The Indian Journal of Fisheries is published quarterly by the Indian Council of Agricultural Research (ICAR). Original contributions in the field of fish and fisheries science will be considered for publication in the Journal. The material submitted must be unpublished and not under consideration for publication elsewhere. Papers based on research which kills or damages any species, regarded as threatened/ endangered as per IUCN criteria or is as such listed in the Red Data Book appropriate to the geographic area concerned, will not be accepted by the Journal, unless the work has clear conservation objectives Editorial Board Editors
Central Marine Fisheries Research Institute (on behalf of Indian Council of Agricultural
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Bioluminescent bloom dynamics of Gonyaulax spinifera at Kumbalangi, Kochi, south-west coast of India
Several bioluminescent bloom events have been reported in the coastal, oceanic, and island waters of India since 1890. In recent years, Kerala has experienced multiple episodes of bioluminescent blooms, with Kumbalangi, a well known bioluminescent bloom hotspot on the south-west coast of India, repeatedly witnessing such events for the past several years. To investigate the bloom dynamics and associated environmental drivers, the Kumbalangi bloom area was monitored regularly from May 2023 to September 2024. During this period, a total of 67 species of diatoms, 19 species of dinoflagellates, 10 species of Chlorophyceae, 11 species of Cyanophyceae, and a few representatives of Euglenophyceae and Amoebozoa, were identified, with diatoms constituting the dominant component of phytoplankton community. Bioluminescent blooms of the dinoflagellate Gonyaulax spinifera were observed during the pre-monsoon season from ,,,,,,,,,,,,,. Principal component analysis (PCA) revealed that the aquatic environment was mainly influenced by salinity, dissolved inorganic nitrogen (DIN), and dissolved inorganic silicate (DISi). G. spinifera exhibited a strong positive correlation with salinity (r=0.75, p<0.05), suggesting that elevated salinity favoured its proliferation. The high Simpson dominance index, coupled with low Simpson diversity index, and Shannon‒Wiener diversity index values, confirmed the occurrence of a monospecific bloom of G. spinifera during the bloom period. Presence of G. spinifera cysts were also recorded from the area, which indicates its potential for persistence and recurrence under favourable environmental conditions. Keywords: Dinoflagellates, Environmental variables, Salinity, Phytoplankton composition
Bioluminescent bloom, Diversity indices, environmental parameters, Gonyaulax spinifera
Copyright (c) 2026 Indian Journal of Fisheries https://creativecommons.org/licenses/by-nc-nd/4.0
Insights into biological parameters of Macrognathus pancalus (Hamilton, 1822) from the river Ganga, Bihar, India
Growth pattern, sex ratio, gonadosomatic index (GSI), hepatosomatic index (HIS), size at first maturity, fecundity, and ova diameter of Macrognathus pancalus (Hamilton, 1822) from the river Ganga were studied. A total of 450 specimens were collected from two fish landing sites namely, Digha Ghat Patipul and Fatwah Ghat, located along the river Ganga. Females ranged from 75.83 to 165.20 mm in total length (TL) with corresponding body weights of 1.47 and 17.39 g, and males ranged from 77.50 to 153.70 mm in TL, weighing between 1.05 and 10.65 g. Both sexes exhibited positive allometric growth; the allometric coefficient was slightly higher in females. Overall M: F sex ratio was 0.9:1, which did not deviate statistically from the hypothetical value of 1:1, indicating an approximately equal representation of both sexes in the population. GSIindicated bimodal spawning season, with peaks in February and August–September. Males attain sexual maturity at a smaller size and lower body weight than females. A significant positive correlation was observed between HIS and GSI (r = 0.69, p<0.0001). Mean absolute and relative fecundities were 715.17± 2.08 eggs per female and 87.34±5.08 eggs g⁻¹ body weight, respectively. Eggs were spherical in shape, with a mean diameter of 1.17±0.02 mm. Fecundity appeared to increase with fish weight rather than length. These findings will be valuable for stock assessment studies of the species in this region, as well as for the conservation and sustainable management of the species. Keywords: Fecundity, Growth pattern, Size at maturity, Spiny eel, Spawning season
Reproductive biology, gonadal histology and feeding ecology of the damselfish Neopomacentrus cyanomos (Bleeker, 1856) from the south-west coast of India
The present study documents the reproductive biology, gonadal histology, and feeding ecology of the damselfish Neopomacentrus cyanomos (Bleeker, 1856) from the Vizhinjam coast, south-west India. Gonadal development was examined through detailed morphological and histological analyses to characterise gametogenesis and seasonal reproductive patterns. Ovarian development was categorised into five maturity stages, with oocyte diameters ranging from 36.89±8.01 µm in oogonia to 830±21.67 µm in fully mature oocytes, indicating asynchronous oocyte development and prolonged spawning activity. Testicular development also progressed through five distinct stages, from spermatogonia to mature spermatozoa, reflecting continuous spermatogenic activity. Gut content analysis revealed that N. cyanomos is predominantly zooplanktivorous, with copepods forming the major dietary component (41%), followed by ostracods (17%), decapod crustaceans (14%), amphipods (8%) and cirripeds (6%). Seasonal variation in feeding intensity was evident, with peak gastrosomatic index (GaSI) values recorded during July (3.7) and August (3.6), and the lowest values during January (0.74) and June (0.55). These trends coincided with periods of enhanced reproductive activity. This study provides the first comprehensive histological description of gonadal development in N. cyanomos from Indian waters and offers insights into its reproductive strategy and trophic ecology. The findings contribute baseline biological information essential for understanding the reproductive dynamics of pomacentrid fishes and for supporting future ecological assessments and management of coral reef-associated fish populations. Keywords: Asynchronous oocyte, Gastrosomatic index, Gonadosomatic index, Pomacentrids, Zooplanktivorous
