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2026 · Photo: Boaz Liebes
Rabbit sapsucking slug
Philippines · Indo Pacific - South China Sea
A tiny sacoglossan whose Japanese name 'usagi' means rabbit, for its long black rhinophores. It moves with a jerky, hopping motion, throwing the rhinophores back and forth, and keeps functional chloroplasts from the alga it eats.
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Large eyes set close together between the bases of black rhinophores; head and tail otherwise unpigmented. Median cerata grey (green in small animals), outer cerata black; all cerata have a white band below a black tip. Anterior foot corners tentacle-like; tail long and pointed.
Costasiella kuroshimae has white, black-tipped rhinophores and green cerata, without the black outer cerata.
On Avrainvillea algae in shallow water, from about 0.5 m to around 10 m.
Sucks the green alga Avrainvillea, notably A. erecta, retaining its chloroplasts.