crustacea text index | photo index
Phylum Arthropoda > Subphylum Crustacea > Class Malacostraca > Order Decapoda
Photo index of crabs on Singapore shores
Large crabs with last pair of legs paddle-shaped

size indicated is for body width

Red swimming crab

Thalamita spinimana

Blue swimming crab
Thalamita danae

Blue-spined
swimming crab

Thalamita prymna
.

Mottled swimming crab
Thalamita sp.
5-7cm. Body rectangular, eyes wide apart. With 5 spines on the sides. Body and pincers plain bright orange or red, some with a short thin white vertical line between the eyes. Coral rubble and reefs. Commonly seen on many of our shores. Body width 5-7cm. Body rectangular, eyes wide apart. With 5 spines on the sides. Body and pincers plain blue without any markings. 'Fingers' are often black with a white tip. Coral rubble and reefs. Commonly seen on many of our shores. 5-7cm. Body rectangular, eyes wide apart. With 5 spines on the sides, fourth spine much smaller, bright blue with dark tips. Pincers have similar blue spines. Coral rubble, reefs. Commonly seen on many of our shores. 4-5cm. Body rectangular, eyes wide apart. With 5 spines on the sides, fourth spine smaller. Body mottled, edge finely banded blue-brown. Coral rubble, reefs. Sometimes seen on some of our shores. 5-7cm. Body rectangular, eyes wide apart. With 5 spines on the sides. Body plain, pincers with powder blue claws and blood red tips. Coral rubble, reefs. Commonly seen on some of our shores.

Purple-legged
swimming crab

Charybdis hellerii

Banded-leg
swimming crab

Charybdis annulata

Orange-clawed
swimming crab

Charybdis anisodon

Ridged swimming crab
Charybdis natator

Blood-spotted
swimming crab

Portunus sanguinolentus
5-7cm. Body fan-shaped with 6 spines on the sides. Eyes not wide apart. Legs are purple, pincers orange claws with dark tips. Commonly seen on our Northern shores. 5-7cm. Body fan-shaped with 6 spines on the sides. Eyes not wide apart. Legs banded dark brown and bright blue, pincer tips similarly banded. Sometimes seen on some of our shores. 5-7cm. Body fan-shaped with 6 spines on the sides. Eyes not wide apart. Olive green with orange claws and white tipped pincers. Sometimes seen on on our Northern shores. 5-7cm. Body fan-shaped with 6 spines on the sides. Eyes not wide apart. Body beige, limbs reddish brown, pincers with many bumps, black claws with blue spots at the base. Sometimes seen on some of our shores. 5-7cm. Body fan-shaped with 9 spines on the sides. Eyes not wide apart. Body with three red spots. Rarely seen on our shores.

Mud crab
Scylla
sp.

Flower crab
Portunus pelagicus

Crucifix swimming crab
Charybdis feriatus
 

Tiny swimming crab
Portunus pelagicus
5-20cm. Can be enormous! Body fan-shaped with 9 spines on the sides, last pair not enlarged. Eyes not wide apart. Seagrass areas. Sometimes seen on some of our shores. 5-20cm. Body fan-shaped with 9 spines on the sides, the last pair enlarged into a protruding spike. Eyes not wide apart. Seagrass areas. Commonly seen on many of our shores. 5-7cm. Body fan-shaped with 6 spines on the sides. Eyes not wide apart. Orange with bold brown markings on the body and limbs. Sometimes seen on many of our shores.   Body width 2-6cm. Body fan-shaped with 8-9 spines on the sides. Eyes not wide apart. Seagrasses and seaweeds. Commonly seen on our Northern shores among seagrasses and seaweeds.

How to tell apart the swimming crabs



photo index of
crustaceans on this site
Crustaceans
all crustaceans

Crabs
all crabs and crab-like

small

body width <2 cm

small with long eyestalks


small porcelain crabs

3 pairs walking legs

medium
body width 3-5cm

large
body width >5cm

swimming crabs
last pair of legs paddle-shaped

hermit crabs
live in shells
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