The Yellowline Arrow Crab (Stenorhynchus seticornis) is one of the strangest crabs I have yet to encounter. Spider-like in appearance, these very relaxed and often friendly crustaceans live under small rocky overhangs and crevices, picking at little morsels in the sand or those floating by. Their thin legs and fine facial details make them an ideal macro photo op! They have an interesting adaptation to falling over a drop-off, when they raise all their legs over their ‘head’ and point them straight up, essentially becoming a aerodynamic downward travelling arrow that speeds through the water column to the safety of the sea floor. Clever.
Originally posted on instagram @sea_anguilla with the text: Yellowline Arrow Crab – probably one of the strangest crab species found in Anguilla. They have very long spindly legs and tiny claws which they use to pick among sand grains for food. Their docile nature means they can be easily approached, obviously relying on camouflage as a defense. But most curious of all is how they straighten their legs back up over their heads if they fall from an overhanging reef ledge, streamlining themselves so that they reach the sea floor as fast as possible. Clever. This one was photographed near Sandy Island.