46 — Sand dollar urchin, Fellaster zelandiae

Fellaster zelandiae Pilot Bay,
Mt. Maunganui, 10/16.

Fellaster zelandiae, Mount Beach,
Mt.Maunganui, 27/7/18

Fellaster zelandiae, coming up through the sand
at Cheltenham Beach, Auckland, 17/6/18.

A dead F. zelandiae Mount Beach 16/7/18.

The sand dollar Fellaster zelandiae (Gray, 1855) is usually seen washed up as broken segments (a bit like small pizza slices), so people don't usually see what they really look like alive. Sand dollars are a type of sea urchin, but an extremely flattened one, with very short spines.

They're deposit-feeders, which means they eat sediment, digest any organic matter they find and then excrete out the rest.

Fellaster zelandiae is found on the east coast of Australia, Tasmania, and throughout North Island down to the upper half of the South. These are about 10cm across.

These sand dollars display what's called pentamerous symmetry (having parts arranged in groups of five), a feature common to most echinoids.





















More info:

NIWA echinoderm identification guide

https://marineinfo.otago.ac.nz/publications/cid/707/