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Pink ear emperor, Lethrinus lentjan (Lacepede, 1802), belonging to the family Lethrinidae (oder: Perciformes) is an important food fish in India, Arabian Gulf and other South East Asian countries. The present communication gives detailed information on its captive broodstock maturation in RAS, natural spawning, larval rearing and seed production for the first time. Fertilized eggs (714.21 ± 11.91 μ) were transparent, pelagic, non-adhesive with single oil globule (146.63 ± 3.51 μ). Green water system was used for larval rearing. Size of hatchling ranged from 1355.1 μ to 1534.6 μ and mouth (110–148.2 μ) opened on 2nd dph. Larvae were reared using copepods, rotifer, artemia and micro diet. Squamation and intense pigmentation on the body began by 22 dph and by 25–30 dph larvae started moving from pelagic to benthic realm. Larvae became juvenile (length – 19.2 mm; weight – 0.096 g) after 35 dph resembling the adult fish colourations and by 46 dph, they attained an average body length of 27.83 mm and average body weight of 0.276 g. Fishes spawned throughout the year in RAS without any hormonal manipulation. Average percentage survival at seed stage was 2.85 ± 1.41.

Marcia's anthias, Pseudanthias marcia Randall and Hoover, 1993, belonging to the subfamily Anthiinae (family: Serranidae) is a highly sought after marine ornamental fish mainly due to its vibrant pink shade. The present study reports the first successful captive brood stock development, spawning, and larval rearing of P. marcia. Brood stock was developed in a 5-ton recirculation aquaculture system (RAS) using 12 wild caught juveniles. After 6 months of rearing, the fish (8–9.5 cm size) started courtship behavior. Spawning occurred at 1900 to 2100 h. The eggs (mean size - 617.9 ± 14.9 μ) were transparent, pelagic, non-adhesive and with single oil globule. The eggs hatched out after an incubation period of about 14–16 h at a water temperature of 29 °C. Newly hatched larvae measured 1206.6 ± 100.02 μ in total average length and increased to 1852.9 ± 24.68 μ at 48 h post hatch (ph). Mouth opened at 48–50 h post hatch (ph) and measured 76 to 80 μ. Larval rearing trials were conducted using rotifer (L and S type), wild zooplankton, copepod nauplii, artemia nauplii and microparticulate diet. Primordial fin development started by the 10th day post-hatching (dph) (larval size ~2.9 mm) while the opercular and dorsal spines were fully formed by 15 dph (total length of the larva was 4.4 mm). Larvae metamorphosed to miniature adult shape by 32–34 dph and on 50 dph they reached the pink colored juvenile stage (42–43 mm) and at this stage, they were transferred to nursery rearing tank. Four treatments with different feed combination were tried and treatment III with wild copepod gave an average survival of 5.2 ± 1.07% and treatment IV with Parvocalanus crassirostris gave an average survival of 7.3 (±2.51) %.

A new species of Apocyclops Lindberg (Cyclopoda: Cyclopoida: Cyclopidae) is described based on specimens collected from marine waters of Karwar, Karnataka, India. At present, there are 11 valid and accepted species excluding one extinct species (fossil) in this genus which are widely distributed in fresh and brackishwater areas in the tropics and subtropics. Five valid species of Apocyclops are reported from the Asian region, including two species from India. The new species is closer to the previously reported Indian species, A. royi (Lindberg) and A. dengizicus dengizicus (Lepeshkin). Apocyclops cmfri sp. nov. differs from these in the size of caudal rami, in the characteristic shape of disto-medial part of coxa and basis of first to fourth pleopods (P1-P4) and in the presence of a single broad spinous expansion with a pointed tip in between exopod and endopod in basis of P1 to P4. Only one terminal spine is present in the second segment of endopod of P1. In P2 to P4, both exopod and endopod terminate in a spine and a seta of almost equal size. Maxillule highly dentate and maxilla basis form a large dentate claw with inner serration. All these characters form distinct identification features of the new species in comparison with the 12 accepted species under the genus. A key to all the species of the genus including the newly described species is proposed here. Molecular identification of the new species was carried out by mitochondrial cytochrome c oxidase 1 (CO1) gene sequencing and the sequence was submitted to NCBI, GenBank. Genetic differentiation and divergence between A. cmfri sp. nov. and species belonging to other closely related genera; Thermocyclops, Mesocyclops and Eucyclops were compared using CO1 gene sequences. The new species belonging to Apocyclops showed significant divergence from Apocyclops borneoensis with K2P value of 10.2% and from species under the genera Mesocyclops, Thermocyclops and Eucyclops with K2P values of 26.6, 27.5and 34.9% respectively.

