FAO Species Identification Guide for Fishery Purposes Western

Sepiidae 749
Sepia plangon Gray, 1849
Frequent synonyms / misidentifications: Solitosepia plangon
adhaesa Iredale, 1926 / None.
FAO names: En - Striking cuttlefish.
Diagnostic characters: Left ventral arm (IV) of males hectocotylized:
5 rows of normal suckers proximally, followed by 5
rows of reduced suckers then remainder normal to arm tip;
reduction slight, suckers equal sized across series; oral surface
as for remaining arms, not wide, fleshy. Tentacular club suckerbearing
face flattened; with 5 suckers in transverse rows, differing
markedly in size; swimming keel extends well beyond suckerbearing
face; dorsal and ventral protective membranes fused
at base of club; joined to stalk at base of club, not separated from
stalk by a membrane; protective membranes extend beyond
sucker-bearing face along stalk, dorsal membrane forming deep
cleft at junction with stalk. Cuttlebone blunt-pointed anteriorly;
rounded posteriorly; dorsal median rib distinct, sides approximately
parallel; lateral ribs indistinct; spine present, with ventral keel;
striated zone concave, last loculus flat; sulcus extending length of
cuttlebone, deep, narrow, flanked by rounded ribs (giving striae
a wavy appearance); anterior striae inverted V-shape; inner cone
limbs of uniform width; outer cone narrow anteriorly, broadens
posteriorly. Colour: deep purplish brown.
Size: Maximum mantle length 135 mm.
Habitat, biology, and fisheries: Intertidal to a depth of 83 m. Taken
as bycatch of prawn and mixed species trawl fisheries.
Distribution: Eastern Australia.
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10 mm
ventral view
cuttlebone
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