Stargazer shrimp, photograph by Guido Zsilavecz

New shrimp species found in False Bay

Guido Zsilavecz is the author of two essential reference books on the marine life around the Cape Peninsula: Nudibranchs of the Cape Peninsula and False Bay, and Coastal Fishes of the Cape Peninsula and False Bay. He is also one of the founder members of SURG, the Southern Underwater Research Group, and monitors the questions at email address to which you can send pictures of all the creatures you can’t identify. Despite this prolific marine biology-related output, he is actually a computer scientist by day – photographing and researching marine life is a passion rather than a profession for him.

We were delighted to see an article on the front page of the Weekend Argus two weekends back, announcing Guido’s discovery of a new shrimp species in False Bay: the striking little stargazer shrimp, named Mysidopsis zsilaveczi after him! You can read another news report about it here.

Stargazer shrimp, photograph by Guido Zsilavecz
Stargazer shrimp, photograph by Guido Zsilavecz

Guido very generously answered a barrage of questions from me about the shrimp, and the process of scientific discovery, and agreed to let us publish his answer here (thank you Guido!). If you’re a citizen scientist in the making, or a regular diver who appreciates False Bay’s biodiversity, and you want to know how you can contribute to new discoveries, read on – it’s a fascinating and encouraging story:

The first photographic record I have of the stargazer shrimp is from Windmill – in 2002. That I took a photo shows that it was something that caught my eye and interest. Normally when I see something new and unusual I file it into the back of my mind, so I keep a casual look-out for it – as the key to any of these things is to be able to “target” it, i.e. find it consistently. A single sighting doesn’t really help, as there’s every chance the animal was there by accident as that it could be its habitat. So over the years I’ve photographed some here and there (including, by the way, the Atlantic side – that seems to have been lost in the article), generally when I was going slowly with macro. It was during dives where I was using super-macro (beyond 1-to-1) that I started finding it more often.

Crustacea, like shrimps and crabs, are often very hard to identify for non-experts – very often you need to look at minute physical characteristics in order to determine what it is. From its overall look I figured out it had to be a mysid, but beyond that, well, I don’t have the right equipment or reference material to figure that out. But, I also know from interactions with the scientific community that if you draw attention to them regarding something like this, that they struggle just as much with just photos as we do, and that they need a specimen just as much in order to identify it. So, unless you can actively target it, there’s actually usually little point in bringing it to their attention. So, when I was in such a position, I approached Prof. Charles Griffiths, with whom I had been working before, and asked him if he knew what it was. He said no, and asked for the requisite specimen. I got that to him, and even with that he couldn’t identify it, so he contacted Prof. Karl Wittmann, who is an expert. He concluded that it was indeed new, and Charles (Charlie) decided that after having helped with other things in the past, to have it named after me – which is of course quite an honour!

There are a few interesting things about this shrimp: the eyes are the first bit that stand out – those rings seem to be quite unique, although not all of them have those. Another feature is that very often there are two blue-and-orange semi-circles on the “shoulders” – again, not all of them have that. All the specimens I’ve collected are male, and were found on bare rock (sometimes on growth on rocks), individually (rather than in swarms, as many mysids are found), and they are not particularly skittish – they are not easy to spot, and you need to get your eye in, but going slowly over rocks does yield a few specimens. I’ve seen them from Castle to Windmill, and Oudekraal – places I dive commonly, but that means they should be everywhere, in depths from a few meters to 15m or so – more indicative of the dives you can do, rather than delineating environment.

The big question still is, where are the females? That we hope to find out sooner or later.

Whether something is a new species is done both via taxonomic (physical) comparisons, as well as DNA – both work well enough – in this case it was simply a taxonomic inspection – and Prof. Wittmann probably has all the relevant material to be able to determine this.

What does one do if one thinks one has something new? If you have exhausted your own resources (guide-books, for example), ask us! The reason we formed SURG is to be the link between research scientists and normal divers. Research scientists are busy, so the less one disturbs them with “trivial” stuff, the more they are inclined to help with the non-trivial stuff. Not to blow our own trumpets, but between ourselves the SURG team have vast experience and knowledge, so we’ll be able to quickly spot something that’s interesting vs. something that is common. Most of the time I get questions about things which are not unusual – and I’m perfectly happy answering those questions (SURG’s by-line for me is “conservation through education” – if you know what it is, you’re less likely to destroy it – and “trivial” questions with non-trivial answers is part of that!) – if we do find something unusual, we can then pick up on it and take it further. Of course, we don’t have all the answers – for example, I recently received a number of questions about sponges – they are impossible to ID visually, except for some few species, and you really need tissue samples to find out what they are – even passing photos on is mostly pointless, but these are more the exception than the rule.

Have contributors to SURG helped? Absolutely! By creating this forum where people can ask questions we get a big group of eyes and cameras looking – more so that the few of us can cover. So we’ve had many sightings of visitors, range extensions (if something is seen often enough and the reference guides say it isn’t found here – well, this shows it does, and one can re-draw boundaries), as well as new species – I think Carel van der Colff’s Sydney Opera House nudibranch is the most distinctive of new findings – but there are others.

So, what do we do when we get something very interesting? First of all I encourage that person to keep their eyes open in case they see it again, and to take pics. Very often I also try to find it myself after asking the person more detailed questions as to where, when, depth, environment, etc. I do some preliminary research, and if I then don’t find a reference, I contact a research scientist somewhere, and we take it from there.

Can one as a “garden variety” diver contribute to this? Absolutely – remember that, as such, I’m such a garden variety – I don’t do this for a living! It is all a question of being interested, following it up, reading up about it, and so on.

One thing worth remembering is that that scientists at places like UCT have a very focused job, whereas we garden variety divers go to have fun – that means we can look at everything – and that means that, collectively, we see more than the scientists do! And people like Prof. Griffiths really appreciate that, because they help him immensely as well!

Are we interested in anything specific? No, not really – we like everything! And largest group with undescribed species – yes, invertebrates – but that’s a huge group to start off with, so a bit unfair to say that. I think fish and nudibranchs are best known, followed by crustaceans, and then we go onto the much harder groups – and those are often the least studied, and hence more likely to have more new species.

Finding something new is a question of luck, definitely, but also building up an ability to distinguish the known from the unknown (to yourself), continuously reducing the latter list, until you maybe have something new! And, even though False Bay has been studied a lot, there’s still many new things that can be found, we are sure!

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Lapsed mathematician, creator of order, formulator of hypotheses. Lover of the ocean, being outdoors, the bush, reading, photography, travelling (especially in Africa) and road trips.

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