NIWA launches two new marine identification e-guides: Coastal Crabs and Splendid Sponges


Where in New Zealand might you find a witchy finger sponge or a pie-crust crab?

The answer will be found in New Zealand’s first series of electronic identification guides for marine invertebrates.  Initially launched in 2012, these guides were designed to help amateur marine biologists at the beach and in the water this summer.

This first edition of the crab guide identifies the most common weird and wonderful, slightly creepy crawly, and occasionally edible coastal crabs.

Coastal Crabs

Coastal Crabs is a fully illustrated working identification e-guide to the common coastal crabs of New Zealand.  These hard-shelled invertebrates are found everywhere from the intertidal zone all the way down to the deep ocean trenches and abyssal plains. So you have a good chance of spotting them when you are out and about doing your own investigations of our beautiful coast and oceans. 

Splendid Sponges

Splendid Sponges is a fully illustrated working identification e-guide to the common and colourful marine sponges that inhabit our coasts, harbours and ocean depths.

Both e-guides start with a simple introduction to the different groups, followed by a morphology (shape) index, species index, detailed individual species pages, and finally, icon explanations and a glossary of terms. The species pages have high quality images of the animals and describe features that enable you to differentiate the species from each other. As far as possible, we have used characters that can be seen by eye or magnifying glass, and language that is non-technical.

COASTAL CRABS and SPLENDID SPONGES are just two in a series of e-guides on New Zealand marine invertebrates that NIWA’s Coasts and Oceans group is presently developing. ‘Awesome Ascidians’ and ‘Extraordinary Echinoderms’ are already available for download now and more e-guides are currently being developed.

The guides are designed for New Zealanders who live near the sea, dive and snorkel, explore our coasts, make a living from it, and for those who educate and are charged with kaitiakitanga, conservation and management of our marine realm.

NIWA says it will be updating the existing e-guides online as new species are discovered and described.

You can download Extraordinary Echinoderms, Awesome Ascidians, Splendid Sponges and Coastal Crabs for free on the link below:

Marine identification guides and factsheets

You can now have a name and information about the paddle crab which nipped your toe at the beach (Ovalipes cathurus) or the colourful orange golf-ball sponge lurking under a shady rocky overhang (Tethya burtoni).

By the way, those witchy finger sponges (Petromica sp.) are found along the Rodney Coastline and Poor Knights Islands and the pie-crust crab (Metacarcinus novaezelandiae) is found all around New Zealand, under stones or among seaweeds – keep an eye out for them when you are diving.


The page of the Coastal crabs e-guide describing the identifying features and distribution of the pie-crust crab Metacarcinus novaezelandiae (Hombron & Jacquinot, 1846) around New Zealand.
The page from the Splendid Sponges e-guide describing the identifying characters and distribution of the orange golfball sponge, Tethya burtoni Sarà & Sarà, 2004.