T. Francis ¹, C. B. T. Rajagopalsamy ¹, N. Jeyakumar ¹, M. Venkatasamy ¹, C. Archana Devi ¹

Affiliations
1 Department of Fisheries Biology & Resource Management, Fisheries College and Research Institute, Thoothukudi, 628008, IN

Abstract

No Abstract

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T. Francis ¹, C. Archana Devi ¹, M. Selvamagheswaran ¹

Affiliations
1 Department of Fisheries Biology and Resource Management, Fisheries College & Research Institute, Thoothukudi – 628008, Tamil Nadu, IN

Abstract

A successful cryopreservation method would offer many advantages to an aquaculturist. Cryopreservation can provide a year round supply of seeds from desired species regardless of the spawning season and allow hybridization, greater ease in carrying out selective breeding and stock improvement. Studies were conducted on cryopreservation of spermatozoa from Indian major carps. Effect of different concentration of glycerol and equilibration periods on the post thaw motility of spermatozoa from Catla, Rohu and Mrigal were observed. The maximum motility (80 - 85%) was observed with the equilibration period of 20 - 40 minutes with the concentration of 10-15% of glycerol. Rohu showed the same trend with the maximum motility of 78-87%. In Mrigal maximum motility (85-88%) was observed with the equilibration time of (20-40 minutes) with the concentration of glycerol in between (10-15%). Like glycerol, the same type of experiment was conducted with Dimethyl sulphoxide (DMSO). Post thaw motility of cryopreserved spermatozoa in DMSO showed the same way as glycerol. Apart from the above, percentage of motility of spermatozoa was observed with respect to different thawing temperatures. Maximum motility was observed at the thawing temperature of 40oC in catla (85%), Rohu (80.00%) and Mrigal (83%). Interesting results were obtained from the fertilization studies of cryopreserved spermatozoa of Catla with the eggs from the matured Catla breeders. Fertilization rate of 75-80% and the hatching rate of 60% was observed from the above study. From the above results, it could be possible to use cryopreserved spermatozoa for commercial production of fish seeds in fish hatcheries.

Keywords

Cryopreservation, Catla, Rohu, Mirgal, DMSO, Fertilization Rate

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Mohamed Faizullah ¹, C. B. T. Rajagopalsamy ¹, B. Ahilan ¹, T. Francis ¹

Affiliations
1 Fisheries College and Research Institute, TNFU, Thoothukudi, IN

Abstract

In the present study, the impact of biofloc technology on the growth of goldfish young ones was investigated. In the mean value of water temperature, pH, dissolved oxygen, ammonia-N, nitrite-N, nitrate-N and Floc Volume (FV) in biofloc treatment system where goldfish young ones were reared was 25.5oC, 7.9, 3.4 mg/l, 51.92 μg-at-N/l, 1.15 μg-at-N/l, 364.52 μg-at-N/l and 5.25 ml/l respectively. The control set registered the mean value of water temperature (28.6oC), pH (8.1), dissolved oxygen (3.9mg/l), ammonia-N (64.96μg-at-N/l), nitrite-N (2.42μg-at-N/l), nitrate-N (165.22 μg-at-N/l) and FV (0.24ml/l) more than the treatment excepting the nitrate-N and Floc volume. Chlorella sp., Oscilatoria sp., Stephanodiscus sp., Coscinodiscus sp., Navicula sp., Amphiprora sp., Nitzschia sp., Chaetoceros sp., Cyclotella sp., Triceratium sp., Cymbella sp., Stentor sp, Paramecium sp, Cyclidium sp, Peranema sp, Petalomonas sp, Rotifer, Nematode or round worm, Chaetonotus sp. and Cyclops sp. were observed in the biofloc treatment tank while the control tank had only Chlorella sp., Coscinodiscus sp. and Chaetoceros sp. The maximum SGR (25.78) was observed in biofloc treatment while in control the same was 22.87. 91.8 percent survival rate was registered in the young ones of Goldfish reared under biofloc treatment. 52.88 percent growth increment was recorded in goldfish young ones under biofloc treatment when compared with the control.

