FAO Species Identification Guide for Fishery Purposes Western

756 Cephalopods
Sepiella inermis Férussac and dOrbigny, 1835
Frequent synonyms / misidentifications: Sepia
(Sepiella) microcheirus Gray, 1849; Sepia affinis
Eydoux and Souleyet, 1852; Sepiella mandroni
Rochebrune, 1884 / None.
FAO names: En - Spineless cuttlefish; Fr -Sepia
inerme; Sp - Sepia inerme.
dorsal view lateral view
cuttlebone
(after Adam, 1939)
ventral view
dorsal view
Diagnostic characters: Arms in both sexes with tetraserial
suckers. Hectocotylus present, suckers reduced and widely
spaced on proximal half of club. Tentacular club with 12 to 24
equal-sized suckers in transverse rows; swimming keel
shorter than sucker-bearing face of club; dorsal and ventral
protective membranes not fused at base of club, extending
proximally along stalk as low ridges. Cuttlebone width
approximately 33 to 43% the length; spine absent; sulcus
extending entire length of cuttlebone; anterior striae m-shape;
outer cone chitinous, flared, spoon-shaped, indented at posterior
end of striated zone. Colour: dorsal mantle greyish brown with
8 or 9 reddish patches along base of each fin.
tentacular club
hectocotylus
(after Adam, 1939)
Size: Maximum mantle length 125 mm. In the Gulf of Thailand, most animals caught range between 20
and 80 mm mantle length, with the maximum size recorded at 105 mm mantle length.
Habitat, biology, and fisheries: A demersal, shallow-water species, depth range to 40 m. Probably a species
complex. Highly abundant in the Gulf of Thailand, and Andaman Sea, it occurs from the shallows to a depth of
40 m, with most caught between 10 and 20 m. Sepiella inermis is an object of several small fisheries in the waters
of Indochina. It is important to the commercial cuttlefish fishery in Thailand. Cuttlefish in this region are usually
caught using squid light lures, traps, push nets, purse seines and hook-and-line. This species has been reared
successfully in culture
experiments conducted by the
Thai Coastal Culture Division,
Department of Fisheries and
there is hope to convert this
work to a commercial basis.
Distribution: Mouth of
Zambezi River (Mozambique),
Indian Ocean, southern Red
Sea, Gulf of Aden to Andaman
Sea, eastern Indonesia, the
?
Gulf of Tonkin and the
southern South China Sea.