Migration and spawning behaviour of the pharaoh cuttlefish Sepia pharaonis Ehrenberg, 1831 along the south-west coast of India

Abstract

The area west of Kollam (38-51 m depth) and south-west of Cochin (38 – 45 m depth) seems to be the preferred region for spawning of the pharaoh cuttlefish Sepia pharaonis along the south-west coast of India. Juveniles appear to stay for some time in the spawning ground and then undertake offshore migration towards relatively deeper areas of the Wadge Bank in 117-132 m depth range. This migration appears to take place via west of Vizhinjam in the depth range of 60 - 86 m. Fecundity varies from 146 to 1400 eggs, depending upon the size of the animal. S. pharaonis appears to spawn intermittently with group-synchronous ovulation. Spawning appears to be monocyclic and egg-laying occurs in separate batches during the spawning period. Egg capsules are either inserted in to the muddy substratum or fastened on the preferred objects apart from entangling with each other.