Stenorhynchus seticornis

Stenorhynchus seticornis is a decapod crustacean belonging to the family Inachoididae. Its geographic range includes mainly the waters of the western Atlantic Ocean, from the coasts of North Carolina to Argentina, being a very frequent species throughout the Caribbean Sea. As for the preferred habitat of Stenorhynchus seticornis, we will find it in reef and/or rocky areas from relatively shallow waters (8-10 meters) to relatively deep (180 meters) waters. It is a species of predominantly nocturnal habits and very territorial, which during the day will avoid the regions very exposed to light, and usually seek refuge by establishing a symbiotic relationship with certain anemones (especially Lebrunia danae), corals or even sponges. It is common to find this species of crab together with specimens of Ancylomenes pedersoni or Periclimenes yucatanicus.

Also known as yellowline arrow crab or arrow crab, this species is very easily identifiable due to its peculiar morphology. It has very long legs, up to 10 cm long, which are very thin and resemble the limbs of spiders, hence one of the common names of the species. The rostrum is characteristically very elongated and spiny at the edges, and has a strongly calcified triangular-shaped carapace of very small size compared to the total length that the species reaches from one end to the opposite end. As for the coloration of Stenorhynchus seticornis, the predominant color is reddish, with purplish-gray pincers, and the joints of its extremities with an intense red color and with brown and black stripes.

The diet of Stenorhynchus seticornis consists predominantly of small crustaceans and invertebrates that it captures with its claws among the corals and rocks where it lives.

As for reproduction, Stenorhynchus seticornis does not have a specific breeding period, but reproduce throughout the year when two critical factors trigger mating, which are water temperature and light intensity. Males transfer a spermatophore to females, which they will use to fertilize their clutches. The fertilized eggs will be carried in the abdomen by the female until the small larvae hatch. The larvae will become part of the plankton where they will be dispersed by the predominant currents of the area, and after several molting phases, they will undergo a metamorphosis process to give rise to an adult specimen.


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