Neopomacentrus cyanomos, Damselfish, Reproductive Biology, GaSI, GSI
Dietary antioxidants supplementation increases sperm motility, fertility and oxidative enzyme activity during cryopreservation of koi carp Cyprinus carpio Linnaeus, 1758
In aquaculture, oxidative stress is considered a major problem as it impairs sperm motility and cell viability, especially during cryopreservation. This can be overcome by dietary supplementation of antioxidants, which is essential during gametogenesis and spermiation. Hence, the present study aimed at evaluating the influence of dietary antioxidants on sperm quality and oxidative enzyme activity during cryopreservation. Experimental fishes (Cyprinus carpio L.) were fed with feed supplemented with vitamin C and E at three different concentrations, which consisted of 6 treatments and a control (without vitamin inclusion). The experimental feed was fed to the fish until satiation for 60 days, after which, milt was collected from the fish and cryopreserved for 30 days. After 30 days of cryopreservation, fertilisation was done using cryopreserved milt and fresh milt. The oxidative enzyme activity, such as glutathione peroxidase, catalase and superoxide dismutase, was recorded. The values of motility duration, fertilisation and hatching rate showed an overall linear and quadratic significant differences (p<0.05) among the treatments. The histological analysis of the ovary was also documented to analyse the effect of antioxidants on the ovarian development. Feed supplemented with vitamin E at 200 mg kg-1 (T4) exhibited higher motility value, fertilisation and hatching rates and oxidative enzyme activities in comparison to other treatments. Keywords: Fertilisation, Gametogenesis, Hatching rate, Histology, Spermiation
Cyttopsis indica, sp.nov., a new species of dory (Zeiformes: Parazenidae) from the Indian Ocean
A new species of dory fish of the genus Cyttopsis Gill, 1862 (Zeiformes: Parazenidae), Cyttopsis indica sp. nov., is described based on six specimens collected from deep waters off south-west India, caught at depths of 350–500 m along the continental slope of the eastern Lakshadweep Sea. The new species is distinguished from its congeners, Cyttopsis rosea (Lowe, 1843) and Cyttopsis cypho (Fowler, 1934), by a unique combination of meristic and morphometric characters, including the presence of 2 anal fin spines, caudal fin formula of 3+13+3 and a relatively high number of lateral line scales, a broader interorbital region, fewer number of lower gill rakers (1–2+5–7 vs. 1–2+8–10 in C. rosea), and a shorter post-orbital length (12.7–13.9% SL). Cyttopsis indica sp. nov., formed a distinct clade in the phylogenetic tree based on mitochondrial cytochrome c oxidase subunit I (COI) gene sequence and exhibited 4.6–11% genetic divergence from its congeners, providing molecular support for its recognition as a new species. Keywords: Deep-sea biodiversity, DNA barcoding, Integrative taxonomy, Meristics, Morphometrics, Parazenidae
India, deep-sea, new fish, taxonomy, Parazenidae
Production, export and competitiveness of fish and fishery products in India: An analysis across technology and policy phases
India's marine product sector has seen significant growth, benefiting consumers, boosting foreign exchange earnings, and supporting livelihoods. This progress is attributed to the research and development (R&D) efforts and the supportive policies. The Government of India has implemented targeted schemes to enhance fish production and exports, drawing from past experiences to inform future strategies. This study identifies five structural breaks in fish production and exports, coinciding with shifts in technology, policy, and institutions. From 1980–81 to 2018–19, national fish production increased annually by 6.3% for inland fish and 2.4% for marine fish. However, production performance varied widely across states. The study examines export performance in terms of growth, instability, and competitiveness, revealing variations across product groups and structural break periods since 1995. Although marine products exports show competitiveness according to revealed comparative advantage (RCA), this advantage has diminished over time. Granger causality analysis indicates a bidirectional causation between fish production and exports, emphasising the importance of comprehensive R&D and policy interventions along the value chain. The study underscores the critical role of enhancing production and value addition through favourable R&D and policies to sustainably boost fish production and its value. Keywords: Fish production, Granger causality, Marine exports, Research and development policy, Structural breaks
Fish production, marine exports, competitiveness, research and development policy, structural breaks, Granger causality
Copyright (c) 2026 Indian Journal of Fisheries https://creativecommons.org/licenses/by-nd/4.0
