Egg collection and larval rearing of cephalopods- Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

Cephalopods are the largest, most active invertebrates. About 1, 17, 278 tonnes of cephalopods are exploited during 2003 in India (Annam et al., 2004). During 2002-2003 India has exported 41,381 tonnes of frozen cuttlefish and 37838 tonnes of frozen squid valued at US$ 166.2 million to countries such as Japan, USA and the European Union (Anon, 2003). Cephalopods are unique because they are 85% protein by dry weight (16-21% by wet weight) (Lakshmanan and Balachandran, 2000) and are considered a delicacy in seafood restaurants. Recent years have witnessed a significant amount of research interest in cephalopod culture, in order to develop technology for commercial farming as well as to produce multiple laboratory generations for research in neurobiology (Minton et al. 2001). They are highly promising biomedical models because of their giant axons and are of interest to neurobiologists. Squids 4 months old have giant axons larger than 450ìm in diameter. Studies have shown that the ultrastructure and physiology of these systems rival the sophistication of their vertebrate counterparts, the vestibular end organs and the vestibulo-oculomotor system. In detail, many parallels exist, e.g., the dynamic response characteristics (gain and phase lag values) of the cephalopod angular acceleration receptor systems are similar to those of the vertebrate semicircular canals, the putative transmitters in the afferent and efferent fiber systems are similar, and the cephalopod brain pathways involved in oculomotor control have vertebrate-like organizations. Thus, these systems are interesting invertebrate models that can substantially contribute to our understanding of the basic principles of morphology, physiology and pathology of these systems in higher vertebrates, including man. Choe and Oshima (1963) and Choe (1966) reared three species of the genus Sepia, the squid Sepioteuthis lessoniana and the sepiolid Euprymna berryi from egg to adult size