Scientific Name: Aplysia nigrocincta (sometimes reported as Aplysia parvula in earlier literature)
Common Name: Black-ringed Sea Hare / Dwarf Sea Hare

Adult Size: 20 – 40 mm (dwarf species)
Depth Range: 0.5 – 15 m; most often in shallow lagoons, tide pools, and reef flats
Biotope / Habitat: Rock and coral surfaces covered with filamentous red or green algae; also on seagrass blades in sheltered bays
Diet: Herbivore grazing on fine turf algae and diatoms; body color shifts with diet, from olive-green to reddish-brown, always trimmed by the diagnostic black margin around the parapodia
Reproduction: Simultaneous hermaphrodite; forms “mating chains” where several individuals link head-to-tail. Egg masses are laid as tangled pale-orange spaghetti on algae or rubble; larvae hatch planktonic before settling.
Fun Fact: When startled, this tiny sea hare can release a purple ink cloud just like its larger cousins—an impressive defence for such a small gastropod!

Small, swift, and edged in black, Aplysia nigrocincta glides over algae-coated rocks like a living leaf. Its graceful parapodial “wings” undulate as it feeds, making it a delightful—but easily missed—subject for keen macro photographers.