The prevalence of sailfin catfishes (Pterygoplichthys spp.) in inland waters, including vast aqua... more The prevalence of sailfin catfishes (Pterygoplichthys spp.) in inland waters, including vast aquaculture systems of India is rising. This might be a serious threat to the country's native freshwater biological resources and aquaculture production. Therefore, studies were carried out to evaluate the impact of Amazon sailfin catfish Pterygoplichthys pardalis on different life-stages of native fishes. First, we analyzed the impact of three different size classes (small: 9.95 ± 0.70 cm, medium: 21.74 ± 0.87 cm and large: 30.81 ± 1.59 cm total length) of Amazon sailfin catfish on the survival of early life-stages (eggs, hatchlings, first-feeding fry, and 10-day-old fry) of two native fishes; native carp Labeo rohita (rohu) and native catfish Ompok bimaculatus (butter catfish). All size classes of Amazon sailfin catfish showed preference towards fish eggs over aquatic macro-invertebrates (Tubifex worms) and ingested over 90% of the eggs of both the native species. However, their effects on native species' mobile life stages (hatchlings forth) were found to be insignificant in terms of mortality. We then assessed the competition between advanced stages (fingerlings, advanced fingerlings, and sub-adult) of the Amazon sailfin catfish and the native fishes by evaluating growth and survival in three different experimental setups (indoor tanks with artificial feeds; outdoor tanks with natural food and artificial feed; and earthen pond with natural food) and in different combinations for a period of three to six months. In indoor experiment, no discernible impact of Amazon sailfin catfish on the growth of fingerlings of native species was found. But, in the outdoor experiment, growth of advanced fingerlings of rohu and butter catfish was decreased by 18.8-23.4% and 28.9-36.7%, respectively, in low-and high-biomass Amazon sailfin catfish treatments. The growth of rohu and butter catfish sub-adult was also reduced in the pond experiment, by 29.7% and 32.2%, respectively. However, impact of Amazon sailfin catfish on survival of native fish species at advanced stages was found minimal. Overall findings of this study indicate that sailfin catfish may have an adverse effect on the survival and growth of native fishes by either directly consuming or destroying native fish eggs or by competing with them for food and space.
Pterygoplichthys disjunctivus, commonly known as the vermiculated sailfin catfish, is a species i... more Pterygoplichthys disjunctivus, commonly known as the vermiculated sailfin catfish, is a species in the family Loricariidae described from the Madeira River basin, between Bolivia and Brazil. It is part of a complex of species often called 'plecos', and due to their hardiness and ability to keep aquaria and enclosures free from excessive algal growth, they are popular pet species. Probably as the result of releases from aquarists and escapes from fish farms, P. disjunctivus has become invasive in tropical, subtropical and warm-watered regions around the world, with some isolated populations recorded from colder settings, and they occupy all sort of inland water bodies. This species is recorded as introduced in USA and Mexico, Central America and the Caribbean, northern South America, South Africa and Asia. The genus Pterygoplichthys has a complicated taxonomic history, including numerous generic and specific synonymies, making the reconstruction of past invasions difficult. Current taxonomy relies heavily on colouration patterns, which are not reliable. Further genetic studies, especially on native populations, are needed to delimit species. These loricariid catfishes are very resilient and exhibit most of the characteristics that predispose certain species to successful invasion: (1) high fecundity, (2) broad physiological tolerance (i.e. salinity, pH, pollution, heavy metals, nutrient enrichment and hypoxia), (3) rapid growth, (4) an armoured exterior with powerful pectoral spines, (5) relatively long life span, and (6) highly valued as pets. Environmental impacts of Pterygoplichthys spp. are not fully understood, but they are known to cause considerable disturbance, especially on erosion and nutrient availability and recycling. The information on impacts is often generalized to the entire genus and usually cites potential impacts instead of observed impacts for P. disjunctivus. P. disjunctivus, in particular, is responsible for induced behavioural modifications in the threatened Trichechus manatus latirostris (Florida manatee), serving as vector for non-native fish parasites, and causing damage to fishing gear and industry. Once established, loricariid catfishes are extremely difficult to eradicate as there is just one successful eradication of P. disjunctivus documented. Pictures Picture Title Caption Copyright Predation Pterygoplichthys disjunctivus (vermiculated sailfin catfish); Predation by a giant otter (Pteronura brasiliensis). Porto Jofre, Brazil. August 2016.
