Most divers once qualified start diving with a view to seeing large creatures such as turtles and sharks, but they will be soon disappointed as large creatures are generally few and far between. There are many smaller creatures around which are easier to find, some of which are extremely delightful to photograph.
Mention to somebody in the UK that you like to photograph slugs and you may be rewarded by some unusual responses, as their first impression is of the long black creatures leaving slime trails over paving stones or eating vegetables in the back garden. Mention to a Frenchman that you like slugs and he will perhaps give you his favourite recipe for cooking them. However mention slugs to a diver and you will have a totally different response.
For me sea slugs provide some of the most colourful and diverse subjects to photograph and the waters around UAE contain some really fantastic opportunities despite the low visibility at times.
Sea slugs, more commonly called nudibranchs (which is Latin for “Naked Gills”), are underwater snails without shells, collectively known as opisthobranch molluscs. The “nudibranchs” in particular are a subclass of gastropods (literally a stomach on a foot) which can vary in length from almost a meter (Californian Sea Hare) down to a few millimeters.
Finding them can sometimes be a bit of a challenge; however, as many are so colourful, they usually stand out quite well. Knowing what they eat also helps, especially for finding the less colourful specimens, as most creatures of the sea are always looking for food. Noting these points turns the average diver into an amateur marine biologist, which can be helpful to the many professionals who actually study these creatures.
Food sources are varied including anemones, algae, ascidians, bacteria, hydroids, and tunicates. However the easiest to find are usually those whose diet is sponge or hydroids, which are commonly found not just on reefs but also on wrecks. The diet of these creatures can also change depending on various factors such as age, geography and depth.
Generally we are looking for small creatures of an average size between two and six centimeters and living at depths from two meters downwards. For this reason I prefer to photograph them with a micro lens suitable for 1:1 reproduction and really take “life size” photographs.
Some of the most common slugs found around the UAE and Oman coastline include the following:
Chromodoris annulata
Commonly known as the “spectacle” or “fried egg” nudibranch, I have observed this species on the wrecks in the Persian Gulf; however there is some variation between the Persian Gulf species and those found in the Gulf of Oman and Red Sea where the purple line joining the rings around the rhinophores and gills does not exist. Up to 5cm in length, the Chromodoris annulata is often seen moving along waving the front of the mantle.
Risbecia pulchella
Another common nudibranch found primarily off the east coast, generally in pairs with one following closely behind the first. Note the similarity in colours between this species and C. annulata: all that is missing are the rings. This particular slug can grow to 10cm in length, and is fairly common off the east coast of UAE and around the Damaniyat islands and off the coast of Oman. More usually it is between 6-7cm in length.
Dermatobranchus sp. (Spot Edged Dermatobranchus)
Frequently seen in groups eating Dendronephthya soft corals, this species also demonstrates the trailing behavior as usually found with Risbecia. These can be found off the east coast of UAE, sometimes in fairly shallow (5m) water. 3-4cm in length.
Hypselodoris nigrostriata
4cm feeds on sponges. This species is restricted to the Gulf of Oman, the Red Sea, and the western Indian Ocean. It is covered in large yellow pustules and criss-crossed with deep violet lines.
Hypselodoris dollfusi
5cm. An unusual species in that it was described in 1933 and disappeared till recently. It is now found occurring in the Gulf of Eilat, the Gulf of Suez, and the Gulf of Oman.
Hypselodoris infucata
3.5-4cm. Ubiquitous species found through-out the Indo-West Pacific, and has migrated from the Red Sea to establish itself in the warmer waters of the Mediterranean.
Hypselodoris capensis
Another sponge eater, about 2.5 to 3 cm in length. Found from South Africa up to the Gulf of Oman
Chromodoris obsoleta
4-5cm in length, it is usually found in shallow water reefs, endemic to the Red Sea around the Arabian Peninsula to the Persian Gulf.
Ceratosoma trilobatum
A monster in comparison to the others at 17cm, this particular example is one of two found on one dive at the Damaniyat Islands, Oman. It is often found exposed on coral reefs, hard sea beds, and soft sediment. The extended lobes contain concentrations of defensive glands, and often parts of these are missing.
The photographs taken for this article have been shot using various Nikon cameras with Nikkor micro lenses, generally the 60mm micro lens. I currently use a Nikon D300 in a Sea & Sea housing with double Sea & Sea 110α strobes. Lenses used for micro photography are Tokina ATX 35mm DX lens, 60mm, 85mm and 105mm Nikkor micro lenses depending on diving and visibility conditions.
About the author:
Gordon has been living and working in the Middle East since 1986. Born in Canada, Gordon was brought up in Scotland, UK. He has dived extensively in the Red Sea whilst living in Saudi Arabia as well as Scotland, South Africa, Egypt, Jordan, UAE, Maldives, Thailand, Malaysia, Singapore, Indonesia and Philippines.
Published in April 2011
