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A History of Fishes

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... Questi ecosistemi hanno un notevole valore ambientale dal momento che ospitano un'elevata biodiversità. 4 Alcune specie come il tonno rosso (Thunnus thynnus) sono apprezzate sin dall'antichità, come documentano le tradizionali tonnare in azione nel Mediterraneo da tempo immemorabile, 5 che testimoniano tra l'altro come la diffusione e l'abbondanza di questa specie fossero ben diverse dallo stato attuale di sovra-sfruttamento. Se consideriamo inoltre che questi due ecosistemi ospitavano in passato altre specie di elevate dimensioni come la foca monaca (Monachus monachus), la tartaruga di mare (Caretta caretta), squali, mammiferi e uccelli marini, ci rendiamo conto di come il Mediterraneo e il Mar Nero siano oggi poco più dell'ombra di un passato che tuttora non conosciamo pienamente. ...
... dal 1570 al 1820 3 , che favorisce la messa a punto di un nuovo sistema di conservazione con l'uso di ghiaccio e neve, consentendo anche d'estate spedizioni di quantitativi consistenti di prodotto fresco verso mercati interni precedentemente impossibili da raggiungere proprio per l'alta deperibilità della merce. 4 Sono questi gli impulsi nuovi che stanno alla base dello straordinario cambiamento nello sfruttamento delle risorse del mare che si registra fra Sei e Settecento. ...
... La Tabella 1 contiene alcune di queste fonti. 4 Lo stato, co-munque, sembrava avere maggiore interesse nell'acquicoltura che nella pesca in mare. Nel konounname del XVI e XVIII secolo si stabiliva che il pesce catturato negli allevamenti doveva essere equamente diviso tra il sultano e i pescatori, 5 mentre in un altro kanounname dell'inizio del XVI secolo si stabiliva che gli allevamenti di pesce di Salonicco dovevano essere assegnati al miglior offerente, il quale si doveva assumere la responsabilità di pagare il 10 per cento alla dogana, così come un'altra tassa uguale ad 1/100 del valore del pesce al capo della polizia cittadina. ...
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Questo volume raccoglie le sintesi delle comunicazioni tenute nell'ambito del II Workshop Internazionale del programma HMAP (History of Marine Animal Populations - Storia delle Popolazioni Marine) del Mediterraneo e Mar Nero, organizzato dal 27 al 29 settembre del 2006 da ISPRA (STS Chioggia) con il sostegno del progetto internazionale EuroCoML (European Census of Marine Life - Censimento delle popolazioni marine), dell'Associazione "Tegnùe di Chioggia" - onlus e della Regione Veneto. Nel contesto del workshop, storici, archeologi, antropologi ed ecologi marini hanno affrontato la tematica della storia della pesca e delle conseguenze ecologiche dello sfruttamento delle risorse marine in relazione a diverse aree del Mediterraneo e del Mar Nero dall'Epoca Romana al XIX secolo. I contributi descrivono le attività di pesca, commercio e conservazione del pesce e riportano alcune evidenze dei segnali di crisi registrati, fin da tempi remoti, per alcune specie o gruppi di specie marine. Una sezione del volume è, inoltre, dedicata allo sviluppo di approcci multi-disciplinari (sia in termini di raccolta delle fonti che di approcci analitici e modellistici) per poter ricostruire l¿ecologia storica e la storia ambientale del Mediterraneo.
... planks and timbers of vessels, some to the depth of 30 inches (Gudger, 1940;Norman and Greenwood, 1975;Smith and Heemstra, 1986). Although many of these accounts may be cor rect, two commonly cited incidents are misi dentifications and should be credited to mem bers of the family Istiophoridae. ...
... platypterus) was the species responsible. On the other hand, Norman and Greenwood (1975), who recognized the confusion with the names and believed all billfish to have similar habits, did not implicate any particular billfish (swordfish or spearfish) in the incident. ...
... Unfortunately, we must rely on published accounts for information about this specimen because it was apparently destroyed when the Hunterian Museum was bombed in 1941 (letter dated March 1, 1994 from E. Allen, Hunterian Museum, Royal College of Surgeons, London, England). Gudger (1940) did not give dimensions of the rostrum, but Norman and Greenwood (1975) stated that it was a foot long and five inches in circumference. Figure 12 in Gudger (1940) reveals a rostral segment that is complete to its distal tip and that broke off in its solid region, probably near or distal to 0.5L. ...
... Rafinesque's reference to paddlefish teeth is open to interpretation. Adult and sub-adult paddlefish are traditionally described as toothless (Mitchill et al., 1827;Beach, 1902), but other sources note that the jaws are "armed with small teeth" (e.g., Norman, 1948). One taxonomic reference describes paddlefish teeth in some detail: double rows in the upper jaw and a single row in the lower jaw of "sharp, curved, and serrated teeth" (Shaw, 1804). ...
... At one time, the rostrum was believed to be an implement used by the paddlefish to acquire food, either by digging and stirring aquatic invertebrates into the water column or by manipulating aquatic plants for grazing (Mitchill et al., 1827;Beard, 1878;Beach, 1902). The rostrum-asutensil hypothesis persisted for decades (Norman, 1948). Doubts were raised nearly a century ago, however, and the theory is given little credibility today (Stockard, 1907;Grande and Bemis, 1991). ...
... Habitats with wide temporal or spatial ranges in salinity also provide good hotspots for transitions because the acclimation response depends on the physiology of the fish and the timescale of fluctuations. Lower temperatures are prevalent at mid latitudes and these conditions favor higher rates of colonization, since salinity and temperature interact to affect energetic demands, ion uptake rate and membrane permeability of fishes (Norman & Greenwood, 1975as cited in Bamber & Henderson, 1988McDowall, 1988;Lee & Bell, 1999;Schultz & McCormick, 2013). ...
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Coastal habitats in Chile are hypothesized to support a number of diadromous fish species. The objective of this study was to document migratory life histories of native galaxiids and introduced salmonids from a wide latitudinal range in Chilean Patagonia (39-48 • S). Otolith microchemistry data were analysed using a recursive partitioning approach to test for diadromy. Based on annular analysis of Sr:Ca ratios, a diadromous life history was suggested for populations of native Aplochiton taeniatus, A. marinus, and Galaxias maculatus. Lifetime residency in freshwater was suggested for populations of A. zebra and G. platei. Among introduced salmonids, populations of Oncorhynchus tshawytscha and O. kisutch exhibited patterns consistent with anadromy, whereas the screened population of O. mykiss appeared restricted to freshwater. Salmo trutta exhibited variable patterns suggesting freshwater residency and possibly anadromy in one case. The capacity and geographic scope of hydropower development is increasing and may disrupt migratory routes of diadromous fishes. Identification of diadromous species is a critical first step for preventing their loss due to hydropower development.
