Search

The fishery and population dynamics of Otolithoides pama (Hamilton, 1822) were studied from the Hooghly-Matlah estuary of West Bengal from November 2016 to April 2018. The average annual catch of sciaenids for the last five years was estimated at 22 mt and formed 12.66% of the total marine production of the state of West Bengal, India. The peak landings of O. pama were found during March from gill net catches and November–December from bag net catches. The species followed continuous recruitment throughout the year with two distinct peaks during March–August and July–October. The probability of capture was estimated to be 148.35 mm, while the length at recruitment was 104.5 mm. The rate of exploitation (0.73) was found to be higher than Emax (0.58), indicating a higher fishing pressure of the species. The length-based Virtual Population Analysis revealed that the highest fishing mortality occurred from the 140–159 mm length group onwards. Both Beverton and Holt yield per recruit analysis and Thompson and Bell prediction analysis revealed higher fishing effort being employed for the species, which would need to be reduced by 20% for sustainable management of the species at the studied estuarine system.

The present paper deals with the infestation of freshwater fishes Labeo boggut, Oreochromis niloticus, Systomus sarana, and Xenentodon cancila by the parasitic isopods Alitropus typus and Tachaea spongillicola in Tapti, a westward freshwater flowing river of India. The isopods Alitropus typus H. Milne Edwards, 1840 and Tachaea spongillicola Stebbing, 1907 were identified with the taxonomic keys of Milne Edwards (1840) and Stebbing (1907), respectively. It is the first record of the infestation of parasitic isopods Alitropus typus, and Tachaea spongillicola in the freshwater fishes of river Tapti with new hosts’ species Labeo boggut, Oreochromis niloticus, and Systomus sarana.

The relation of fish size with that of its otolith of pama croaker, Otolithoides pama (Hamilton, 1822) was established. Fish specimens were collected from the bagnet catch from Narmada estuary, India for a period of 8 months (November 2018 to June 2019). To understand the relationship between fish and otolith size, the sagittal otoliths were extricated, cleaned, measured, and photographed. The Otolith length (OL), Otolith breadth (OB), and Otolith weights (OW) were measured from each specimen to the nearest size of 0.01 mm and weight of 0.01 g. The observed length and weight of the fish were in the range of 85 to 288 mm (175.79±33.13 mm) and 3.0 to 186.56 g (43.68±27.67 g), respectively. The recorded otolith length, breadth, and weight were in the range of 2.65 to 12.54 mm (7.20±1.77 mm), 2.01-10.48 mm (5.95±1.33 mm), and 0.02 g to 0.75 g (0.23±0.11 g), respectively. The data fitted well to the power model for the OL, OB, OW, and fish length and weight. High values of the coefficient of determination (R2) were recorded between fish length and otolith length (R2 = 0.978), fish length and otolith weight (R2 = 0.931), fish length and otolith breadth (R2 = 0.985), fish weight and otolith length (R2 = 0.942), fish weight and otolith weight (R2 = 0.922), and fish weight and otolith breadth (R2 = 0.962). The study also depicted a high correlation of otolith dimensions with the size of the fish.

The diversity of finfish in river Narmada and its tributaries in central and western India has been reviewed. We could compile a total of 196 species from both freshwater and brackish water habitats, under 14 orders, 51 families, and 126 genera. The order Cypriniformes represented the highest diversity with 78 species (i.e., 39.8%) followed by Perciformes (47 species), Siluriformes (32 species), Clupeiformes (15 species), etc. As per the IUCN Red List category, the maximum number of species are under Least Concern (129), followed by Not Evaluated (36), Near Threatened (14), Data Deficient (11), Vulnerable (4), and Endangered (2). The species Tor khudree and Tor putitora were found Endangered in the system. Out of 196 finfish species, 77 are food fishes, 33 having both ornamental and food fish value, 21 are truly ornamental value, and 31 as sports fishes. Habitat wise distribution of the fishes indicates that 79 species are truly freshwater and 3 species are truly marine, while 58 species range between freshwater and brackish water habitats, 21 between brackish water and marine habitats and 35 species range from freshwater to marine habitats. This review presents up-to-date information on finfish biodiversity of river Narmada. It will help in making appropriate conservation and management planning of fisheries in this river.

The study reported Thryssa stenosoma, as a new host of isopod Nerocila depressa infestation. Furthermore, the record of Nerocila depressa from the Narmada estuary is of first kind in the West Coast of India. Thryssa stenosoma, commonly known as slender thryssa forms an important commercial fish species at Bhadbhut, a part of the Narmada estuary. The prevalence of N. depressa infestation was 17.39% with a mean intensity of 2.8. in T. stenosoma, showing a low rate of infestation. The present information would form a new addition of isopod infestation to the list of parasitic diseases of estuarine fishes in India.