Structural dynamics of Sri Lankan artisanal tuna fisheries: Evidence from a 73 year time series and econometric analysis
This study employed advanced econometric methods to analyse 73 years (1950-2023) of catch data for skipjack (Katsuwonus pelamis) and yellowfin (Thunnus albacares) tuna from Indian Ocean Tuna Commission (IOTC) database. Bai-Perron tests identified four structural breaks at 1966, 1985, 2005 and 2014 (p<0.01), delineating five developmental phases. Regime switching models revealed differential volatility patterns, with skipjack showing higher volatility. Low volatility regime for skipjack showed mean returns of 0.084 (SD = 0.156, duration 8.7 years) while high volatility regime showed returns of -0.023 (SD = 0.387, duration 4.2 years). Johansen cointegration confirmed long-run equilibrium (trace=23.47, p<0.01) with error correction coefficient -0.31 (half-life 3.2 years). Non-linear ARIMA-GARCH models achieved 42% and 34% MAPE (Mean Absolute Percentage Error) reduction for skipjack and yellowfin respectively versus linear models. These findings demonstrate complex nonlinear catch dynamics, providing robust frameworks for tropical tuna management under changing conditions. Keywords: ARIMA-GARCH models, Econometric analysis, Regime switching, Skipjack tuna, Structural breaks, Yellowfin tuna
Thushani Suleka Madhubhashini Elepathage
Characterization of fish protein concentrate from underutilised red-toothed triggerfish Odonus niger (Ruppell, 1836)
Odonus niger, despite being nutritionally comparable to many commercially important species, continues to remain underutilised in the food sector. Owing to its high content of quality protein, it represents a promising raw material for developing fish protein concentrate (FPC). FPC prepared using a combination method (alkaline sodium bicarbonate washing followed by acetic acid precipitation) was characterised for yield, bulk density (UTBD and TBD), water holding capacity (WHC), oil absorption capacity (OAC), water activity (aw), colour (L*, a*, b*), proximate composition, and amino acid profile. The developed FPC exhibited a proximate composition meeting the requirements mentioned in IS:9808 standards for FPC, containing 89±0.20% crude protein, 9.54±0.10% moisture, 0.36±0.04% crude fat, and 0.31±0.03% ash. A total of 21 amino acids were identified, with essential amino acids including lysine (12.79%), leucine (15.07%) and methionine (13.29%) constituting the major fraction of the total amino acid profile The FPC demonstrated good physicochemical quality with a yield of 13.56±0.38%, UTBD and TBD of 0.65±0.03 and 0.75±0.01 g ml-1, respectively, OAC of 0.79±0.03 g g-1, WHC of 7.96±0.63 ml g-1, aw of 0.40±0.02 and L*, a*, b* values of 76.88±0.36, 3.33±0.53, and 24.43±0.78, respectively. The results demonstrated that the characteristics of the developed FPC were. in agreement with those reported in earlier studies. Therefore converting O. niger into a stable protein preparation represents an effective approach for its optimal utilisation, with potential incorporation into suitable value added food products. Keywords: Amino acid profile, Bulk density, Functional properties, proximate composition, Water activity
Characterisation and evaluation of novel bacterial consortium as a biofloc inoculum for nursery rearing of Labeo rohita and Oreochromis mossambicus
The present study explored isolation, characterisation and formulation of a probiotic bacterial consortium for application as a biofloc inoculum to enhance growth and survivability during seed rearing of rohu (Labeo rohita) and tilapia (Oreochromis mossambicus). Six potential probiotic bacterial strains viz., Priesta aryabhattai, Bacillus cereus, Exiguobacterium indicum, Acinetobacter indicus, Mixta calida, and Bacillus altitudinus, were isolated from autochthonous sources and identified using 16s rDNA PCR, sequencing and phylogenetic analysis. The probiotic potential of these bacterial isolates was assessed through comprehensive in vitro assays along with safety analyses. All the isolates and their combination exhibited antimicrobial potency against important fish pathogens; tolerance to a wide range of pH and bile concentrations and strong adhesion properties including autoaggregation, co-aggregation,biofilm formation capacity, and cell surface hydrophobicity. All the isolates were non-haemolytic, non-pathogenic to fish when at high doses (5x109 cells) and demonstrated significant free radical scavenging activity. Further, all the isolates showed tolerance to ammonia, nitrite and nitrate and ability to grow on fish mucus. The efficacy of the consortium was further validated through fry to fingerling rearing trials in biofloc systems for rohu (L. rohita) and tilapia (O. mossambicus), with jaggery as a carbon source. Fish fry were stocked at one fish per litre and reared for 90 days without water exchange and fed with feed containing 30% crude protein. On termination of the experimental trial, higher survival rates 80% for rohu and 100% for tilapia, were observed in the treatment groups, compared to control groups (71% for rohu and 92% for tilapia. The present study highlights the effective utilisation of a bacterial consortium as biofloc inoculum for seed rearing of rohu and tilapia, along with improved growth performance. The study demonstrated effectiveness of the bacterial consortium as a biofloc inoculum for enhancing seed rearing efficiency in rohu and tilapia. Keywords: Probiotics, Adhesion properties, Growth performance, Rohu, Seed rearing, Survival, Tilapia
Biofloc; Labeo rohita; Oreochromis mossambicus; Probiotics; Survivability; Seed rearing.
