A thin-shelled bubble snail grazing algal film in the shallows, and the prey most often taken by Philinopsis.
A small bubble shell, most animals between one and two centimetres, with a thin, globose, almost transparent shell that the body cannot fully withdraw into. The flesh is pale olive, green-brown or grey with fine darker speckling, and it shows through the shell as much as around it. A broad headshield covers the front of the animal, and a pair of parapodial lobes rises from the sides of the foot and folds partly over the shell, so a moving animal looks softer and larger than the shell alone would suggest.
It is a grazer, working over the film of diatoms, algae and cyanobacteria on sheltered shallow sediment, weed and seagrass, and it is normally found in numbers rather than singly. The spawn is a soft gelatinous coil or sausage, cloudy white to pale yellow, attached to weed or to a shell by a short thread, and it is more conspicuous than the animal that laid it. Bullina lineata, on the same ground, keeps a solid patterned shell it can withdraw into completely and hunts worms; this genus does neither.
It also matters as food. Philinopsis and the other predatory headshield slugs follow mucus trails across the sediment and swallow Haminoea whole with the shell intact, so a stretch of shallow sand that holds one usually holds the other. Species are separated on the shell and on internal anatomy and records stay at the genus. Recorded from the intertidal to about 12 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
