Undertaking kick-off; Decrease Heterobranchia and Pyramidellidae of Norway

Since September 2023, a brand new taxonomic venture began on the College Museum learning the biodiversity of sea snails (with shell) and sea slugs (with out (seen) shell) in Norwegian marine habitats. This venture is in a approach a comply with up from the “Sea slugs of Southern Norway” venture between 2018–2020, however this time with a deal with poorly studied habitats together with seagrass meadows, maerl coralline algae beds and landlocked fjords (“polls”). The goal teams of this venture are tiny sea snails of just some millimeters, that are a part of a gaggle referred to as “Decrease” Heterobranchia and Pyramidellidae (Picture 1) that along with the previous ophistobranchs (e.g. the ocean lugs), and pulmonates (slugs and land snails) type the Heterobranchia, one of many primary evolutionary lineages of the Gastropoda.

Picture 1: Instance of shells of a “Decrease Heterobranchia” (A) and a Pyramidellidae species (B). Image CRauch & MMalaquias.

The range of those tiny sea snails is poorly understood in Norway. At the moment, 9 households are identified within the nation: Acteonidae, Cimidae, Mathilidae, Murchiconellidae, Omalogyridae, Rissoellidae, Tjaernoeiidae, Xylodisculidae and Pyramidellidae (Høisæter 2014), however their small dimension and related shells make it difficult to determine the species. Throughout this venture these sea snails will likely be studied in Norway for the first-time combining DNA barcoding and morphology. Sampling will likely be primarily based on the usage of dredges, grabs, and snorkeling by accumulating the substrate they stay on.

Pyramidellidae are ectoparasites and are sometimes discovered residing on different molluscs or different marine invertebrates, but additionally on gentle sediments. The College Museum of Bergen has already an excellent assortment of “Decrease” Heterobranchia and Pyramidellidae from Norway, however a big a part of this materials shouldn’t be appropriate for DNA extraction because of the authentic fixation strategies primarily based on the usage of formaldehyde. Due to this fact, after the primary months of cataloguing the “previous” assortment and establishing protocols for DNA extraction, we lastly set out in February to gather recent materials. We visited two totally different websites round Bergen to check out accumulating specimens by snorkeling and take a look at the effectivity of a not too long ago acquired transportable hand-dredge (Picture 2).

Picture 2: The hand dredge which was used for accumulating specimens. Image MMalaquias.

Our first fieldwork day occurred on the Marine Organic Station of UiB at Espegrend. The sphere station is a handy place because it includes a absolutely outfitted laboratory (Picture 3), and simply in entrance of the station there’s a seagrass meadow dominated of Zostera marina. This eelgrass is commonly present in shallow and sheltered coastal areas between 0.5 m to 10 m depth on flat sandy bottoms. Seagrass meadows are various and productive and may harbor lots of of related species from many alternative teams of animals. One staff member swam with the dredge over the seagrass meadow and dropped it about 30 m from the shoreline, whereas the opposite staff member pulled it again by hand. As well as, substrates like algae, blue mussels, and ascidians have been hand-picked by snorkeling.

Picture 3: First fieldwork for the brand new venture, with venture chief Manuel Malaquias behind the stereomicroscope trying to find sea snails and slugs at Espegrend Marine Organic Station. Image CRauch.

These efforts yielded the primary specimens, particularly the “Decrease” Heterobranch species Ammonicera rota (Picture 4) and the ocean slug Elysia viridis (Picture 5).

Throughout our second sampling occasion, due to unhealthy climate situations with robust southern winds, we determined to go to a sheltered well-liked swimming space (though at the moment of the yr not so well-liked!) positioned north of Bergen referred to as Helleneset (Picture 6). Helleneset is a rocky shore space wealthy in algae and kelp with sand flats in between.

Picture 6: Second fieldwork journey, on the well-liked swimming space referred to as Helleneset, on a moist and chilly February day abandoned. Within the image Manuel Malaquias and Cessa Rauch. Image CRauch & MMalaquias 

This time the algae and kelp mats collected by snorkeling in ziplock plastic luggage didn’t yield a lot, however an in depth examination of the sand (with assist of stereomicroscopes) collected once more with the hand-dredge revealed the presence of many little gastropod snails. One among these little snails was our first Pyramidellidae; the identification shouldn’t be but utterly confirmed, nevertheless it appears to be like like Eulimella ventricosa (Picture 7).

Picture 7: A Pyramidellidae discovered from Helleneset, a attainable Eulimella ventricosa. Image MMalaquias.

These two first samplings days have been an excellent take a look at for the way we greatest can gather these snails that are small and basically just a little plentiful. The dredge is simpler to function with two folks working collectively; one to deploy it and the opposite to tug it again to shore. Sandy samples yield higher outcomes if left to relaxation for a number of hours and even days in trays or buckets as a result of anoxic situations start to type, forcing the animals to crawl out of the sediment.

That is only the start, if you wish to be a part of the journey of the range of “Decrease” Heterobranchia and Pyramidellidae in Norway, we will likely be usually updating tales and findings on this channel, and our social media accounts @SeaslugsofNorway (each Instagram and Fb), see you there!

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References

Høisæter, T. 2014. The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjoining waters. A taxonomic evaluate. Fauna Norvegica, 34: 7-78.