With seven successful Melbourne Sea Slug Census events to date, our records of sea slug species found in Victorian coastal waters are continuing to grow. Collecting photos of sea slugs present at different times throughout the year will enable us to monitor these species and track any changes, but we’ll need your help!
The seventh Melbourne Sea Slug Census was held between Friday 13 and Monday 16 March. The report is now available for viewing below.
SOUTHERN SEA SLUGS PHOTO COMPETITION
Our stay-at-home friendly alternative to the Sea Slug Census, the Southern Sea Slugs Photo Competition, has closed and our guest judge has made their decisions. All of the fabulous entries we received, including the winning photo and runners up, can be viewed below.
Thanks to everyone who submitted photos to the competition and to all of our southern sea slug enthusiasts for their support and understanding for the need to provide alternatives to our regular Census activities during this difficult time. Unfortunately we can’t yet say when we’ll next be able to bring you a Melbourne Sea Slug Census, but for updates on Sea Slug Census events occurring at other locations across the country, you can check out the Sea Slug Census facebook group.
With many areas along the coast again subject to stage 3 restrictions, we sadly needed to cancel the winter Sea Slug Census planned for 10-13 July. More information about current restrictions can be accessed at the Victorian health department page.
In Partnership with the Melbourne Sea Slug Census:-
The Sea Slug Census is supported by the Victorian Government.
Caption: Tambja verconis, a nudibranch commonly spotted in Port Phillip Bay. Photo Liz Harper
What is a sea slug and how will you know if you’ve found one?
Sea slugs are actually snails i.e. they are sea snails (marine gastropod molluscs) that have seemingly lost their shells. Also known as nudibranchs, they are found in most marine habitats, occurring in shallow rock pools and in the deep sea. Knowing when you find one can be easy when they are the size of a football, or extremely difficult when they are smaller than the nail on your pinkie finger. Generally, if it is in saltwater and it moves like a slug it is most likely a ‘sea slug’. If you are unsure, take a photo and we will let you know.
Sea Slugs are one of the most popular and most photographed groups of marine invertebrates, with ~400 species known in Victoria. They are excellent indicators of environmental change because they have rapid life-cycles (less than 12 months), very specific food requirements, and respond to changing oceanographic conditions.
Yet there is very little basic knowledge on their diversity, distribution and ecology. To learn more about them we teamed up with Southern Cross University to have Victoria’s first Sea Slug Census in Port Phillip Bay, Westernport Bay and surrounds. The information gathered during Sea Slug Censuses will help marine scientists to update knowledge about the diversity and distribution of this spectacular group of molluscs.
To learn more about sea slugs in Victoria, check out these links:
**Please note: the 2020 winter Census (July 10-13) has sadly been cancelled. We’ll keep you posted with alternate stay-at-home friendly activities**
With many areas along the coast again subject to stage 3 restrictions, we sadly needed to cancel the winter Sea Slug Census planned for 10-13 July. More information about current restrictions can be accessed at the Victorian health department page, Parks Victoria, and Park and Forest closures (includes notices of beach closures).
Photographing sea slugs for identification:
To help our experts with their identification, try to get a clear shot of the slug’s body from the side and/or include as many creature features (rhinophores, gills/cerata, oral tentacles) as possible. As always when out and about in nature, be mindful of limiting your impact on your subject and their surrounds.
A note on water quality:
Heavy rain can impact water quality on our coasts, especially after fires and periods of smoke haze. In general the EPA recommends avoiding swimming near stormwater or river outlets 24–48 hours after heavy rain. Within Port Phillip Bay, you can check your local beach conditions at the Yarra and Bay Beach Report- https://yarraandbay.vic.gov.au/
We’re very pleased to share with you all the stunning entries we received in our Southern Sea Slugs Photo Competition. These talented photographers certainly met the brief by showcasing how wonderful and diverse our temperate species really are.
It might come as no surprise that the competition was dominated by those beautiful dorid and aeolid nudibranchs, but we did have one colourful headshield slug representing the non-nudi species!
Photos were judged by Dr Julian Finn of Museums Victoria. Julian is a researcher and museum curator focusing on marine invertebrates. He is also a talented photographer and cameraman, and his images are featured in many field guides as well as Museum Victoria’s Marine Life Exhibition. You can check out some of his work, both in marine science and visual storytelling, here.
Winning Photo
PT Hirschfield, Two Verconia verconis
The award for winning photo goes to PT Hirschfield, for this incredible shot of two Verconia verconis crawling over their food sponge. In his judging Julian noted:
“This image features a pair of chromodorid nudibranchs Noumea [Verconia] verconis, that imitate the colour and shape of the sponge they feed on.
A highlight of this image is the framing, with the forward-facing individual in the foreground and the rear-facing individual in the background. This framing produces a superb image that is both pleasing to the eye and extremely informative. By providing two perspectives of the same species, the viewer can gain a greater understanding of the morphology of this intriguing animal and fully appreciate its beauty.”
Congratulations PT, fantastic work!