Comparative analysis of MHC class II A gene in Trachinotus mookalee and Trachinotus blochii: Molecular identification and in silico characterisation
Trachinotus mookalee and Trachinotus blochii are the two commercially important pompano species successfully farmed in aquaculture, and are susceptible to various infectious diseases. As in higher vertebrates, the major histocompatibility complex (MHC) gene superfamily plays crucial role in the adaptive immunity of teleost fishes by mediating the recognition and presentation of pathogen derived antigens to T cells, thereby contributing to disease resistance. The present study reports the identification and in-silico characterisation of the MHC class II A gene in T. mookalee (Trmo-DAA) and T. blochii (Trbl-DAA). The coding region of the target gene in both species was 1026 bp in length, comprising 4 exons and encoding a polypeptide of 241 amino acids. Phylogenetic analysis revealed that the MHC II A gene of T. blochii is more closely related to Trachinotus ovatus than to T. mookalee. In-silico analysis highlighted that the target gene is involved in the processing and presentation of exogenous antigen, as supported by domain and motif prediction, Gene Ontologies (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and STRING-based protein-protein interaction networks. The predicted secondary structure (2D) majorly comprised random coils and β strands, while the tertiary structure (3D) showed the highest similarity to the MHC class II A protein of Lates calcarifer. Ramachandran plot validation suggested that the predicted 3D structure of Trbl-DAA exhibits better stereochemical stability than that of Trmo-DAA. These findings provide valuable insights into the molecular and structural characteristics of MHC class II A genes in Trachinotus species and may support future studies on disease resistance and selective breeding. Keywords: Disease resistance, Indian pompano, Selective breeding, Silver pompano, Snubnose pompano, Trmo-DAA, Trbl-DAA
MHC II A; Silver Pompano; Indian Pompano
Biological insights into the vulnerable Hyporhamphus xanthopterus from Vembanad Lake: Fishery trends and growth parameters
This study examined the fishery characteristics, length-weight relationship (LWR), and condition factor of Hyporhamphus xanthopterus (Valenciennes, 1847), T from Kumarakam region of Vembanad Lake, Kerala, during 2020-2021. This investigation provides the first sex-wise analysis of length–weight relationships (LWR) and season-wise evaluation of condition factor (Kn) for H. xanthopterus population. A total of 657 specimens (304 males and 353 females) were caught employing 18 mm mesh sized gillnets, and measured for total length (TL) and total weight (TW) to estimate growth patterns using the allometric model. Males exhibited isometric growth (b=3.004) (R2 =0.94), while females displayed slightly negative allometric growth (b=2.857) and R2=0.96. When all the individuals are pooled, the estimated growth exponent b was 2.918 (R2=0.96). Seasonal analysis of condition factor indicated statistically significant variation, with higher Kn values observed in both males and females during Season 3 (post-monsoon), likely reflecting ecological influences such as food availability, reproductive activity, and environmental stress. These findings highlight distinct sex-specific growth patterns and seasonal physiological shifts, offering valuable insights into the biology and ecological adaptation of H. xanthopterus. The baseline data provided here can inform future research, resource management strategies, and biodiversity conservation efforts targeting H. xanthopterus and the broader aquatic ecosystem of Vembanad Lake. Keywords: Condition factor, Conservation, Length-weight relationship, Management, Ramsar site
Vulnerable, Ramsar site, Length-weight relationship, Condition factor, Conservation, Management
Assessment of reproductive potential and spawning patterns of Barilius bendelisis (Hamilton, 1807) in tributaries of the Ganga River in the Garhwal Himalayan region
Understanding reproductive strategies is essential for the biological conservation and management of hill-stream fishes in dynamic freshwater ecosystems. The present study investigated the reproductive biology of Barilius bendelisis (Hamilton, 1807), a key cyprinid species inhabiting three different streams and tributaries of the Ganga River viz.: the Song River, Sahastradhara, and Henval River in the Garhwal Himalayan region. The study was conducted from September 2023 to May 2025, covering all major seasons. Key reproductive parameters, including sex ratio, gonadosomatic index (GSI), Dobriyal index (DI), fecundity, and sexual dimorphism, were examined to determine spawning periodicity and reproductive potential. A female-biased sex ratio was consistently observed across all sites, with overall sex ratios of 1:1.14, 1:1.1, and 1:1.45 in the Song, Sahastradhara, and Henval Rivers, respectively. Peak GSI and DI values were recorded during the summer and monsoon seasons, indicating these seasons as the primary spawning period, with DI showing greater precision in identifying spawning periods. Fecundity varied among sites and showed a strong positive correlation with gonad weight, reflecting site-specific reproductive investment. Notably, males displayed prominent breeding tubercles during the spawning phase, serving as markers for sexual dimorphism. Overall, the findings reveal spatial variation in reproductive traits and highlight adaptive strategies of B. bendelisis in Himalayan hill-stream ecosystems. These insights offer a scientific foundation for developing season-specific conservation strategies, regulating fishing pressure during peak breeding periods, promoting the sustainable management of freshwater biodiversity in the Garhwal Himalayas. Keywords: Conservation, Dobriyal index, Fecundity, Gonadosomatic index, Hill-stream ecosystems, Indian hill trout, Sexual dimorphism
Morphological and molecular evidence for range extension and taxonomic validation of Sperata aorides (Jerdon, 1849) in the Western Ghats, India
Sperata aorides (Jerdon, 1849) is a commercially important freshwater catfish endemic to the Cauvery River basin, including its tributary, the Bhavani River. The present study report a range extension of the species to the Bharathappuzha River in Kerala, documenting its previously unrecorded distribution based on morphometric and molecular evidence. Specimens for the study were collected from different river systems in the Western Ghats, including the type locality at Erode, Tamil Nadu. Morphometric comparisons revealed minor variations between populations in head proportions, particularly in interorbital distance (19.5-24.5% vs 15.8-22.1% in HL) and eye diameter (12.0-17.3% vs 8.8-17.9% in HL). Mitochondrial cytochrome c oxidase subunit I (COI) gene sequencing confirmed species identity. Phylogenetic analysis showed that S. aorides forms a distinct clade, with low intraspecific genetic divergence (0.19%) between Cauvery and Bharathappuzha populations and higher divergence (4.61-9.85%) from congeners. These findings confirm the taxonomic validity of S. aorides and extend its known distribution to the Bharathappuzha River in the southern Western Ghats. Keywords: Bharathappuzha, Catfishes, COI gene sequencing, Distribution, Tamil Nadu