Egyptian Journal of Aquatic Biology and Fisheries, 2024
This research focused on assessing the population dynamics and exploitation rate of the climbing ... more This research focused on assessing the population dynamics and exploitation rate of the climbing perch in Huai Kho Reservoir to inform fishery management. A total of 336 climbing perch were sampled, with fork lengths ranging from 90 to 185mm (average: 130.82 ± 18.46mm) and weights ranging from 19.0 to 126.0g (average: 49.78 ± 21.69g). The growth performance index (ϕ) was calculated as 3.87 per year, with an asymptotic length (L∞) of 194.25mm and a growth coefficient (K) of 0.25. Capture probabilities were estimated as L25% = 107.18mm, L50% = 101.99mm, and L75% = 114.80mm. The length-weight relationship equation, W = 0.026938L¹˙⁵⁶⁹⁶³ (r² = 0.95), indicated a strong correlation between length and weight, with a b-value of less than 3.00, demonstrating negative allometric growth. Mortality rates included total mortality (Z) of 0.84 per year, natural mortality (M) of 0.45 per year, and fishing mortality (F) of 0.40 per year. Recruitment peaked from November to January. The exploitation rate (E) was found to be 0.47, lower than the maximum exploitation rate (Emax) of 0.702. The study estimated a total biomass of 1.90 tons of the climbing perch, suggesting the species is currently underexploited, with a higher natural mortality than fishing mortality, likely due to fish behavior and biology. To ensure sustainable fishery management, it is recommended that fishermen shift from using pelagic gillnet fishing to demersal gillnet fishing.
Egyptian Journal of Aquatic Biology and Fisheries, 2024
This research focused on assessing the population dynamics and exploitation rate of the climbing ... more This research focused on assessing the population dynamics and exploitation rate of the climbing perch in Huai Kho Reservoir to inform fishery management. A total of 336 climbing perch were sampled, with fork lengths ranging from 90 to 185mm (average: 130.82 ± 18.46mm) and weights ranging from 19.0 to 126.0g (average: 49.78 ± 21.69g). The growth performance index (ϕ) was calculated as 3.87 per year, with an asymptotic length (L∞) of 194.25mm and a growth coefficient (K) of 0.25. Capture probabilities were estimated as L25% = 107.18mm, L50% = 101.99mm, and L75% = 114.80mm. The length-weight relationship equation, W = 0.026938L¹˙⁵⁶⁹⁶³ (r² = 0.95), indicated a strong correlation between length and weight, with a b-value of less than 3.00, demonstrating negative allometric growth. Mortality rates included total mortality (Z) of 0.84 per year, natural mortality (M) of 0.45 per year, and fishing mortality (F) of 0.40 per year. Recruitment peaked from November to January. The exploitation rate (E) was found to be 0.47, lower than the maximum exploitation rate (Emax) of 0.702. The study estimated a total biomass of 1.90 tons of the climbing perch, suggesting the species is currently underexploited, with a higher natural mortality than fishing mortality, likely due to fish behavior and biology. To ensure sustainable fishery management, it is recommended that fishermen shift from using pelagic gillnet fishing to demersal gillnet fishing.
International Journal of Fisheries and Aquatic Studies, 2024
Asian Journal of Fisheries and Aquatic ResearcThe climbing perch (Anabas testudineus) is a highly... more Asian Journal of Fisheries and Aquatic ResearcThe climbing perch (Anabas testudineus) is a highly sought-after fish in northeastern India, but the lack of a standardized breeding method presents a significant challenge for the development of its aquaculture. This study aimed to induce the breeding of Anabas testudineus in an aquarium using SGnRHa. The broodstock was injected intramuscularly, typically in the muscle just below the tip of the dorsal fin, at a 45° angle. The fish were left to spawn in the aquarium at a male-to-female ratio of 2:1. Males received an injection of 0.1 ml/kg, while females were given 0.3 ml/kg. Spawning was observed 8-10 hours after the SGnRHa injection, followed by fertilization. The first cleavage occurred within 20 minutes, with the 4-cell, 8-cell, 16-cell, and 32-cell stages observed at approximately 1 hour and 5 minutes, 1 hour and 25 minutes, 1 hour and 55 minutes, and 2 hours and 15 minutes, respectively. The morula, blastula, and gastrula stages were completed at around 3-4 hours, 7 hours, and 8-9 hours post-fertilization. Detailed photographs were taken to document the fertilized eggs, cleavage, and various developmental stages. Healthy larvae hatched 32-34 hours after fertilization.h
Behavior represents the strategies of an individual to deal with environmental challenges. The ob... more Behavior represents the strategies of an individual to deal with environmental challenges. The objective of this study was to determine the effect of social stress on the temporal consistency of behavior and its relationship with animal well-being and productive performance. This study was conducted at the Faculty of Agricultural Sciences, University of Panama. A completely randomized design was used with two factors: animal personality (proactive, reactive, intermediate) and feeding conditions (high competition, low competition). Each treatment was evaluated in triplicates. Animal personality traits showed significant differences in latencies for the first escape attempt at the end of the trial (p<0.001). The proactive group showed greater final weight, weight gain, feed conversion rate, and specific growth rate than the mixed and reactive groups (P <0.001, P <0.001; p<0.001; p<0.001, respectively). The percentage of individuals with fin lesions differed significantly according to animal personality (p=0.005). The phenotypes showed a higher percentage of lesions under the high-competition feeding condition (p=0.002). Under the high-competition feeding condition, the proactive and mixed groups showed a higher percentage of fin lesions than the reactive group (p<0.001 and p<0.001, respectively). Selection for animal personality traits showed consistent differences in behavior at the end of the trial, which were not affected by feeding conditions. The proactive ones showed better productive performance than the mixed and reactive ones did. The percentage of damage to the fins reflects that the proactive individuals were more likely to suffer injuries, especially in the high-competition feeding condition.
