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The reproductive biology of the dab Limanda limanada (L.) in the North Sea: Gonadosomatic index, hepatosomatic index and condition factor
... Fulton's condition factor (K)) samkvaemt jöfnunni: þar sem W er þyngd einstaklingsins (g), og L er lengd einstaklingsins (cm). 45 Að maelingum loknum fengu seiðin að jafna sig í fersku vatni í fötu og var síðan sleppt aftur, að undanskildum 10−20 fiskum frá hverri stöð sem notaðir voru til frekari svipfars-og erfðagreiningar. Þeir fiskar voru valdir með slembiúrtaki (með rand() fallinu R-inu) nema þeir sem drápust við veiðar eða maelingar sem urðu hluti af þýðinu. ...
Nursery grounds of juvenile fish provide them shelter and food making them essential for the life of an individual, the population and species as a whole. In Lake Þingvallavatn, Iceland, two species of salmonids inhabit the lake, Brown trout (Salmo trutta) and Arctic charr (Salvelinus alpinus). Extensive biological studies have been conducted on adult fish of both species in the lake and its catchment area, but much less is known about the biology of age-0 fish and the ecology of their first 1−2 years in the life. Given the critical importance of nursery areas for the existence of fish populations and their contribution to biological diversity, research was undertaken to examine the distribution of charr and trout juveniles in the surf zone of Lake Þingvallavatn and in streams connected to the lake. The research questions were, 1) Where in the lake and connected streams are juvenile fish found? 2) Has the density of charr and trout juveniles changed in the last twenty years? 3) Is there a connection between the environmental conditions and the presence of juvenile fish? Data from Veiðimálastofnun (now Hafrannsóknastofun) surveys of salmonid juveniles in Þingvallavatn and adjacent rivers, spanning 2000 to 2021, were analyzed. In the summer of 2022, ten locations in Þingvallavatn were surveyed, fish were caught and measured, and several environmental factors were assessed using electrofishing. Fish were counted, identified by species, and measured for length and weight. Additionally, environmental factors, including the lake bottom composition and shoreline vegetation, were documented. The results show that the two species utilize different juvenile habitats, trout predominantly occupy river habitats, whereas charr are more abundant in the surf zone of the lake. There was a significant increase in density of the Brown trout over the 19-year period, but density of Arctic charr remained relatively stable with a sign of subtle decline. In 2022, six possible nursery sites were documented in the surf zone, four with majority of Arctic charr and two with mainly Brown trout. There was little overlap in the species distribution. Vegetation on the shoreline was the only environmental factor significantly correlated with the presence or absence of juvenile fish on a given site. Further studies on juvenile fish biology in the lake and adjacent streams and river might explore the interplay of environmental factors and genetics in shaping the size and morphology of adult fish in both species´ populations. This is particularly relevant for Arctic charr, which features four distinct sub-populations (or morphs) differing in size, shape, trophic morphology and ecology.
... K was estimated following Htun-Han (1978): W divided by L 3 , multiplied by 100 percent, where L = total length and W = wet weight. ...
Background
The freshwater prawn Macrobrachium vollenhovenii is one of the largest Macrobrachium species, a biological agent against human schistosomiasis, and a cheap protein source in riverine communities in West Africa. However, its aquaculture development for sustainable utilization is challenged by cryptic identity amidst the presence of morphotypes of unknown size and genetic relatedness. This study aimed to investigate the maximum sizes and evolutionary links of chelae morphotypes in M . vollenhovenii for precise identification and utilization in a 3 × 2 randomized block experimental design. Ninety biggest encountered samples of M. vollenhovenii chelae morphotypes—those possessing equal left and right side chelae, longer left chelae, and shorter left chelae—were obtained from fisherfolks’ catches at each of Asejire Lake and Ogun River during peak seasons (July–September) bimonthly field survey, representing EAAL, LLAL, SLAL—GAALs, and EAOR, LLOR, SLOR—GAORs. These were analyzed for differences ( p < 0.05) in size-linked parameters—length (L (cm)), weight (W (g)), and condition factor (K). Specimens’ 16S rRNA nucleotide sequences were utilized to infer phylogenetic linkages, single-nucleotide polymorphism (SNP), and amino acid translations alongside NCBI references (NCBIrefseq).
Results
Weight (W) and condition factor (K), among GAALs, for SLAL and LLAL were similar; EAAL was significantly lowest; among GAORs, SLOR and LLOR were similar; and EAOR was significantly lowest. In GAALs, EAAL, LLAL, and SLAL had higher L, W, and K than counterpart GAORs. Sequences formed two polyphyletic groups: EAOR branch from EAAL, in which 100.0%EA rooted 75.0% NCBIrefseqs, forming a clade; and GAOR-SLOR and LLOR branch form GAOR-LLAL rooted SLAL, in which 100.0%LL and SL rooted KJ463387.1 (Badagry), forming another clade. SNP Locus 91 separated 100.0%GAOR from 100.0%GAAL and 100.0%NCBIrefseqs translating to valine; SNP Locus 171 separated 100.0%EA and its co-rooted NCBIrefseqs from 100.0%LL, SL, and their co-rooted NCBIrefseq, translating to glycine/glutamic acid change.
Conclusion
The equal left and right side chelae and the unequal left and right side chelae specimens are, respectively, small- and robust-sized, irrespective of habitat. They are divergent size-linked clades having protein translate differences, delineable at 16S rRNA SNP Locus 171; their size variant habitat strains are delineable at SNP Locus 91. These SNP markers will be useful for precision identification and selection of the size variant chelae morph strains for sustainable utilization.
... At monthly intervals, growth of fish in terms of total body length (TBL) and body weight (BW) was measured with random sampling of 10 fish specimens from each experimental feed treatment, while survival of fish was recorded at the time of total harvest after 180 days of culture. Growth performance of fish in terms of TBL gain (TBLG), net weight gain (NWG), specific growth rate (SGR), food conversion ratio (FCR), protein efficiency ratio (PER) and condition factor (K-value), was calculated as per following formulae [32], [38]. ...
Efficacy of shatavari (Asparagus racemosus) root powder (SRP) as growth promoting and immuno-modulatory fish feed additive was evaluated by feeding fingerlings of freshwater carp, Cyprinus carpio (Linn.) with experimental feeds (180 days) containing SRP @ 1 (SRP1), 2 (SRP2), 3 (SRP3) and 4% (SRP4). Feed without SRP served as control (SRP0) treatment. Shatavari supplementation improved fish growth performance significantly (P≤0.05), resulting into 50.85% higher net weight gain (SPR4) and improved condition factor (k-value- 1.06) as compared to control (0.89), with an upregulated thyroid hormone (T4/T3) production. SRP also improved fish health status supported by 1.30 (SRP1) to 2.14 (SRP4) times higher Hb concentration, 1.12 (SRP1) to 1.59 (SRP4) times higher Hct values, enhanced immunity (total protein, albumin, globulin and total immunoglobulin); and positive metabolic changes in respect to liver function, lipid profile and digestive enzymes. SRP feeding also improved fish flesh quality resulting in 12.31% increase in protein content and 21.07% decrease in lipid content. Further, 10-days challenge test of SRP fed fish exhibited relative percent survival (RPS) of 30.76% (SPR3) to 70% (SPR4) against pathogenic bacteria, Aeromonas hydrophila, as compared to control fish. The results indicate that A. racemosus can serve as a potential organic feed additive to produce 56% more fish with improved flesh quality at 4% incorporation level.
... Fulton's condition factor (K): Fulton's condition factor (K) was calculated according to Htun-Han (1978) equation as per formula given below: ...
The hatchery production and mariculture of the sea cucumber species Holothuria fuscogilva Cherbonnier, 1980, commonly known as white teatfish, represent a potential remedy for the decreasing population of this extensively exploited species, owing to its considerable nutritional and medicinal value. The Sea Cucumber Research and Development Center at Mindanao State University in Naawan is actively formulating a comprehensive protocol for the large-scale production of H. fuscogilva through hatchery methods. Within hatchery rearing for mass production, selecting an optimal feed type influences the growth and survival rates of H. fuscogilva juveniles. To address this, an experiment employing a complete block randomized design was executed, utilizing four distinct feed types—Navicula sp., tilapia waste + commercial probiotics (CP), Spirulina powder, and commercial feed (mixed feed for Penaeus monodon #1)—each replicated three times. This 90-day laboratory experiment involved 960 individuals of 90-day-old hatchery- reared H. fuscogilva juveniles with an initial weight of 0.11±0.004g. The results revealed that Navicula sp. and Spirulina powder significantly contributed to higher average body weight, average weight gain, growth rate, and specific growth rates compared to commercial feed and tilapia waste + CP. Notably, Navicula sp. demonstrated the highest % survival rate (87.92±3.88%) over the 90 days, surpassing the rates observed for tilapia waste + CP (63.75±7.11%), Spirulina powder (26.67±6.40%), and commercial feed (20.00±4.30%). These findings suggest that the Navicula sp. was the ideal feed for H. fuscogilva juveniles at this stage supporting better survival and growth.
... Fulton's condition factor (K): Fulton's condition factor (K) was calculated according to Htun-Han (1978) equation as per formula given below: ...
