A recurring population of the sea hare Bursatella hirsuta (Gastropoda: Aplysiidae) at Rottnest Island, Western Australia
Wells, F.E.; Bessey, C.; Gagnon, M.M.; Keesing, J.K.; Prince, J. (2021). A recurring population of the sea hare Bursatella hirsuta (Gastropoda: Aplysiidae) at Rottnest Island, Western Australia. Moll. Res. 41(4): 285-288. https://dx.doi.org/10.1080/13235818.2021.2007750
In: Molluscan Research. Malacological Society of Australasia: Sydney. ISSN 1323-5818; e-ISSN 1448-6067, more
|  |
| Keywords |
Aplysia Linnaeus, 1767 [WoRMS]; Bursatella hirsuta Nimbs & N. G. Wilson, 2020 [WoRMS]
Marine/Coastal |
| Author keywords |
Aplysia; intertidal; Indian Ocean; boom-and-bust |
| Authors | | Top |
- Wells, F.E.
- Bessey, C.
- Gagnon, M.M.
|
|
|
| Abstract |
In many, but not all, years a recurring population of the marine aplysiid Bursatella hirsuta occurs on an intertidal limestone platform stretching between Little Armstrong Bay and North Point at Rottnest Island, Western Australia. Using a transect/quadrat method, we measured densities of B. hirsuta during the austral summer of 2020/2021. No individuals were present in December 2020, but a population with a mean density of 16.5 ± 1.6 (SE) inds m−2 was present on 17 January 2021. Density was low in bare sand (2.6 ± 3.2 inds m−2) and in the seagrass Amphibolis antarctica (2.0 ± 1.4 inds m−2), high in mixed algae, mostly Phaeophyceae (18.2 ± 1.8 inds m−2) and greatest (27.2 ± 14.3 inds m−2) in a small number of quadrats with a mixture of sand and algae or sand and A. antarctica. The population was estimated at >600,000 individuals. The species was present in February but had disappeared by late March 2021. The population at Little Armstrong Bay and North Point provides a fertile opportunity for developing a better understanding of the biology of B. hirsuta and broader questions of boom-and-bust populations. |
|
