Tag Archives: master student

Sea slug day 2020; Jorunna in the spotlight

Today we celebrate Sea Slug Day! ✨

The day coincides with the birthday of Terry Gosliner, who has discovered one-third of all known sea slug species (more than a 1000!). Here’s a link to how October 29th became #SeaSlugDay.

And what better way to celebrate it than introducing a new species to the world. Today it will all be about the Jorunna tomentosa species complex that our master student Jenny Neuhaus studied for the last two years.

Jorunna tomentosa, picture Cessa Rauch

Jorunna tomentosa is known to occur in a wide variety of colour patterns, which tossed up the question whether we are actually looking at a single species at all, or maybe dealing with cryptic lineages.

The colour diversity of Jorunna tomentosa, picture by Anders Schouw, Nils Aukan, Cessa Rauch, Manuel A. E. Malaquias

Jenny compared specimens from Norway, Ireland, Spain, Azores and South Africa, both genetically as well as anatomically. She used different gene markers like COI, 16S & H3 to check how these morphotypes compare with each other and evaluate the meaning of genetic distances. But she also did an elaborate morpho-anatomical study to look for differences between these colour patterns. Together with Dr. Marta Pola in Madrid, they dissected the different J. tomentosa specimens and looked at parts of the digestive (radula & labial cuticles) and the reproductive systems. These are all key to help unraveling putative different species and characterize them.

About Jorunna tomentosa

Jorunna tomentosa has an oval-elongate body shape with different colours varying from grey-white to cream-yellow and pale orange. They can reach a size up to 55 mm and occur at depths from a few meters down to more than 400m. they feed on sponges of the species Halichondria panicea, Haliclona oculata and Haliclona cinerea. J. tomentosa can be found from Finnmark in northern Norway, southwards along the European Atlantic coastline, the British Isles, the French coast, Iberian Peninsula, Mediterranean Sea up to Turkey, and the Azores and Canary Islands,. Besides the species has even been recorded from South Africa.

Before Jenny studied J. tomentosa, the various colour morphs were regarded as part of the natural variation of the species. By combining molecular phylogenetics with morpho-anatomical characters Jenny investigated the taxonomic status of the different colour morphs of J. tomentosa.

Jorunna sp. nov.?

Jenny sequenced 78 specimens of which 60 where successful for using in the final phylogenetic analyses. Her results supported a new Jorunna species, and a possible case of incipient speciation in J. tomentosa with two genetic lineages morphologically undistinguishable.

From left to right Jorunna spec. nov. Jorunna tomentosa lineage A and down Jorunna tomentosa lineage B

The new Jorunna species was based on material collected from Norway (Kristiansund, Frøya & the North Sea). Jorunna spec. nov. has a distinct colour pattern of cream-yellow with dark small dots (plus, as important; major differences in the radula and reproductive system).

Jorunna spec. nov.

It has been our pleasure to have Jenny here as a student, and she has done excellent work. Last year she won best student poster award last year with her work on Jorunna tomentosa at the World Congress of Malacology in California, USA. Most recently, Jenny defended her thesis on October 26 and passed with an A for her great work – congratulations from all of us at the Museum!

-Cessa Rauch

Sea slugs of Norway Instagram: @seaslugsofnorway

Sea slugs of Norway Facebook: www.facebook.com/seaslugsofnorway

Travelogue from Jenni’s field-trip to California Academy of Sciences, San Francisco

Sea slugs and San Francisco

Phanerophthalmus sp. from Mozambique. Photo: Manuel A. E. Malaquias

Phanerophthalmus sp. from Mozambique. Photo: Manuel A. E. Malaquias

I am three months into the second year of my masters in marine biology, and was lucky enough to start off this semester with a three week trip to San Francisco in order to collect material for my project.

I am writing my master thesis for the University museum of Bergen on the phylogenetic systematics and evolution of a small marine gastropod.