Filistriatus arabicus, a new species of threadfin (Polynemidae) from the northern Arabian Sea, India
A new species of threadfin, Filistriatus arabicus n. sp., is described based on three specimens (163-315 mm TL) collected from the coastal waters of Maharashtra (India), Arabian Sea. Filistriatus arabicus n. sp. can be distinguished from congeners by the presence of the following characters - 5 pectoral filaments, pectoral filament length 35.4-37.8% SL, reaching to or extending slightly beyond pelvic fin tip; black anterior lateral line spot absent; first dorsal fin with 8 spines, all spines equally robust; second dorsal fin with one spine and 13-14 soft rays; pectoral fin rays 15-16, length 4.5-4.7 in SL, origin below the lower end of maxilla horizontally; anal fin with 3 spines and 11 soft rays. 6-7 dark stripes along the scale rows above the lateral line, 7-8 scales above the lateral line, and 11-12 scales below the lateral line. Lateral line unbranched, 54-58 lateral line scales; 9-11+11-13 (20-24) gill rakers; upper jaw length 15-15.1% SL; distal margin of dorsal fins and pectorals black and anterior margin of pelvic dusky to black. The mitochondrial DNA (COI) sequence of F. arabicus exhibited a 6.6 to 10.3% sequence divergence from closest congeners. Key words: DNA, Filistriatus, Northern Indian Ocean, Polynemidae,Taxonomy
taxonomy, Polynemidae, DNA, Polydactylus, India, Arabian Sea, northern Indian Ocean
Stock discrimination of Indian sand whiting Sillago sihama (Forsskal, 1775) using truss morphometry along the Maharashtra and Goa coasts of India
The present study aimed to assess the stock structure of Sillago sihama (Forsskal, 1775) along the Maharashtra and Goa coasts using truss morphometric analysis. A total of 180 specimens were collected from six locations including Satpati, Mumbai, Harnai, Ratnagiri, Malvan, and Panaji between September 2024 and May 2025.Twenty truss distances, generated from ten anatomical landmarks, were subjected to statistical analyses comprising ANOVA, MANOVA, Principal Component Analysis (PCA), and Discriminant Function Analysis (DFA) to assess morphometric variation among populations. Nineteen out of twenty morphometric traits showed significant variation among locations. PCA revealed that most variation was concentrated in the caudal and dorsal regions, while DFA correctly classified 78.9% of specimens, with 70.6% accuracy in cross-validation. The distinct clustering patterns suggest the presence of multiple morphometric stocks. These results highlight the presence of significant morphological variability among S. sihama populations and underscore the effectiveness of truss morphometry in stock discrimination for sustainable fisheries management. Keywords: Anatomical landmarks, DFA, Fisheries management, Morphometric traits, PCA, Populations, Truss distances
Schizothorax esocinus (Heckel, 1838) in Dal Lake and Jhelum River: physiological traits and population trends in the Kashmir Himalayas
This study investigated the physico-chemical characteristics of Dal Lake and the Jhelum River along with evaluation of the morphometric traits, biometric growth parameters, biological indices, physiological attributes, and biochemical profiles of Schizothorax esocinus populations inhabiting these freshwater systems. The physico-chemical assessment revealed distinct environmental differences between the two habitats, with Dal Lake characterised by relatively warmer water, greater hardness, near-neutral pH, and comparatively lower dissolved oxygen levels than the Jhelum River. Correspondingly, fish from the Jhelum River exhibited greater body size and weight, whereas individuals from Dal Lake showed comparatively smaller morphometric dimensions. Biometric growth analysis indicated positive allometric growth in both populations, with notable variations in growth patterns between the two habitats. Biological indices differed between sites and sexes, reflecting habitat specific reproductive and metabolic conditions. Although haematological parameters showed no marked genderbased differences; however, site and age-related variations were evident, suggesting the influence of environmental conditions on physiological status. Overall, the findings highlight habitat driven differences in environmental quality and associated biological responses in S. esocinus, providing valuable insights for conservation planning and sustainable fisheries management in the freshwater ecosystems of Kashmir. Keywords: Aquatic environment, Condition factor, Hematological indices, Morphometric traits, Physico-chemical parameters
Growth dynamics of the common sole Solea solea, in the Morroccan Atlantic coastal waters
This study investigated the growth parameters, mortality and exploitation rate among the common sole Solea solea in the waters off the Moroccan Atlantic coast. Monthly samples were obtained from commercial bottom trawl fishing operations in the Safi fishing area, from January to December 2022. A total of 847 specimens were examined, ranging from 13 to 33 cm total length. The length-weight relationships were determined as W= 0.0097 L3.012 for females and W= 0.01089 L2.969 for males. The von Bertalanffy formula was applied to estimate growth parameters, revealing L∞, K, and t0 values for males (L∞=23.98 cm, K= 0.945 year−1, t0=-0.001 years) and females (L∞=23.71 cm, K= 0.884 year−1, t0=-0.002 years). The estimated age ranged from 0 to 8 years. The total mortality (Z), natural (M) and fishing mortality (F) rates were estimated as Z=4.48, M=1.84 and F=2.64 respectively. The estimated exploitation rate (E=0.59), indicated overexploitation of S. solea in the studied fishing area. Based on these results, it is essential to formulate sustainable management strategies to safeguard this marine resource and support the development of fishery plans. Keywords: Exploitation rate, Growth, Management strategy, Mortality, Safi fishing
Captive breeding and seed production of lyretail anthias Pseudanthias squamipinnis (Peters, 1885) in a recirculating aquaculture system (RAS)
