FAO Species Identification Guide for Fishery Purposes Western

Key to Brachyura 1065
13a. Opening for afferent respiratory current below orbits, adjacent to endostome, with
distinct canal present along sides of buccal cavern (Fig. 22a) when third maxillipeds
pushed aside; sides of carapace never expanded to form a clypeiform process (= expanded
posterior edge); larger chela never with specialized cutting tooth; legs never
paddle-like (Fig. 23) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leucosiidae
13b. Opening for afferent respiratory current at base of chela, no canal present along sides
of buccal cavern even when third maxillipeds pushed aside (Fig. 22b); sides of carapace
may be expanded to form a clypeiform process; larger chela may have a specialized
cutting tooth (Fig. 24); propodus and dactylus of legs may be paddle-like (Fig. 25) . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calappidae (p. 1091)
3 rd
maxilliped 3rd respiratory maxilliped
canal
a) Leucosiidae b) others
Fig. 22 presence or absence of respiratory canal
specialized tooth
Fig. 24 right chela (Calappidae)
no respiratory
canal
Fig. 23 Leucosiidae
(after Shen, 1932)
a) subfamily Calappinae b) subfamily Matutinae
Fig. 25 Calappidae
14a. A small platelet-like structure always intercalated present between edges of sixth
abdominal segment and telson (Fig. 26a); fourth leg strongly reduced, present only as
a short appendage (only partially subchelate in 1 Atlantic species); no known carrying
behaviour (Fig. 27). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dynomenidae
14b. No platelet-like structure intercalated between edges of sixth abdominal segment and
telson (Fig. 26b); fourth leg reduced but always distinct, with most segments slender,
relatively long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 15
6
5
4
3
platelet-like
structure
a) b)
6
5
4
3
Fig. 26 male abdomen Fig. 27 Dynomenidae