The hatchery production and mariculture of the sea cucumber species Holothuria fuscogilva Cherbonnier, 1980, commonly known as white teatfish, represent a potential remedy for the decreasing population of this extensively exploited species, owing to its considerable nutritional and medicinal value. The Sea Cucumber Research and Development Center at Mindanao State University in Naawan is actively formulating a comprehensive protocol for the large-scale production of H. fuscogilva through hatchery methods. Within hatchery rearing for mass production, selecting an optimal feed type influences the growth and survival rates of H. fuscogilva juveniles. To address this, an experiment employing a complete block randomized design was executed, utilizing four distinct feed types-Navicula sp., tilapia waste + commercial probiotics (CP), Spirulina powder, and commercial feed (mixed feed for Penaeus monodon #1)-each replicated three times. This 90-day laboratory experiment involved 960 individuals of 90-day-old hatchery-reared H. fuscogilva juveniles with an initial weight of 0.11±0.004g. The results revealed that Navicula sp. and Spirulina powder significantly contributed to higher average body weight, average weight gain, growth rate, and specific growth rates compared to commercial feed and tilapia waste + CP. Notably, Navicula sp. demonstrated the highest % survival rate (87.92±3.88%) over the 90 days, surpassing the rates observed for tilapia waste + CP (63.75±7.11%), Spirulina powder (26.67±6.40%), and commercial feed (20.00±4.30%). These findings suggest that the Navicula sp. was the ideal feed for H. fuscogilva juveniles at this stage supporting better survival and growth.
... Advancements in fish condition assessment have introduced several new approaches to estimate fish condition. The Fulton condition factor was calculated using the formula from reference [16] as follows: ...
A study was conducted on the length-weight relationship and condition factor of the commercially important fish, Silver Pomfret (Pampus argenteus), in the Damanganga estuary in Daman. Fish samples were collected from January 2021 to March 2021, with a total of 330 randomly sampled fish collected from fishermen. The average total length was 23.309±0.775 cm and the average total weight was 259.606±20.144 grams measured using standard methods. The 'b' value of Pampus argenteus showed a negative allometric (b<3.0) growth pattern, with the total length being positively correlated with the total weight of the fish (r²=0.829). The growth pattern was negative allometric while the Fulton condition factor (2.03±0.114) indicated good condition. Therefore, further studies on the length-weight relationship should focus on the sustainable management of the fisheries.
... Prevalence was defined as the percentage of fish infected with a certain species of parasite; mean intensity was defined as the average number of a certain species of parasite on the infected fish; and abundance was the average number of a given species of parasite on the fish examined (infected or not infected). The condition factor was calculated using the formula in Htun-Han (1978): ...
Red-bellied pacu (Piaractus brachypomus) is a popular exotic fish cultured globally for ornamental and human consumption purposes. In Indonesia, this fish is mainly cultured in Java, including to supply seed to other regions for the ornamental fish trade or aquaculture. Although this exotic fish in widely cultured, information on parasitic infections is negligible. Red-bellied pacus were purchased from a fish farmer and examined for monogenean parasite infection. Monogenean parasites were identified based on morphological and molecular characteristics. Histopathological examinations were performed on gills from heavily infected fish. DNA was extracted from an individual monogenean; 18S rRNA PCR product was sequenced and a phylogenetic tree constructed. Morphological and molecular traits identified the monogenean as Mymarothecium viatorum, the first report of the neotropical M. viatorum in this region. The parasite was most likely introduced to Indonesia through the importation of ornamental fish. This parasite had a prevalence of 79% and a mean intensity of 7.1. There was no significant correlation between the parasite abundance and the condition factor of the fish. M. viatorum was more abundant on smaller fish than on larger fish. Gill histopathology showed oedema, severe haemorrhage, and infiltration of inflammatory cells. The occurrence of these parasites could pose a serious threat to the development of red-bellied pacu culture.
... Growth among treatments was compared using Fulton's condition factor, which was calculated using the following equation (Htun-Han, 1978): ...
The current study profiled the dual isotopes of carbon and nitrogen in feeds and muscles of farmed Penaeus monodon for evaluation of feed efficiency in making up the prawn muscle. Signatures of both feed and resulted muscles of P. monodon were subjected to two‐ and three‐source linear mixing models to elucidate the contribution of each feed item in the building of the muscle. The results revealed that carbon and nitrogen in different feed substances have different influences on the growth and nutrient uptake by the prawn. Different growth stages showed isotopic switching within prawn muscles in the course of their building up. Generally, marine sources were the most enriched in both δ¹³C and δ¹⁵N. Likewise, δ¹³C of wild‐caught prawns (−16.30 ± 0.72‰) were superior over farmed prawns (−18.00 ± 0.59‰) (p < 0.01), whereas no significant differences were observed in δ¹⁵N values between wild (8.03 ± 0.65‰) and farmed (8.38 ± 1.39‰) (p > 0.01). The isotopic composition of P. monodon mirrored those of the ingredients contained in its feed and varied across treatment levels. Comparing to other ingredients, marine macroalgae exhibited significantly higher (p < 0.01) feed efficiency, and as a result, they improved the growth of P. monodon compared to the other ingredients. The same treatment recorded significantly lower (p < 0.01) feed conversion ratio compared to other treatments. However, muscle somatic index, specific growth rate and condition factor were not significantly different across treatments (p > 0.01). Moreover, a clear distinction was observed between wild and farmed P. monodon, and such a distinction is clearly explained by δ¹³C composition. In conclusion, multiple sources of δ¹³C and δ¹⁵N in feeds are incorporated more efficiently in muscles than single sources.
... Histopathological analysis was carried out on gill and liver samples that were immediately fixed in Bouin Solution and acetic acid (20:1) and stored in 70% ethanol after 24 h. Fulton's condition factor (K) was calculated according to Htun-Han (1978) equation with the following formula: ...
Highly anthropized areas as ports represent complex scenarios that require accurate monitoring plans aimed to address the environmental status. In this context, the activities of the EU Interreg Project “GEstione dei REflui per il MIglioramento delle Acque portuali (GEREMIA)” were focused on comparing sites differently affected by human presence, as the Port of Genoa and the natural area of the S’Ena Arrubia fishpond: a panel of analyses was carried out on Mugilidae fish sampled in these two areas, aimed to address trace metal accumulation in the liver, gills, and muscle, as well as cytochrome P450 (CYP450) induction in liver and biliary polycyclic aromatic hydrocarbon (PAH) metabolites, and histopathological alterations in the liver and gills. Chemical analyses in the liver, gills, and muscle of specimens collected in the port area showed an overall higher degree of trace metal contamination compared to the natural fishpond, and similar results were obtained in terms of CYP450 induction and biliary PAH metabolites, suggesting a higher exposure to organic compounds. In addition, histopathological analyses revealed a significant alteration and then a loss of functionality of liver and gill tissue in individuals from the port. Overall, this study describes the complex environmental pollution scenario in the Port of Genoa, confirming the importance of using multidisciplinary approaches and different types of analyses to address both the presence and the effects of contaminants in marine environments.
... Fulton's condition factor (K) was calculated according to Htun-Han (1978) equation as per the formula given below: = × 100/ 3 Where, W= weight of fish (g), L= Length of fish (cm). All the statistical analyses were performed at 95% confidence limits using Excel 2016 and SPSS.16 computer software. ...
Age and growth of the Isfahan tooth-carp, Esmaeilius isfahanensis, was studied in the Zayandehrud River, in central Iran, from June 2016 to May 2017. Among the 485 specimens, age groups in both sexes ranged from 0 + to 2 +. The overall sex ratio was 1M: 1.2F. Maximum total length and weight were 44.9mm and 1.6g for males and 53.6mm and 2.4g for females. The Minimum total length and weight was 26.8mm and 0.40g for males and 32.0 mm and 0.5g for females. The most frequent age groups were 1 + in both sexes. The highest value for the condition factor was observed in July. The von Bertalanffy growth parameters of E. isfahanensis were estimated as k= 0.36, L∞= 34.98mm, t0=1.10 for males and k= 0.53, L∞= 41.02mm and t0= 0.14 years for females. The length-weigh relationship was described as W= 0.00005L 2.84 (r 2 = 0.84) for males and as W= 0.00005L 2.84 (r 2 = 0.83) for females, indicating an isometric growth pattern in both sexes. The Growth performance index φ` was estimated as 6.08 for males and as 6.79 for females, indicating a faster growth rate in females.
... Then Fulton's condition factor (K) was calculated according to Htun-Han's (1978) equation as per the formula given below: ...
Triclosan, a broad-spectrum antimicrobial agent, which is widely used in several pharmaceutical and personal care products, has been known to pose adverse impacts on various groups of aquatic organisms, including fish. The present study aimed to compare the sensitivity of five selected freshwater fishes toward triclosan exposure. The acute toxicity or median lethal concentration (LC50-96 h) of triclosan determined using probit analysis was 1.76 mg L-1 in Anabas testudineus, 448 µg L-1 in Danio rerio, 700 µg L-1 in Gambusia affinis, 1.35 mg L-1 in Oreochromis mossambicus, and 750 µg L-1 in Pseudetroplus maculatus. Based on the length-weight relationship, the lowest condition factor, or K value, was recorded in Danio rerio (0.931) while the highest value was observed in Anabas testudineus (2.343) indicating negative allometric growth. Similarly, the weight of fishes and gill weight declined significantly (p < 0.05) in their respective LC50-96 h groups with concomitant alterations in the rate of oxygen consumption denoting respiratory distress. Triclosan exposure also resulted in the modification of fish behavior and histomorphological damage in gill tissues. The alterations in all parameters tested were more prominent in Danio rerio and thus considered the most sensitive species, while Anabas testudineus comparatively tolerated the toxicant to some extent. The study provides the baseline data that variation in the length-weight relationship is one of the major factors that influences the toxic effects of triclosan on the selected freshwater fishes.