Lyretail anthias, Pseudanthias squamipinnis (Peters, 1885), belongs to the subfamily Anthiinae (Family:Serranidae), is a highly priced (US$ 30) coral reef fish distributed in the Indo-West Pacific region. The present study investigates and describes the captive maturation, volitional spawning, larval rearing, and seed production of the P. squamipinnis, for the first time globally. Broodstock maintained in 2 t recirculating aquaculture system (RAS) spawned naturally without any hormonal induction. Fertilised eggs were planktonic, spherical, non-adhesive, transparent, and measured between 596 to 615 µm in size and had a single oil globule (152.14±4.24 µm). A green water medium consisting of a combination of microalgae was used for larval rearing. Eggs were maintained at 35 ppt salinity and 28±1°C temperature, which hatched out within 15-16 h after spawning. Newly hatched larvae were planktonic and measured 1.43±0.09 mm in total length (TL). The yolk sac was completely absorbed by 3 days post-hatch (dph). The preflexion stage was observed till 14 dph, and flexion began by 15 dph, which was completed by 20 dph. Between 30-40 dph, the larvae metamorphosed into juveniles with adult orange-yellow colour. Larvae were reared using copepod nauplii (Parvocalanus crassirostris) as the first feed, and in later stages, they were fed with copepods, Artemia and micro-encapsulated feed. The present study provides an improved RAS-based broodstock development protocol that enables the simultaneous rearing of several pairs of the same species or different species. It also provides an improved larval rearing and feeding schedule, resulting in improved survival rates compared with previously reported works. Keywords: Broodstock, Larval rearing, Micro-encapsulated feed, Serranidae, Volitional spawning
Serranidae, Lyretail anthias, RAS, Captive breeding, larval rearing, seed production
Ecological sustainability assessment of the Netravathi–Gurupur estuarine ecosystem in south-west India: Implications for fisheries management
Tropical estuaries are dynamic, productive ecosystems with rich biodiversity, typically influenced by anthropogenic activities. The ecological integrity of the Netravathi Gurupur estuarine ecosystem in the south-western coast of India is under increasing pressure from habitat degradation and pollution. Given the estuary's significant economic importance coupled with scarce information regarding its ecological status and trophic interactions, an assessment of the ecological sustainability focusing on fish production was conducted using the Ecopath modeling approach. The model comprised 28 functional groups spanning primary producers (trophic level, TL 1.0) to top predators (TL 3.9), depicting a trophic structure predominantly regulated by bottom-up control. Most fish groups exhibited relatively low ecotrophic efficiencies (EE), suggesting limited exploitation pressure and substantial energy dissipation within the system. In contrast, crustaceans emerged as the most intensively exploited groups, with crabs (EE=0.952), shrimps and prawns (EE=0.819) approaching full utilisation, indicating strong fishing pressure at lower trophic levels. System-level indices indicated high total system throughput (22,655.12 t km-² yr¹), reflecting high ecosystem productivity, but low ascendancy (38.33%), consistent with a developing ecosystem that retains resilience but remains sensitive to continued anthropogenic disturbances. These metrics provide a quantitative basis for evaluating ecological sustainability by identifying both vulnerable functional groups and critical trophic pathways requiring management attention. The findings facilitate ecosystem-based management recommendations, such as regulating crustacean harvests, protecting nursery habitats, and regulating pollutant inputs, thereby promoting sustainable resource use while maintaining ecosystem structure and services that support local fisheries and livelihoods. Keywords: Ecology, Ecopath modeling, Ecotrophic efficiency, Fishing pressure, Food-web, , Trophic structure
Dietary sodium butyrate improves growth performance of Nile tilapia Oreochromis niloticus (Linnaeus, 1758) reared in biofloc system
This study evaluated the effects of dietary sodium butyrate (SB) supplementation on the growth performance and intestinal morphology of Nile tilapia Oreochromis niloticus (Linnaeus, 1758) cultured in a biofloc system. A 120 day experiment was conducted using a completely randomised design with five treatments: control (biofloc only) and four SB supplemented diets (0.5%, 1%, 1.5% and 2%), each in triplicate. Fish (Initial mean weight 4.9±0.2 g) was stocked at a density of 40 fish per 0.4 m³ in each tank. The results indicated no significant differences (p>0.05) in survival, daily weight gain and feed conversion ratio (FCR) among the treatments. However, final mean weight, total harvest weight and net fish yield were significantly higher (p<0.05) in treatments fed 1.5% and 2% SB supplemented diets. Water quality improved in SB supplemented treatments, with significantly lower ammonia and nitrate levels and higher floc volume. Bacterial and phytoplankton abundance increased significantly with higher SB inclusion, whereas zooplankton abundance remained unaffected. Histological analysis revealed enhanced intestinal villi length in SB fed treatments, indicating the improved nutrient absorption. Overall, the integration of sodium butyrate with biofloc technology demonstrated the synergistic effects by improving bacterial abundance, phytoplankton abundance, zooplankton abundance, water quality and fish growth. The study suggests that 1.5–2% dietary SB is optimal for enhancing productivity of Nile tilapia in biofloc system. Keywords: Aquaculture nutrition, Biofloc technology, Microbial dynamics, Phytoplankton abundance
Food and feeding dynamics of the checkered snapper Lutjanus decussatus (Cuvier, 1828) in the reef ecosystems of Andaman Islands, India
The food and feeding dynamics of the checkered snapper Lutjanus decussatus (Cuvier, 1828), inhabiting the reef ecosystem of the Andaman Archipelago in the Bay of Bengal, were studied from September 2019 to August 2021. Gut contents of 692 specimens in the length range of 15.70 to 29.80 cm were examined, where 338 stomachs were empty and 354 stomachs were found in different degrees of fullness. Each prey was identified to the lowest possible taxon and quantified based on numeric and gravimetric abundance. The diet composition, diet breadth and diet shift between the male, female and sexually undifferentiated fishes were analysed seasonally. The species fed dominantly on crustaceans [dietary coefficient (QI) of 94.98% and index of relative importance (IRI) of 93.01%] followed by teleosts (QI of 4.88% and IRI of 6.84%). The seasonal diversity indices, vacuity index, most preferred prey items and the fullness index of each sex were calculated. The findings of the present study will form baseline information on the feeding dynamics of the checkered snapper that would be helpful for fishery managers in formulating management strategies. Keywords: Fisheries management; Gut content, Prey, Trophic levels
