embrionário de Rhamdia sapo (Valencieness, 1840) Eigenmann y Eigenmann, 1888 (Pisces, Pimelodidae). I. Segmentación, morfogénesis y organogenesis temprana
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Biologia do Desenvolvimento
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Gilbert, S.F. (2003). Biologia do Desenvolvimento. Ribeirão
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Princípios de Biologia do Desenvolvimento
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Criação, manejo e reprodução do peixe Betta splendens
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Early life history stages of fishes and their characters
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Ovos e Larvas de Peixes de Água Doce: Desenvolvimento e Manual de Identificação
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de Peixes de Água Doce: Desenvolvimento e Manual de
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The genus Polypterus (Bichir)
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Criação, manejo e reprodução do peixe Betta splendens (Regan 1910)
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