The present study confirmed the occurrences of Walton’s mudskipper Periophthalmus waltoni Koumans 1941 under the family Gobiidae as the first kind of record from the estuarine region of river Narmada of Gujarat, India. A total of 21 specimens were collected with the size ranging from 124 to 145 mm and from 10.7 to 26.2 g, respectively, from Jageshwar fishing sites during the monsoon period (July–September 2019). Walton’s mudskipper was reported to be found in countries like Iran, Iraq, Oman and Pakistan, but its availability in Indian waters is questionable. The present findings confirmed the occurrences of the species in the Narmada estuary, Gujarat, India drainage to the Arabian Sea.

The Indian frogfish distributed from East Africa and the Persian Gulf east to India and Sri Lanka is a truly marine species. Frogfish of the family Antennariidae is distinguished by the presence of three well-developed dorsal spines, laterally-directed eyes, largemouth and laterally compressed body. There are no reports of the occurrence of frogfishes in river Narmada. The present study confirms the occurrence of Indian frogfish in the Narmada estuary Gujarat, India, as the first record.

The present paper deals with the infestation of freshwater fishes Labeo boggut, Oreochromis niloticus, Systomus sarana, and Xenentodon cancila by the parasitic isopods Alitropus typus and Tachaea spongillicola in Tapti, a westward freshwater flowing river of India. It is the first record of the infestation of parasitic isopods Alitropus typus, and Tachaea spongillicola in the freshwater fishes of river Tapti with new hosts’ species Labeo boggut, Oreochromis niloticus, and Systomus sarana.

The study reported Thryssa stenosoma, as new host for isopod Nerocila depressa, infestation. Furthermore, the report is of first to record Nerocila depressa from the Narmada, the largest estuary of west coast of India. Thryssa stenosoma forms a commercially important fish species at Bhadbhut, a part of the Narmada estuary. The prevalence of isopod infestation was 17.39% with mean intensity 2.8 in T. stenosoma, indicating the low, at the present ecological conditions. Looking at the future proposed developmental river valley projects at Bhadbhut estuarine zone, our present information would form baseline to the parasitic diseases in estuarine fishes in Narmada estuary, India.

In the present study, an attempt was made to document the spatial distribution and diversity inventory of macro-benthic fauna from 21 sampling stations of the Indian Sundarbanfor a period of six months from November 2014 to April 2015. A total of 1,871 individuals belonging to 35 species were recorded which comprised 12 species of molluscs, 20 species of crustaceans, one species each of xiphosurid, sea anemone and fish. The frequency analysis of species revealed that the most dominant species were Telescopium telescopium and Tubuca rosea among molluscs and crustaceans, respectively. The density analysis of the species showed that Pirenella cingulata and T. rosea had maximum values among molluscs and crustaceans, respectively. The average values of Shannon-Wiener diversity index, Simpson diversity index, dominance index and Margalef diversity index were found to be 2.712, 0.888, 0.111 and 4.513, respectively. Keywords:Indian Sundarban, Macro-benthic fauna, Spatial distribution, Species diversity

Pama croaker, Otolithoides pama (Hamilton, 1822) is one of the commercially important demersal fish of Hooghly-Matlah estuarine system, West Bengal, India. Reproductive biology of 618 samples of O. pama (Hamilton, 1822) collected from the Hooghly-Matlah estuarine system of West Bengal, India for a period of 18 months (November 2016 to April 2018) was investigated. The total length (TL), body weight (BW) and ovary weight (OW) of the samples varied from 100-384 mm, 7.29-470.71 g and 1.5-29.49 g, respectively. The sex distribution was 1 male for 1.07 female and the ratio did not differ statistically. The length at first maturity (L m ) was recorded as 183 mm for males and 196 mm for females. The reproductive activity was found throughout the year with three peak spawning season with high gonadosomatic index (GSI) values, i. e ., during February-March, June and September-November. The absolute fecundity ranged from 4652 to 170688 eggs (24950±32441.2) and relative fecundity ranged from 96 to 808 eggs per g body weight (382±176.83). Fecundity exhibited a relatively higher significant correlation with ovary weight (r = 0.973, p

