Revival of short neck clam Paphia malabarica Chemnitz, 1782 In Kali

estuary, Karwar, Karnatak

Dube, Praveen

Philipose, K K

Sadhu, N

Sharma, S R Krupesha

Sadhu, Narasimhulu

CMFRI Digital Repository

Marine Fisheries Information Service T&E Ser., No. 216, 2013 9Fig. 1. Female broodstock of Epinephelus tauvina in cageFig. 2. Intra-ovarian biopsy (cannulation) of Epinephelustauvina to assess the maturityFig. 3. Female fish with intra- ovarian ova of diameter >450µ (10 x)is the most important prerequisite for successfulproduction of seeds of any finfish or shellfish in ahatchery. The availability of high quality spawnersof both the sexes in sufficient numbers and in goodcondition is a primary concern in broodstockdevelopment and maintenance. This involvesdevelopment of male brooders and improvementof the quality of female brooders.Attempts were made at the VisakhapatnamRegional Centre of CMFRI for broodstockdevelopment of the wild collected adult groupers(2.0 -5.0 kg). Groupers when hauled up from theirhabitat, gulp in air and usually are landed in abloated condition due to the air filled in bladders.After reaching the hatchery the fishes weredegassed and given prophylactic treatment with 200ppm formalin for 30 minutes and freshwater dipfor 5 minutes and then transferred to HDPE cagesmoored off Visakhapatnam (Fig 1). The fishes werePIT tagged and history of individual fish wasmaintained. The fish were fed twice a day with squidand trash fish fortified with Vitamin E, Vit-Min mixetc. Maturity stages of female broodstock wereexamined (Fig. 2) every month by intra-ovarianbiopsy (IOB) and those with ova diameter >450 µ(Fig. 3) were used for induced spawning.Foreign objects observed in the stomach of a cobia (Rachycentroncanadum) reared in sea cage at KarwarKrupesha Sharma S. R., Narasimhulu Sadu, Praveen Dube and Philipose K. K.Karwar Research Centre of CMFRI, KarwarA cobia (4.5 kg, 40 cm) reared in the grow-outcage of Karwar Research Centre of CMFRI was founddead on 15 March 2012. Externally, erosion onpectoral and caudal fins was found. Internally,stomach portion of the alimentary canal wasenlarged. When the stomach was cut open, a betelnut (5 cm diameter) and a small plastic pouch werefound inside (Fig. 1). The stomach was filled withmucus and the wall was extremely hypertrophied(Fig. 2). In the wild, cobia fish are fast swimmingMarine Fisheries Information Service T&E Ser., No. 216, 201310Fig. 1. Presence of a betel nut and a plastic pouch in thestomach of cobiaFig. 2. Hypertrophied stomach wall of cobiacarnivores that feed on a wide variety of fishes,cephalopods, and crustaceans, especially crab.Cobia often follow sharks, turtles and manta rays inhope of scavenging a meal. The present findingreveals that under confinement, the fish becomesindiscriminate eaters, feeding even onanthropogenic wastes.A simple and portable seawater filtering device using pipette fillerAnasukoya A. and Kaladharan P.Calicut Research Centre of CMFRI, Westhill P.O., Kozhikode -673 005Filtration of seawater from the intertidal andcoastal areas for separating chlorophyll pigmentsor particulate organic matter (POM) requiresvacuum and for creating vacuum, a suction pumpoperated using AC/DC is essential. From the fieldor sea, large quantities of water samples have tobe saved, brought to the laboratory and preservedby freezing until the filtration. Seawater filtrationin remote areas with no power supply or portablesuction pump is difficult but can be made possibleby deploying a simple device involving filtering flask,a rubber hose and a safety pipette filler.Requirements1. Filtration funnels with magnetic base (300 ml,Gelman Sciences Inc)2. Glass fibre filter paper (GF 52, Schleicher &Schuell)3. Vacuum filtering flask with a glass hoseconnection- (1000 ml, Merck- 0101730)Fig. 1. Thearrangement of thefiltration unit4. Safety pipette filler (Cole - Parmer KH- 24805-10)5. Rubber hose (10 mm dia., 25 cm long)ProcedureConnect one end of rubberhose with the side arm offiltering flask and the otherend with safety pipette fillerby inserting the hose about0.5 cm as shown in the Fig. 1.Place GF filter paper inbetween filter funnel andmagnetic base and place itover the flask. Pour knownquantity of seawater on thefiltering funnel. To createvacuum for suction ofseawater, press the filler bulb to expel the air andthen squeeze the valve with the thumb and the indexfinger. Repeat this for 3-5 times until sufficient

Foreign objects observed in the stomach of a cobia (Rachycentron canadum) reared in sea cage at Karwar

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