Overview
Tanaids are crustaceans, related to slaters and hoppers, but they live mostly in the sea. Though tiny, they are everywhere – there might be a 100 in a handful of sand. This abundance indicates that they are ecologically important.
Te Papa’s Rick Webber and tanaid expert Graham Bird are describing a new species in the genus Macrolabrum. This species has been known for about 20 years, but only now is it getting specialist attention. It is only recorded from New Zealand, in shallow waters around the north-eastern North Island. Similar species occur in Australia, New Caledonia and other places with warm seas.
Most tanaids build tubes to live in, but a few, including Macrolabrum species, prefer prefabricated housing in the form of empty snail shells. They even have coiled bodies for a snug fit, just like hermit crabs. This adaptation has evolved in parallel, as tanaids and hermit crabs, although both crustaceans, are not closely related. An interesting question is whether tanaids and hermit crabs compete with each other for empty shells or whether there are actually plenty to go round.
New Zealand has 80-plus tanaid species – and counting.
Te Papa blog post on tanaid research.
Note: Te Papa’s collections of tanaids are not yet online.