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Reproductive biology of Venus clam Gafrarium tumidum (Roding, 1798) from Southeast coast of India 总被引：1，自引：0，他引：1
The reproductive biology of tumid venus clam Gafrarium tumidum (Roding) was studied in detail from the Southeast coast of India. Sample size ranged from 10.3 to 41.3 mm. Sexes are separate but not differentiated externally. Annual sex ratio male:female (M:F) deviated significantly from the 1:1 ratio with females dominating. Based on ova diameter progression of gonad smear and histology, four and two maturity stages of gonads were differentiated in female and male clams, respectively. Peak spawning was observed during November and a minor one in April. The monthly average condition index based on wet/dry flesh weight ranged from 7.24 (November) and 14.14 (September) and 8.82 (October) and 14.38 (August), respectively. The condition index observed by both the methods is comparable and corresponds with the spawning season. Water content observed for male and female clams varied negligibly and showed positive correlation with spawning period. Size at first maturity was estimated to be 22.3 mm. 相似文献
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Lessons on broodstock maintenance,spawning, larval rearing and juvenile production of marine gastropods of ornamental value 
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下载免费PDF全文 Iyadurai Jagadis Mookaiah Kavitha Jaganathan Padmanathan Ashok Maharshi Arumugam Varadarajakumar 《Aquaculture Research》2017,48(5):2581-2592
Research on marine gastropod breeding in India is in its infancy and scanty literature is only available. To fill the lacunae, marine gastropods of three ornamentally valued and conservation important groups such as Cyprids, Strombids and Muricids were held under captivity and studied for their broodstock maintenance, spawning behaviour, larval rearing and metamorphosis into juveniles at the Shellfish Hatchery of Central Marine Fisheries Research Institute, Tuticorin. Valuable information on the focal themes of the article was obtained for Strombids and Muricids leading to the successful life cycle closing for Lambis lambis and Chicoreus virgineus are reported earlier. In the present study, experiments were conducted on aspects such as post‐metamorphosed juvenile rearing up to 76 days post hatch for L. lambis, spawning, larval development and life cycle closing and reasonable level of juvenile production (8.8%) for Chicoreus ramosus. In addition, the primary observations on the captive breeding of Cypraea tigris with reference to its egg mass, brooding habit and early development is reported. However, while studying these groups few unanswered questions and bottle necks in their breeding nature, larval rearing and metamorphosis arose. The following account details the experiments conducted and results obtained in each of the focal themes of the paper and the constraints faced. 相似文献
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Spawning and successful rearing of larvae of honeycomb grouper Epinephelus merra Bloch 1793 upto juvenile stage was accomplished at the finfish hatchery of Mandapam Regional Centre of Central Marine Fisheries Research Institute during 2004. The fertilized eggs were free, spherical and buoyant with size ranging from 710 to 730 μm. Complete early embryonic development took place within 24–27 h and hatching occurred. The hatchlings measured 1.5 mm. Mouth opening (115 μm) appeared at 72 h when the larvae were 2.2 mm in size. Pectoral fin developed on the fifth day. Complete metamorphosis took place and by the 60th day the larvae transformed into juveniles (45 mm) and attained skin colouration and honeycomb pattern. 相似文献
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