Perspectives and Applications of Indigenous Small Fish in India
Feeding ecology is a broad study encompassing quantification and identification of food items, mi... more Feeding ecology is a broad study encompassing quantification and identification of food items, microbial, chemical, and enzymatic conditions of the fish stomach, morphological adaptations to suit its feeding habit, and foraging strategies for acquiring food items. Understanding the dietary composition of fish has several advantages to culture and fisheries management aspects. This chapter discusses commonly used methods for food and feeding habits, dietary composition, and other aspects of the feeding ecology of selected Small Indigenous fish species (ISFs), i.e., Amblypharyngodon mola, Labeo bata, Puntius sarana, Gudusia chapra, Mystus cavasius, Channa punctatus, Anabus testudineus, Trichogaster fasciata, Nandus nandus and Macrognathus aral. This chapter also discusses the loopholes in the feeding ecology of ISFs. This chapter will serve as an important source of combined information on the food and feeding habits of ISFs.
The Nutrient Film Technique (NFT) in aquaponics is a closed aquaculture system favored by Indones... more The Nutrient Film Technique (NFT) in aquaponics is a closed aquaculture system favored by Indonesian aquaculturists due to its environmental friendliness and can be applied on a small scale. Climbing perch (Anabas testudineus) has the potential to be cultured in this system as small-scale livestock. This research aims to determine the performance of the NFT aquaponics system of Anabas testudineus and Brassica chinensis with different stock densities. A completely randomized design within four stock density treatments and five replications was applied to this study. The results showed that the specific growth rate, survival rate, and feed conversion rate (FCR) of A. testudineus differed significantly across treatments (p < 0.05). The best performance of specific growth rate (1.96 ± 0.15%), FCR (1.31 ± 0.13), and survival rate (88 ± 4.69%) were shown in the second treatment (50 fish/tank). On the other hand, the fourth treatment (100 fish/tank) yielded the tallest B. chinensis at 20.7 ± 0.90 cm and a leaf number of 10.68 ± 0.28. Higher fish stocking density resulted in a slower fish growth rate but a faster plant growth rate. It can be concluded that the aquaponics system of NFT with a density of 50 fish/tank could be applied to small-scale livestock. The amount of organic matter that plant roots can use as nutrients is the factor that determines the growth rate of B. chinensis.
Fish differ consistently in behavior within the same species and population, reflecting distinct ... more Fish differ consistently in behavior within the same species and population, reflecting distinct behavioral types (BTs). Comparing the behavior of wild and reared individuals provides an excellent opportunity to delve into the ecological and evolutionary consequences of BTs. In this work, we evaluated the behavioral variation of wild and reared juvenile gilthead seabreams, Sparus aurata, a highly relevant species for aquaculture and fisheries. We quantified behavioral variation along the five major axes of fish behavioral traits (exploration-avoidance, aggressiveness, sociability, shyness-boldness, and activity) using standardized behavioral tests and a deep learning tracking algorithm for behavioral annotation. Results revealed significant repeatability in all five behavior traits, suggesting high consistency of individual behavioral variation across the different axes in this species. We found reared fish to be more aggressive, social and active compared to their wild conspecifics. Reared individuals also presented less variance in their aggressiveness, lacking very aggressive and very tame individuals. Phenotypic correlation decomposition between behavioral types revealed two different behavioral syndromes: exploration-sociability and exploration-activity. Our work establishes the first baseline of repeatability scores in wild and reared gilthead seabreams, providing novel insight into the behavior of this important commercial species with implications for fisheries and aquaculture.
