FAO Species Identification Guide for Fishery Purposes Western

1134 Crabs
Chaceon bicolor Manning and Holthuis, 1989
Frequent synonyms / misidentifications: None / None.
FAO name: En - Pacific golden crab.
Diagnostic characters: Carapace hexagonal; dorsal
surface not inflated; anterolateral teeth low. Merus of legs
long, slender. Dactylus of legs not laterally flattened,
height at midlength greater than or subequal to width at
midlength.Colour: reddish tan to purplish black (anterior
half of carapace may be differently coloured than posterior
half), sometimes cream-white throughout.
Size: Maximum carapace width 18 cm (males) and
15 cm (females).
Habitat, biology, and fisheries: Like most
of the known species of the genus,
Chaceon bicolor lives on muddy substrates
in deeper waters at depths between
200 and 1 600 m, and apparently burrows
sometimes into the sediment. Occasionally
caught throughout its range, especially in
Australia. Taken in bottom trawls and lobster
pots, and is believed to be commercially
valuable in the future, being
supposedly quite abundant in some areas.
Distribution: New Caledonia, northwest
and eastern Australia, and Loyalty Islands.
Chaceon granulatus (Sakai, 1978)
Frequent synonyms / misidentifications: None / Chaceon affinis (A. Milne Edwards and Bouvier, 1894).
FAO name: En - Japanese golden crab.
Diagnostic characters: Carapace hexagonal; dorsal
surface (especially branchial regions) distinctly inflated;
anterolateral teeth low in adults. Merus of legs
long, slender, with dorsal subdistal tooth; dactylus of
legs laterally flattened, height at midlength less than
width at midlength. Colour: uniform tan to cream
colour overall.
Size: Maximum carapace width 30 cm.
Habitat, biology, and fisheries: On soft substrates
in deep waters from 300 to 1 500 m. Caught on a
regular basis in Japan, but never in large numbers.
When it does appear in markets, it commands high
prices (up to US$60 to US$80 for a fresh crab of
20 cm width). Also caught for sale in Palau.
Distribution: Japan, China, Taiwan Province
of China, and Palau.
Remarks: Only 3 Pacific species of
Chaceon, C. granulatus, C. karubar,andC.
manningi belong to the group in which the
dactylus of legs is laterally flattened, and the
height at midlength is less than the width at
midlength. Specimens from Saipan and
Palau which have been identified with C.
granulatus possibly belong to separate species,
but studies on these are still ongoing.
For the moment, crabs from these 2 islands are tentatively identified as C. granulatus. The Palau specimens
were recently recognized as belonging to a new species.