... outside the aquatic condition. Thus, the wide gill opening fish dies more rapidly than those with the narrow gill opening as described by (Norman, 1963) and confirmed by (Abumandour & Gewaily, 2016). ...
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The present investigation was designed to describe the surface ultrastructure of the gill system of tilapia Zilli. The gill system is formed from four gill arches and each gill arch carries a row of gill filaments on its convex border and two rows of the gill rakers on its concave border. The quadrilateral interbranchial septum has elevated part at the level of the third gill arch. By SEM observations, the gill arch was divided into three regions: rostral, middle and caudal region. The caudal region contained two characteristic structures: oval leaf‐like structure and rounded‐shaped structure. Each oval leaf‐like structure carried two lateral rows of the triangular pointed spines separated by a median groove. All surfaces of gill arches, rakers and filaments were covered with a mosaic of the polygonal pavement cells, in addition to the opening of chloride cells and mucous cells. The gill arch and gill raker had only one appearance of taste buds named type I. Meanwhile, the filaments contained two types of different appearance of the taste buds named: type I and type II. Type I was the main common and similar to that present in gill arch and raker and characterized by its blunt end, while type II had hair‐like structures that projected from the volcano‐shaped depression. The gill rakers were formed from central axis surrounded by two lateral lobulated regions which carry pointed spines, taste buds and the opening of chloride cells. The surface of triangular lower pharyngeal jaw carries numerous teeth‐like papillae which originated from the socket‐like depression.
... In Table 1, Species 1 has a beneficial effect on Species 2, but Species 1 is not affected by Species 2. A well-known example of commensalism is the relationship between remora and sharks. A remora adheres to the body of a shark and feeds on the leftovers of the shark's meal, but a shark is neither benefited nor harmed by a remora (Norman, 2007). ...
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System evolution prediction is critical for designers to make R&D and outsourcing decisions. Many descriptive models are used for this purpose, but they have several limitations. In this paper, we extend the Lotka–Volterra equations as an ecosystem model to predict the performances of the system and its components. This model comprises a set of differential equations that describe symbiosis, commensalism, and amensalism relationships between a system and multiple components. We associate every parameter in the model with its causal factors, develop a three-step application of the model, and illustrate the application through a case study on passenger airplane fuel efficiency. Our model identifies the key components in a system. The identified components help designers generate strategies to boost system performance. https://www.sciencedirect.com/science/article/pii/S0142694X18300711
... Thus, many species of macroscopic nektonic organisms minimize turbulent drag in order to fulfill their food requirements from defined ranges. The sleek, streamlined body forms they have adopted attest to the evolutionary convergence of traits adapted for life in the pelagic [14]. ...
Chapter
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The term ‘pelagic zone’ refers essentially to the open ocean, beyond the continental shelves. However, ‘the pelagic’ is understood by freshwater ecologists to mean simply ‘the open water’ of large lakes and reservoirs. In either instance, the notion of a liquid environment, remote from the shores and bottom of the containing basin, is clear. In extent, the marine pelagic is, by far, the greatest of the world's major ecosystems, covering some 361 × 10⁶ km² (or 71% of the planet's surface) and accommodating an estimated volume of 1.35 × 10⁹ km³. In contrast, the aggregate volume of the world's lakes and rivers is a relatively modest 225 × 10³ km³.
... Fishes are at the top of the aquatic food chain and may concentrate large amount of metals in their body which in turn are consumed by man. Fish gills are the main site of respiration, excretion and osmoregulation (Norman 1963;Moyle & Cech 1996). The injury to gill epithelium appears earlier than any other organ as fish gills are in direct contact with the toxicants and therefore are more prone to morphological and functional disturbances (Maina 1998;Wendelaar Bonga & Lock 2008). ...
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Labeo rohita fingerlings were reared in freshwater and exposed to different concentrations of Lead Nitrate. After the exposure, one fish was sacrificed from each dose and the gill arches were removed. The ultrastructural changes on the gills of this cyprinid fish were investigated through scanning electron microscope (SEM). Lead treated gill tissues showed certain marked changes such as uplifting, hyperplasia and fusion of the secondary lamellae, swollen and distorted pavement cells, broken and swollen microridges, broken tips and upliftment of gill rakers, cellular extrusions, heavy exudation of mucous, and disorganisation of secondary lamellae. The changes were more rapid and intensive at higher concentrations as compared to lower concentration revealing that the alterations caused in the tissues of gills are highly dose dependent.
... Our study revealed that the wide ventrolaterally gill opening covered by the operculum was reported in most teleost fish species (Eiras-Stofella & Charvet-Almeida, 1997; Eiras-Stofella & Charvet-Almeida, 2000; Alsafy; Elsheikh), in contrast, Zayed & Mohamed reported that the catfish has a small gill opening. This variation about the size of the gill opening was explained by Norman & Greenwood (1963) which reported that fishes with a wide external gill opening die more rapidly than those which have a small opening meanwhile, in the puffer fisch (Abumandour & Gewaily) reported that the slit-like gill opening was characterized by the absence of gill cover which located cranial to the base of the pectoral fin. ...
Article
The purpose of the current investigation was to describe the gill morphology of two bottom feeders Mediterranean Sea fishes: Striped red mullet fish (M. surmuletus) and grey gurnard fish (E. gurnardus) that showed the same feeding habits. The gill system of the grey gurnard consisted of four pairs of gill arches while consisted of three pairs of gill arches in the striped red mullet. Our study focused on the scanning electron microscopical (SEM) features of the gills, where some differences in the gill arches and gill rakers surface in both species were observed. Our results marked that there was an interbranchial septum carrying a four transverse elevated crest in grey gurnard while in striped red mullet carrying a median longitudinal elevated crest. There are some similar structure on the gill arch of two fishes as; no angle between a ceratobranchial part and epibranchial part and also the gill arch has a region of many longitudinal microridges demarcated the region between gill rakers and gill filaments. By SEM, in striped red mullet, the smooth surface of gill arch and gill rakers was characterized by the presence of high number of taste buds. By SEM in grey gurnard, gill raker appeared as a round short projected body with high number of curved apex spines. Furthermore, in striped red mullet, gill raker appeared as short projected body with high number of rod-like spines. Gill filaments were long at middle and short at extremities of gill arch in both species.
