Studies on Egg Morphology, Availability and Hatching of Four Species of Cephalopods along Vizhinjam Coast, Kerala

Availability and characteristics of cephalopod egg mass along the Vizhinjam coast was studied and peak availability of egg mass of  squids  Uroteuthis (Photololigo) duvaucelii, Sepioteuthislessoniana, was noticed during August to October, whereas, the peak availability of egg mass of  cuttlefishSepiellainermis, and Sepia pharonis was noticed during December to February. Egg clusters of Uroteuthis (Photololigo) duvaucelii, Sepiellainermis, and Sepia pharoniswereobtained from shore seine catches, whereas the egg mass of Sepioteuthislessoniana was found attached to coconutspadices and nylon ropes hung from rafts moored at Vizhinjam bay. Eggs of Uroteuthis (Photololigo) duvaucelii were encased in gelatinous, whitish, transparent, club shaped capsules. The egg capsule measured4.5 - 6cm in length and 1.5-2cm in width, contained 120-130 eggs. It took total of 8 days for complete hatching. Egg cluster of Sepioteuthislessoniana consisted 50-70 creamy white, slender, finger like capsules. Length of the egg capsules ranged from 5.3-9.2cm, whereas, the width 1.2-2.2cmand contained 4 to 9 eggs organised in a well-spaced single row. Maximum period of incubation was 21 days and hatching period was 17 days. The eggs of Sepia pharonis were creamy white coloured, opaque and lozenge or ovoid in shape.  The length of the capsules on the first day was2cm -2.5cm and width was 1.4 -1.8 cm.Total incubation period recorded in case of Sepia pharonis was 22 days and period of hatching was 11 days. The eggs of Sepiellainermiswere ovoid, lozenge shaped, with a proximalthin stalk and a conical protruberance at its tip. Eggs of Sepiellainermis were externally covered by a multilayered elastic, gelatinous coating and it was pigmented black. Maximum incubation period of S. inermis was16 days and hatching period was 5 days.