Mollusc goes with the flow from the Indian Ocean


Clay Bryce collecting in murky waters.
Image: Gary Cranitch

 

 By Angus Livingston
 Tuesday 26 May  2009:
 
ONE of the molluscs now residing in a specimen jar at Ningaloo reef has a different story to the others.
 
Molluscs are a large and diverse group of soft-bodied, invertebrate shellfish, with members ranging from the oyster to the octopus.
 
Most of the molluscs found on Australia's west coast are of Pacific Ocean origin, having travelled on the currents down through Indonesia.
 
However this particular specimen – Drupa lobatum – is of Indian Ocean origin.
 
While most mollusc larvae move down the Western Australian coast on a warm current from the north, this particular specimen has dropped off one of the Indian Ocean currents that glance into the continental shelf and joined the southern flow. Clay Bryce collecting in murky waters.
 
It's just one of a number of species Clay Bryce, from the WA Museum, has found that aren't usually to be seen on this side of the country.
 
Clay is senior project manager of the mollusc section at the WA Museum and is back at Ningaloo after also making the trip last year.
 
So far he and Corey Whisson have found a large number of mollusc specimens in the few days they've been on site.
 
Another unusual visitor to these shores is the Chromodoris lochi, which Clay found in 30m of water.
 
Named after Ian Loch from the Australian Museum, it had not been found off this coast before.
 
The Platydoris formosa, in contrast, has only been found once off Western Australia before.
 
Those are just three of the many, many mollusc samples Clay and Corey have found.
 
"There's just so much to identify and we're only looking at molluscs that are greater than half a centimetre," he said.
 
"What I'd like to have a look at is some of the more cryptic forms, like the ones that live on soft coral."
 
As well as finding new or previously unseen species, Clay is also building a picture of the biodiversity of this part of Ningaloo reef.
 
He has been checking different habitats on the reef to learn where molluscs are living.
 
Eventually he will be able to use the information from these expeditions to compare this section of the reef to other marine areas, and gain a better insight into which organisms are living here and how they travel.