... Some early publications on natural history attributed ages as great as 150 years to the Carp (Cyprinus carpio) and 200 years to the Pike (Esox lucius). These records have been shown to be fables (Norman 1949). Flower (1925) quoted Buffon (1769) on the two ways to determine the age of a fish: by counting the annular marks in scales (the denser zones of the concentric rings that represent a period of slower growth) or by recording its life span in captivity. ...
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The life span of fishes has been determined primarily by survival time in public aquaria and by counting the annular marks of otoliths. The fishes with the longest duration of life are deeper-water species, such as rockfishes of the genus Sebastes, some with validated ages in excess of 100 years. The goby Eviota sigillata, maximum length 21 mm, has the shortest published life span, 59 days. However, other smaller gobies, such as Trimmaton nanus (mature at 10–12.5 mm), the neotenic gobiod fishes of the family Schindleriidae (mature as small as 8.5 mm), and the miniature cyprinid fishes of the genus Paedocypris, (mature as small as 7.9 mm), might be expected to have even shorter life spans. Predation, parasites, disease, and catastrophic environmental events shorten the lives of fishes in nature. We report here the longevity of the following small gobiid fishes in aquaria in Hawai'i: Kelloggella oligolepis, 22 months; Eviota nigriventris, 23 months; Trimma rubromaculatum and T. tevegae, 12–20 months; Priolepis nocturna, 3 years and 3 months; Asterropteryx semi-punctata, at least 11 years, and Gobiodon okinawae, at least 13 years. A table is provided of 15 species of fishes that have lived from 13 to 24 years in the Waikiki Aquarium , Honolulu. The life span of fishes is believed to be related to their adult size, with small species having the shortest duration of life, as we might deduce from mammals by comparing the longevity of a shrew with that of an elephant. While this is true of fishes in general, there are many exceptions. The Dolphinfish (Coryphaena hippurus), which reaches a length of 2.1 m and a weight of 40 kg, has a life span of only four to five years. We will show that some gobiid fishes smaller than 10 cm in total length can live more than 10 years in aquaria, where they are free from predation, and with proper care, from disease. Some early publications on natural history attributed ages as great as 150 years to the Carp (Cyprinus carpio) and 200 years to the Pike (Esox lucius). These records have been shown to be fables (Norman 1949). Flower (1925) quoted Buffon (1769) on the two ways to determine the age of a fish: by counting the annular marks in scales (the denser zones of the concentric rings that represent a period of slower growth) or by recording its life span in captivity. He then reported on the longevity of 42 species of fishes representing
... Thus, many species of macroscopic nektonic organisms minimize turbulent drag in order to fulfill their food requirements from defined ranges. The sleek, streamlined body forms they have adopted attest to the evolutionary convergence of traits adapted for life in the pelagic [14]. ...
Chapter
Full-text available
... One example is sounds produced during feeding activities. These result from collision of the buccal teeth, e.g. in Balistes capriscus (Vincent, 1963), or occur during grating of pharyngeal teeth in B. capriscus, Balistes vetula and Odonus niger (Norman, 1931;Fish, 1948;Fish et al., 1952;Moulton, 1958). Because these sounds are mainly heard while crushing mollusks and hard corals (Fish, 1948(Fish, , 1954Tavolga, 1965;Tricas and Boyle, 2014), it is unclear whether they are used for communication. ...
... Th^ sroc\r* 61 isat:'a1 canal situated in the centre of the spinal cord (1 and2). Greenwood (5) described the spinal cord as a structure of uniform shape extending from the last portion of medulla oblongata to location of the caudal fin.ln some fish6s, however, medulla oblongata is short as in globe fishes, whereas in the sun frsh Mola mola it is distinctly short, being shorter than length of the brain Materials and methods A total of 100 individuals of the common carp (Cyprinus carpio) were collected, from Basrah University fish farm at Mariire Science Centre., by cast net, to execute the present study. Examined individuals were of various sizes. ...
... One example is sounds produced during feeding activities. These result from collision of the buccal teeth, e.g. in Balistes capriscus (Vincent, 1963), or occur during grating of pharyngeal teeth in B. capriscus, Balistes vetula and Odonus niger (Norman, 1931;Fish, 1948;Fish et al., 1952;Moulton, 1958). Because these sounds are mainly heard while crushing mollusks and hard corals (Fish, 1948(Fish, , 1954Tavolga, 1965;Tricas and Boyle, 2014), it is unclear whether they are used for communication. ...
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The ability to produce sounds has been known for decades in Balistidae. Sounds of many species have been recorded and a variety of sound producing mechanisms have been proposed including teeth stridulation, collision of buccal teeth, and movements of the fins. The best supported hypothesis involves movements of the pectoral fins against the lateral parts of the swimbladder called a drumming membrane. In this study, we describe for the first time the sounds made by the Blackbar triggerfish Rhinecanthus aculeatus that sound like short drum rolls with an average duration of 85 ms, 193 Hz dominant frequency and 136 dB SPL level at 3 cm distance. Sounds are a series of pulses that result from alternate sweeping movements of the right and left pectoral fins, which push a system of three scutes that are forced against the swimbladder wall. Pulses from each fin occur in consecutive pairs. High-speed videos indicate that each pulse consists in two cycles. The first part of each cycle corresponds to the inward buckling of the scutes whereas the second part of the cycle corresponds to an apparent passive recoil of the scutes and swimbladder wall. This novel sound production mechanism is likely found in many members of Balistidae because these peculiar scutes are found in other species in the family. Comparison of sound characteristics from fishes of different sizes shows that dominant frequency decreases with size in juveniles but not in adults.
... The main preoccupation of early investigations was with the mechanisms and structures that animals use to gather food and to process it once consumed. In broad terms, it was recognized that different types of prey demanded different styles of finding and capturing food (e.g., Norman, 1936, Chapters 6 and 7). The main deficiency in this approach was that there was no attempt to understand why fish had evolved such structures or processes. ...
Chapter
As with all animals, finding food is a continuous task for fish. Selection pressure on food finding behaviour, or foraging, is intense. The main preoccupation of early investigations was with the mechanisms and structures that animals use to gather food and to process it once consumed. In broad terms, it was recognized that different types of prey demanded different styles of finding and capturing food (e.g., Norman, 1936, Chapters 6 and 7). The main deficiency in this approach was that there was no attempt to understand why fish had evolved such structures or processes.
... Studies on the detailed structure of fish scale are very important in the nomenclature, classification and identification of fish to major groups [30,45,35] and species levels [3,6,31], phylogeny [27,28], sexual dimorphism [22], age determination [10,44,19,21], past environment experienced by fish scale due to water pollution of the water body [12,13,16], and for growth studies [5,43,21,16,4,37,38,32,14]. ...
