Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Guide to New Zealand's freshwater invertebrates

Tanaids ( Tanaidaceae : Sinelobus )

Diagnostic features

Sinelobus (formerly Tanais) is one of the few freshwater members of the Order Tanaidaceae. The body is reminiscent of a slender isopod (and they are related), but in the tanaids the head and thorax are fused, and there are large chelipeds (pincers) on the second pair of legs. Sinelobus is small, at less than 4mm long.

Typical habitats

Sinelobus are found in the lower reaches of streams and rivers but there are also populations in the Rotorua lakes in the central North Island.


Marine tanaids feed on organic detritus and the associated micro-organisms, and it is assumed Sinelobus has a similar diet.

Indicator value

Tanaids have a very patchy distribution, but they are known from rivers and lakes in largely farmland catchments. They have been assigned tolerance values of 4 (hard bottom sites) and 6.8 (soft bottom sites).