FAO Species Identification Guide for Fishery Purposes Western

798 Cephalopods
Chiroteuthidae CHIROTEUTHIDAE
Chiroteuthid squids
by M.C. Dunning
Diagnostic characters: Small to mediumsized
squids (less than 400 mm mantle
length) with somewhat gelatinous bodies. Characterized
by an oval mantle-funnel locking apparatus,
the funnel cartilage with 1 or 2 knobs
projecting towards the centre of the cavity.
Arms with biserial, toothed suckers; ventral
pair (IV) greatly enlarged. Some species possess
very elongate tentacles (up to 5 times the
mantle length) and distinctive clubs with
tetraserial suckers on long stalks. Buccal
connectives attached to ventral border of ventral
arms. Abundant light organs present along
tentacle stalks and ventral arms; large light organs
also present ventrally on the eyes, at the tips
of the tentacular clubs, and embedded in the ink
sac on both sides of the intestine.
Habitat, biology, and fisheries: Although considered
to be predominantly oceanic, Chiroteuthis
imperator was taken recently in demersal
trawls in continental slope waters at depths from
300 to 600 m off northern Australia and is also
caught in “jala-oras”, light-lured surround nets, in tentacular
Indonesian waters. In deeper oceanic waters, club
adult Chiroteuthis apparently occur below 500 m
during the day but are distributed throughout the
water column during the night. Diel vertical migration
is also evident in some species. Nothing is
known of the life history biology of these species.
Chiroteuthids form part of the diet of lancetfish
and yellowfin tuna in the tropical Indo-West Pacific
waters. Off Japan, C. imperator feeds on
micronektonic crustaceans, molluscs, and fish.
Chiroteuthids have no commercial fisheries potential,
due to their soft gelatinous bodies. funnel locking
ventral view
cartilage
Similar families occurring in the area
Mastigoteuthidae: also with enlarged ventral arms, but distinguished by the following characters: funnel
locking cartilage with posterior knob and (occasionally) medial knob poorly developed; tentacles with many
hundreds of small suckers, not tetraserially arranged.
List of species occurring in the area
Asperoteuthis acanthoderma (Lu, 1977)
Chiroteuthis imperator Chun, 1913
Reference
Kubota, T., M. Koshiga, and T. Okutani. 1981. Rare and interesting squid from Japan VII. Some biological data on
Chiroteuthis imperator from Suruga Bay, Japan. Venus, 40:150-159.