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Scales have numerous hidden details in their structures that contribute effectively to fish identification and classification. A traditional approach has been made to study the scale morphology of the Indian goatfish Parupeneus indicus using a stereomicroscope in tandem with a 12.2 megapixel Samsung ST500 digital camera in which digitized images were processed using Adobe Photoshop CS4 Extended software. Two specimens of fish sample of both sexes were described qualitatively and observed quantitatively. Thirty scales in every region were obtained for description and comparison. In describing the scales, several distinguishable characteristics were considered such as the type of the scale, overall scale shape, scale size, the shape of the posterior margin group of ctenii square, the position of the focus, circuli appearance, and the type of radii. Results of the study revealed that there are significant variations of shapes observed between male and female species. The presence of disrupted circuli, the same type of radii existing in each body regions in both sexes of the fish cannot be used to establish sexual dimorphism in P. indicus due to their similarities. The existence of an oblong scale shape is unique to males and that of a cycloid shape unique to females. Also, the variation of other scale shapes in region G where male has rectangular while female has triangular shapes but both have square scale shape and in region J where male has rectangular shape while female has square shape but both have triangular shape. Thus, these are significant indicator of sexual dimorphism between the sexes of P. indicus.
... En los peces las aletas pélvicas fungen como un órgano para la maniobrabilidad, además de ser considerada como una estructura para el frenado durante la natación activa. Sin embargo, estudios como el realizado por Norman (1963), han demostrado que la ausencia de ellas, a pesar de ser una limitante, ha permitido a los peces sobrevivir y seguir creciendo. Al considerar algunos experimentos anteriores, donde se había demostrado que la extirpación de dichas aletas en varios grupos de peces no incurría en cambios notables, Standen (2008) sugiere que incluso en los grupos no tan derivados, como en los Salmoniformes, la funcionalidad que tiene este par de aletas es compleja. ...
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RESUMEN Se presenta el primer registro anormal, sin aletas pélvicas, de un organismo de la especie Albula vulpes recolectado en las costas del Golfo de México, Atlántico occidental. El ejemplar es un organismo maduro de 327 mm de longitud total. Se presenta una comparación con un espécimen sin malformación para mostrar los cambios anatómicos. ABSTRACT This paper records for time first the bonefish Albula vulpes without pelvic fin, from Gulf of Mexico, Western Atlantic. The specimen is a mature organism of 327 mm in total length. Comparison of this specimen with a normal shows considerable anatomic changes in the pelvic fin region.
... Stegastes rectifrenum presents 1 row of premaxillar teeth, a character related to herbivorous species as M. chrysurus (Emery, 1973;Frédérich et al., 2006;Gluckmann & Vanderwalle, 1998) and the mandibular arch has thick and compact pieces, character related to grazer damselfish species as Plectroglyphidodon lacrymatus (Quoy & Gaimard, 1825) (Frédérich et al., 2006). Also, it presents characters related to omnivorous species with preference for algae as some Dascyllus, Chrysiptera and Pomacentrus species: the dentary is almost flat and the retroarticular is long and thin; the premaxillar and dentary present incisor teeth; the teeth of the dentary are shorter than the premaxillar teeth; the anterior teeth are longer than the laterals; the angle of the ascending process of the premaxilla and the dentate area form an angle 90 • approximately; and the connection between the metapterigoides and quadrate is thin (Frédérich et al., 2006;Frédérich, Pilet, Parmentier, & Vanderwalle, 2008;Gluckmann & Vanderwalle, 1998;Norman & Greenwood, 1963). ...
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Pomacentridae is one of the most abundant fish families in coral and rocky reefs of tropical and temperate waters. Stegastes rectifraenum (Gill, 1862), as other members of the genus, is territorial and actively farm algae on its territory, helping in the regulation of the algal community structure and the reef productivity. It is endemic and one of the most abundant species along the Mexican Pacific coast. Even with its strong relationship with algae, this species is omnivorous. In this analysis, we present the first complete anatomical description of a species of Pomacentridae, focusing in one research question: which structures allow S. rectifraenum to have an omnivorous diet? Through the analysis of the skeletal, muscular and digestive systems, the anatomy of the species was described. The complex anatomy of S. rectifraenum shows a set of characters previously described for grazers (mandibular muscles), herbivorous (mandibular teeth), omnivorous with preference for algae (general skull osteology) and zooplanktivorous species (intestine shape and pharyngeal teeth). According to our results, S. rectifraenum is a grazer, omnivorous with preference for algae. Finally, the key character that facilitates S. rectifraenum access to a wider range of resources is the shape of the pharyngeal teeth, which can effectively grind, fasten and tear.
... The ancient Greek naturalists, especially Aristotle, were highly knowledgeable about many aspects of fish biology. 1 In the mid-20th What is a fish? ...
... The piranha (Serrasalmus) of South America are the only group of pack-hunting fish, to my knowledge, which attack prey larger than themselves. However, as Norman (1963) points out, they usually feed on fish smaller than themselves. In all the instances reviewed by Radakov (1973) the fish were feeding on small prey. ...
Article
(1) The general feeding biology of Morter obscurus is described. (2) First instar larvae, because they use a different pit construction technique, have steeper-walled pits than later instars. Pit diameter and larval length are linearly related. (3) Capture success is determined mainly by the relative sizes of predator and prey. For a given relative size instar 1 larvae are more successful because of the steep-walled pits. Capture success drops to zero when ants can place some of their legs outside the pit. Third instar larvae were more successful than second instar larvae in pits of the same size. Capture success, particularly for large larvae, is 100% over much of the prey size range. (4) Successful attacks on ants with thick exoskeletons occurred almost exclusively via the gaster whereas mandible insertion for ants with thin exoskeletons frequently occurred elsewhere. (5) Differences in pit morphology and prey capture behaviour in Macroleon lynceus are documented and related to habitat differences. In Morter, pit morphology is crucial for prey capture, while strength is more important for the larger Macroleon. (6) Handling time was divided into time to capture (Tc), time to death (Td), and time to extract body contents (Te). Tc was constant for small prey but increased rapidly for larger prey. Td was constant for all sizes of predator and prey. Te increased with prey size and decreased with increasing predator size and temperature. Te seems to depend not only on the amount of extractable food but also on the shape of the victim. (7) Hunger has no effect on prey handling time or food extraction efficiency. However hungry larvae are more likely to move their pits. Ant-lions can capture prey falling into the pit when already feeding and so increase their food supply. (8) Growth rates of larvae feeding on different sized prey were measured. Large larvae grew more slowly than small ones when fed on the same sized prey because of higher maintenance costs. For a given sized predator, growth per unit weight of prey received declined with increasing prey size because of increased feeding costs. Each size of ant-lion had a prey size for which the costs per unit return were a minimum, this size changing abruptly from very small prey for the first two instars to large prey for the final instar. (9) The feeding biology of the three instars is compared and contrasted. First instar larvae are adapted to achieve a high capture success rate on a small prey size range because feeding costs are high and escapes therefore expensive. For large larvae, maintenance costs are more important and selection has favoured a large size range of catchable prey. While the behaviour of ant-lion larvae is consistent with an energy maximizer strategy it is concluded that the approach is of limited value in this instance.
