Saturday 28 July 2018

116 — Oar brittle star, Ophiopteris antipodum

A short video of O. antipodum, Pilot Bay,
Mt. Maunganui, 17/7/18.
This is a very striking brittle star: deep purple in colour and with oar-like spiny projections on the arms—which is where they get their name.

Although Ophiopteris antipodum reaches sizes of ~10cm they're not often seen. This is not because they are particularly rare, but possibly because they live under rocks at and below low tide, so unless you're turning rocks and looking underneath, you're unlikely to see one. If you do find one, you'll quickly realise some things about them: they don't like light, will try and get away from it as fast as they can, and will do this quite rapidly.

They are found throughout New Zealand and are endemic. They seem to prefer sandy and/or rocky habitats down to depths >100m. It is thought that they feed on small invertebrates (Mills et al., 2017).

These ones came from Pilot Bay and Warrior Rocks, Mt. Maunganui, July 2018. They range in size between about 8 and 10cm across.

Ophiopteris antipodum, Pilot Bay,
Mt. Maunganui, 27/7/18



O. antipodum, Pilot Bay,
Mt. Maunganui, 27/7/18. This image is
lightened, so that the granular nature
of the disc can be seen.










O. antipodum, Pilot Bay,
Mt. Maunganui, 27/7/18. Underside of one of
the arms showing the salmon-coloured tube feet.

Ophiopteris antipodum, Pilot Bay,
Mt. Maunganui, 27/7/18.
The oral side of the brittle star.

O. antipodum, Pilot Bay, Mt. Maunganui, 17/7/18.
The underside of one of the arms
showing the salmon-coloured tube feet.




















































































More info:

Mills et al. (2017). Extraordinary echinoderms. A guide to the echinoderms of New Zealand.