Cistopus Gray, 1849

Sreeja, Vijayamma, Norman, Mark D. & Kumar, Appukuttannair Biju, 2015, A new species of pouched octopus, Cistopus Gray, 1849 (Cephalopoda: Octopodidae) from the southwest coast of India, Zootaxa 4058 (2), pp. 244-256 : 245

Genus Cistopus Gray, 1849

Type species: Octopus indicus Rapp, 1835 in Ferussac and d’Orbigny, 1834 –1848.

Diagnosis (slightly modified from Norman et al. 2014). Moderate to large species. Mantle ovoid to elongate. Stylets long, non-mineralized. Arms long, up to 6 times length of mantle, dorsal arms longer than ventral pair (arm formula 1>2>3>4). Arm autotomy at distinct plane absent. Webs of moderate depth ~15 to 20% of longest arm, dorsal web deeper than ventral web (WF typically A=B>C>D>E). Interbrachial web pouches present on oral surface of webs close to mouth; pores located at level of 3rd to 4th proximal sucker. Suckers in two rows. Enlarged suckers present on arms in mature males of at least three member species. Funnel organ W-shaped. Gills with 9 to 11 lamellae per demibranch. Radula with 9 elements, 7 rows of teeth plus marginal plates. Posterior salivary glands moderate to large, slightly larger than buccal mass. Distinct crop present as side-branch off oesophagus. Ink sac present. Anal flaps present. Third right arm of male hectocotylised, around two thirds length of opposite arm. Ligula a tiny blunt stump (~0.5% of arm length), calamus present or absent. Spermatophores of moderate length, unarmed. Egg size small to large (species dependent).

Colour typically uniform grey to pink, iridescent pink on lateral and ventral mantle in at least one species. Live animals capable of displaying dark maroon colour in at least one species. Skin smooth with few, scattered, low papillae on dorsal mantle. Primary papillae absent. Skin ridge around lateral margin of mantle absent.