Tube pea crab

Pinnixa chaetopterana

Family Pinnotheridae - Pea crabs

Distinguishing
Characteristics
Carapace oval, more than twice as wide as long, color white but covered with small brown or blackish dense hairs; ridge on posterior margin of carapace, interrupted in the middle with indentation, not extending to the lateral borders of carapace; 3rd walking leg longest and broadest, propodus (next to last segment) less than 2 times longer than broad; upper movable finger of claws curved at a 90 degree angle in male, bottom finger short with single tooth near finger; in females the upper finger of claw is straighter and bottom finger is longer.
Similar Species
The only other pea crab in the area with similar hooked claws is P. cristata which has an uninterrupted ridge that extends to the lateral borders of the posterior end of the carapace.
Habitat
Larger crabs are found in the tubes of the parchment worm, Chaetopterus variopedatus and the ornate worm Amphitrite ornata. Seldom found outside the tubes. Smaller crabs can be found in the mud burrows of mud shrimps (Callianassa sp.)
Maximum Size
1.4 cm (1/2 in) carapace width
Other Common Names
Previous Scientific Names
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