FAO Species Identification Guide for Fishery Purposes Western

1140 Crabs
a) Grapsus albolineatus
triangular
spine
subtruncate
base
b) Grapsus tenuicrustatus
Fig. 7 carpus of cheliped
a) Grapsus albolineatus
b) Grapsus tenuicrustatus
Fig. 8 chela
broad
pectinated tip
narrow
pectinated tip
a) Grapsus albolineatus
6 th
segment
shorter
than 5 th
6 th
segment
longer
than 5 th
b) Grapsus tenuicrustatus
Key to food species of Sesarminae occurring in the area
1a. Tubercles on dorsal margin of dactylus of chela numbering 64 to 76 (Fig. 10a); male
first gonopod with broad, truncate pectinated tip (Fig. 11a); most of outer surface of palm
and proximal part of dactylus purple to reddish, dactylus white distally, pollex orangish
red to pink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Episesarma chengtongense
1b. Tubercles on dorsal margin of dactylus of chela numbering less than 61; male first
gonopod tip not as above; outer surface of palm not coloured as above . . . . . . . . . . . . . → 2
2a. Tubercles on dorsal margin of dactylus of chela similarly sized throughout length,
numbering 40 to 50 (Fig. 10b); male first gonopod with broad, rounded pectinated tip
(Fig. 11b); outer surface of palm light brown with white fingertips . . . . . Episesarma palawanense
2b. Tubercles on dorsal margin of dactylus of chela increasing in size towards finger tip;
male first gonopod not as above; outer surface of palm light brown with white fingertips
or coloured in other ways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 3
3a. Outer surface of palm violet at the proximal part, distal part and fingers white; tubercles
on dorsal margin of dactylus of chela 40 to 48 (Fig. 10c); male first gonopod with
relatively narrow truncate pectinated tip (Fig. 11c) . . . . . . . . . . . . . . Episesarma versicolor
3b. Outer surface of palm uniformly red or brown; tubercles on dorsal margin of dactylus of
chela 35 to 60; male first gonopod tip not as above . . . . . . . . . . . . . . . . . . . . . . . . → 4
4a. Tubercles on dorsal margin of dactylus of chela numbering 35 to 45 (Fig. 10d); male
first gonopod with relatively broad, bent pectinated tip (Fig. 11d); outer surface of palm
uniformly red to chestnut brown . . . . . . . . . . . . . . . . . . . . . . Episesarma singaporense
4b. Tubercles on dorsal margin of dactylus of chela numbering 40 to 60 (Fig. 10e); male
first gonopod with relatively narrow, bent pectinated tip (Fig. 11e); outer surface of palm
light brown with white fingertips . . . . . . . . . . . . . . . . . . . . . . . . . . Episesarma mederi
64-76 tubercles 40-50 tubercles 40-48 tubercles 35-45 tubercles
a) Episesarma
chengtongense
b) Episesarma
palawanense
c) Episesarma
versicolor
Fig. 10 dactylus of chela (lateral view)
d) Episesarma
singaporense
6
5
6
5
Fig. 9 male abdomen
40-60 tubercles
e) Episesarma
mederi