Great Sea Slug Sunday wrap-up

Thanks to everyone who contributed to the first Great Sea Slug Sunday event as part of the Great Southern Bioblitz, and the Sea Slug Census program.
Together, we made 1,021 observations recording a total of 310 taxa. Many of these could be identified only to a taxonomic level higher than species, sometimes with multiple species comprising the taxon (e.g. Genus Dermatobranchus ), so the actual number of discrete species will be much higher than this total. Almost a quarter of observations (242) are still listed as Casual Grade (so please check them out and see if you can suggest an identification). This is also symptomatic of the fact that many of the species we observe from across the Southern Hemisphere have yet to be described – but a big thank you to those dedicated taxonomists who are, slowly but surely, describing these taxa.

For this first collection project, we also included observations from the Northern Hemisphere, with some really interesting finds (check them out in the Project). However, for this summary, I’ll focus on observations from the Southern Hemisphere which came from French Polynesia, New Caledonia, New Zealand, Australia, South Africa, Brazil and Ecuador. Major focal points for observations were around False Bay - Cape Town, in South Africa, and Sydney, Melbourne and the NSW North coast in Australia.

Our top 10 observers were @seastung (85 obs., 33 species), @ianscholey1 (69, 29), @diveinn_capetown (61, 37), @paul_isotope (56, 27), @profmollusc (50, 31), @nicklambert (49, 24), @drelodiecamprasse (36, 21), @pfuller (36, 15), @drmattnimbs (34, 19) and @katesherry (24, 12).

The most-observed species, with 23 observations, was the brown-lined paper-bubble (aka rose-petal bubble shell) Hydatina physis with all observations being made on the East coast of Australia between Sydney and the NSW north coast. This was closely followed by the white-speckled sea hare (Aplysia argus) with 20 observations over the same geographic area.

Image of Hydatina physis by @pamelaviolet

In South Africa, the most frequently observed species was the spectacular gas-flame nudibranch Bonisa nakaza

Image of Bonisa nakaza by @alisonbeere

There were some spectacular images of some beautiful sea slugs with a number of images really standing out:

Goniobranchus kunei taken by @judyasarkof

A feeding Tambja capensis taken by @seastung

A pair of Polycera janjukia taken by @ianscholey1

Goniobranchus leopardus taken by @divercraig

Leminda millecra taken by @seastung

A huge thankyou to the 98 identifiers who spent time going through the images and suggesting identifications. Our top 10 identifiers were: @hsini_lin, @predomalpha, @profmollusc, @pbsouthwood, @seastung, @anudibranchmom, @ben_travaglini, @nickoshaw, @w_martin and @glycymeris.

I have little doubt that, with the growing interest is sea slugs, they will feature even more strongly in the next Bioblitz event. Thanks again for all your contributions.

Posted on November 20, 2021 12:43 AM by