FT Vol.39(1)
Permanent URI for this collection
Browse
Recent Submissions
- ItemRelationship between Development of Secondary Sex Characters and Androgenic Gland in Macrobrachium idella (Hilgendorf)(Society of Fisheries Technologists (India)Cochin, 2002)The secondary sex characters such as length of cheliped, length of appendix masculina and number of spines on it, and the width of vas deferens are under the control of the androgenic gland and have no relationship with the body size of the prawn, Macrobrachium idelk. Of the 30 individuals randomly selected, 22 had a body length to cheliped length ratio below 1:1.5. The size of the androgenic gland and appendix masculina were not fully developed in them, indicating that they are reproductively inactive. Remaining 8 individuals, having a body length to cheliped length ratio above 1:1.5, had well-developed androgenic gland and appendix masculina showing that there is positive correlation between the biomass of androgenic gland and the degree of development of secondary sex characters.
- ItemModified Extensive Culture of Penaeus monodon Using Indigenous Feed(Society of Fisheries Technologists (India)Cochin, 2002)Short-term monoculture of Penaeus monodon was done using an indigenously developed feed to evaluate the efficiency of the feed with respect to growth, survival, production, food conversion ratio and cost benefit ratio. P. monodon post-larvae were stocked at the rate of 5 nos.m"2 (12 mm; 7 mg) during 1995 and 3 nos.m 2 (15 mm; 10 mg) during 1996. The feeding schedule and other management practices were identical in both the trials. The . shrimps were harvested at the end of 85 days and a production of 732.5 kg.ha"1 (average size: 150 mm; 20 g) was obtained in 1995 and 647.5 kg.ha"1 (average size: 160 mm; 26 g) in 1996.
- ItemEffectiveness of Fish Aggregating Devices in Freshwater Reservoir Fishery(Society of Fisheries Technologists (India)Cochin, 2002)Two types of bottom set Fish Aggregating Devices (FADs), one of pyramidal shape and another of semi-prismatic shape were constructed using used tyres having a total outer surface area of 60 m2 . They were tested for their aggregating efficiency in an artificial freshwater reservoir stocked with freshwater carps such as catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigala) and silver carp (Hypopthalmicthys molitrix). The gill net catch around FADs and in non-FAD sites showed significant difference. Pyramidal FAD of 1.6 m height with tyres arranged in vertical orientation attracted more of surface feeders such as catla and silver carp compared to semi-prismatic FAD of 1.3 m height with tyres arranged in horizontal pattern. The gill net catch around pyramidal FAD was significantly higher than that of semiprismatic FAD. The use of pyramidal FAD to improve catch per unit effort of gill netting in perennial reservoirs of the country, is suggested
- ItemEffect of Square Mesh Panels on Catches of Stationary Bag Net in Hooghly Estuary(Society of Fisheries Technologists (India)Cochin, 2002)Effect of incorporation of square mesh panels in stationary bag nets operated in Hooghly estuary (West Bengal) on fish landings was studied through comparative fishing experiments. The results showed that catches of juveniles of prawns and finfishes was significantly lower in the experimental gear with square mesh panels of 20 mm bar mesh size, compared to the control net. 50% retention lengths (L ) of Metapenaeus sp. and Macrobrachium mirabk, Macrobrachium lamerri and sciaenids were also higher in the experimental bag net compared to the control net. Results indicated that provision of square mesh panels in bag nets would help in the conservation and management of estuarine fishery resources
- ItemEffect of Plant Proteins in Iso-caloric Feeds on Growth Performance of Freshwater Prawn Macrobrachium idae (Heller)(Society of Fisheries Technologists (India)Cochin, 2002)Macrobrachium idae juveniles (0.9 - 1.3 g) were fed on eight formulated diets containing 32-42% crude protein to assess their growth performance. Prawns fed on groundnut oil cake meal (GOC) and soybean meal (SBM) showed the best growth rate (SGR) (0.46 and 0.43%.day"1, respectively), food conversion ratio (FCR) (2.16 and 2.53, respectively) and protein efficiency ratio (PER) (0.84 and 0.78, respectively). Hydrilla verticellata (HV) and drumstick leaves (DRM) diets resulted in poor growth and decreased PER and SGR with elevated FCR. The efficiency of absorption and net conversion ranged between 84-90% and 3.81-7.8%, respectively. Increase in dietary protein content (3-8%) produced elevated growth rates and protein efficiency ratio. The dietary protein-energy ratio for maximum growth of prawns was 97.2 mg.kcal"1 with a digestible energy of 431 kcal.lOOg"1 of feed