Keywords

Biofloc, Goldfish, Growth and Survival, Length Weight Relationship, Proximate Composition

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R. Saravanan ¹, P. Jawahar ², T. Francis ², B. Ahilan ², R. Santhakumar ², A. Anand ³

Affiliations
1 Regional Centre of Central Marine Fisheries Research Institute, Mandapam Camp, Ramanathapuram District - 623 520, Tamil Nadu, IN
2 Fisheries College and Research Institute, Thoothukkudi – 628 008, Tamil Nadu, IN
3 Regional Remote Sensing Centre–Central (ISRO), Nagpur - 440 010, Maharashtra, IN

Abstract

The present study was conducted to find out whether the abiotic factors in Gulf of Mannarviz., Sea Surface Temperature (SST) and Day light photoperiod would have an effect on the Gonado somatic index of the dominant sea urchin species Salmacis virgulata. A sampling survey for 20 months was conducted from October-2013 to May-2015 in Vedalai landing centre, along the Gulf of Mannar. The freshly collected sea urchin were brought to Mandapam CMFRI and their Gonado Somatic Index (GSI) was estimated. The remote sensing data of the SST from Gulf of Mannar sourced from ICOADS and the daylight photoperiod were compared with the GSI data for 20 months in order to assess the synchrony among the three parameters. The pearson correlation coefficient of the association among the GSI, SST and Photoperiod revealed that there was no significant correlation (p>0.001). The result of the present study revealed that the Gonado Somatic Index of S. virgulata is independent of abiotic factors, which is in contrast to the temperate sea urchin species, where SST and Photoperiod play a major role in gonadal development.

Keywords

Gonad Index, Gulf of Mannar, Sea Urchin, Salmacis

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N. Jayakumar ¹, T. Francis ¹, P. Jawahar ¹, C. B. T. Rajagopalsamy ², R. Santhakumar ³, A. Subburaj ¹

Affiliations
1 Department of Fisheries Biology and Resource Management, Fisheries College and Research Institute, Tamil Nadu Fisheries University, Thoothukudi – 628008, Tamil Nadu, IN
2 Department of Inland Aquaculture, IN
3 Department of Fisheries Extension, Fisheries College and Research Institute, Tamil Nadu Fisheries University, Thoothukudi – 628008, Tamil Nadu,, IN

Abstract

Background / objective: The heavy metal, Cadmium enters aquatic environment through natural / anthropogenic sources and exerts deleterious effects in fish. Hence, the present study is aimed at investigating the acute Cd toxicity induced histological alterations in the liver and kidney of catfish, Heteropneustes fossilis. Methods: The bioassay was performed in a static renewal regime with H. fossilis exposing to varying acute toxicity concentrations viz., 18.45, 36.9, 73.7, 147.4 and 294.8 mg/l for 96 h. The LC50 was determined to be 44.13 mg/l. Since 100 % mortality occurred in the highest concentrations after 96 h, liver and kidney tissues were collected from fish exposed to the first three lower concentrations. Standard histology protocol was followed to study the histological alterations. Findings: The histological alterations like increased kupffer cell and pycnotic nucleus, ruptured hepatic tissue and nucleus, cellular necrosis and focal necrosis were observed in the liver of fish exposed to Cd. Similarly, vacuolation, increased periglomerular and peritubular space, shrunken glomerulus, melanomacrophages and loss of cytoplasm were observed in the kidney of fish treated with Cd. The intensity of the histological alterations in both liver and kidney was found to be concentration and duration dependent. Hepatic tissues were found to be ruptured in the liver of fish exposed to all the three concentrations viz., 18.45, 36.9 and 73.7 mg Cd/l. The appearance of melanomacrophage aggregates is a generalized non-specific marker, indicating environmental stress. In the present study, melanomacrophages were observed in kidney of fish exposed to 36.9 and 73.7 mg Cd/l. Our present observations on histological alterations in the liver and kidney of H. fossilis were in conformity to the histological observations made in the liver and kidney of various fish species exposed to different toxicants. Applications: The histological alterations in liver and kidney H. fossilis induced by Cd suggest that Cd can be a potential toxicant and hence these alterations can be used as biomarkers to monitor aquatic pollution.

Keywords

Acute Toxicity, Cadmium, Histology, Heteropneustes fossilis, Kidney, Liver

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