Identifying Stress Coping Styles (SCS) in new species of interest for aquaculture has important i... more Identifying Stress Coping Styles (SCS) in new species of interest for aquaculture has important implications for its future domestication and adaptation to captivity. Individual variability allows to select the potential positive characteristics for fish production. The main aim of this study was to identify phenotypic individual differences and characterize proactive and reactive SCS in flathead grey mullet (Mugil cephalus) juveniles by exposing fish to different stress situations and evaluating their individual and group responses to level behavioural and physiology. Juveniles were subjected to one group test (risk-taking) and five individual tests (predator, first feeding after stress, restraining, new environment and confinement). All assays were repeated twice, with a one-month interval between tests. Blood samples were taken from each individual (before and after stress) to quantify cortisol and glucose plasma concentrations. Flathead grey mullet juveniles exhibited a high inter-individual variability with two extremes of behaviours: proactive and reactive profiles that were characterized by opposed behavioural (activity time and escape attempts) and physiological (levels of cortisol and glucose) responses to stress and were consistent over time and across contexts. The flathead grey mullet juveniles showed differences in their predisposition for risk taking. Likewise, the Principal Component Analysis showed that three individual stress tests (predator, restraining and confinement tests) were reliable to characterize SCS in this fish species. This work reported for the first time the existence of stress coping styles in M. cephalus juveniles and the selection of a set of reliable behavioural tests to identify phenotypic profiles in flathead grey mullet. These results might be of interest for the aquaculture industry to improve fish welfare and health and to adjust management protocols for rearing this fish species in captivity.
Atlantic salmon (Salmo salar) is one of the worlds most domesticated fish. As production volumes ... more Atlantic salmon (Salmo salar) is one of the worlds most domesticated fish. As production volumes increase, access to high quality and sustainable protein sources for formulated feeds of this carnivorous fish is required. Soybean meal (SBM) and soy-derived proteins are the dominant protein sources in commercial aquafeeds due to their low-cost, availability and favorable amino acid profile. However, for Atlantic salmon, the inclusion of soybean meal (SBM), and soy protein concentrate (SPC) in certain combinations can impact gut health, which has consequences for immunity and welfare, limiting the use of soy products in salmonid feeds. This study sought to address this challenge by evaluating two gut health-targeted enhancements of SBM for inclusion in freshwater phase salmon diets: enzyme pre-treatment (ETS), and addition of fructose oligosaccharide (USP). These were compared with untreated soybean meal (US) and fish meal (FM). This study took a multi-disciplinary approach, investigating the effect on growth performance, gut microbiome, and behaviors relevant to welfare in aquaculture. This study suggests that both enhancements of SBM provide benefits for growth performance compared with conventional SBM. Both SBM treatments altered fish gut microbiomes and in the case of ETS, increased the presence of the lactic acid bacteria Enterococcus. For the first time, the effects of marine protein sources and plant protein sources on the coping style of salmon were demonstrated. Fish fed SBM showed a tendency for more reactive behavior compared with those fed the FM-based control. All fish had a similar low response to elicited stress, although ETS-fed fish responded more actively than US-fed fish for a single swimming measure. Furthermore, SBM-fed fish displayed lower repeatability of behavior, which may indicate diminished welfare for intensively farmed fish. The implications of these findings for commercial salmonid aquaculture are discussed.
Fish differ consistently in behavior within the same species and population, re ecting distinct b... more Fish differ consistently in behavior within the same species and population, re ecting distinct behavioral types (BTs). Comparing the behavior of wild and reared individuals provides an excellent opportunity to delve into the ecological and evolutionary consequences of BTs. In this work, we evaluated the behavioral variation of wild and reared juvenile gilthead seabreams, Sparus aurata, a highly relevant species for aquaculture and sheries. We quanti ed behavioral variation along the ve major axes of sh behavioral traits (exploration-avoidance, aggressiveness, sociability, shyness-boldness, and activity) using standardized behavioral tests and a deep learning tracking algorithm for behavioral annotation. Results revealed signi cant repeatability in all ve behavior traits, suggesting high consistency of individual behavioral variation across the different axes in this species. We found reared sh to be more aggressive, social and active compared to their wild conspeci cs. Reared individuals also presented less variance in their aggressiveness, lacking very aggressive and very tame individuals. Phenotypic correlation decomposition between behavioral types revealed two different behavioral syndromes: explorationsociability and exploration-activity. Our work establishes the rst baseline of repeatability scores in wild and reared gilthead seabreams, providing novel insight into the behavior of this important commercial species with implications for sheries and aquaculture.