The present study analysed the morphometric and meristic characters of Otolithoides pama (Hamilton, 1822) collected from the Hooghly-Matlah estuarine system of West Bengal, India. A total of 618 specimens (298 males and 320 female) were collected during the period of 18 months from November 2016 to April 2018 with length ranging from 100-384 mm and weight 7.29-470.71 g, respectively. The analysis of 14 morphometric characters revealed that standard length has the fastest growth rate when compared to total length, while eye diameter has the lowest growth rate when compared with head length. A high degree of significant positive correlation with the ‘r’ values ranging from 0.978 to 0.997 was observed among different morphometric characters of O. pama. Among nine of the meristic counts, the coefficient of variation was found to be highest in anal fin rays (6.31%) and minimum in dorsal fin rays (1.12%). Based on the meristic counts, the fin formula of O. pama from the present study can be described as B. 7 , D. 9-10/1/44-45, P. i/16-17, V. 1/5 , A. 2/7-8, C. 19-21, L. 48-52. The number of gill rakers on the first left gill arch ranged from 19-21. Keywords: Hooghly-Matlah Estuary, Morphometric characters, Meristic counts, Otolithoides pama, West Bengal

Hilsa, Tenualosa ilisha is a highly prestigious fish for esteemed delicious taste, high market demand and price. It forms an important fishery of funnel-shaped 72 km long Narmada Estuary. Rapid decline in hilsa catch has been recorded in the Narmada Estuary over last few decades. Hilsa catch was recorded 5180 ton in 2006–07 that reduced to only 419 ton in 2014–15. Pre-impoundment of dam showed that T. ilisha contributed to the tune of 977.1 to 3727 ton from 1974–75 to 1982–83 and the highest catch of hilsa was 15319 ton during 1993–94. Sardar Sarovar Dam started functional in the year 1994 which has impacted natural water flow of the river and resulted in a reduction of freshwater availability in the estuary; the development of sand bars at the mouth of the estuary also reduced the tidal ingress into the system; low depth, loss of breeding, nursery and feeding grounds, over fishing may be the most important factors affecting hilsa fishery in Narmada estuary. Catching of juvenile hilsa during winter by ‘Golava’ net (small meshed bag net) also led to a rapid decline in hilsa catch. To maintain the sustainable yield of hilsa, selective fishing and control of juvenile catch are the prerequisites along with maintaining regular flow from the dam.

During the period (July 2014–June 2015) of investigation, 85 finfish species belonging to 65 genera, 35 families and 12 orders were encountered from 72 km stretch of Narmada estuarine region. The order Perciformes was found dominant (30 species) followed by Siluriformes (18 species), Cypriniformes (15 species), Clupeiformes (8) etc. Four species such as Tor tor, Wallago attu, Ompok bimaculatus and Ailia coila found under Near Threatened and Cyprinus carpio as a Vulnerable category during the investigation. During 2014–2015, the total fish production from Narmada estuary was 1618 tonnes and it exhibited a decline trend with species like Tenualosa ilisha, Tor tor, Labeo fimbriatus, Rita rita, Rita gogra and Notopterus notopterus being the most affected species. It could be attributed to various factors like the construction of dams, industrial effluents, domestic sewage, over fishing and habitat destruction. It needs suitable interventions for conservation of rich fish diversity of the estuary.

The present study explains the population structure and genetic diversity of medium carp Labeo gonius by analyzing partial sequence of mitochondrial DNA cytochrome b gene. Labeo gonius is a lower risk Near Threatened species, distributed throughout the North Indian major rivers, reservoirs and lakes. This species has a larger scope as an alternative candidate species in carp aquaculture system. In the present investigation, 223 individuals of Labeo gonius were collected from five locations of phylo-geographically isolated riverine ecosystems of India resulted in 12 haplotypes. These haplotypes showed 14 variables, out of which 9 were singletons and 5 were parsimony informative sites of nucleotide positions. The haplotypes H1 was considered as ancestral haplotype. All the haplotypes were connected to each other by 1-4 nucleotide mutations. The Narmada haplotypes (H10; H11 and H12) were isolated from H1 by four nucleotide mutations. The analyses resulted maximum expansion events (τ = 4.13672) in Narmada, with Fst scores more than other population pairs. The analysis of molecular variance (AMOVA) showed significant genetic differentiation among populations (ØST = 0.69470, p .000). The genetic differentiation patterns were significantly consistence with geographical distributions. This study rejected the null hypothesis of single panmictic population of medium carp, Labeo gonius in Indian water.

The length-weight relationships (LWRs) of Otolithoides pama (Hamilton, 1822) from the Hooghly-Matlah estuarine system of West Bengal were estimated. The study is based on 618 samples (298 male and 320 female) collected at monthly intervals for a period of 18 months (November 2016 to April 2018) from artisanal catch. No significant difference (p>0.01) was observed in growth rate for both the sexes. The ‘b’ values were estimated at 2.88, 2.84 and 2.86 with ‘r2‘values as 0.96, 0.95 and 0.95 for male, female and pooled samples respectively. The growth pattern was found to be negatively allometric. The month-wise mean ‘K’ value ranged from 0.70±0.07 to 0.78±0.07 for male and 0.71±0.05 to 0.89±0.11 for female. The length-wise estimated mean ‘Kn’ value varied from 0.92 to 1.17 for male and 0.76 to 1.29 for female indicating the moderately good condition of the fish in the study area. The results can be used for sustainable management and conservation of this commercially important species in this estuary

