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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