The prevalence of sailfin catfishes (Pterygoplichthys spp.) in inland waters, including vast aqua... more The prevalence of sailfin catfishes (Pterygoplichthys spp.) in inland waters, including vast aquaculture systems of India is rising. This might be a serious threat to the country's native freshwater biological resources and aquaculture production. Therefore, studies were carried out to evaluate the impact of Amazon sailfin catfish Pterygoplichthys pardalis on different life-stages of native fishes. First, we analyzed the impact of three different size classes (small: 9.95 ± 0.70 cm, medium: 21.74 ± 0.87 cm and large: 30.81 ± 1.59 cm total length) of Amazon sailfin catfish on the survival of early life-stages (eggs, hatchlings, first-feeding fry, and 10-day-old fry) of two native fishes; native carp Labeo rohita (rohu) and native catfish Ompok bimaculatus (butter catfish). All size classes of Amazon sailfin catfish showed preference towards fish eggs over aquatic macro-invertebrates (Tubifex worms) and ingested over 90% of the eggs of both the native species. However, their effects on native species' mobile life stages (hatchlings forth) were found to be insignificant in terms of mortality. We then assessed the competition between advanced stages (fingerlings, advanced fingerlings, and sub-adult) of the Amazon sailfin catfish and the native fishes by evaluating growth and survival in three different experimental setups (indoor tanks with artificial feeds; outdoor tanks with natural food and artificial feed; and earthen pond with natural food) and in different combinations for a period of three to six months. In indoor experiment, no discernible impact of Amazon sailfin catfish on the growth of fingerlings of native species was found. But, in the outdoor experiment, growth of advanced fingerlings of rohu and butter catfish was decreased by 18.8-23.4% and 28.9-36.7%, respectively, in low-and high-biomass Amazon sailfin catfish treatments. The growth of rohu and butter catfish sub-adult was also reduced in the pond experiment, by 29.7% and 32.2%, respectively. However, impact of Amazon sailfin catfish on survival of native fish species at advanced stages was found minimal. Overall findings of this study indicate that sailfin catfish may have an adverse effect on the survival and growth of native fishes by either directly consuming or destroying native fish eggs or by competing with them for food and space.
Pterygoplichthys disjunctivus, commonly known as the vermiculated sailfin catfish, is a species i... more Pterygoplichthys disjunctivus, commonly known as the vermiculated sailfin catfish, is a species in the family Loricariidae described from the Madeira River basin, between Bolivia and Brazil. It is part of a complex of species often called 'plecos', and due to their hardiness and ability to keep aquaria and enclosures free from excessive algal growth, they are popular pet species. Probably as the result of releases from aquarists and escapes from fish farms, P. disjunctivus has become invasive in tropical, subtropical and warm-watered regions around the world, with some isolated populations recorded from colder settings, and they occupy all sort of inland water bodies. This species is recorded as introduced in USA and Mexico, Central America and the Caribbean, northern South America, South Africa and Asia. The genus Pterygoplichthys has a complicated taxonomic history, including numerous generic and specific synonymies, making the reconstruction of past invasions difficult. Current taxonomy relies heavily on colouration patterns, which are not reliable. Further genetic studies, especially on native populations, are needed to delimit species. These loricariid catfishes are very resilient and exhibit most of the characteristics that predispose certain species to successful invasion: (1) high fecundity, (2) broad physiological tolerance (i.e. salinity, pH, pollution, heavy metals, nutrient enrichment and hypoxia), (3) rapid growth, (4) an armoured exterior with powerful pectoral spines, (5) relatively long life span, and (6) highly valued as pets. Environmental impacts of Pterygoplichthys spp. are not fully understood, but they are known to cause considerable disturbance, especially on erosion and nutrient availability and recycling. The information on impacts is often generalized to the entire genus and usually cites potential impacts instead of observed impacts for P. disjunctivus. P. disjunctivus, in particular, is responsible for induced behavioural modifications in the threatened Trichechus manatus latirostris (Florida manatee), serving as vector for non-native fish parasites, and causing damage to fishing gear and industry. Once established, loricariid catfishes are extremely difficult to eradicate as there is just one successful eradication of P. disjunctivus documented. Pictures Picture Title Caption Copyright Predation Pterygoplichthys disjunctivus (vermiculated sailfin catfish); Predation by a giant otter (Pteronura brasiliensis). Porto Jofre, Brazil. August 2016.