... [15,16,27] The correlative changes between liver weight and gonadal activity have been shown to be associated with energy requirement of the ovary for the development of oocytes. [28] Patil and Kulkarni (1996) [29] had also shown that GSI and HSI have relationship and this relationship is directly related to gonadal activity. In present study, HSI was the lowest during the month of March and September in captive reared female fish and the highest during the month of May to June and January to February, with similar trend in both, control treated and groups [ Figure 2]. ...
Addressing the issue of gonadal maturity and breeding in captive condition for a commercially important indigenous Coldwater fish, snow trout, Schizothorax richardsonii, field study was conducted with dietary supplementation of the blend of Ashwagandha (Withania somnifera) root powder, dried powder of garlic (Allium sativum), and hing (Ferula asafoetida). Experimental fish of 3 years age were reared in FRP tanks (n = 4) of 1200 L capacity with stocking density of n = 60 in each tank and fed with control (CD) and experimental (TD) diets in duplicate at the feeding rate of 3–5% of their body weight twice in a day. Gonadosomatic index (GSI) and hepatosomatic index (HSI) were recorded for annual breeding cycle coupled with breeding indices in breeding season and regular monitoring of water quality parameters. In female stock, the GSI values ranges from 0.87 to 12.83 and 1.84 to 15.42 in control and treated groups, respectively. Two peaks of GSI values reflects the two breeding season of the species during the month of March and September. Similarly, HSI was lowest during the month of March and September in captive reared female fish and highest during the month of May to June and January to February, with similar trend in both, control treated and groups. In captive condition, 80% specimens were observed mature for spawning in treated group, while only 15% females were ready to spawn in control stock. The fecundity of the fish was observed in the range of 20210-23710 eggs/kg body weight with 80–94.2% fertilization rate. The egg size was observed in the range of 3.5–3.8 mm. The study revealed that 1.0% supplementation of blend of herbs in the diet is beneficial for gonadal maturity of females and better spawning of S. richardsonii in captive Coldwater condition.
... For computation of the condition factor of fish species, Fulton's condition factor (K) was calculated by Htun-Han [11] equation as per formula given as: ...
Length-weight relationship and condition factor are important in fishery assessment studies since it provide information about the growth of the fish, its general wellbeing and fitness in aquatic habitat. LWRs for 2 fish species –Clarias gariepinus (Burchell 1822) and Oreochromis nilotica (Linnaeus 1758) collected from Orashi River were established and their growth condition was evaluated. The study was carried out from September 2019 to August 2020. The biometric measurement (length/weight) shows that the weight of the fish increased in proportion to its length as indicated by the slope (b) of the relationship. The mean value shows strong relationship because coefficient of determination (R2) is >0.5 and range from 0.795-0.985. Higher values of both length and weight were recorded for Catfish over Tilapia. The results indicated that almost all the fish sampled exhibited a positive allometric growth and trended to grow bigger. All relationship were statistically significant (p=0.05). The mean Fulton’s condition factor (K) of the fish range from Catfish (1.24-1.80) and Tilapia (1.5-3.7) in the 5 stations sampled. The result showed that Tilapia had a high mean range and therefore was in better conditions than the Catfish. This gives information on the food supply, timing and duration of breeding cycle. The indices may also be used in the general assessment of the “well being” of a fish [1]. Multiple comparison tests using Turkey Kramer showed that the condition factor of Catfish from Okwuzi (station 1) was significantly different from that of Ndoni and Omoku but Ebocha and Obrikom was not significantly different from each other. With regards to seasonal variation, dry season recorded higher values than rainy season.
... The condition factor (K) and the hepatosomatic index (HSI) can provide an estimate of seasonal variations in energy reserves (Lambert and Dutil 1997). Seasonal variations of HSI, K, GSI, and the monthly proportion of macroscopic maturity stages can help determine the moment and the duration of maturation of gonads considering the energy transfers towards gonads are considerable (Htun-Han 1978). ...
The aim of this study was to provide additional insight into the reproductive activity of Mugil cephalus L. along the Algerian coast. All specimens were sampled from local commercial fisheries from January 2017 to January 2018. The reproductive period and the size at first sexual maturity were determined. Our results show that the males reach sexual maturity at smaller lengths (28.8 cm) than females (34.5 cm) and that sex ratio is female-skewed (63% vs 37%). The peak of reproductive activity took place from August to October, and spawning took place in November. Sexual rest occurred during subsequent months with a tendency of fattening from December to April. The seasonal evolution of the gonadosomatic index suggests that M. cephalus breeds from August to October. The analysis of the evolution of hepatosomatic index and Fulton’s K apparently reveal no contribution of liver and muscle tissues to the reproduction activity of this species. The high fecundity estimated could be considered a reproductive strategy to maximise the survival of juveniles.
... Fulton's condition factor (K) was calculated according to the Htun-Han (1987) equation [34] as per the formula given below: ...
Starry flounder (Platichthys stellatus) is a commercially important cold-water fish. Our aim was to investigate the effects of fluctuating water temperature on flounders after periods of starvation and feeding. Fish were divided into starvation and feeding groups. The water temperature was increased stepwise in experiment 1; more focused variations, based on the results of experiment 1, were studied in experiment 2. At temperatures ≤27 °C, there was no significant difference observed in survival. At 28 °C, mortality increased, survival was lower (21%) in the starvation group than in the feeding group (46%), and weight loss was the highest (15%) in the starvation group. In experiment 2, survival was ≥86%, and there was no significant difference between the starvation/feeding groups. However, when the water temperature was increased to 27 °C after being decreased to 12 °C, weight loss was the highest (11%). Glucose, cortisol, superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels increased with increasing water temperature, and then gradually decreased. Glutamic pyruvic transaminase (GPT)/glutamic oxaloacetic transaminase (GOT) levels showed large variations among individuals. Triglyceride, cholesterol, and protein levels gradually decreased with long-term starvation. Survival was not affected by water temperature drop ≤27 °C after starvation/feeding. These results indicate that 27 °C is the upper limit of tolerable water temperature for the survival of starry flounders. Therefore, aquaculture farms should ensure maintaining water temperatures at ≤27 °C during high-temperature periods.
... Sampling for weight and length data for biometrics was conducted at 35 days and 50 days of the feeding trial. The condition factor (K) was calculated according to equation of Htun-Han (1978), and the relative condition factor (Kn) was determined following the method of Le Cren (1951). The length and weight relationship coefficient (b) was determined using the equation of Froese (2006). ...
A 50 days feeding trail was conducted to evaluate the efficiency of spent oleaginous yeast Lipomyces starkeyi by-product from wheat straw as a probiotic supplement on juvenile red sea bream (Pagrus major). Elements that were investigated includes physiological condition, digestive enzyme, haemato-biochemistry, antioxidant, immune and stress. 300 juvenile P. major (9.13±0.05 g) were randomly distributed into 200 L polyethylene tank (20 fish per tank) in triplicate of 5 treatments; CD1 control (0 g/kg supplement), D2 (1%, 10 g/kg supplement), D3 (1.5%, 15 g/kg supplement), D4 (2%, 20 g/kg supplement), D5 (2.5%, 25 g/kg supplement). The fish were fed twice daily and sampling for weight and length were conducted at 35 and 50 days of the feeding trial. Whole body samples, digestive organs and blood collection was done at the end of the feeding trial. The results of the combine parameters assessed by multivariate analysis revealed that fish group fed on D5 has significantly better performance followed by D4, D2 and D3 compared to the fish group fed the control diet D1 (ANOSIM, P
... Fingerlings were harvested after 90 days by repeat netting followed by complete draining and were counted individually for each species. Fulton's condition factor (K) was calculated according to equation of Htun-Han (1978) to find the growth and robustness of the fingerlings. The specific growth rate (SGR), net weight gain (NWG) and K-values were calculated separately for three phases of rearing (1st, 2nd and 3rd months), using the following formula. ...
Influence of varied water exchange (total of 0%, 40%, 60%, 80% and 100% in four phases during three months) on fingerling production of Indian major carps-catla, rohu and mrigal under polyculture was evaluated in large outdoor concrete tanks (50 m²). Rearing density of 30 fry m⁻³ was used. Survival in the control tanks reduced during the 2nd month unlike the treatments, attributed to lack of water exchange in the tanks. While no marked variation in water quality was observed among the control and treatments, graded water exchange led to proportionate improvement in the fingerling performance in terms of survival and growth in the treatments. Harvested total lengths of fingerlings were similar in all, irrespective of varied exchange levels. Although no significant variation in net weight gain (NWG) and specific growth rate (SGR) were observed among the treatments during 1st and 2nd months of rearing in any of the species, these attributes increased significantly during 3rd month with higher water exchange in treatments. The harvested body weight (HBW) also increased significantly with increased exchange level. However, survival, HBW, NWG and SGR remained similar in all species between the 80% and 100% water exchange levels. Treatment with 80% water exchange had higher water productivity in terms of number and biomass production of fingerlings per unit (m⁻³) of TWU and CWU for which, the study recommended 80% to be the ideal total water exchange required for fingerling production of IMC in concrete tanks.
... From these biometrics, Fulton's condition factor (i.e. factor K) was assessed at T 0 , T 1 and T 6 by the formula of Htun-Han (1978): ...
