Experimental validation of periodicity of increment formation in the Statolith of bigfin reef squid Sepioteuthis lessoniana (Cephalopoda: Lolignidae) from tropical Indian waters

Abstract

Sepioteuthis lessoniana (Lesson, 1830) is a neritic squid that inhabits coral, rocky reefs, seaweed and seagrass beds of the IndoPacific region. Increment validation or the periodicity of increment formation in squid statolith is fundamental for age determination, longevity estimation and life history traits, hence it is critical for fishery management and species conservation. Although studies have established one-increment-per-day hypothesis in neritic squids, it has never been validated for tropical Indian Seas. Squids are the dominant component of fauna in the Indian waters, hence an investigation on the statolith increment formation was undertaken for S. lessoniana, as a representative of Loliginid squids