Egyptian Journal of Aquatic Biology and Fisheries, 2024
This research focused on assessing the population dynamics and exploitation rate of the climbing ... more This research focused on assessing the population dynamics and exploitation rate of the climbing perch in Huai Kho Reservoir to inform fishery management. A total of 336 climbing perch were sampled, with fork lengths ranging from 90 to 185mm (average: 130.82 ± 18.46mm) and weights ranging from 19.0 to 126.0g (average: 49.78 ± 21.69g). The growth performance index (ϕ) was calculated as 3.87 per year, with an asymptotic length (L∞) of 194.25mm and a growth coefficient (K) of 0.25. Capture probabilities were estimated as L25% = 107.18mm, L50% = 101.99mm, and L75% = 114.80mm. The length-weight relationship equation, W = 0.026938L¹˙⁵⁶⁹⁶³ (r² = 0.95), indicated a strong correlation between length and weight, with a b-value of less than 3.00, demonstrating negative allometric growth. Mortality rates included total mortality (Z) of 0.84 per year, natural mortality (M) of 0.45 per year, and fishing mortality (F) of 0.40 per year. Recruitment peaked from November to January. The exploitation rate (E) was found to be 0.47, lower than the maximum exploitation rate (Emax) of 0.702. The study estimated a total biomass of 1.90 tons of the climbing perch, suggesting the species is currently underexploited, with a higher natural mortality than fishing mortality, likely due to fish behavior and biology. To ensure sustainable fishery management, it is recommended that fishermen shift from using pelagic gillnet fishing to demersal gillnet fishing.
Egyptian Journal of Aquatic Biology and Fisheries, 2024
This research focused on assessing the population dynamics and exploitation rate of the climbing ... more This research focused on assessing the population dynamics and exploitation rate of the climbing perch in Huai Kho Reservoir to inform fishery management. A total of 336 climbing perch were sampled, with fork lengths ranging from 90 to 185mm (average: 130.82 ± 18.46mm) and weights ranging from 19.0 to 126.0g (average: 49.78 ± 21.69g). The growth performance index (ϕ) was calculated as 3.87 per year, with an asymptotic length (L∞) of 194.25mm and a growth coefficient (K) of 0.25. Capture probabilities were estimated as L25% = 107.18mm, L50% = 101.99mm, and L75% = 114.80mm. The length-weight relationship equation, W = 0.026938L¹˙⁵⁶⁹⁶³ (r² = 0.95), indicated a strong correlation between length and weight, with a b-value of less than 3.00, demonstrating negative allometric growth. Mortality rates included total mortality (Z) of 0.84 per year, natural mortality (M) of 0.45 per year, and fishing mortality (F) of 0.40 per year. Recruitment peaked from November to January. The exploitation rate (E) was found to be 0.47, lower than the maximum exploitation rate (Emax) of 0.702. The study estimated a total biomass of 1.90 tons of the climbing perch, suggesting the species is currently underexploited, with a higher natural mortality than fishing mortality, likely due to fish behavior and biology. To ensure sustainable fishery management, it is recommended that fishermen shift from using pelagic gillnet fishing to demersal gillnet fishing.
International Journal of Fisheries and Aquatic Studies, 2024
Asian Journal of Fisheries and Aquatic ResearcThe climbing perch (Anabas testudineus) is a highly... more Asian Journal of Fisheries and Aquatic ResearcThe climbing perch (Anabas testudineus) is a highly sought-after fish in northeastern India, but the lack of a standardized breeding method presents a significant challenge for the development of its aquaculture. This study aimed to induce the breeding of Anabas testudineus in an aquarium using SGnRHa. The broodstock was injected intramuscularly, typically in the muscle just below the tip of the dorsal fin, at a 45° angle. The fish were left to spawn in the aquarium at a male-to-female ratio of 2:1. Males received an injection of 0.1 ml/kg, while females were given 0.3 ml/kg. Spawning was observed 8-10 hours after the SGnRHa injection, followed by fertilization. The first cleavage occurred within 20 minutes, with the 4-cell, 8-cell, 16-cell, and 32-cell stages observed at approximately 1 hour and 5 minutes, 1 hour and 25 minutes, 1 hour and 55 minutes, and 2 hours and 15 minutes, respectively. The morula, blastula, and gastrula stages were completed at around 3-4 hours, 7 hours, and 8-9 hours post-fertilization. Detailed photographs were taken to document the fertilized eggs, cleavage, and various developmental stages. Healthy larvae hatched 32-34 hours after fertilization.h
Behavior represents the strategies of an individual to deal with environmental challenges. The ob... more Behavior represents the strategies of an individual to deal with environmental challenges. The objective of this study was to determine the effect of social stress on the temporal consistency of behavior and its relationship with animal well-being and productive performance. This study was conducted at the Faculty of Agricultural Sciences, University of Panama. A completely randomized design was used with two factors: animal personality (proactive, reactive, intermediate) and feeding conditions (high competition, low competition). Each treatment was evaluated in triplicates. Animal personality traits showed significant differences in latencies for the first escape attempt at the end of the trial (p<0.001). The proactive group showed greater final weight, weight gain, feed conversion rate, and specific growth rate than the mixed and reactive groups (P <0.001, P <0.001; p<0.001; p<0.001, respectively). The percentage of individuals with fin lesions differed significantly according to animal personality (p=0.005). The phenotypes showed a higher percentage of lesions under the high-competition feeding condition (p=0.002). Under the high-competition feeding condition, the proactive and mixed groups showed a higher percentage of fin lesions than the reactive group (p<0.001 and p<0.001, respectively). Selection for animal personality traits showed consistent differences in behavior at the end of the trial, which were not affected by feeding conditions. The proactive ones showed better productive performance than the mixed and reactive ones did. The percentage of damage to the fins reflects that the proactive individuals were more likely to suffer injuries, especially in the high-competition feeding condition.