The title of my project is “Patterns of speciation in the Indo-West Pacific, with a systematic review of the genus Phanerophthalmus (Cephalaspidea, Haminoeidae).

I will be using an integrative taxonomic approach combining fine-scale anatomical dissections and molecular phylogenetics to revise the taxonomy and be able to better understand the relationships of the species. The group is restricted to the shallow waters of the Indo-West Pacific and may therefore be used as a good model to study speciation and the historical biogeography of other organisms in this region.

In order to obtain specimens for this project loans have been made from various museums and academic institutions around the world. In total I have 60 specimens on loan from these various institutions, however they still only represent part of the diversity of the genus with limited geographical coverage. The California Academy of Sciences (CAS) in San Francisco holds the largest collection of sea slugs in the World, including specimens of the genus Phanerophthalmus, with over 100 specimens. So, it was arranged for me to visit this large collection and assess what was important for my project. Travelling to CAS also meant I was able to work alongside Dr. Terry Gosliner, a leading expert in the field of malacology.

Phanerophthalmus crawling on seagrass

Phanerophthalmus crawling on seagrass

Pier 39 and California sea lions

Pier 39 and California sea lions

So, on January 16th I got on a 10 hour flight to San Francisco. I stayed at a guest house in the Richmond district of San Francisco, about 40 min walk or 30 min bus from CAS.

Waking up on Sunday morning I was a bit jetlagged, but super excited to be in San Francisco. As it was Martin Luther King Jr. day tomorrow (Monday), I had two days to recover from the flight and adjust to the time difference (9 hours behind Bergen!).

I decided to go and explore the city so I took a bus to downtown San Francisco and went to Fisherman’s Wharf, to Pier 39 where the Aquarium of the bay is and also the California sea lions.

On Monday I went to see where I was going to be spending the next three weeks: at the California Academy of Sciences. Situated in Golden Gate park, the surroundings were beautiful.

Golden Gate park

Golden Gate park

Golden Gate Bridge

Golden Gate Bridge

 

After visiting the grounds of CAS I wandered over to the Golden Gate Bridge. There was rain in the air and the fog was coming down but the view of the bridge was spectacular.

 

 

 

 

 

 

California Academy of Sciences

California Academy of Sciences

Tuesday morning I arrived at CAS eager to dive into the collections. Terry met me at the staff entrance and after a chat and a coffee we got to work. The CAS database contained more than 100 specimens of Phanerophthalmus. The first few days were spent examining labels and matching live photos with specimens. The amount of material was a bit overwhelming and even though I would have liked to look at it all, this would not be possible during my short three week visit. So with guidance from my supervisor, Manuel Malaquias, I was able to focus on the most important specimens. As I am looking at the phylogeny of Phanerophthalmus it is important for me to have specimens which I can extract DNA from. It is also useful to know what these animals looked like live in order to maybe use the external morphology as a character for determining species.

The three weeks flew by so quickly. I spent my days with the collections, dissecting specimens and also got the opportunity to try the academy’s brand new scanning electron microscope. Terry was an amazing host and kept me busy. A huge thank you to him for dedicating so much time towards helping me out. Also, a huge thank you to everyone else at the academy for being so nice and welcoming. After my three weeks at CAS I had a few days to be a tourist in the city. My last weekend in the city happened to be Super Bowl 50 weekend and the city was buzzing with people and events. All in all I had a great visit, and now I have lots of material to carry on working with back in Bergen.

The collections (top), my dissection station (bottom left) and the male reproductive of Phanerophthalmus

The collections (top), my dissection station (bottom left) and the male reproductive of Phanerophthalmus

Scanning electron microscope session with Terry

Scanning electron microscope session with Terry

Alcatraz

Alcatraz

The amazing redwood trees at Muir Woods just outside the city

The amazing redwood trees at Muir Woods just outside the city

Keep calm and focus on sea slugs

Keep calm and focus on sea slugs

-Jenni