Forbes Sea Star

Asterias forbesi

The Forbes sea star (Asterias forbesi) is a medium-sized starfish found in the northwestern Atlantic. Adults reach 12-20 cm in diameter and typically have 5 arms, occasionally 4 or 6, with a small orange madreporite (sieve plate) visible on the dorsal surface. Coloration ranges from tan and olive to brown and reddish-purple, with a lighter underside covered in rows of tube feet. They inhabit rocky shores, jetties, pilings, and sandy substrates at depths of 0-50 meters. They are voracious predators of bivalve mollusks, gripping both shell halves with their tube feet, prying them apart, and inserting their stomach to digest the prey externally. They can regenerate lost arms over several months. They play a significant ecological role in controlling mussel and oyster populations. Divers commonly encounter them on rocky substrates and man-made structures throughout the northwestern Atlantic, where their predatory behavior on bivalves can be directly observed.