The data comes from O. cyanea derived from visual strip transects and commercial catch sampling carried out around Agatti and Kavaratti islands (Arabian Sea) during three survey periods between November 2008 and 20 April 2012. Given that octopus fisheries in these islands are constrained by depth owing to the nature of spear-fishing and gleaning techniques (Silas et al., 1985; Appukuttan et al., 187 1989), we surveyed only the lagoon and intertidal areas of the two islands. The depths of the surveyed areas varied from 0.5 to 3 m. Mantle length (ML = dorsal mantle length) was measured using a 1 mm graduated 210 tape and weight (TW = total body weight) was obtained using a spring balance graduated with 50 g intervals.