The last remaining population of European sturgeon (Acipenser sturio) lives in the Gironde-Garonne-Dordogne (France) catchment (GGD). Captive young individuals are released into the GGD hydrosystem each year, as part of a restocking programme. This study aims to assess the health status of juveniles A. sturio to current conditions in the GGD hydrosystem, to evaluate their capacity to survive and grow in a moderately anthropized ecosystems. 3-month-old farmed sturgeons were exposed for one month in experimental conditions that mimic the environmental conditions in the Garonne and Dordogne rivers, followed by five months of depuration. After one month of exposure, fish exposed to Dordogne and Garonne waters bioaccumulated higher levels of metals and persistent organic pollutants, displayed a reduced hepato-somatic index, and had depleted levels of lipids and glycogen content in their liver, when compared with the Reference group. However, metabolic and swimming performance, as well as the costs of swimming were not impaired. After the 5 months depuration, a significant decrease of K was observed for all exposure conditions. HSI also decreased with time. The overall health status and adaptive capacity of juvenile A. sturio appeared to be maintained over the experimental 6 months’ period. Juveniles of A. sturio seem to have the adaptive capacity to survive and grow in the GGD hydrosystem, after being released as part of a restocking programme.
... log W = log a + b log L (b) Fulton's condition factor (K) was calculated according to Htun-Han (1978) where, W=weight of fish (g), L=total length of fish (cm) (c) Specific growth rate (SGR) was calculated with the following formula: ...
... The gonadosomatic index (GSI) was calculated for examined P. segnis females according to the formula GSI = (OW/(TW-OW)) ×100 (Gibson and Ezzi, 1978), and the monthly mean values were also estimated in order to describe the reproductive activity (maturity and spawning season or months) of the species along the sampling period. In addition, the Fulton's Condition Factor (CF) which enables also to have an idea on the maturity and condition of P. segnis, was calculated using the formula CF = (TW/CW 3 ) × 100 (Htun-Han, 1978). Because only few data were collected in 2013 (compared to 2014), the data of both years were combined to represent the monthly variations in GSI and CF of P. segnis males and females. ...
The blue swimming crab, Portunus segnis (Forskål, 1775), formerly known as P. pelagicus (Linnaeus, 1758) has become a major fishery resource in the Gulf. Yet, there are no regional studies on the stock population dynamics and life history processes of this species. Considering the extreme oceanographic features of the Gulf (high salinity and high temperature variations), which is hypothesized to cause fast growth of P. segnis, a study was conducted to determine the abundance/biomass distribution of its stocks, growth rates, sexual maturation, and natural mortality in the territorial Saudi waters in the Arabian Gulf. The study was based on trawling surveys, landing sites monitoring, and records of fisheries catch and efforts and juvenile habitat surveys. The spatial distribution patterns supported by generalized linear model indicated the occurrence of P. segnis in the nearshore shallow waters, and its absence from the offshore deeper waters, attributed to the variability of environmental conditions including salinity, temperature, and trophic resources. Manifa, one of the productive areas in the northern Saudi waters of the Gulf, had high abundance of the crab. In agreement with the hypothesis, the growth rate of the Saudi P. segnis was found to be the higher (2.12 K year ⁻¹) compared to other parts of the Gulf (1.1–1.7 K year ⁻¹) or other sea areas of tropical regions (0.95–1.68 K year ⁻¹). The study shows that P. segnis can spawn throughout the year, with at least three peaks, one each in winter, late spring-early summer and autumn. The L50% record obtained in this study with females (127 mm) and males (125 mm) are larger than those reported with the same species from the other parts of the Gulf (113 mm) or with other congeneric blue species crabs reported from other tropical regions (61 – 113 mm). The present study is expected to provide basic data to develop a management strategy for the fishery of P. segnis in the region.
... Growth parameters, including net weight gain (NWG), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER) were calculated according to the standard formulae (Halver, 1957). Further, Fulton's condition factor (K-value) was calculated as per Htun-Han (1978). Flesh quality of harvested fish, in terms of total protein, total lipids, carbohydrates, moisture and ash contents, was estimated as per the standard methodology (AOAC, 2005). ...
Efficacy of ashwagandha (Withania somnifera) root powder (ARP) supplemented feeds on survival, growth and flesh quality of an Indian major carp, Labeo rohita (Ham.) fingerlings was evaluated through an outdoor study. Four experimental feeds, containing ARP at 0 (Control), 1 (ARP-1), 2 (ARP-2) and 3 (ARP-3) per cent levels, were fed to fingerlings at 2% of fish body weight for 180 d. In all the treatments, the water quality parameters remained well within the recommended range. In ARP fed treatments 93.75 to 95.63% fish survival was recorded as compared to 92.50% in control. Net weight gain (NWG) and specific growth rate (SGR) of fish were significantly improved (P<0.05) in all the ARP fed treatments, with significantly higher condition factor in ARP-2 and ARP-3 treatments (K-value 1.25 and 1.20, respectively) as compared to control (K-value 1.12). However, among all the treatments, fish recorded the best growth (NWG 134.16 g and SGR 1.51%) at 2% ARP inclusion level as compared to control (NWG 76.87 g and SGR 1.20%). Further, the FCR and protein efficiency ratio also improved significantly (P<0.05) in all the ARP fed treatments than control (1.80 and 2.19) and among ARP treatments, best FCR and PER were recorded in ARP-2 treatment (1.59 and 2.50, respectively). ARP supplementation also improved the flesh quality of fish significantly (P<0.05) by increasing the total protein content (wet weight basis) by 11.94% at 2% inclusion level. The overall results revealed that ashwagandha root powder can serve as a potential feed additive at 2% in the grow out feed of L. rohita for enhanced growth performance and improved flesh quality.
... Fulton's condition index (Fulton, 1904) was used and calculated as K = 100 × W /L 3 , where W is the wet weight of the crab in grams and L is the carapace length of the crab in millimeters. The gonadosomatic index (GSI = (GW/TW) × 100) (GW = Gonad weight, TW = Total weight) formulated by Htun-Han (1978) was used in calculating the spawning potential of the crabs. ...
The aim of the present study was to determine the population structure and bioecological characteristics of the portunid crab, Carcinus aestuarii in Çardak Lagoon. In this study, the crabs were sampled by means of fyke-nets at 6 different stations between April 2015 and March 2016. A total of 2458 individuals (686 females, 1755 males, and 17 juveniles) were captured. The average carapace length was measured as 38.85 ± 0.17 mm in females, and 47.65 ± 0.16 mm in males. The highest number of specimens was observed in November with 239 individuals, while the lowest number (125 specimens) was observed in February. The reproductive period in both sexes was between November and February and females with eggs were found in November, February and March. An average number of eggs in a female was 61 390 ± 8.48 and the egg diameter was 345 μ m. The female : male ratio was 0.39 : 1. This paper includes the first published data on population structure, growth, and reproduction characteristics of C. aestuarii in a protected lagoon in the Turkish Straits System.
... The Fulton's condition factor (K) was estimated according to Htun-Han (1978) from the relationship K=100W/L 3 to assess the fish condition in Sri Lankan waters. ...
The neritic tuna catch in Sri Lankan waters is mainly composed of Auxis thazard (frigate tuna), Auxis rochei (bullet tuna), Euthynnus affinis (kawakawa) and Scomberomorus commerson (narrow-barred Spanish mackerel). Among them, frigate tuna is the dominant species presently contributing over 40% to the total neritic tuna production. Though several studies have been conducted to estimate some biometric parameters of the frigate tuna in Sri Lankan waters, all of the studies have focused on fishery dependent data. This paper attempts to estimate the biometric parameters of frigate tuna using both fishery independent data and fishery dependent data. Length-weight relationship (LWR) was calculated using the equation W = aL b and the Fulton's condition factor (K) was estimated from the relationship K=100W/L 3 (W = total weight; L = total length) to assess the condition of the selected fish. Fishery dependent data from 373 specimens was obtained from the samples collected from the coastal fisheries catches from October 2015 to September 2017. Fishery independent data of 254 specimens was obtained from the samples collected from R/V Dr. Fridtjof Nansen Ecosystem survey conducted in Sri Lankan waters from 24 June 2018 to 16 July 2018. The total length and the weight of the fishery dependent samples ranged from 21.50 cm-44.20 cm and 118.89 g-1430.90 g respectively while those parameters of fishery independent samples ranged from 14.00 cm-19.00 cm and 20.00 g-80.00 g respectively. The LWR for the commercial catch and the fishery independent catch were W = 0.003L 3.428 and W = 0.037L 2.540 respectively. The estimated K value for the commercial catch and fishery independent catch were 1.48 ± 0.15 and 1.03 ± 0.16 respectively. Considering the growth pattern of the two studies, commercial catch showed a positive allometric growth while fishery independent survey showed a negative allometric growth. Based on the results of the K, it can be concluded that the population consisting of larger fish from the commercial catches was at a better condition than the juvenile population studied during the fishery independent survey. According to the results of the IOTC-2019-WPNT09-12 fishery independent survey, two possible nursery grounds for Auxis thazard in the Sri Lankan waters were identified.
... TBL and final Av. BW to evaluate growth performance of fish, in terms of total body length gain (TBLG), net weight gain (NWG), specific growth rate (SGR), condition factor (Kvalue), feed conversion ratio (FCR), protein efficiency ratio (PER), as per following formulae [14,15] . TBLG = Av. ...