... The streaked gurnard Trigloporus lastoviza L., is a common gregarious benthic species in coastal waters of the Mediterranean and the Eastern Atlantic, found typically in sandy and muddy areas between 20 and 160 m depth (Fischer, 1973;Labropoulou & Machias, 1998). As in other gurnards, the first three rays of each pectoral fin are separated and used as tactile organs to search the sea bed for food (Wheeler, 1969) and for locomotory assistance (Norman & Greenwood, 1963). The pectoral fins are larger and have conspicuous rows of large cobalt-blue dots on the dorsal surface (Fischer, 1973). ...
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The streaked gurnard Trigloporus lastoviza produced only one sound type, a growl, lasting up to 3 s and consisting of repeated groups of typically one to three pulses. The foraging fish followed two different strategies. In the first, the fish circled the feeding area, grasped a food item and fled, sometimes displaying aggressively to competitors. With this foraging strategy, fish usually made sounds as they circled, grasped and fled. Fish that growled while circling were more likely to grasp a food item subsequently than were silent fish. The second feeding strategy occurred when a fish had already ingested food or failed to get any. In this case, typically fish searched for food on the substratum or approached and touched other individuals that were feeding, sometimes grabbing food that was spat out during food handling by the other fish. Although payback experiments would be needed to draw firm conclusions on the communicative function of growling during competitive feeding in the streaked gurnard, the results suggest that sound production confers advantages Co individuals competing for limited food resources. (C) 2000 The Fisheries Society of the British Isles.
... Segundo GREENWOOD (1975), ocorre um incremento gradual na abundância, riqueza e diversidade de espécies com a redução da latitude, atingindo a maior diversidade na zona tropical. Neste estudo, os valores médios dos índices de diversida-de e equitabilidade foram influenciados diretamente pelas flutuações sazonais das populações, variando em torno da amplitude esperada para a ictiofauna de regiões costeiras (ZANI-TEIXEIRA & PAIVA-FILHO 1981, PAIVA-FILHO & SCHMIEGELOW 1986, PAIVA-FILHO & TOSCANO 1987, YAÑEZ-ARANCIBIA et al. 1988, PEREIRA 1994, onde poucas espécies numericamente dominantes, aparentemente são características comuns em associações de peixes demersais (ANSARI et al. 1995). ...
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The ichthyofauna bycatch in sea-bob-shrimp's fishery was monthly studied from August 1996 to July 2003, in the artisanal fishing grounds at Armação do Itapocoroy, Penha. It had been used two net-of-drag with doors, mesh of 3.0 cm in the sleeve and body and of 2.0 cm in the sacker, pushed for whaleboat with average speed of 2.0 km/h. Mean values of bottom water temperature and salinity remained uniform in a seasonal fluctuation, showing no significant differences among the studied years. A total of 60 species were collected, in which 22 were considered common species along the sampled period. Sciaenidae, Carangidae and Clupeidae families presented the highest number of specimens, accounting to 92% of catches, being Stellifer spp., Paralonchurus brasiliensis and Isopisthus parvipinnis, the dominant species, occurring regularly along the years. Seasonal fluctuations were observed in the abundance and diversity of ichthyofauna, with significant differences observed among the sampled years and biomass, as well as numerical abundance. The monitoring of trawling fishery targeting sea-bob-shrimp may contribute in a way to maintain the exploited stocks and guarantee the subsistence of traditional communities along Santa Catarina's coast.
... During the year, the diversity index ranged between 1.04 and 1.98 in Balneário Barra do Sul and between 0.74 and 1.80 in Penha. GREENWOOD (1975) argued that there is a gradual increase in species diversity with decreasing latitude. Also, according to ROSENZWEIG (1995), the highest richness values are generally obtained in the tropical zone. ...
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Trawling for shrimp is an efficient method to catch tar-get species, but it also accidentally captures a great variety of organisms called accompanying fauna or bycatch (ALVERSON et al. 1994). There is a consensus that shrimp trawling is respon-sible for the highest rates of incidental catches of demersal organisms (ANDREW & PEPPERELL 1992, KELLEHER 2005, GILLETT 2008). In tropical regions, the accompanying fauna associated with penaeid shrimp fisheries represents approximately 68% of the collected biomass (KELLEHER 2005), and fish comprise over 25% of this biomass (HAIMOVICI & MENDONÇA 1996). Artisanal fleets contribute a significant share to the total crustacean production in the shallow waters of the Brazilian continental shelf. For instance, in 2004 alone, they caught approximately seven thousand tons of biomass (MMA/IBAMA 2005). It is estimated that, on average, for every kilogram of shrimp, between 1 and 12 kilograms of fish are incidentally caught (RUFFINO & CASTELLO 1992, VIANNA & ALMEIDA 2005, BRANCO & VERANI 2006b, SOUZA et al. 2008). In most regions where shrimp trawling is practiced, a tiny portion of the bycatch is consumed (fish of low commercial value), and the remainder is discarded (ALVERSON et al. 1994, AMBROSE et al. 2005, BAIL & BRANCO 2007). Understanding the impact of shrimp trawling on marine resources is fundamental for maintaining the sustainability and balance of coastal ecosystems and the trophic chain of the ex-Spatiotemporal variations of the ichthyofaunal structure accompanying the seabob shrimp, Xiphopenaeus kroyeri (Crustacea: Penaeidae), fishery in important fishery areas of the Santa Catarina shore, Brazil
... Segundo GREENWOOD (1975), ocorre um incremento gradual na abundância, riqueza e diversidade de espécies com a redução da latitude, atingindo a maior diversidade na zona tropical. Neste estudo, os valores médios dos índices de diversida-de e equitabilidade foram influenciados diretamente pelas flutuações sazonais das populações, variando em torno da amplitude esperada para a ictiofauna de regiões costeiras (ZANI-TEIXEIRA & PAIVA-FILHO 1981, PAIVA-FILHO & SCHMIEGELOW 1986, PAIVA-FILHO & TOSCANO 1987, YAÑEZ-ARANCIBIA et al. 1988, PEREIRA 1994, onde poucas espécies numericamente dominantes, aparentemente são características comuns em associações de peixes demersais (ANSARI et al. 1995). ...
