Phyllidiid Suctorial Feeding
We are occasionally fortunate enough to encounter and record a nudibranch feeding, that is, to actually see that they are feeding, because most often the process is hidden from us beneath them. In those instances, with the sponge-feeders, the buccal mass can be seen protruding and pressed against the sponge tissue that is being rasped away by their radula and leaving a scar.
Of course some sponge-feeders don’t have a radula, feeding instead by secreting digestive enzymes upon the sponge tissue and sucking up the liquified tissue – suctorial feeding. These are the porostomes – the Phyllidiidae and Dendrodorididae families of nudibranchs.
This process is definitely hidden from us and requires a little bit of intervention to actually see what is going on underneath them. The following sequence illustrates what was revealed when a large Phyllidiella pustulosa was carefully detached from a sponge upon which it was feeding.
Images recorded on the Gneering Shoals, Sunshine Coast, Queensland, Australia.
(Sometimes, in order to know and record just what is happening the animal has to be removed. I would not suggest the above to be a regular practice as it takes an inordinate amount of time and patience to get phyllidiids to reattach themselves to the substrate.)
David A. Mullins – July 2021
– Brunckhorst, D. J. (1993). The Systematics and Phylogeny of Phyllidiid Nudibranchs (Doridoidea). Records of the Australian Museum, Supplement 16: 1–107.
– Rudman, W. B., (1998). Family Phyllidiidae Pp.1000-1001 in Beesley, P. L., Ross, G. J. B. & Wells, A. (Eds) Mollusca: The Southern Synthesis. Fauna of Australia. Vol.5 CSIRO Publishing, Melbourne, Part B 565-1234 pp.
– Mullins, D. A., (2020). Uniquely United But Deceptive Display – The Suctorial Feeding Porostomata Nudibranchs. NudiNotes at www.nudibranchdomain.org