Marine species conservation awareness and community perceptions among tribal fishers of Car Nicobar, India
Understanding the perceptions, attitudes, and awareness levels of tribal fishers who interact daily with fragile marine ecosystems is vital, as these communities depend heavily on these resources for their livelihood and food security. Nicobarese fishers (n=195) from Car Nicobar Island in the Bay of Bengal were interviewed to assess their knowledge, awareness, and attitudes towards marine conservation, including perceptions of species protection, enforcement, community participation; threats to marine biodiversity and the sustainability of marine fauna. Awareness of conservation regulations was moderate, with 81% of respondents familiar with Wildlife (Protection) Act, 1972, and 72% supporting protected status for marine species, citing rarity and their restricted distribution as key reasons. However, institutional mechanisms were weak, 74% of respondents reported lack of tribal-level management plans, while 97% indicated that no formal legal framework for marine conservation existed within tribal councils. Nearly all respondents (97%) reported encountering rare marine species encountering during fishing activities, but their responses varied, with 44% releasing such speice back into the wild, and 27% consuming them. Perception scores reflected strong support for species conservation (4.02±0.68) and enforcement measures (3.97±0.62), although confidence in existing management practices and community consensus was only moderate. Generalised Linear Model (GLM) analysis revealed that age, fishing experience, and especially education were significant predictors of conservation awareness (p<0.05), whereas village-level variations were not significant. The findings emphasised a strong conservation commitment among Car Nicobar’s fishing communities, but also revealed weak institutional frameworks and community mechanisms. To better align conservation knowledge with sustainable marine resource management, it is crucial to strengthen environmental education, establish conservation regulations through tribal councils, and launch targeted awareness campaigns. Keywords: Marine conservation, Socio-demographics, Community awareness, Traditional fisheries, Stakeholder perceptions
Preservation of yellowfin tuna (Thunnus albacares) chunks using edible wraps prepared from under-utilised Averrhoa bilimbi fruit juice, infused with chitosan and fish gelatin
The study aimed to investigate the bioactive properties of Averrhoa bilimbi fruit juice, focusing on its antioxidant and antimicrobial activities, and to evaluate its use as edible wraps infused with chitosan and fish gelatin for preserving tuna chunks under chilled conditions (4 °C). The wrap comprised A. bilimbi fruit juice (BJW 50% and BJW 100%) blended with fish gelatin (5%) and chitosan (0.5%). Antioxidant activity increased in a concentration-dependent manner and was positively correlated with the phenolic content of bilimbi juice. In the disc diffusion antimicrobial assay, 100% BJW showed the largest zone of inhibition against Lysteria monocytogenes (24.70±0.01 mm). During refrigerated storage, the psychrophilic bacterial counts in the control, GCW (gelatin-chitosan wrap), and BJW 50% wraps exceeded the acceptable limit of 7 log CFU g-1 by the 12th day of storage. In contrast, the samples wrapped with the BJW 100% remained within the acceptable limits until the 15th day, which corresponded well with the results of the antimicrobial assay, demonstrating the preservative potential of BJW. Similar trends were observed for lipid oxidation and spoilage indicators, Thiobarbituric acid reactive substances (TBARS) and total volatile base nitrogen (TVB-N) values, of the control, GCW, and BJW 50% samples exceeded permissible limits on the 6th day of storage, while BJW 100% treated samples exceeded the limits only after the 15th day. Overall, A. bilimbi juice-based edible wraps effectively maintained the microbiological and biochemical quality of tuna chunks, demonstrating their potential as a safe and effective biopreservative for seafood applications. Keywords: Antioxidant properties, Antimicrobial assay, Chilled storage, Phenolic content, TBARS, TVB-N
Copyright (c) 2025 Indian Journal of Fisheries https://creativecommons.org/licenses/by-nd/4.0
First successful trial of seaweed (Kappaphycus alvarezii) cultivation in Karnataka, India
This study highlights the successful raft-based cultivation of Kappaphycus alvarezii in the Yadamavinahole Estuary, Uppunda, Karnataka over a period of 72 days during pre-monsoon season (February to April, 2025). A total of 20 net tubes were deployed, yielding 180 kg of fresh biomass and the mean biomass per tube was 8.94 ± 0.10 kg. The growth performance was promising with a specific growth rate of 2.06±0.04% day⁻¹ and a daily growth rate of 2.16 ± 0.03% day⁻¹. Optimal water quality conditions supported consistent growth. The trial success underscores the potential for scalable seaweed farming in the region and provides essential insights for enhancing future commercial cultivation practices. Keywords: Blue economy, Coastal communities, Commercial cultivation, Livelihoods
Seaweed, Kappaphycus alvarezii, Karnataka
Taxonomic assessment and diversity of sea slugs (Gastropoda: Heterobranchia) along the Karnataka Coast, India
Sea slugs in Karnataka's marine ecosystems have been understudied, resulting in limited documentation. To address this gap, extensive field surveys were conducted across the rocky reefs and off-shore patchy reefs of Karnataka, extending up to a depth of 38 m. During the surveys nine sea slug species were documented, representing four genera (Goniobranchus, Phyllidia, Coryphellina, and Elysia), belonging to four families (Chromodorididae, Phyllidiidae, Flabellinidae, and Plakobranchidae). Six of the nine species recorded are new additions to the sea slug fauna of the Karnataka Coast. By combining data from the current surveys with historical records, an annotated checklist of 36 species of sea slugs found in Karnataka was compiled. Keywords: Annotated checklist, Rocky reefs, Marine ecosystems, Patchy reefs
Biological parameters of the revalidated cyprinid Osteobrama dayi, endemic to the Godavari River, India