t In the present communication, an attempt has been made to review the ichthyofaunal diversity of the important Indian rivers such as Ganga, Brahmaputra, Mahanadi, Godavari, Krishna, Cauvery, Tapti, Narmada, Yamuna, etc. Secondary data in the form of research articles, technical reports, technical bulletins, books, etc., were reviewed, bulk of which were published by ICAR-CIFRI and a few other institutions. Among these rivers, the fish diversity of the Yamuna, the Gandak, the Kathajodi, and the Tons (Tamas) have been studied for the first time by ICAR-CIFRI. River Ganga was the most frequently studied river while the ichthyofaunal studies of the river Tapti was done in a gap of over 50 years. Similarly, the entire stretch of the river Cauvery was studied after a gap of 28 years. The study highlights the need to explore fish fauna of the whole stretches of the major rivers of India at regular intervals to build a comparable database that might be utilized by the stakeholders for research, planning and management activities. Key words Fish biodiversity, Ganga, Mahanadi, Godavari, Krishna, Cauvery

Temporal variations in selected bio-indices of length-weight relationships (LWRs) like relative condition factor (Kn), relative length of gut (RLG), hepato-somatic index (HSI), gonado-somatic index (GnSI) and gastro-somatic index (GaSI) of Nile tilapia (Oreochromis niloticus) were carried out in 341 samples collected at fortnightly intervals in East Kolkata wetlands, a Ramsar site. The exponent b value of LWRs was 2.9869, 2.8316 and 2.9163 with r2 value being 0.938, 0.936 and 0.935 for male, female and the pooled sample respectively showing negative allometric growth of the fish. The Kn values ranged 1.01 to 1.09 and 1.05 to 1.12 for male and female samples respectively exhibiting significant difference (p

The present study was conducted to isolate and characterise the genetic variations in Saprolegnia species and to study epidemiology of the fungal infection in rainbow trout hatcheries of Kashmir. A total of 145 infected fish samples were examined during October to March. The fungus infected trout showed signs of lethargy, irritation, loss of appetite, haemorrhages at the base of fins and deep wounds at the sites of severe infection associated with cottony wool like tufts on both dorsal and ventral side of body. Wet mount from infected lesions showed masses of mature and immature sporangia filled with spores of Saprolegnia. The colonies on fungal agar appeared with tufly of long hairs, whitish in colour that finally turned blackish after some days. The hyphae appeared profusely branched, aseptate and multinucleate. A total of 29 DNA samples were amplified by RAPD-PCR which revealed negligible genetic variations among the isolates indicating that a group of closely related strains of Saprolegnia having high degree of homology was present in the hatcheries of Kashmir. Key words Fungus, Fish, Cotton-wool disease, RAPD, Winter Introduction

The growth, mortality and exploitation status of Otolithoides pama collected from the Hooghly-Matlah estuarine system of West Bengal, India from November 2016 to April 2018 were estimated. The sample specimens were collected from the artisanal fishery, mainly from drift gillnets and bagnet with mesh size 15–70 mm and the length-frequency distribution was analyzed employing the FiSAT programme. The growth parameters L α , K and t 0 were estimated at 418 mm, 0.58 yr − 1 and -0.1356 years, respectively. The lengths of the fish at the end of 1st, 2nd, 3rd, 4th and 5th year were recorded as 202, 297, 350, 380 and 397 mm, respectively. The total mortality (Z), natural mortality (M) and fishing mortality (F) were 4.16, 1.14 and 3.02 yr−1, respectively. The exploitation level (E) was observed as 0.73 which surpassed the optimization value of 0.5 considered for sustainable fisheries. The present study revealed that the fishery is overexploited and calls for an urgent need to reduce the fishing pressure to accomplish a sustainable fishery.

Tade gray mullet (Chelon planiceps) forms a lucrative fishery in the Hooghly-Matlah estuarine system. During eight months of investigation 232 specimens were examined to study length-weight relationship and relative condition factor (Kn). The length and weight of fish was varied from 41 to 283 mm and 0.81 to 208 g respectively. Two length-weight relationship equations were obtained from the analysis, W=0.0000397L2.952 for 187 mm size group. The size at first maturity was recorded as 187 mm. The b value was not significantly different from 3 indicating isometric growth. The monthly mean Kn for the male and female were 1.041–1.125 and 1.009–1.236 respectively. The highest Kn value was recorded in July for both the sexes, which may be due to advance maturity stages. The present study will be useful in the context of biological management of mullet fishery as well as to find out aqua-farming potential of Tade gray mullet.