Sunday, December 16, 2007

Aeolid Nudibranch

Nudibranchs have got to be one of the prettiest and most colourful marine invertebrates. No dives or intertidal walks would be complete without seeing one. I have been very fortunate to see several different species throughout the years. Nudibranchs are classified into four suborders and my personal favourite are nudibranchs from the suborder Aeolidina.

Aeolids are typically longish in body shape and have a pair of cephala tentacles that’s distinct from rhinophores. But what makes them stand out are the rows of cerata on their back. I always thought it gives them a funky and rebellious demeanor.
The cerata are actually respiratory organs. In certain species, a cnidosac occurs at the tip of each ceras. These functions as storage for nematocysts capsules for defence and many aeolids obtain the stinging nematocysts from their food source, for example hydroids.

This aeolid nudibranch spotted at Beting Bronok is an absolute attraction. It most probably is from the family Facelinidae. For exact identification to species, its radula would have to be examined.

A team of University of Queensland researchers studying sea slug pheromones have named the chemicals attractin, enticin, temptin and seductin……..very apt names for an alluring group of animals.



Pictures taken at: Beting Bronok, October 2007.


References:

Behrens, D. W., 2005. Nudibranch Behavior. New World Publications, USA.

Graduate Contact 2007, No. 36. University of Queensland, Australia.