"Ventral adhesion" to hard substrates: A thigmotactic response in sepiid cuttlefish (Mollusca, Cephalopoda)

The adhesive "settling" response to hard substrates observed in young cuttl efish involves well defined dermal structures of the ventral surface of the mantle and ventral arms, which are able to act as a set of suckers. This b ehaviour, which was first described more than a century ago, is probably a common sepiid feature characterizing the early post-hatching phase. In some species, generally small to medium-sized, it is retained in the adult stag e. Ventral adhesion allows an individual to immobilize itself on a hard sub strate and thus resist the shearing forces of moving water. This paper repo rts on aquarium experiments demonstrating the efficiency of ventral adhesio n in newly hatched Sepia officinalis, provides some information on ventral adhesion in the dwarf cuttlefish Sepia pulchra and addresses the question o f the evolutionary origin of this behaviour.