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The ichthyofauna bycatch in sea-bob-shrimp's fishery was monthly studied from August 1996 to July 2003, in the artisanal fishing grounds at Armação do Itapocoroy, Penha. It had been used two net-of-drag with doors, mesh of 3.0 cm in the sleeve and body and of 2.0 cm in the sacker, pushed for whaleboat with average speed of 2.0 km/h. Mean values of bottom water temperature and salinity remained uniform in a seasonal fluctuation, showing no significant differences among the studied years. A total of 60 species were collected, in which 22 were considered common species along the sampled period. Sciaenidae, Carangidae and Clupeidae families presented the highest number of specimens, accounting to 92% of catches, being Stellifer spp., Paralonchurus brasiliensis and Isopisthus parvipinnis, the dominant species, occurring regularly along the years. Seasonal fluctuations were observed in the abundance and diversity of ichthyofauna, with significant differences observed among the sampled years and biomass, as well as numerical abundance. The monitoring of trawling fishery targeting sea-bob-shrimp may contribute in a way to maintain the exploited stocks and guarantee the subsistence of traditional communities along Santa Catarina's coast.
... Exterior caudal fin shape is related to different ways of swimming and to ecological features of species (Norman, 1963), but only anatomical studies of skeleton can give systematic and phylogenetic information. ...
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The caudal skeleton is one of the most important tools to evaluate teleostean interrelationships, but just the anatomy of few species have been investigated. Black-striped pipefish (Syngnathus abaster) has never been examined for its caudal morphology. Here, red alizaryn is applied as specific staining for calcified structures, providing a better understanding of caudal skeleton organization. Our results and interpretation just partially fit with previous knowledge on other Syngnathus species. This emphasizes both the importance of facing same problems with new technics and methodologies, and the existence of a heterogeneous situation between close-related taxa
... The work on the freshwater fishes of Pakistan, which has been published so far, does not include the zoogeographical aspect with the exception of a few cursory remarks by some ichthyologists (Day, 1880;Zugmayer, 1913;Hora, 1937a;Berg, 1940;. The (Darlington, 1957;Lagler et al., 1962;Norman & Greenwood, 1963 Darlington (1957) carried it still further and recognized three levels: a) geographical distribution, in the broadest sense, over the whole world, b) regional distribution in selected areas of the world, and c) local distribution which includes species geography and ecology. ...
Article
The freshwater fish fauna of Pakistan is briefly discussed. It is predominantly South Asian but High Asian and West Asian elements are also present. The African element is hardly perceptible. Five zoogeographical divisions of Pakistan are proposed on the basis of the composition of their fish fauna: (I) the High Asian Division; (II) the Aba-Sinh Division; (III) the Northwestern Montane Division; (IV) the Indus plain and adjoining hills Division; and (V) the Northwestern Baluchistan Division. South Asia and High Asia are recognized as two subregions within the Oriental Region, while West Asia is treated as a transitional region.
... Fish with truncated or rounded tails are comparatively slow swimmers and, although capable of sudden bursts of speed, are unable to swim for long times at high speed (cf. Norman & Greenwood, 1963). All the studied serranids are lurking predators, and the distinction of their caudal fins in truncated or rounded is also in accordance to their life-style: the rounded fin of the dusky groupers is in accordance with its more sedentary habits, while the truncated fin shape of the Diplectrum species and M. acutirostris are in accordance with their more active feeding habits. ...
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Diplectrum formosum (the sand perch), Diplectrum radiale (the aquavina), Epinephelus marginatus (the dusky grouper) and Mycteroperca acutirostris (the comb grouper) are four sympatric serranid of remarkable ecological and commercial importance. This study investigated the feeding of these four species in the Sao Sebastiao Channel, Sao Paulo State (southeastern Brazil), comparing their diet, habitat utilization and morphological features related to foraging. These four serranids are opportunistic visual predators that use a total of nine different tactics to capture their preys, feed mostly on crustaceans during the day and twilight, and keep stationary and quiescent at night. The ecomorphological study was conducted to test its predictive value to infer lifestyles. It was verified that such analysis should be used carefully and must be complemented by field observations. Although morphologically and behaviorally very similar, D. formosum and D. radiale showed different preferences to the substratum type used by large individuals, which are exclusively sit-and-wait predators. On the other hand, E. marginatus displayed more sedentary habits than M. acutirostris, the most versatile predator from the studied species. The studied species of Diplectrum and E. marginatus can be regarded as benthic serranids, while M. acutirostris could be viewed as a nektobenthic species.
... In accordance with Ellertsen et al. (1980), we have assumed that the simbladder did not affect the buoyancy determinations in our experiments, particularly as the fish were anaesthetized. Moreover, in physoclistous fish such as cod, filling of the air bladder occurs with the passage of gas from the rete mirabile (Marshall 1965), a process which does not occur rapidly (Norman & Greenwood 1963). Hence, it is unlikely that fish were able to compensate for a tendency to sink using their simbladders over the relatively short period that the measurements were made. ...
... The piranha (Serrasalmus) of South America are the only group of pack-hunting fish, to my knowledge, which attack prey larger than themselves. However, as Norman (1963) points out, they usually feed on fish smaller than themselves. In all the instances reviewed by Radakov (1973) the fish were feeding on small prey. ...
... Western Atlantic Apogonidae and Atherinidae species names were taken from Robins et al. (1980). Higher classification was taken from Norman and Greenwood (1975), Greenwood et al. (1966) and Collette et al. (1984). ...
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The genus Mothocya is fully revised. Irona Schioedte and Meinert is placed in synonymy with Mothocya. All named species but one, including 18 new species, are described and figured in detail. A further eight undescribed species are listed. With one exception Mothocya species are all gill parasites found principally on atherinomorph fishes of the families Hemiramphidae, Belonidae, and Atherinidae. Brief accounts are given of the biogeography, biology and host-parasite interaction of the species of Mothocya. Keys to the species are provided for the different major biogeographic regions.
... Juveniles fully squamated are more tolerant to a wider range of environmental factors than larvae lacking scale protection. (Norman, 1975;Lagler et al, 1982). Scale formation is completed at 10-14 mm total length for the sea bream Pagrus major (Fukuhara, 1976in Foscarini, 1988, at 25 mm standard length for the red drum (Holt, 1987). ...