Runners Up
Nick Shaw, Phyllodesmium macphersonae
A striking shot of this fascinating aeolid. Julian had this to say about Nick’s photo:
“This image features an aeolid nudibranch Phyllodesmium macphersonae with deep blue, yellow-tipped cerata, each containing a duct of the digestive tract.
The orientation of the subject in the frame makes this image a standout. With the nudibranch facing the lens, and with sufficient depth of field, the key features (i.e. the oral appendages, smooth rhinophores and anterior cerata) are all in focus. The rear of the animal blurs smoothly, giving the image depth. An impressive image.”
Astute readers may also recognise this one from way back in the very first Melbourne Sea Slug Census report from April 2018! Well done Nick.
Liz Harper, Ceratosoma brevicaudatum
This beauty was captured in fine detail here in Liz’s shot- you can clearly see even the minute eggs coiling around inside the egg ribbon that the slug is laying down. Julian notes:
“This image features the chromodorid nudibranch Ceratosoma brevicaudatum, reportedly Victoria’s most common nudibranch and, on account of its large size, often the first nudibranch observed by new divers and snorkelers.
Unlike most images of this species, this image includes both the animal and a coil of freshly laid eggs. The framing and exposure of this image draws the viewers eye from the nudibranch to the eggs. The orientation of the nudibranch in the image results in all of the key structures (i.e. rhinophores, gills and branchial appendages) being in focus. This makes for a very pleasing, informative and natural-looking image.”
Well done Liz for an exceptional entry!
Please enjoy the full gallery of competition entries:
Stephanie Weiser’s Ceratosoma brevicaudatum fills the frame of this great shot with its beautiful colours, gradients and patterns, which seem to spill out onto the surrounding rocks in the form of tiny shells and casings
Stephen Goodall’s photo of a solitary Phyllodesmium serratum sitting out alone on the sand draws our attention to the fine, transparent cerata filled with pinkish, winding digestive tracts that the animal is so well known for
Tina Havill’s vibrant Ceratosoma brevicaudatum shows this animal in the process of retracting its bright red gills inside its mantle cavity, where they are safely stored inside a handy pocket
Elodie Camprasse has captured a beautiful, lace-etched Goniobranchus tinctorius in the midst of laying its cream coloured egg ribbon in this fantastic shot
Glenys Greenwood’s photo of two Tambja verconis following each other through a garden of algae, and featuring the curling egg ribbon of the species, is a lovely combination of warm yellows and cool blues- much like the focal slugs themselves.
Iain Davis puts this Phyllodesmium serratum under a spotlight and gives us a stunning shot showing great detail in the slug’s delicate features
Ian Scholey’s shot of a curious Coryphellina sp. sensing the water around it captures this colourful yet tiny animal in superb detail, where even the minute eyespots can be clearly seen
Jack Breedon’s Polycera janjukia is a playful close up of this beautiful nudibranch, with exceptional focus showing the detail in the club-shaped rhinophores
Jak Grimm’s Ceratosoma brevicaudatum out foraging among the algae is a captivating shot that casts this boldly coloured slug in a pleasant, pastel light
John Olden has given us an extraordinary close up of Tambja verconis. This photo prominently features the open extra-sensory organ beneath the rhinophores, a rare thing to capture
Karen Barwise’s entry of this delicate orange dorid sharing the spotlight and seemingly conspiring with a fishy friend tells a wonderful, if not fantastical, story
Kim Bremner’s Tubulophilinopsis lineolata was the only non-nudibranch sea slug entered into our competition, but it holds its own. The colour and detail in the focus around the head of this slug makes for a stunning shot
Liz Harper’s photo of Ceratosoma brevicaudatum laying eggs shows the features of this well known slug in breathtaking detail and was also judged runner up for the best photo
Mark Morrisy’s Ceratosoma amoenum stands out by showcasing this animal in a much cooler tone than most of the other entries, and seems to capture the slug moving across a seafloor littered with shells and fragments of lace corals with great purpose
Mick Morley’s portrait of Ceratosoma brevicaudatum perfectly captures why this slug is so often one of the first species that many of us will see in Victoria, drawing us in to its striking patterns and colours as it stands out against the algal backdrop
Nick Shaw’s runner up photo of Phyllodesmium macphersonae was recorded during our first Melbourne SSC and remains one of the most stunning entries on file, a great example of an artistic shot that still conveys the necessary biological information for our experts
Peter Mosse’s candy-coloured Ceratosoma amoenum stands out beautifully from its surroundings and looks good enough to eat- but this species stores unpleasant chemicals in its mantle to discourage would-be predators
Rachel Price’s vibrant Coryphellina sp shows the finer details in the rhinophores and oral tentacles of this slug and warms us with its flame-like cerata
Rob Paule’s fantastic close up of a Dendrodoris arborescens crawling across a pale sponge showcases the intense red of the mantle fringe and the white rhinophoral tips of this species
PT Hirschfield’s wonderful, winning photo of two Verconia verconis is reminiscent of an artistic naturalist’s plate and shows the details of this spectacular slug from two different angles
Between 13-16 March 2020 people right across Port Phillip Bay, Westernport and beyond submitted their findings to the seventh Melbourne Sea Slug Census. All in all, we had submissions from 14 individuals or teams and as we’ve come to expect there were some fantastic finds. As Steve Smith of the SSC project put it, our “accomplished spotters and photographers…. makes viewing the report a real pleasure”. We hope you agree, and you can download the report for your own viewing below.