Perspectives and Applications of Indigenous Small Fish in India
Feeding ecology is a broad study encompassing quantification and identification of food items, mi... more Feeding ecology is a broad study encompassing quantification and identification of food items, microbial, chemical, and enzymatic conditions of the fish stomach, morphological adaptations to suit its feeding habit, and foraging strategies for acquiring food items. Understanding the dietary composition of fish has several advantages to culture and fisheries management aspects. This chapter discusses commonly used methods for food and feeding habits, dietary composition, and other aspects of the feeding ecology of selected Small Indigenous fish species (ISFs), i.e., Amblypharyngodon mola, Labeo bata, Puntius sarana, Gudusia chapra, Mystus cavasius, Channa punctatus, Anabus testudineus, Trichogaster fasciata, Nandus nandus and Macrognathus aral. This chapter also discusses the loopholes in the feeding ecology of ISFs. This chapter will serve as an important source of combined information on the food and feeding habits of ISFs.
The Nutrient Film Technique (NFT) in aquaponics is a closed aquaculture system favored by Indones... more The Nutrient Film Technique (NFT) in aquaponics is a closed aquaculture system favored by Indonesian aquaculturists due to its environmental friendliness and can be applied on a small scale. Climbing perch (Anabas testudineus) has the potential to be cultured in this system as small-scale livestock. This research aims to determine the performance of the NFT aquaponics system of Anabas testudineus and Brassica chinensis with different stock densities. A completely randomized design within four stock density treatments and five replications was applied to this study. The results showed that the specific growth rate, survival rate, and feed conversion rate (FCR) of A. testudineus differed significantly across treatments (p < 0.05). The best performance of specific growth rate (1.96 ± 0.15%), FCR (1.31 ± 0.13), and survival rate (88 ± 4.69%) were shown in the second treatment (50 fish/tank). On the other hand, the fourth treatment (100 fish/tank) yielded the tallest B. chinensis at 20.7 ± 0.90 cm and a leaf number of 10.68 ± 0.28. Higher fish stocking density resulted in a slower fish growth rate but a faster plant growth rate. It can be concluded that the aquaponics system of NFT with a density of 50 fish/tank could be applied to small-scale livestock. The amount of organic matter that plant roots can use as nutrients is the factor that determines the growth rate of B. chinensis.
Fish differ consistently in behavior within the same species and population, reflecting distinct ... more Fish differ consistently in behavior within the same species and population, reflecting distinct behavioral types (BTs). Comparing the behavior of wild and reared individuals provides an excellent opportunity to delve into the ecological and evolutionary consequences of BTs. In this work, we evaluated the behavioral variation of wild and reared juvenile gilthead seabreams, Sparus aurata, a highly relevant species for aquaculture and fisheries. We quantified behavioral variation along the five major axes of fish behavioral traits (exploration-avoidance, aggressiveness, sociability, shyness-boldness, and activity) using standardized behavioral tests and a deep learning tracking algorithm for behavioral annotation. Results revealed significant repeatability in all five behavior traits, suggesting high consistency of individual behavioral variation across the different axes in this species. We found reared fish to be more aggressive, social and active compared to their wild conspecifics. Reared individuals also presented less variance in their aggressiveness, lacking very aggressive and very tame individuals. Phenotypic correlation decomposition between behavioral types revealed two different behavioral syndromes: exploration-sociability and exploration-activity. Our work establishes the first baseline of repeatability scores in wild and reared gilthead seabreams, providing novel insight into the behavior of this important commercial species with implications for fisheries and aquaculture.