The present study was carried out to evaluate efficacy of Aloe vera powder (AVP) asa herbal feed additive, for improving survival, growth and flesh quality of rohu (Labeo rohita Ham.). Fishes were fed @ 2% of total fish biomass daily with feeds supplemented with AVP @ 0% (T0), 1%(T1), 2%(T2) and 3%(T3), respectively. Feed without AVP (T0) served as control. Physico-chemical parameters of water in all the treatments remained within the recommended range for carp culture, with adequate plankton production. AVP supplementation improved fish survival and enhanced fish growth (net weight gain, specific growth rate and feed conversion ratio) and enhanced flesh quality significantly (P≤0.05) at all inclusion levels (1-3%). However, best results were obtained at 3% AVP inclusion level, which resulted in 48.19, 21.37 and 24.59%, higher NWG, SGR and protein content over control with better feed conversion ratio and protein efficiency ratio. Introduction With intensification of aquaculture systems, prophylactic and therapeutic use of antibiotics and other chemicals have increased in aquaculture for health management to achieve high production targets. Unlike terrestrial animals, application of antibiotics and other chemicals in an aquaculture system is quite expensive besides being associated with negative impacts including development of antibiotic resistance, residues in cultured species and accumulation in environment. It not only affects the non target species, but also poses serious health hazards for the consumers, which has attracted more attention to formulate eco-friendly alternatives (organic immuno-stimulants, vaccines and probiotics) for health management in aquaculture in the recent past [1]. In this direction, more attention is now being diverted towards use of organic or herbal innovations for growth enhancement and health management in aquaculture. Application of herbal dietary supplements has emerged as a promising alternative due to presence of various useful bio-active compounds, which not only improves the health of aquatic organisms (fish/shellfish), but has also been reported to enhance survival, growth and quality of many aquatic species reared for food purpose [2]. Many medicinal herbs possess growth promoting immuno-stimulatory potential, due to presence of several bio-active compounds (phenols, polyphenols, alkaloids, flavanoids, quinones, sulphur, lectins and polypeptides) and serve as very effective alternatives to antibiotics, vaccines, chemicals and other synthetic therapeutics [3, 4]. In aquaculture, a wide range of herbal medicinal plants like ginger, turmeric, garlic, onion, tulsi, ashwagandha, Aloe, amla and neem, have been reported to improve survival and growth; strengthen immune system; and promote maturation in aquatic species due to their antioxidant, antimicrobial and anti-stress properties [3]. These herbs, which are being used for treatment of many infectious diseases, since ancient times, can serve as an inexpensive biodegradable alternative for health management without any consumer safety and environmental issues. Among various known herbal plants, Aloe vera is a perennial plant of the Aloeaceae family, which grows in hot dry climate. It is one of the known immuno-stimulant used to control pathogenic bacteria in animals, including fish. Aloe gel consists mainly of water (>98%) and polysaccharides like pectins, cellulose, hemicellulose, glucomannan, acemannan and mannose derivatives [5]. Aloe is an amazing mixture of 200 constituents, including active compounds like galacto-mannan, beta-mannan, glycoproteins, lectins, salicylic acid, phenols, sulphur,
... After culture period of 180 days, total fish was harvested from each treatment to record survival and growth of fish. Growth performance of fish, in terms total body length gain (TBLG), net weight gain (NWG), specific growth rate (SGR), condition factor (K-value) and feeding efficiency in terms of food conversion ratio (FCR), protein efficiency ratio (PER) was calculated as per following formulae [11,12] . Proximate composition of harvested fish (flesh quality) in terms of total protein, total lipids, total carbohydrates, moisture and ash content was assessed as per standard methods [9,13,14] . ...
The present study (180 days) was carried out to assess the possibility of utilizing garlic powder (GP) as feed additive for improving survival, growth and flesh quality of rohu (Labeo rohita Ham.) stocked in outdoor cemented tanks of 80m 2 (80 fingerlings tank-1). Fish were fed @ 2% of total fish biomass daily with garlic powder (GP) supplemented feeds (@ 0, 1, 2 and 3%) in T0, T1, T2 and T3 treatments, respectively. T0 (without GP) served as control. Water quality in all the treatments remained within optimum levels for carp culture and survival of fish improved with GP supplementation. Significantly higher net weight gain, specific growth rate and flesh protein content (p≤ 0.05) were recorded in all GP treatments (T1-T3) and was highest at 2% (20g kg-1 feed) inclusion level, being 57.67, 24.79 and 39.6% higher as compare to control, respectively. Although, GP supplementation increased the feed cost, but growth increment compensated for the cost, indicating that GP can be incorporated in rohu, fingerlings feed @ 20g kg-1 feed (2%) for improved growth, flesh quality and fish production, hence higher income thereof. Introduction Aquaculture represents one of the fast growing food producing sectors of the world with an average annual growth rate of 8.9%. With global fish production of 170.9 million tonnes (mt), including 46.81% share (80.0 mt) from aquaculture sector in (2017-18), world's total fish and shell fish production is projected to cross 185 mt mark in 2030 [1]. To achieve higher production targets, use of antibiotics and other chemicals have also increased for health management in aquaculture sector, but due to their negative impact on environment, food safety issues and enhanced awareness amongst consumers, focus on organic or herbal food production is gearing up in the modern world. As wide range of medicinal herbs possess growth promoting and immuno-stimulating properties, offering cost effective, eco-friendly alternative for health management without any side effects and environmental hazards. Among potential medicinal herbs, Garlic (Allium sativum L.), belonging to family Liliaceae, is used as spice and in traditional medicine since ages. It is one of the natural immuno-stimulants [2] , used to control pathogenic bacteria and fungi in animals, including fish [3]. Garlic contains at least 33 sulphur compounds, 17 amino acids, several enzymes, minerals and vitamins. It has been reported to be antibacterial, antiviral, antifungal, antioxidant, antiprotozoal and an effective immuno-stimulant, growth promoter and improves flesh quality owing to the presence of various organ sulphur compounds [4]. Allicin is the most powerful organ sulphur component present in garlic that actively kills parasites and pathogenic bacteria; [5] and has been found to regulate oxidative stress and immune responses by enhancing immuno-competence, improving gastrointestinal motility and modulating the secretion of various enzymes to improve digestion and nutrient absorption. It also improves digestion by promoting the performance of the intestinal flora, thereby enhancing the utilization of energy and improving growth [6]. Although, garlic has been found to eliminate principal pathogenic bacteria, strengthen immunity, uplift health status, enhance growth and improve flesh quality in freshwater fish like common carp (Cyprinus carpio), tilapia (Oreochromis niloticus), rainbow trout (Oncorhynchus mykiss), African catfish (Clarias gariepinus) and shrimp (Penaeus monodon) [7, 8] , but work in respect to its efficacy in carps in general and rohu (Labeo rohita) in particular is inadequate.
... After measuring the body weight and total length of the fish species, Fulton's condition factor (K) was determined according to [13] using the formula: ...
Information available on the present growth pattern of two important fish species which are Clarias gariepinus and Parachanna obscura at Egbe dam in Ekiti State of Nigeria is limited. Hence, this study was aimed at updating the existing knowledge on the weight-length relationships and condition factors (K) of these dominant fish in the dam. These fish species were sampled and examined between September 2019 and January 2020. The weight-length relationship had a positive correlation coefficient, r, which varied from 0.37 to 0.84 while the coefficient of determination, r 2 , varied between 14% and 71.3% for the length and weight of male and female of C. gariepinus and P. obscura respectively. These showed the variation that was related in each sex for the two species. The regression coefficient b revealed a negative allometric growth (b<3) for all the specimens analysed. Condition factor values ranged from 0.38 to 0.59 in C. gariepinus and 0.89 to 0.98 in P. obscura. These data could be valuable for setting up a management system for the improvement of the studied fish species.
... The Fulton condition factor (k) which is an indication of the degree of robustness or the state of wellbeing of an individual organism was calculated according to Htun-Han (1978). ...
The presence of trace metals in the sediment, water, and biota of the Epe lagoon has been recently linked to oil exploration and municipal perturbations around the lagoon. The study was aimed at assessing the concentrations and associated health risks of Fe, Zn, Cu, Ni, Pb, Cd, Cr, Mn, Co and V in the water, sediment, and Gymnarchus niloticus of Epe lagoon and to evaluate the role of the enteric parasite Nilonema gymnarchi in bioaccumulation of the metals in the fish. The temperature, pH, redox potential, conductivity, turbidity, dissolved oxygen (DO), total dissolved solids (TDS), and salinity were determined in-situ using a handheld multi-parameter probe (Horiba Water Checker Model U-10). The concentrations of Fe, Zn, Cu, Ni, Pb, Cd, Cr, Mn, Co, and V were determined in the surface water, bottom sediment, Gymnarchus niloticus, and its enteric parasites, Nilonema gymnarchi in Epe lagoon using the Flame Atomic Absorption Spectrometer (Philips model PU 9100). The bioaccumulation factors and target hazard quotients of the trace metals in the infected and uninfected fish were estimated and compared. The intestinal tissue sections of the infected and uninfected fish were examined using a binocular dissecting microscope (American Optical Corporation, Model 570) using hematoxylin and eosin (H&E) stain. Biochemical markers such as reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation (MDA) were determined in the liver of the infected and uninfected fish. The SOD level was higher in the uninfected fish than the infected ones supports the indications deduced from the bioaccumulation analysis. Strong positive correlations between SOD and most of the metals-Fe (0.916), Zn (0.919), Cu (0.896), and Ni (0.917) suggests that the metals may have inflicted more toxicity in the uninfected. The histopathological comparisons made between the uninfected and infected fish showed consistency with the outcomes of other comparisons made in this study. These evidence were marked by tissue alterations in the infected fish ranging from no observed changes to mild alterations, while the uninfected exhibited more severe tissue injuries such as hemorrhagic lesions, severe vascular congestion, edema, the increased connective tissue of the submucosa, and vascular congestion. The condition factors of the infected (0.252) and uninfected (0.268) fish indicated slenderness and unfitness possibly due to environmental stressors such as trace metals. The parasitized fish showing better-coping potentials than the uninfected, coupled with the significant bioaccumulation interferences exhibited by the parasite Nilonema gymnarchi is an indication that the parasites may be a good metal sequestration agent for the f ish and can be used to forestall the significant health hazard quotient posed by the current level of iron and the synergy of all metals analyzed in the lagoon.
