FAMILY : ONCHIDIIDAE
Onchidium daemelii Semper, 1882 ?

The most common species in the river, found in mud and amongst mangrove root.
Able to slightly extend pneumostome and "snorkel" while crawling through very
shallow pools in mangroves (below).



"An unexpected characteristic of certain species of Onchidiidae is that in addition to an eye
at the end of each tentacle, there are numerous "eyes" on the back which is rough looking
and covered with coarse papillae. The eyes, in groups of two, three or four, are situated on
top of these papillae. The papillae themselves are retractile, so that the tip can be let down
and in. This retraction can be observed when one touches a papilla, but it does not seem to
happen unless actual contact is made. In other words evidence that the eyes can "see" or
are sensitive to shadow is difficult to obtain."

W.J.Dakin. 'Australian Seashores'

 

Pneumostome ( breathing hole) at rear of animal

© All images Copyright 2013 Denis Riek. All rights reserved.