Jan 16, 2011

Yellowline Arrow Crab

 The Yellowline Arrow Crab's most defining feature are its spindly legs
The yellowline arrow crab is golden-brown in color with a triangular body and pointed snout.  Its exoskeleton is decorated with fine dark lines and the claws usually have purple tips.  The most noticeable feature of this crab is its long, spindly legs.  The body of the crab gets no larger than three inches in length.

Stenorhynchus seticornis is a crustacean and belongs to the same order as lobsters and shrimp.  The yellowline arrow crab is a true crab, or Brachyura.  True carbs have reduced abdomens and tails and a flattened carapace.  The first pair of legs have developed claws that are used in defense and to manipulate food.  The defining feature of true crabs is that they have four pairs of walking legs.  Hermit or porcelain crabs have only three pairs of walking legs.  The yellowline arrow crab more specifically belongs to the Majidae family of crabs, or spider crabs.

The yellowline arrow crab is found in the southern United States and throughout the Caribbean.  They are typically found on shallow, nearshore reefs.  This crab is mainly a nocturnal scavenger but will occasionally prey on tiny reef organisms.  Divers especially like to come across the yellowline arrow crab because they will give the diver a "high-five."  If one extends his or her palm slowly to these crabs they will extend one of their legs and touch their hand.

References: Humann, Paul, and Ned Deloach. Reef Creature Identification: Florida, Caribbean, Bahamas. Jacksonville, FL: New World Publications, 2003. 166, 264. Print.