Monday, 1 September 2008

Marine Isopod

...Zuzara venosa

It's been tossing down rain most of the day and I don't fancy getting wet so I thought I'd share something from my archive of photos. It's a type of crustacean known as an Isopod.

There are nine suborders of Isopods. The Oniscidea are the ones most people are familiar with. They are the slaters and woodlice in your back garden. There are also freshwater Isopods but most are actually found in the marine environment. The marine Isopods include the suborder Flabellifera to which the one in my photos belongs. It is Zuzara venosa, a species found from Victoria to South Australia as well as around the coast of Tasmania. They are usually found under rocks in the intertidal zone where they feed on algae.

This species grows up to 20mm in length. Note the large flipper like appendages on the side of the tail fan. These are known as uropods. Also the large central process (sticky out bit) on the last thoracic segment indicates that this is a male.

(Click to Enlarge)

Zuzara venosa - Dorsal View

Zuzara venosa - Ventral View

Zuzara venosa - Defensive position


  1. Very interesting. The copulatory organs of male Oniscidea are n the ventral side.

  2. Thanks Aydin Örstan - I read a couple of your Isopod posts. Most informative!

  3. I found this critter at Bambra Reef, Roches Beach, Lauderdale, today. Don't know if I had ever seen it before but your images of it were the first I found online and enabled me to identify it. Thanks!

    As another coincidence, I am a fairly regular visitor to Aydin's blog, for obvious reasons!

  4. Thanks Kevin for the feedback. It's always good to know when someone finds something useful on here.