We recorded 61 species of sea slug for March 2020, up from the same time last year, and we’re expanding our list of recorded species with each new Census. Well done to everyone, but in particular, here are the winners of our regular Census awards!
Best photo: John Olden, Tambja verconis
What a fantastic shot of one of Victoria’s most iconic nudibranchs. In his letter to us with the results of his identifications Bob Burn stated “I keep going back to this shot because it clearly shows the internal detail of the ribbing within the accessory sensing organ. I know of only one other image showing this fully open and in use.” Great work John for capturing some science in your art.
Steve nominated Nick Shaw’s Trinchesia sp. RB2 as an honourable mention in this category. This is a great shot of this colourful aeolid, clearly showing detailed creature features such as the tiny eyespots and the striking, bright blue oral tentacles typical of this species.
John Olden’s winning Tambja verconis combined a clear but artistic shot with a fascinating look at how this slug senses the world around it
Nick Shaw’s crisp and colourful Trinchesia sp. RB2 was nominated for an honourable mention in the best photo category
Most interesting species: Rebecca Lloyd, Elysia sp. RB4
The most interesting species as judged by Bob Burn, Rebecca’s striking Elysia is the most easterly report of this species to date. Elysia sp. RB4 is known from South Australia and western Victoria, but Rebecca spotted it at Beaumaris in Port Phillip Bay. It is distinguished from the similar looking Elysia furvacauda by the presence of small white pustules on the parapodial margins (in E. furvacauda the margins are smooth). Great find Rebecca, and it goes to show how having the extra pairs of eyes (and cameras!) out in the water is expanding our knowledge of the behaviour and distribution of these animals.
An honourable mention in this category goes to Corinne Telford for her Tamanovalva babai. Steve Smith noted that this tiny species of sap-sucking slug is very hard to spot amongst its food source, and Corinne actually found 2 different individuals! It has been described by Bob Burn as having a limited range, endemic to eastern SA, central Vic and northern Tas, and Steve himself has never seen one. Well done Corinne.
Rebecca Lloyd’s Elysia sp. RB4 spotted at Beaumaris was a surprising discovery as this species was previously only known from South Australia and western Victoria.
Corinne Telford’s Tamanovalva babai was a great find. This small and inconspicuous species is a first for our Melbourne SSC records and rarely spotted.
Ultimate nudi hunters: Paul Sorenson and Rebecca Lloyd
Again the award for most species spotted is a tie between two enthusiastic divers- well done Paul and Rebecca for finding 30 species apiece.
Caption: Paul Sorenson’s shot of two Doriopsilla carneola side by side shows how much variation in colour (and size) we see in one of our favourite “orange blobs”!
Thanks again to everyone who contributed photos to the March Census, and for your understanding around the decision to cancel the July Census. COVID-19 is creating a lot of uncertainty, and while we are hoping to schedule another Census this year, we will continue to monitor the advice and regulations from health authorities before making a decision. Please stay safe out there.
250 photos were submitted to the Census for March, and with everything going on we had to rely on snail mail to get them through to our expert Bob Burn for identification and judging. We ended up recording 61 species of sea slug! And we’re still adding species to our project records each new Census. Well done everyone.
Smoke from the recent bushfires had severely impacted much of the Victorian coast this weekend, but around 100 intrepid nudi hunters made the best of conditions and submitted over 200 photos to the Census. We still recorded 72 species of sea slugs! And the quality of photos made Bob Burn’s judging of the competition a tricky task. Thanks to everyone who submitted to our first true summer edition of the Census.
What can we say other than we were blown away by the number of nudis spotted this time! 88 species to be exact, some new additions to our records and a few entries that left our experts pleasantly surprised. October certainly seems like a busy time for both our nudis and the keen citizen scientists who search for them!
Our winter wonderland edition of the Melbourne Sea Slug Census saw many people brave the cold water, but only 6 groups of nudi hunters managed to photograph slugs during that time. Still, 29 species of slug were sighted, with some really beautiful submissions and new species to add to the Melbourne census records. A commendable effort for a very chilly weekend!
Melbourne Sea Slug Census III was held over the 15-18 March. Many groups reported seeing far less slugs than expected, but all in all, over 100 nudi hunters that were out and about across the weekend recorded 48 individual species between them. Well done everyone!
The second Melbourne Sea Slug Census took place on the 12-15 October. Over four days, enthusiastic teams and individuals managed to find an incredible 75 species of sea slugs! It was a fantastic effort and the overall quality of images submitted impressed everyone involved in sorting and identification. Some of the species photographed during this Census have rarely been seen in Victoria, even by our leading experts!
The first Melbourne Sea Slug Census was held on the on the weekend of 21-22 April. Thank you to the over 150 people who photographed different sea slugs (nudibranchs) in Port Phillip Bay, Western Port Bay and surrounds and submitted them to ReefWatch. Together, we found a total of 53 species of nudibranch!