... Trong nghiên cứu sinh học động vật thân mềm Chân bụng, CF được thể hiện thông qua điều kiện phát triển của cá thể tại từng thời điểm khảo sát (Htun-Han, 1978;King, 1995) và sử dụng để đánh giá mức độ gia tăng khối lượng của ốc bươu đồng so với mức độ gia tăng chiều cao. Nguyên nhân của sự gia tăng nhanh này trong một khoảng thời gian nhất định chủ yếu là do sự gia tăng khối lượng tuyến sinh dục của ốc bươu đồng trong giai đoạn thành thục sinh dục của chúng, đặc biệt là ốc bươu đồng cái, vào thời điểm có nguồn thức ăn tự nhiên phong phú (vào mùa mưa) ốc sẽ sử dụng nhiều thức ăn hơn so với điều kiện bình thường. ...
... Condition factor (K) was estimated as per Htun-Han (1978) formula K = W X 100/L 3 W here W = Weight of fish 9g) and L = Length of fish (cm) ...
Background: Harike wetland (31°08¢ N to 31°23¢ N latitudes and 74°90¢ E to 75°12¢ E longitudes) is an internationally important Ramsar site, supports rare, vulnerable and endangered plants, fish and other faunal species. Weed infestation, pollution and encroachment are considered as important threats of its biota thus time series data with respect to fish diversity, catch composition and genetic variability has an utter importance to interpret changes over time. Cyprinidae family of freshwater fishes includes carps is the largest fish family found in Harike wetland comprising around 50% of total fish composition by weight basis and among carps, Rohu (Labeo rohita) is one of the commercially important food fish species available throughout the year and preferred by consumers. As river Beas and Sutlej, two major rivers of Indus river system confluence at Harike thus possibility of variation within fish stock is very high. With this background present study was carried out to evaluate the fish biodiversity and catch composition of Harike wetland. Study also emphasized on biometrics, length –weight relationship and genetic diversity based on mitochondrial marker genes of commercially important food fish Labeo rohita. Methods: Assessment of fish catch composition and diversity were conducted in landing centre adjacent to Harike wetland through Rapid Fisheries Assessment by Market Survey (RFAMS) technique. Fin tissue samples were collected for genetic diversity analysis of L. rohita by cytochrome oxidase subunit I (COI) gene sequencing, From the fish genomic DNA a partial fragment of approximately 655bp was PCR amplified by FishF1 (5'-TCAACCAACCACAAAGACATTGGCAC-3') and FishR1 (5'-TCGACTAATCATAAAGATATCGGC AC-3') primer pair. Calculation of intraspecific mean and pairwise distances was performed by MEGA 6.0 software using the K2P parameters Results: Total 30 species of fishes were recorded from Harike wetland and these belong to 14 families and 21 genera. In L. rohita average weight (Wt), total length (TL), standard length (SL) and forked length (FL) were recorded 2600±5.64g (1700-3600 g), 58.2±5.65 cm (51.3-67.6cm), 48.0±8.54 cm (42.5-55.5cm) and 46.0±0.25 cm (38.0-54.5cm), respectively. Biometric study revealed that sufficient numbers of mature L. rohita are available in wetland. L. rohita established negative algometric growth (b= 2.701); thus species became slender as it increased in length. The pairwise distances ranged from 0.00 to 18.49% with a mean ±S.E value of 4.70%±0.40. Total of 9 haplotypes were observed in L. rohita COI sequences. The diversity in haplotype and nucletide values were observed 0.848 and 0.024, respectively. The present study states that L. rohita stocks in Harike wetland are genetically diverse.
This study evaluated the potential of fermented fish offal silage as a protein source for the Nile tilapia (Oreochromis niloticus) fry. The silage was made from minced fish offal, 15% molasses, and 5% yogurt, and was stored for 35 days. During storage, the pH was stabilized at 4.30, maintaining good organoleptic characteristics, with a dark brown color and a pleasant malty aroma, showing no signs of spoilage. The dried silage contained 13.03 ± 0.89% protein, 41.9 ± 0.35% fat, 3.99 ± 0.43% ash, and 6.92 ± 0.53% moisture. Levels of non-protein nitrogen, total volatile base nitrogen, peroxide value, and free fatty acids were within acceptable limits. The silage was deemed microbially safe, with pathogens either below risk levels or absent. Three isoproteinous and isocaloric diets were formulated with 60, 80, and 100% of fermented fish offal silage replacing fish meal and were fed for O. niloticus fry for 27 days in a feeding trial. The best growth of fish occurred at the lowest inclusion level (60%) offal silage diet (FFO 60) yielding weight of 4.53g and length of 6.01cm. The length-weight relationship revealed a positive allometric growth. The 80% replacement of fish meal resulted in the lowest mean weight gain (4.12 ± 0.11g), while the 60 and 100% replacements yielded better mean weight gains compared to the reference diet, i.e., 4.27 ± 0.48g and 4.23 ± 0.25g, respectively. The cost of the reference diet for 1kg of weight gain was the highest at Tk 102.80/kg, followed by the lowest inclusion level of fermented fish offal silage diet (FFO 60) at Tk 72.16/kg. This study suggested that fish offal silage can replace up to 60% of fish meal in the diet of O. niloticus fry without any retardation of growth, no significant changes in carcass protein, and at a reduced cost.
The genus Titanolebias comprises the largest-bodied seasonal killifishes, inhabiting temporary wetlands of the La Plata Basin and adjacent areas in South America. Here, we describe a new species from the Eastern Chacoan region, representing the first record of the genus in this area, providing important biogeographic and evolutionary insights. Phylogenetic analyses confirm the monophyly of Titanolebias, placing Titanolebias monstrosus as the sister species to the remaining species of the genus and recovering the new species as sister to a clade composed of Titanolebias prognathus, Titanolebias elongatus, and Titanolebias cheradophilus. Titanolebias species, exhibits reduced sexual dimorphism, potentially associated with a trophic shift toward larger prey in the origin of this genus and presents several potential cases of aggressive mimicry. Megalebias genus represents a case of convergent evolution towards ichthyophagy with Titanolebias. Morphological analyses reveal that the new species present the diagnostic characters of the genus Titanolebias and can be distinguished by its unique coloration and other morphological traits. Behavioral and ecological data are also provided. Despite its restricted distribution and the vulnerability of ephemeral wetlands to habitat loss, the species is found within a National Park. This discovery provides valuable insights into convergent evolution linked to trophic shifts and contributes to the understanding of the evolution, phylogeny, ecology, and biogeography of Neotropical fishes, offering new avenues for future research and conservation policies for this threatened group of fishes.
Fulton’s condition factor (K) and length-weight relationship (LWR) are widely used in fisheries biology for comparing the condition, fatness, well-being of fish and to determine the growth characteristics. The present study aimed to understand the spatial variation in the LWRs and the K of Lethrinus olivaceus (Valenciennes, 1830) and Lutjanus lutjanus (Bloch, 1790) in Sri Lankan waters. The samples of L. olivaceus (n=288) and L. lutjanus (n=181) were collected from the ecosystem survey conducted in Sri Lankan coastal waters by R/V Dr Fridtjof Nansen from 24th June to 16th July, 2018. The LWRs and K were estimated for populations of two species in six different regions. The estimated LWRs for L. olivaceus populations in the Northeast, Centraleast, Southeast, South, Southwest and Northwest regions were W=0.02L2.87, W=0.02L2.88, W=0.02L2.85, W=0.01L3.23, W=0.01L2.87 and W=0.02L2.97 respectively. The estimated LWRs for L. lutjanus populations in Southeast, South, Southwest regions were W=0.02L2.84, W=0.02L2.89 and W=0.02L2.97 respectively. The mean K values of the L. olivaceus populations in above regions were 1.39 ± 0.14, 1.32 ± 0.10, 1.31 ± 0.17, 1.32 ± 0.09, 1.24 ± 0.06 and 1.25 ± 0.15 respectively. The mean K values of the L. Lutjanus populations in above regions were 1.57 ± 0.13, 1.43 ± 0.15 and 1.50 ± 0.18 respectively. The L. olivaceus populations in Northeast, Centraleast, Southeast regions and all L. lutjanus populations exhibited negative allometric growth. L. olivaceus populations in Southern region exhibited positive allometric growth while populations in Southwest and Northwest region exhibited isometric growth. The L. olivaceus populations in Centraleast, Northeast regions and L. lutjanus populations in Southeast regions likely having better condition/well-being.
Evaluation of lead and cadmium concentrations in the muscles of four fish species: Trigla lucerna, Lithognathus mormyrus, Siganus rivulatus, Liza saliens, collected from Ain AL-Ghazala Lagoon, eastern Libya, during the summer of 2022, were analyzed by Atomic absorption spectrophotometer. The results indicated that the concentration of lead was ranged from 0.1485±0.0278 ppm in L. mormyrus to 0.2533±0.0044 ppm in L. saliens. The cadmium accumulation was ranged from 0.0004±0.000 to 0.0026±0.000 ppm in L. saliens, T. lucerna respectively. There was a significant positive correlation between the condition factor and the concentration of lead and cadmium in L. saliens and cadmium in T. lucerna. And there was a negative significant correlation between lead and cadmium in T. lucerna, while S. rivulatus and L.saliens recorded a positive significant correlation. We found a positive significant relationship between fish length and metals only in S. rivulatus (Cd; R2:0.76, Pb; R2: 0.56) and a negative significant relationship between length and cadmium in L. saliens (R2:-0.69). The estimated daily intake results for lead and cadmium ranged between 0.1056 mg.day-1 to 0.1802 mg.day-1 and 0.0002 mg.day-1 to 0.00187 mg.day-1. The mean of target hazard quotients and total target hazard quotient are below 1.00, so no adverse health effects are expected.
