Diloma arida
Snail-Top, Black (Diloma arida)
Invertebrate
Mollusca
Gastropoda
Trochidae
This snail is very similar to the other black top snails and they are often found together. This snail is solid, globe like with a blunt spire, flattened sides and an angular outline. The surface is smooth with indistinct spiral lines and is black or puplish black, sometimes grey. It may have a few yellowish white spots. The interior of the shell is a reddish colour and is iridescent.
Common especially in southern NZ. Upper to mid intertidal. Mainly under boulders on semi-exposed to sheltered rocky shores.
It feeds on the microalagal films wich cover the surfaces of rocks and on seaweed.
NZ Coastal Marine Invertebrates; Vol 1