Velutinidae
From Natural History of Southeast Alaska
Family: Velutinidae
Group: Marine Invertebrate, Species
Scientific Name | Common Name | Summary |
---|---|---|
Marsenina stearnsii | Stearn's ear-shell | This fascinating little species looks just like a cryptic nudibranch, but careful examination will reveal a dorsal slit in the mantle that eventually widens to reveal the top of the animal's shell. M. stearnsii is differentiated from Marsenina rhombica by its small, evenly spaced pores. Also, M. rhombica may be warty or spotted. M. stearnsii is a noted predator of Didemnid tunicates, and has been observed to feed on the invasive Marine vomit (Didemnum vexillum) in our area. The shell is possibly not a sufficient basis for identification down to the species level. |
Velutina prolongata | Smooth velvet shell | This species differs from Spiral velvet snail (Velutina velutina) by having a smoother shell, a more oblong, less round opening, and, when alive, a yellow-lined mantle. It is usually found on solitary Ascidians, such as the Corellidae Transparent tunicate (Corella willmeriana) and Disc-top tunicate (Chelyosoma productum). It has been found on Marine vomit (Didemnum vexillum), but was not observed feeding on it. In one case, a specimen was found that was overgrown by Marine vomit (Didemnum vexillum) to such an extent that it could no longer move. |
Velutina velutina | Spiral velvet snail | Velutina velutina is distinguished from Smooth velvet shell (Velutina prolongata) by the opening, which is about as wide as it is long, whereas in V. prolongata, it is considerably longer than wide. Also, the periostracum clearly creates ridges on the shell, and a rougher outlook on the whole. when alive, Velutina velutina has a large white mantle with a clearly yellow edge around it. This species usually feeds on tunicates, such as Sea Blisters (Ascidia callosa). |