Observations on Nudibranch Behaviour Patterns Under Laboratory Conditions

Abstract

Phyllidiid Nudibranchs Phyllidia varicosa and Phyllidiella pustulosa were observed under laboratory conditions and abnormal behaviours were recorded. This study described the manoeuvering, mating behaviour, egg laying and abnormal activities. Some abnormal behaviours were recorded while retaining the sample in the aquarium such as emitting noxious chemicals, lifting up the mantle edge to expose the gills and crawling towards the water surface and lie there. Maneuvering behaviour was distinguished when two individuals were interacting with each other before the mating. Mating behaviour started by extending and joining the reproductive organs followed by gamete exchange for several minutes. During the mating behaviour, there was a limited movement like contracting of the body and hiding the rhinophores into the rhino-tube. Egg deposition was observed in the aquarium as natural behavior after mating and as a stress response after placing the sample in the captivity.

First Study on Marine Heterobranchia (Gastropoda, Mollusca) in Bangka Archipelago, North Sulawesi, Indonesia

“…The animals feed on sponges, on which they sometimes leave a scar ( Figure 17G,H). This was already noted before [37,38] where, e.g., Yasman [37] interpreted the scars as an effect of extra-oral digestion.…”

“…When comparing our study in BA with other available studies from Indonesia, e.g., Ambon, Bali, and Papua New Guinea [2,16,38,48], we can consider the number of 149 species as reasonable for this region after only a few collection events. Only the study in Papua New Guinea exhibits a much higher number of species (Figure 28), probably due to the exceptionally high collection effort in this area [48].…”

The chemistry and chemical ecology of nudibranchs

“…232 Potent antifouling activity has been reported for some of these compounds against barnacle larvae 232,237,243,244 and several also possess antimalarial activity against Plasmodium falciparum. 234,239 The lipid content of Phyllidia coelestis 245 and the fatty acid content of P. varicosa 246 and Phyllidiella pustulosa 246 have also been examined.…”

Psychedelics sea slugs: Observations on colour ontogeny in two nudibranch species from the genus Nembrotha (Doridina: Polyceridae)

“…Later, Pola et al (2007Pola et al ( , 2008 provided anatomical and molecular evidence to synonymize several species, but these authors claimed that since they were not able to examine all different variable forms and intermediate states of each species, or even include all the variable forms in the molecular analyses, they preferred to maintain a conservative point of view and retain most of the nominal species of the genus. Furthermore, since most nudibranchs are diet-specific and rarely survive long enough in captivity (Calado and Dinis 2005, Dionisio et al 2013, Alqudah et al 2016, opportunities to follow colour ontogeny are very rare.…”