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The red drum Sciaenops ocellata (Linneaus, 1766) was introduced in Martinique (F.W.I) I) from the United States (Texas and Florida). Thirteen intensive larval rearing attempts, from 7 batches of imported eggs, have been conducted for two years. From newly hatched larvae through metamorphosis, larvae were reared in cylindroconical tanks (300 and 1000 l). Post larvae were weaned and raised up to 1-4 g fingerlings in raceways (18001). Mean stocking density ranged 50-75, 6-23 and 1.5-2.5 larvae per litre for phases 1, 2 and 3, 4 respectively of the rearing. For larval rearing attemps 3, 4, 8 and 11, survival rates were 6, 16, 17 and 5 percent respectively. 30000 two month old fingerlings were produced. Growth of the larvae was widely related to the mean stocking density. Larvae were fed rotifers, followed by brine shrimp nauplii, weaned onto squid and shrimp meat before they were finally fed on commercial pellet (55-60 % protein). During the grow-out phase, the food conversion rate ran- ged from 1.1 :1 to 1.8 :1 and final stocking density fluctuated between 0.7 and 5.5 kg/m'
... Detailed structure of the fish scale can be helpful in the identification of fish up to major groups [1][2][3] and species levels [4][5][6], phylogeny [7][8], sexual dimorphism [9], age determination [10][11][12][13], past environment experienced by fish, discriminating between hatchery reared and wild populations, migration, the pathology of a fish scale due to water pollution of the water body [14][15][16], and for growth studies [17][18][19][20][21][22][23][24][25][26]. ...
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The normal and lateral line cycloid scales of a cyprinid fish Capoeta damascina (Valenciennes in Cuvier and Valenciennes, 1842) have been subjected to the scanning electron microscopy technique in order to study their detailed structure. The scales have the general morphological characteristics of the cycloid scales. In the normal scale located below the dorsal fin, the focus lies towards the anterior region and is covered by reticulate or honeycomb form structures with few mucous pores. There is a clear-cut demonstration between the anterior and posterior region. In the posterior section, the scale has several rows of pigmented granules (tubercles) with different shapes from round to oval, semi-oval and even oblong structure. On the dorsal side, the anterior circuli bear teeth-like structures called lepidonts which help the scale in firm attachment to the skin. The circuli may also have calcium projections. The lateral line scale has a canal which characteristically lies along the anterior-posterior axis, slightly towards the posterior part with two anterior and posterior openings. The anterior opening is wider than the posterior opening and is hidden by an evelike extension cantilevered over it. Based on the obtained results it could be concluded that the shape and size of lepidonts on the circuli crest and also the pattern of reticulate or honeycomb form structures in the focus region may provide reliable taxonomic tools.
... As first noted by White (1968) & Greenwood, 1963;Maisey & Wolfram, 1984), Notidanodon and Weltonia (Ward, 1979) and to Eonotidanus and Notidanoides (Pfeil, 1983;Maisey, 1986 lateral teeth in having about the same number of cusps pointing in opposite directions along the crown. Alternatively, the shark might have possessed teeth only in the limited symphysial area of the tooth row; this is a rare occurrence in sharks being a possibility only in some Palaeozoic petalodontiforms. ...
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The oldest shark teeth so far recorded from Australia are described from the Early-Middle Devonian of western Queensland. The teeth show characters in common with those of the Jurassic-Recent hexanchoid sharks, and the possible relationship to these so-called ‘living fossils’ is discussed. The teeth are ascribed to a new species, Mcmurdodus whitei, of a genus found previously in the Middle-Late Devonian of Antarctica. Scales and prismatic cartilage found in the Cravens Peak Beds probably belong to this shark.
... Thus, many species of macroscopic nektonic organisms minimize turbulent drag in order to fulfill their food requirements from defined ranges. The sleek, streamlined body forms they have adopted attest to the evolutionary convergence of traits adapted for life in the pelagic [14]. ...
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1. Using a model (PROTECH-C) that simulates the simultaneous daily growth of eight phytoplankton species, the following hypotheses were tested: (i) for each given set of simulated conditions, the species with the most appropriate trait, as predicted by a functional group classification, should dominate the community; (ii) with removal of this dominant species, the next best-adapted species should dominate and should be from the same, or a close, functional group where available; (iii) a reduction in the inoculum size of the initially dominant species will not prevent its eventual dominance of the community. 2. For clearer insight into the mechanisms underlying these community processes, a functional group classification based upon species morphology has been used to produce a matrix analogous to Grime's CSR (C, competitor; S, stress tolerator; R, ruderal) paradigm. The effects upon this phytoplankton community of temperature, grazing, limiting light and nutrients over a simulated year were recorded. 3. The results supported all three hypotheses. It was found that, for a given selective constraint, functional traits provided excellent predictors of the dominant types. Also, under conditions of resource competition, the number of functional groups represented decreased. Competition was greatest within functional groups where niche overlap was high, but one species was always clearly the strongest competitor, i.e. its superiority over its nearest functional competitor was regularly expressed even when the difference in inoculum size was great (1000-fold). These conclusions emphasized the power that trait selection can have in the shaping of communities.
... Thus, many species of macroscopic nektonic organisms minimize turbulent drag in order to fulfill their food requirements from defined ranges. The sleek, streamlined body forms they have adopted attest to the evolutionary convergence of traits adapted for life in the pelagic [14]. ...
Chapter
The term ‘pelagic zone’ refers essentially to the open ocean, beyond the continental shelves. However, ‘the pelagic’ is understood by freshwater ecologists to mean simply ‘the open water’ of large lakes and reservoirs. In either instance, the notion of a liquid environment, remote from the shores and bottom of the containing basin, is clear. In extent, the marine pelagic is, by far, the greatest of the world’s major ecosystems, covering some 361 × 10⁶ km² (or 71% of the planet’s surface) and accommodating an estimated volume of 1.35 × 10⁹ km³. In contrast, the aggregate volume of the world’s lakes and rivers is a relatively modest 225 × 10³ km³.
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Clark, Zoila. “Our Monstrous Humanimality in Lucía Puenzo’s XXY and The Fish Child.” Hispanet Journal Vol.5 (2012) [no pagination]. (Journal Article).