The Malabar dwarf puffer, Carinotetraodon travancoricus is the smallest known pufferfish (family Tetraodontidae) and one of the smallest freshwater fishes of the Indian subcontinent. Due to their miniature size, wacky behaviour and appearance, they are much preferred in the international aquarium fish trade, although little is known regarding their breeding activity in captivity and their embryonic development. The purpose of this study was to fill these knowledge gaps. Wild-caught Malabar dwarf puffers were acclimatised to conditions, and pairs were introduced to breeding tanks. Adult fishes were fed with live and frozen diets including Artemia nauplii, moina and bloodworm. During spawning seasons, adult fish displayed elaborate courtship behaviour around sunset. Carinotetraodon travancoricus is a batch spawner releasing 1 to 5 eggs per diem. The eggs were spherical, and non-sticky, with a diameter of 1.48 ± 0.1 mm, and hatching took place after 108 to 116 h post-incubation. The newly hatched larvae were 3.5 ± 0.2 mm in length, and weighed 2.9 ± 0.4 mg. The early larvae have substantial yolk and oil globules as an energy reserve. Histological studies on mature females suggested the batch spawning nature of the species and low fecundity. Given its unique reproductive behaviour and characters, in situ protected habitats are required to ensure their continued survival in the wild, apart from encouraging captive breeding to augment the demand in the international aquarium fish trade.
Bleak Alburnus alburnus is a highly abundant but understudied fish species, and we know little about the trophic ecology of populations inhabiting rivers in central Europe. From an ecosystem perspective, this fish species is interesting as it is known to feed on surface insects, thereby linking the terrestrial with the aquatic habitat. In a previous study, we demonstrated that this flux is intensified, and dietary contribution of terrestrial insects is higher in fish inhabiting sections of the Spree River, Germany, that are polluted from iron oxides occurring from former lignite mining activities, and thus are characterized by lower abundances of aquatic insects. As terrestrial insects can be considered as food of lower quality (measured as long‐chained polyunsaturated fatty acids, n‐3 LC‐PUFAs) compared to aquatic prey, it is reasonable to assume that the higher contribution of terrestrial insects is related to a lower body condition in fish. In this study, we explore the trophic ecology of riverine A. alburnus and their fitness consequences of feeding on terrestrial insects. We therefore modeled a terrestrial index from stable isotopes of hydrogen (δ²H) measured in the A. alburnus muscle tissue and compared individuals caught in locations upstream of a dam that were greatly influenced by iron oxides, with individuals caught in sections located downstream of a dam where passive remediation technologies are applied. The terrestrial index was significantly higher in A. alburnus caught in locations at high‐iron concentrations, characterized by low abundances of aquatic prey, compared to A. alburnus caught in unpolluted habitats at low‐iron concentrations. In contradiction to our hypothesis, the terrestrial index had no significant effect on the body condition of A. alburnus (measured as Fulton's condition factor K) in the sections downstream of the dam (i.e., at low‐iron concentrations) and a significant positive, albeit weak, effect in sections upstream of the dam (i.e., at high‐iron concentrations). However, the condition factor was generally lower in the high‐iron section, potentially related to more direct effects of the iron oxide. We conclude that in A. alburnus, terrestrial insects can be considered as the less‐favored food, unless the fish occur in environments where the aquatic food is of limited availability. Further research is needed to evaluate the direct and indirect effects, including the internal n‐3 LC‐PUFA synthesis as an adaption toward low‐quality terrestrial prey on the fitness consequences of A. alburnus.
Fish communities of streams and rivers might be substantially subsidized by terrestrial insects that fall into the water. Although such animal‐mediated fluxes are increasingly recognized, little is known about how anthropogenic perturbations may influence the strength of such exchanges. Intense land use, such as lignite mining, may impact a river ecosystem due to the flocculation of iron (III) oxides, thus altering food web dynamics. We compared sections of the Spree River in North‐East Germany that were greatly influenced by iron oxides with sections located downstream of a dam where passive remediation technologies are applied. Compared to locations downstream of the dam, the abundance of benthic macroinvertebrates at locations of high iron concentrations upstream of the dam was significantly reduced. Similarly, catch per unit effort of all fish was significantly higher in locations downstream of the dam compared to locations upstream of the dam, and the condition of juvenile and adult piscivorous pike Esox lucius was significantly lower in sections of high iron concentrations. Using an estimate of short‐term (i.e., metabarcoding of the gut content) as well as longer‐term (i.e., hydrogen stable isotopes) resource use, we could demonstrate that the three most abundant fish species, perch Perca fluviatilis , roach Rutilus rutilus , and bleak Alburnus alburnus , received higher contributions of terrestrial insects to their diet at locations of high iron concentration. In summary, lotic food webs upstream and downstream of the dam greatly differed in the overall structure with respect to the energy available for the highest tropic levels and the contribution of terrestrial insects to the diet of omnivorous fish. Therefore, human‐induced environmental perturbations, such as river damming and mining activities, represent strong pressures that can alter the flow of energy between aquatic and terrestrial systems, indicating a broad impact on the landscape level.
We describe Argolebias adrianae, a new species of killifish from a small temporary wetland in the Paraná Forest ecoregion with no regular or predictable temporal pattern of water availability. This habitat is in the Lower Iguazú River Basin, known for its high fish endemism, but until now, only two species of Rivulidae were reported from it, but from the Araucarian Forest ecoregion. The genus Argolebias was previously only known from the lower portions of the Paraguay, Paraná, and Uruguay basins and middle Paraná. The new species is distinguished from all congeners by its unique coloration, which includes a conspicuously dark grey anterior third portion of the dorsal fin and the absence of iridescent spots on the basal half of the pectoral fin in live adult males, as well as dark grey spots on the anterocentral portion of the flanks of females. Our phylogenetic analysis shows A. adrianae to be closely related to Argolebias guarani from the adjacent Middle Paraná basin. We also provide data on the ecology, ontogeny of coloration, and chorion ornamentation of this species. Our findings have important implications for understanding the biogeography, ecology, and evolution of mechanisms that enable organisms to thrive in highly stochastic environments like this one.
Analyzing digestive enzyme concentration in the gut is important to know about the digestive physiology of fish. Therefore, we determined concentrations of protease, lipase, and amylase enzyme in gut extracts of juvenile and adult groups of Notopterus notopterus relative to total body length (TBL), body weight (W), gut length (GL), relative gut length (RGL), Zihler's index (ZI) and condition factor (K). A total of 60 N. notopterus specimens (30 juvenile and 30 adult) were collected, the gut of each removed, homogenized, and evaluated for the concentrations of protease, lipase, and amylase. Protease and lipase concentration were observed significantly (P < 0.01) correlated with increased TBL, W, and GL in both juvenile and adult groups of N. notopterus. Amylase concentration significantly (P < 0.01) increases with an increase in TBL, weight, and GL in the juvenile group, whereas amylase concentration significantly (P < 0.01) decreases with an increase in TBL, W, and GL in the adult group. K had a significant (P < 0.01) positive correlation with protease and lipase concentrations in both juvenile and adult groups, whereas K showed a significant (P < 0.01) positive correlation with amylase concentrations in juvenile and significant (P < 0.01) negative correlation in the adult group. Protease and lipase concentration were observed significantly (P < 0.01) correlated with an increase in ZI in the juvenile and adult groups. Amylase concentration significantly (P < 0.01) increases with an increase in ZI in the juvenile group, whereas amylase concentration significantly (P < 0.01) decreases with an increase in ZI in the adult group. The concentrations of protease (344.12 U/mg) and lipase (172.49 U/mg) were observed high in juvenile and adult groups, whereas amylase concentration (3.80 U/mg) was found low in the juvenile and adult N. notopterus groups. Present study results revealed the digestive physiology and carnivorous behavior of N. notopterus. Moreover, information from the present study about digestive enzyme concentration in juvenile and adult species of N. notopterus provides valuable information to understand the digestive physiology of carnivorous fishes.
Length-weight correlations and condition measures are important in fish biology to determine individual health and potential variations among stocks of the same species. Length-length, length-weight relationships, morpho-meristic characteristics and condition factor were documented for three small indigenous species (Chanda nama, Parambassis lala and Parambassis ranga) equally totaling 600 individuals collected in 'Chalan Beel' using a seine net (mesh size 0.5-1cm) from July 2020 to December 2020. Body weight was determined with an accuracy of 0.01g, and length was calculated to the nearest 0.1cm. The mean body weights of C. nama, P. lala and P. ranga were calculated as 1.75±0.61g, 0.55±0.16g and 0.88±0.31g and their average total lengths were 5.50±0.68cm, 3.18±0.28cm and 3.71±0.42cm, respectively. Standard morphometric and meristic traits were found throughout all three studies species and a strong relationship between length and weight (P<0.05) was observed. The final 'b' values for TL and BW were recorded at 2.52, 3.03 and 3.14 for C. nama, P. lala and P. ranga, respectively, indicating negative allometric growth for C. nama, isometric growth for P. lala and positive allometric growth for P. ranga. Furthermore, condition factors (>1) demonstrated that these species were in excellent condition in their natural habitats. The present observations would be an effective tool to help identify these fish species in varied aquatic environments across Bangladesh and nearby regions, enabling their optimal management and conservation.