The length-weight relationship is of great importance in fishery assessments. In the present study, we estimated the length-weight relationship (LWR) of a recently re-validated endemic cyprinid, Osteobrama dayi, which is endemic to the Godavari River. The specimens were collected from their natural habitat between 2021 and 2023. The “b” value ranged from 3.29 to 3.50 between pre-monsoon and monsoon season, whereas the “a” value ranged between (-)2.25 and (-)2.53, respectively. This study provides the first report on LWR for O. dayi and records the maximum standard length (26.4 cm) and total weight (728 g), recorded for this species from the wild, along with the condition factor (K). The baseline information on LWR and K for O. dayi will be useful in further studies on the stock management of this endemic species. Keywords: Conservation, Condition factor, Cyprinid, Endemic species, Length-weight relationship, Health status
Range extension of the red-tipped halfbeak Hyporhamphus xanthopterus (Valenciennes, 1847) in the Cauvery River, Western Ghats of India: Integrative taxonomy and resolution of taxonomic misidentifications
This study reports a noteworthy range extension of the freshwater halfbeak Hyporhamphus xanthopterus (Valenciennes, 1847) from the Western Ghats of India, with the first confirmed record from the Cauvery River in Tamil Nadu. This discovery significantly expands the known distribution of the species within Indian freshwater ecosystems. This study presents the first molecular validation of H. xanthopterus from Indian waters, integrating mitochondrial DNA data with detailed morphometric and meristic analyses. The findings contribute to resolving taxonomic ambiguities within the genus Hyporhamphus, provide refined diagnostic criteria for accurate species identification and offer new insights into the biogeographical distribution of this poorly understood taxon. These results establish a valuable baseline for future taxonomic, phylogenetic and conservation-oriented research on freshwater halfbeaks in South Asia. Keywords: Cauvery River, Freshwater ecosystems, Meristic counts, Mitochondrial CO1, Molecular validation, Morphometry
Halfbeak, Freshwater, Vulnerable , Cytochrome oxidase I, Conservation
Fisheries Cooperative Governance Quality Index: A novel methodology for assessing primary fisheries cooperative societies
The governance of cooperative societies is an important facet as it indicates success or failure for any cooperative society. The present study was conducted in the purposively selected Pune District of Maharashtra State with randomly selected 41 Primary Inland Fisheries Cooperative Societies (PIFCSs) for assessing quality of governance using novel Fisheries Cooperative Governance Quality Index (FCGQI). The study found that the majority (51.22%) of PIFCSs had medium governance quality scores (0.56-0.70), followed by 34.15% of PIFCSs showing low (<0.55) level of governance quality. The governance quality in PIFCSs perceived by the executive body (0.57) and the general body (0.55) members was found closely aligned. There were significant opinion differences among the executive body (0.47) and the general body (0.40) members about the quality of leadership in IPFCSs. The quality of governance in selected fisheries cooperatives positively correlated with younger leadership, trained executive body members, availability of basic infrastructure, greater interactions with other organizations and higher levels of women empowerment. The regression model with selected independent factors found best fit (R2=0.78). Ensuring regular staff, basic infrastructure, diversified income generating activities, enhancing women and youth participation, along with building leadership capacity and stronger collaborations with research and development institutions would strengthen fisheries cooperatives and sustain member’s livelihoods. Keywords: Inland fisheries, Leadership, Livelihood, Teaming, Women empowerment
Development of a scale to measure the perception of stakeholders towards marine fisheries governance: A methodological approach from a case study in Andhra Pradesh
This study aims at development of a psychological scale to measure the perception of stakeholders towards the Andhra Pradesh Marine Fisheries Regulation Act (APMFRA). The collection of items included 31 statements covering the dimensions such as zonation, registration, licensing, monitoring, implementation, conservation related fishing regulations, penalty structures and effectiveness. The 31 statements were evaluated by a group of 34 judges representing research, education and extension in the field of fisheries and social sciences, through which 18 statements were selected with relevancy percentage of more than 61 %, and mean relevancy score of more than 1.85. Through t-test item analysis, the final perception scale was constructed with 10 statements with t value of more than 1.75, out of the 18 statements. The scale has demonstrated both reliability and validity, confirming its consistency and accuracy in measuring perceptions of APMFRA. The administration of the scale among the stakeholders would elicit their perception towards the Act, and the areas to be strengthened for effective fisheries governance such as the regulations which are to be strengthened with the incorporation of scientific advisories, technological measures and conflict resolution mechanisms. Keywords: APMFRA, Attitude, Fishing regulations, Governance, Psychological scale
Attitude, perception, governance, marine fisheries, APMFRA, stakeholders, perception scale
Optimisation of retort process parameters and evaluation of heat penetration characteristics of the traditional shrimp dish, Iral kootu
The main objective of this study was to optimise the retort process parameters and evaluate the heat penetration characteristics at the optimised time-temperature for the shrimp dish Iral kootu. Three varieties of shrimps were used for the study: White (Penaeus indicus), Tiger (Penaeus monodon) and Flower shrimp (Penaeus semisulcatus). The dishes were prepared and packed in retort pouches and processed to different time-temperature combinations. Preliminary optimisation was done for processing temperatures of 115 and 121°C for 5, 10 and 15 min. Based on sensory evaluation, 115 and 121°C for 10 min were selected for further optimisation. Commercial sterility tests and sensory evaluations of the products from the second trial indicated that both products are commercially sterile, but the product processed at 121°C for 10 min secured a higher sensory score for all the attributes. Heat penetration characteristics were determined using Ball’s graphical and mathematical methods, at 121°C for 10 min. The estimated total process time (B) was 36 min, with a corresponding lethality value (F0) of 8.89 min and a cook value (C) of 59.35 min. Keywords: Cook value, Commercial sterility, Penaeus indicus, Penaeus monodon, Penaeus semisulcatus, Sensory evaluation
Iral Kootu; optimization; commercial sterility, sensory evaluation; heat penetration characteristics