Trawl fisheries sector account more than 50% of the marine fisheries production of India. Annual average fish landing from trawlers was 17, 21, 000 t (2008-2011), which formed around 51 % of the marine fish landing of the coast. In this about 51% of the catch was contributed by the west coast and remaining by the east coast of India. Recent studies of the trawl fishery in India have shown that incidental catches/low value bycatch (LVB) landing and utilization has increased over the period of time. The present study is based on the data collected from major trawl landing centres along the coast of India during the period 2008-2011.The estimated landing of low value bycatch (LVB) in trawl fisheries, increased from 14 % in 2008 to 25 % in 2011, which is reflected as reduction in discard volume by trawlers. On an average the highest quantity of LVB landed was in Veraval (50,000 t) and in Mangalore, LVB landing increased from 3% in (3000 t) in 2008 to 26 % (12,000 t) in 2011.In Mumbai, the percentage of trash fish landed remained around 5% during the study period. In Calicut, the LVB landed in 2011 contributed 26% to the total landings by the trawl. In Kochi, Kerala the total LVB landed in 2011 was 1,992 t forming 7.2 % of the total landing. In Chennai, Tamilnadu, the LVB landing which was 13 % in 2008 increased to 17% in 2011, while in Visakhapatanam, Andhra Pradesh, LVB landing showed a steady increase from 2% in 2008 to 21% in 2011. The landing centre price for LVB showed an increasing trend due to increased demand for trash fish for the production of fish meal and fertilizer. The dominance of finfishes in LVB found to increase the value of LVB and the value realized for 30,000 t of LVB in

An experimental study was carried out to evaluate the efficacy of three commercially available probiotics P1, P2 and P3 consisting of mainly Bacillus spp. and nitrifying bacteria against Vibrio loads in mass culture tanks of the rotifer Brachionus plicatilis. Triplicate tanks were maintained for each of the probiotic treatment as well as for control group. All the tanks were inoculated with 50 rotifers ml-1 and were fed with Nannochloropsis oculata at a density of 1 x 107 cells ml-1. Every alternate day, all the experimental tanks were treated with probiotics at a concentration of 1 x 104 cfu ml-1 and the experiment was carried out for one week. The study showed a significant increase in rotifer density (p

Effect of marine microalgal diet on filtration and ingestion rates of Brachionus plicatilis was studied. Marine microalgae viz., Nannochloropsis oculata, Isochrysis galbana, Chaetoceros calcitrans and a combination of N. oculata and I. galbana (Nanno+Iso) at different cell concentrations were selected for the experiment and triplicates were maintained for each feed. Significant difference (p

Growth rates of cage cultured Asian seabass Lates calcarifer (Bloch, 1790) and cobia Rachycentron canadum (Linnaeus, 1766) in relation to the water and sediment quality of marine farm at Karwar for two consecutive crops (2012-13 and 2013-14) were analysed. No significant variation was observed in the specific growth rate (SGR) of both the species between the crops. But within a crop, variations were observed in the SGR and absolute growth rate (AGR) of both the species (p

Broodstock of the John’s snapper Lutjanus johnii were raised in sea cages from wild collected juveniles of the species. Individual fishes were tagged using passive integrated transponders (PIT), cannulated and gonadal biopsies were examined periodically for assessing the maturity status. The matured fishes were shifted from cages and maintained in indoor FRP tanks. Females were given two doses of human chorionic gonadotropin (hCG) and ovaprim @ 800 - 900 IU kg-1 and 1.25ml kg-1 respectively. Males were given only hCG in a range between 400 and 600 IU kg-1. Two successful spawning were obtained with 80-85% fertilisation rate. In both the trials, embryonic development was observed to be arrested before hatching which could be attributed to nutritional deficiency of the broodfishes and high water temperature in the spawning tank.

Investigations were carried out on the bacterial flora of water and the quality of rotifers in outdoor mass culture tanks. Brachionus plicatilis and B. rotundiformis were cultured in 10 numbers of 1 tonne tanks and the physico-chemical parameters and microbial loads of water, and total bacterial and Vibrio loads of microalgae and rotifers, during the period 2014-15, were studied. The study revealed a significant variation of the ammonia levels and total bacterial loads with different diets (P < 0.05). A positive correlation was observed between the total bacterial loads of algal concentrations and loads of rotifers, but no correlation was observed between Vibrio loads of water and rotifers. The prevalence of Vibrio loads of rotifers was low in tanks fed with Nannochloropsis oculata and maximum Vibrio loads were recorded in Chaetoceros calcitrans fed rotifers. The Vibrio loads significantly varied with days of culture and also with the algal diets. A positive correlation was observed between the total Vibrio loads of water and rotifers.

Asian seabass (Lates calcarifer) has been designated as a candidate species for open sea cage culture in India. A case of vibriosis in Asian seabass reared in open sea floating cages is reported. Haemorrhage and ulcer were observed grossly in the diseased fish. The pathogen, identified as Vibrio alginolyticus based on biochemical and molecular characterization, was isolated from liver, gill, kidney, brain and blood. Histological examination of the diseased fish showed congestion, haemorrhage and necrosis in vital organs. The LD50 studies showed that the organism was virulent to Asian seabass, and the LD50 value was 103.2 CFU g1 fish.

Stocking density is an important factor in cage aquaculture of finfish. Effects of high stocking density (35 fish cubic m(-1)) on a range of biochemical and immunological parameters in Asian seabass reared in open sea floating net cages were compared to fish held in relatively low density (15 fish cubic m(-1)). The results revealed that chronic stress due to high stocking density induced variations in most of the parameters studied as evidenced by increased cortisol and glucose levels and decreased activity of lysozyme, myeloperoxidase and complement. Production of reactive oxygen species, total leucocyte count and total serum protein were also decreased, whereas anti-protease, alkaline phosphatase and acid phosphatase activities were increased in high stocking-density group when compared to low stocking-density group. Effects of chronic stress due to high stocking density were discussed in relation to variations in these parameters.