Trophic and reproductive ecology was studied in the characid fish Argopleura magdalenensis, collected in the high watersheds of the Cauca and Magdalena rivers, Colombia. A. magdalenensis is insectivorous and alguivorous. It was observed that the fish reproduced in the early wet seasons ans is migratory. The male to female ratio was 2.2:1. The fecundity was low and the eggs were small. Physical and chemical variables of the species habitat were measured.
This study described some biological parameters including lengths, length-length relationships and Fulton’s condition factors of Gagata cenia in the Padma River of Bangladesh, based on 1120 specimens collected from May to November, 2012. Maximum 39.78% female fishes were belonging to the length category of 55-60 mm whereas 51.06% male were belonging to 50-55 mm.The highest mean total lengths were found 66.51±10.28 mm (combined sex), 70.12±09.49 mm (female) and 61.08±09.45 mm (male) in the month of June. Similar findings are also presented for standard length, fork length, body depth, dorsal length, pectoral length, pelvic length and anal length. Linear relationships were also studied among mentioned lengths. Strong positive correlations were observed in all cases. Speraman’s Rank test indicated that there was a strong, positive correlation between total length and condition factor in female, which was statistically significant (rs=0.210, P=0.044). In male, there was no significant correlation between these two (rs=0.167, P=0.262). The Mann-Whitney U-test showed that the female individuals had the highest condition factor (Mean rank of 79.76). There was a statistically significant differences in the Fulton’s condition factor between males and females (two tailed, Mann-Whitney U = 1324).
Fish stock identification plays a vital role in the management of fisheries resources. It is regarded as the predecessor to species conservation and crucial for the decline of fish populations. This study has been designed for the assessment of growth patterns, physiological conditions and morphological variations of Nile tilapia (Oreochromis niloticus) inhabiting Indus River with the application of length-weight relationship (LWR), Fulton’s condition factor (K), geometric morphometrics employing truss network system and meristic analysis. A total of two hundred and five (205) fish specimens were collected form two sites i.e., Guddu Barrage (N = 71) and Kandhkot (N = 164) of Indus River during the month of January, 2020. The LWR of Guddu Barrage fish depicted the value of b (growth coefficient) as 2.13 indicating the negative allometric growth (b < 3) along with R2 = 0.46 (46%) and R = 0.682. While for Kandhkot, b was estimated as 2.92 (isometric growth) with R2 = 0.92 (92%) and R = 96. The mean K values for Guddu Barrge and Kandhkot were 1.50±0.24 and 1.52±0.12 g/cm3 respectively indicating the good physiological condition and enough food resources (K > 1) for O. niloticus at both sites. Under geometric morphometrics, a truss network was generated based on 13 landmarks over the fish body to yield 30 truss distances which were extracted from digital images of all specimens using tpsUtil and tpsDig2 softwares. After the standardization of all truss lengths to remove size effect, the univariate ANOVA revealed that out of thirty truss lengths, 10 characters (1–10, 1–12, 2–3, 3–8, 3–9, 4–9, 4–11, 5–8, 9–10, 10–12) varied significantly (P<0.05) between two populations. These characters were related to head region, body depth and caudal region of fish body. The meristic analysis of three randomly selected fish specimens found the number of dorsal fins (spines = 16, soft rays = 13), pectoral fins (soft rays = 13), ventral fins (spines = 1, soft rays = 5), anal fins (spines = 3, soft rays = 9), caudal fins (Soft rays = 19) and lateral line scales (31). As these characters were overlapping with previously described reports so could not be used to discriminate the population. The results of current investigation described that few morphological differences (10 truss lengths) were present between two stocks/population of O. niloticus from Guddu Barrage and Kandhkot sites of Indus River. The studied variations could be due to differences in conditions such as food availability, temperature and hydrological variations like swimming ability, water velocities and turbulence. On the other hand, twenty (20) truss lengths were significantly same in both groups which indicated the presence of same fish stock/population on both sites. Therefore, this study suggested the need of uniform strategy for management of O. niloticus population in the studied area of Indus River. However, more sites are required to investigate to confirm the pattern of fish characters throughout the Indus river which would be helpful for designing strategies for the fish at entire river.
Aim: To standardize the stocking density of GIFT strain of Nile tilapia (Oreochromis niloticus) to optimize survival, growth, biomass production and maximum economic gain in pond cage culture system. Methodology: Study was conducted in triplicate for 180 days in fish cages installed in cemented pond of 726 m-2 area and depth of 2.0 m. Stocking density of GIFT Tilapia was maintained @ 40 m-3 (C1), 50 m-3 (C2), 60 m-3 (C3), 70 m-3 (C4), 80 m-3 (C5) and 90 m-3 (C6), respectively. Water quality and growth parameters were studied at fortnight basis. Supplementary diet (D1) (30.0 % crude protein on dry weight basis) was provided @ 2% body weight. Survival rate, average growth rate, biomass production, specific growth rate (SGR), feed conversion ratio (FCR), length-weight relationship, condition factor, economics and benefit cost ratio were evaluated. Results: All water quality parameters were within the limit suggested for aquaculture. Maximum survival was achieved in C1 (96.25%) and survival rate reduced with increasing stocking density in cages. Decrease in SGR was observed with increasing stocking density. The average growth rate was highest in C1 (112.20 g) and lowest in C6 ( 61.80 g) whereas the maximum biomass (23.136 kg) was harvested from C4 with stocking density of 70 m-3 with best FCR (1.32). Benefit cost ratio was evaluated best in C4 (0.39). Interpretation: Pond cage aquaculture with improved stocking condition is suitable for GIFT tilapia growth, biomass production and maximum economic gain.
The Society of Krishi Vigyan has published its recent issue of the Journal of Krishi Vigyan for the benefit of the scientific community.
Seed stunting of rohu, Labeo rohita (Ham.) carried out for 6 months in 24 large (50 m2) concrete tanks using 20 and 40 fry m−2 rearing densities under open and shade (50% light incidence) conditions. A significant influence of tank shading observed on all the water quality parameters, unlike the density effect only on the dissolved oxygen content in water. Highly significant stunting effects of both higher density and shading observed on juvenile growth and survival after 2‐, 4‐ and 6‐month stunting. Doubling the density caused 22.9 and 27.8% weight suppression after 6‐month stunting under open and shaded conditions respectively. Similarly, shading caused 31.7 and 36.1% suppressed body weight after 6 months in the low‐ and high‐density groups respectively. However, the best stunting effect observed through a compounded effect of high density and shading as 50.7–57.0% growth suppression recorded within 2–6 months stunting. The study revealed both higher rearing density (two times) and tank shading (50% light incidence) to be effective tools for rohu juvenile stunting, while a combination of these factors yielded greater stunting effect. Such protocol can be used for production of stunted carp juveniles to ensure their round‐the‐year availability for stocking grow‐out ponds.
Siganus rivulatus is one of the most successful Lessipsian migrant fish from
the Red Sea to the Mediterranean Sea through Suez Canal. In the present study, a
comparison between the populations in native and new habitats was estimated based
on morphometric characters, meristic count and condition of the fish. A total of 1741
individuals of S. rivulatus (334 from Red Sea; Hurghada, 581 from Suez Canal;
Ismailia and 826 from Mediterranean; Port-Said) were collected seasonally from
autumn 2017 to summer 2018. The total length (TL) fluctuated between 14-28cm in
Red Sea with mode at length-class 16-16.9cm (14.37%), while TL in Suez Canal and
Mediterranean ranged from 8 to 22cm, the mode was 10-10.9cm (25.3%) and 12-
12.9cm (15.25%), respectively. TL, SL and TW displayed significant differences
between sites (ANOVA, P ≥0.05), with the higher values of all morphometric
parameters for Red Sea population. The meristic equation was “D, XIV+10; A, VII+9;
V, I+3+I; P, 15-16” at all studied sites. Length–weight relationships were estimated as
W=0.0112L3.0349, W=0.0085L3.1825 and W=0.0154L2.9091 for Red Sea, Suez Canal
and Mediterranean, respectively. Seasonal variation in Fulton’s condition factor (Kf)
and Clark’s (Kc) were estimated based on total weight (TW) and gutted weight (GW)
respectively. The values of Kf and Kc showed significant differences between sites
(ANOVA, P≥0.05). Kf seemed to be affected by temperature as the maximum value
recorded in summer while the minimum was in winter. was considered another factor
that may affect the condition of the fish as spring (reproductive season) showed high
decrease in the value of Kc at all sites when we removed the mature gonad.
The rapid growth of industrial and agricultural activities in Malaysia are leading to the impairment of most of the rivers in recent years through realising various trace metals. This leads to toxicity, particularly when the toxic has entered the food chain. Perak River is one of the most dynamic rivers for the Malaysian population. Therefore, in consideration of the safety issue, this study was conducted to assess the concentration of such metals (Cd, Cu, Zn, Fe, and Pb) in the muscles of most widely consumed fish species (Barbonymus schwanenfeldii, Puntius bulum, Puntius daruphani, Hexanematichthys sagor, Channa striatus, Mystacoleucus marginatus, and Devario regina) from different locations of Perak River, Malaysia by employing inductively coupled plasma optical emission spectroscopy (ICP-OES). Among the trace metals, Fe and Cd were found to be the highest (29.33–148.01 μg/g) and lowest (0.16–0.49 μg/g) concentration in all of the studied species, respectively. Although the estimated daily intakes (μg/kg/day) of Cd (0.65–0.85), Fe (79.27–352.00) and Pb (0.95–12.17) were higher than their reference, the total target hazard quotients values suggested that the local residents would not experience any adverse health effects from its consumption. In contrast, the target cancer risk value suggested that all fish species posed a potential cancer risk due to Cd and cumulative cancer risk values, strongly implying that continuous consumption of studied fish species would cause cancer development to its consumers.
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