- Black nerites are a type of marine snail (mollusc)
- They have a distinctive round or globe-shaped shell, black or dark grey in colour. The older snails will sometime have a white patch at the flattened tip (apex) of the spirals (whorls) due to weathering.
- Nerites have a white aperture (where the snail comes out) with a black rim and they usually have a black operculum (shell door or lid) but they can sometimes have orange patches on them.
- Size: 20-25mm, can grow up to 31mm.
What to Observe
Search area for 30 minutes and record under the following categories-
- Abundant - found easily with little searching
- Frequent - found with minimal searching
- Rare - only 1 or 2 individuals found with intensive searching
- Not found - not present during search
ClimateWatch Science Advisor
Black nerites, like all marine snails (molluscs), are under increasing stress due to ocean acidification which can weaken their calcium carbonate shells and reduce body condition. This makes them more prone to disease, predation and low reproduction. Increasing water temperature as a result of climate change will likely affect their abundance and cause a southward shift in their distribution.
When To Look
Throughout the year.
Where To Look
- Common on rocky shores, from mid to high tide levels. Usually found on edges of rock pools and in crevices.
- North West Cape WA, SA, TAS, NSW up to Yeppoon QLD
Davey, K. (1998). A Photographic Guide to Seashore Life of Australia. New Holland Publishers Australia Pty Ltd.
Edger, GJ. (2008). Australian Marine Life. The Plants and Animals of Temperate Waters [2nd Ed]. New Holland Publishers Australia Pty Ltd.
Black nerites are common on rocky shores and easily distinguished from most other marine snails by their black colour and rounded shape. Black nerites (Nerita melanotragusa) can be mistaken with a similar species called the ribbed nerite (Nerita costata) which occurs in Queensland and southern NSW. The ribbed nerite has 12-15 ribs that swirl up to the flattened apex of the shell and a grey or green operculum (shell door or lid). The black nerite, is smooth shelled and has a black operculum (sometimes spotted orange).
Did You Know?
Nerites are herbivores and scrape algae from the rock with a specialised rasping tongue called a radula.
Nerites can also be found in estuaries among mangroves.
They are also found in the North Island of New Zealand.