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Argyrosomus hololepidotus (kob) is a top predator in the shallow marine environment of the south-eastern Cape. There is considerable change in prey taken over the size range of predators examined (256-1701 mm). Young A. hololepidotus are planktivorous taking swarming mysids, but as they grow they become piscivorous, feeding on both pelagic and demersal prey associated with soft sediments. The pelagic cephalopod Loligo reynaudi is also taken by large specimens. Prey selection varies with locality and time of year. A field experiment in which the prey were compared with fish caught in a small-mesh net revealed a preference for some slow-moving demersal species. The length distributions of dominant prey species are given and these clearly show that larger prey are preferred by larger predators.Argyrosomus hololepidotus (kabeljou) is 'n vernarne predator in die vlak mariene omgewing van die suidoostelike Kaap. Daar is 'n aansienlike variasie in die prooi wat gevang is in die grootteklasse wat ondersoek is (256-1701 mm). Jong A. hololepidotus is aanvanklik planktivore wat op swermende Mysidae leef. Later word dit visvretend en benut pelagiese sowel as bodem bewonende spesies wat met sagte sedimente geassosieer is. Groot visse voed ook op die pelagiese sefalopood Loligo reynaudi. Prooiseleksie varieer met 'n lokaliteit en tyd van die jaar. In 'n veldeksperiment waar prooi vergelyk is met vis wat in 'n kleinmaastreknet gevang is, word 'n positiewe seleksie vir sommige stadig-bewegende, bodembewonende spesies getoon. Die lengteverspreiding van belangrike prooisoorte word gegee en dit toon duidelik dat groter predatore groter prooi verkies.
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Coelacanths are lobe-finned fishes known from the Devonian to Recent that were long considered extinct, until the discovery of two living species in deep marine waters of the Mozambique Channel and Sulawesi. Despite extensive studies, the pulmonary system of extant coelacanths has not been fully investigated. Here we confirm the presence of a lung and discuss its allometric growth in Latimeria chalumnae, based on a unique ontogenetic series. Our results demonstrate the presence of a potentially functional, well-developed lung in the earliest known coelacanth embryo, and its arrested growth at later ontogenetic stages, when the lung is clearly vestigial. The parallel development of a fatty organ for buoyancy control suggests a unique adaptation to deep-water environments. Furthermore, we provide the first evidence for the presence of small, hard, flexible plates around the lung in L. chalumnae, and consider them homologous to the plates of the ‘calcified lung’ of fossil coelacanths.
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Investigations on fins of the common carp, Cyprinus carpio revealed certain distinguishing fin characteristics that could be used for identification and segregation of larval forms. The study also showed that high amounts of protein, lipid, calcium and phosphorus were present in the fins. The sequence of development of fins showed the order as pectoral, caudal, dorsal, anal and pelvic.
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The scale of Cobitis linea has been studied by employing the different modes of SEM such as SEI, BEI, mixed signals of both SEI and BEI and reverse polarity of SEI and BEI. It appears that for the study of morphology of the scale of this fish, the reverse polarity mode gives better results
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Walter George Ridewood (1867–1921), an English comparative anatomist, was influential for many reasons, including his methods for preparing anatomical specimens and the factual results of his studies, as well as through his approach toward systematic comparative anatomy. Ridewood was not limited to expertise in any particular taxonomic group, but rather researched and published on many groups and anatomical systems, most notably on the hyoid apparatus of basal anurans, the skull of basal teleostean fishes, the gill morphology of lamellibranch molluscs, and the morphology and taxonomy of the pterobranch Cephalodiscus. In this paper, we describe Ridewood's life, and discuss his influence, particularly in regards to the systematic osteology of teleostean fishes. We provide a partially annotated list of Ridewood's published works.
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Juvenile paddlefish (Polyodon spathula) exhibit conspicuous variation in the shape of their rostra and caudal fins. We quantified morphological variation for a composite collection of young-of-year paddlefish (N = 55, 61.9-403.7 mm total length) using nine measurements of the rostrum, body, and caudal fin. Sheared principal component analysis of morphological data resulted in three distinct groups of fish corresponding to three different localities: hatchery-reared fish from the Mermentau River, Louisiana; hatchery-reared fish from the Tombigbee River, Alabama; and field-collected fish from the Mississippi River, Mississippi. Series were segregated from each other based on size of caudal lobes and width of rostrum. With increased body size of fish, relative length of rostrum increased, and mesal expansion of rostrum increased for all three series. For Tombigbee and Mississippi River series, with increased size of fish, caudal asymmetry decreased. Overall, smaller fish had shorter, narrower rostra and highly asymmetrical caudal lobes; larger fish had longer, broader rostra and more symmetrical caudal lobes. Morphological differences among series were most conspicuous for fish > 85 mm eye-fork-length. Fish from Mermentau River had shorter, narrower (leaf-shaped) rostra and asymmetrical (conspicuously heterocercal) caudal lobes. Those from the Tombigbee River had longer, broader (spoon-shaped) rostra and more symmetrical caudal lobes. Those from the Mississippi River had the longest, broadest (paddle-shaped) rostra and symmetrical (superficially “homocercal”) caudal lobes. Locality-based gradient in paddlefish morphology corresponds to a gradient in river hydrology: longer, broader rostra and symmetrical caudal lobes were associated with larger basins, higher gradients, and greater discharge.
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Diving times and hunting success of otters were compared in two freshwater lochs in Aberdeenshire and in the sea off Shetland. During each hunt, otters in the marine habitat caught significantly more prey items and each hunt was of longer duration than in the freshwater habitat. Most recorded prey caught in the sea were smaller and probably of lower nutritional quality than in the freshwater lochs.
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Nur einige der Verhaltensweisen von Tilapia macrocephala (= melanotheron), die in der Brutpflegephase auftreten, werden davon beeinflußt, ob das ♂ Junge im Maul trägt. Alle Brutpflegehandlungen lassen sich von normalen Atmungs-, Körperpflege- und Nahrungsaufnahmebewegungen ableiten. Das Umschichten der Eier im Maul ist wahrscheinlich am wichtigsten. Es bewegt die Jungen im Atemwasserstrom und ändert sich — wie das Fächeln von Substratbrütern — mit dem Entwicklungsstand der Jungen. Es hängt aber auch noch von anderem ab: Umschichten stört, aber ersetzt auch funktionell das Atmen und hängt, wie dieses, mit dem Sauerstoffbedarf des Elterntieres zusammen. Vielleicht führt stärkere Sauerstoffzufuhr zu stärkerer Schwimmblasenfüllung. Diese muß kompensiert werden, ebenso das Gewicht der Jungen und ihr Gewichtsverlust, sobald ihre eigene Schwimmblase funktionsfähig ist. All das müßte das Atmen und Umschichten beeinflussen. Ein Maulbrüter muß Eier und Larven länger im Maul halten als ein Substratbrüter, muß also “Husten” und Schlucken entsprechend unterdrücken. Er muß ferner so gähnen, daß nichts aus dem Maul fällt; das Maulvorstülpen scheint ein derart modifiziertes Gähnen zu sein. Sich-Kratzen tritt während der ganzen Brutpflegezeit, aber nicht im Zusammenhang mit Ausschwimmversuchen der Jungen auf.
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