Identifying Stress Coping Styles (SCS) in new species of interest for aquaculture has important i... more Identifying Stress Coping Styles (SCS) in new species of interest for aquaculture has important implications for its future domestication and adaptation to captivity. Individual variability allows to select the potential positive characteristics for fish production. The main aim of this study was to identify phenotypic individual differences and characterize proactive and reactive SCS in flathead grey mullet (Mugil cephalus) juveniles by exposing fish to different stress situations and evaluating their individual and group responses to level behavioural and physiology. Juveniles were subjected to one group test (risk-taking) and five individual tests (predator, first feeding after stress, restraining, new environment and confinement). All assays were repeated twice, with a one-month interval between tests. Blood samples were taken from each individual (before and after stress) to quantify cortisol and glucose plasma concentrations. Flathead grey mullet juveniles exhibited a high inter-individual variability with two extremes of behaviours: proactive and reactive profiles that were characterized by opposed behavioural (activity time and escape attempts) and physiological (levels of cortisol and glucose) responses to stress and were consistent over time and across contexts. The flathead grey mullet juveniles showed differences in their predisposition for risk taking. Likewise, the Principal Component Analysis showed that three individual stress tests (predator, restraining and confinement tests) were reliable to characterize SCS in this fish species. This work reported for the first time the existence of stress coping styles in M. cephalus juveniles and the selection of a set of reliable behavioural tests to identify phenotypic profiles in flathead grey mullet. These results might be of interest for the aquaculture industry to improve fish welfare and health and to adjust management protocols for rearing this fish species in captivity.
Atlantic salmon (Salmo salar) is one of the worlds most domesticated fish. As production volumes ... more Atlantic salmon (Salmo salar) is one of the worlds most domesticated fish. As production volumes increase, access to high quality and sustainable protein sources for formulated feeds of this carnivorous fish is required. Soybean meal (SBM) and soy-derived proteins are the dominant protein sources in commercial aquafeeds due to their low-cost, availability and favorable amino acid profile. However, for Atlantic salmon, the inclusion of soybean meal (SBM), and soy protein concentrate (SPC) in certain combinations can impact gut health, which has consequences for immunity and welfare, limiting the use of soy products in salmonid feeds. This study sought to address this challenge by evaluating two gut health-targeted enhancements of SBM for inclusion in freshwater phase salmon diets: enzyme pre-treatment (ETS), and addition of fructose oligosaccharide (USP). These were compared with untreated soybean meal (US) and fish meal (FM). This study took a multi-disciplinary approach, investigating the effect on growth performance, gut microbiome, and behaviors relevant to welfare in aquaculture. This study suggests that both enhancements of SBM provide benefits for growth performance compared with conventional SBM. Both SBM treatments altered fish gut microbiomes and in the case of ETS, increased the presence of the lactic acid bacteria Enterococcus. For the first time, the effects of marine protein sources and plant protein sources on the coping style of salmon were demonstrated. Fish fed SBM showed a tendency for more reactive behavior compared with those fed the FM-based control. All fish had a similar low response to elicited stress, although ETS-fed fish responded more actively than US-fed fish for a single swimming measure. Furthermore, SBM-fed fish displayed lower repeatability of behavior, which may indicate diminished welfare for intensively farmed fish. The implications of these findings for commercial salmonid aquaculture are discussed.
Fish differ consistently in behavior within the same species and population, re ecting distinct b... more Fish differ consistently in behavior within the same species and population, re ecting distinct behavioral types (BTs). Comparing the behavior of wild and reared individuals provides an excellent opportunity to delve into the ecological and evolutionary consequences of BTs. In this work, we evaluated the behavioral variation of wild and reared juvenile gilthead seabreams, Sparus aurata, a highly relevant species for aquaculture and sheries. We quanti ed behavioral variation along the ve major axes of sh behavioral traits (exploration-avoidance, aggressiveness, sociability, shyness-boldness, and activity) using standardized behavioral tests and a deep learning tracking algorithm for behavioral annotation. Results revealed signi cant repeatability in all ve behavior traits, suggesting high consistency of individual behavioral variation across the different axes in this species. We found reared sh to be more aggressive, social and active compared to their wild conspeci cs. Reared individuals also presented less variance in their aggressiveness, lacking very aggressive and very tame individuals. Phenotypic correlation decomposition between behavioral types revealed two different behavioral syndromes: explorationsociability and exploration-activity. Our work establishes the rst baseline of repeatability scores in wild and reared gilthead seabreams, providing novel insight into the behavior of this important commercial species with implications for sheries and aquaculture.
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