ECSENIUS AT A GLANCE
While they can fit in to a well-planned and balanced reef tank, the little clown blennies of Ecsenius are regularly overlooked by aquarists. We look at some of the options (sometimes) available.
While they can fit in to a wellplanned and balanced reef tank, the little clown blennies of Ecsenius are regularly overlooked by aquarists.
WORDS NATHAN HILL, ILLUSTRATIONS MADHUSUDHAN GUNDAPPA
SMALL, NERVOUS, surprisingly disease resilient and relatively low risk, the clown blennies of the genus Ecsenius comprise 54 currently known species, and even the largest of them barely reach 10cm fully grown. Naturally they occur across the Indo-Pacific, with representatives in the Red Sea across to the Great Barrier reef of Australia. Wherever they are found, they are found alongside corals, amongst which they make their homes. With just a few considerations, they can thrive in the home reef set-up, where they’ll be both a subtle addition, and a treat when they come out on show.
All are hardcore bottom dwellers, being absent of swimbladders, and all love a cave. That’s the first consideration — a cave is an absolute must. In particular they like burrows of a certain miniature size, usually something with a 1cm or so aperture. There’s no shame in boring out some holes in your live rock for them to dwell in, and they’ll love you for it.
Some can be coral nibblers. Not outright coral biters, but much like some of the dwarf angelfish species, you shouldn’t trust them in every situation. The occasional polyp, the quivering mantle of a clam — all might be tentatively nipped. A couple of species are routinely noted for feeding on the heads of SPS corals —
Ecsenius bicolor and Ecsenius gravieri — though it’s not a given.
Keeping the tank closed is a must. Despite being bottom dwellers, an awful lot of clown blennies find their way on to the floor beside an aquarium if it’s open-topped. Being spooked can be a factor in leaping out, so tankmates need to be chosen carefully.
Point in case, any of the usual piscivorous suspects
need to be avoided. Wartskin anglers and dwarf lionfish will make short work of any Ecsenius, but hostility can also be rife between the blennies themselves. Even in the largest of tanks, it’s sensible to stick with the one specimen, as territoriality is a real issue between these otherwise meek fish. Other outgoing bottom dwellers may harass a clown blenny, so be watchful of the likes of hawkfish and dottybacks. A blenny that cowers in the recesses of the tank (not its usual cave) is usually a strong indication of some harassment.
Ecsenius belong to a group of fish collectively known as the combtooth blennies. Combtooths are largely algae eaters, and will require a diet that caters to this. While algae-based flake food can work, there’s no substitute for the real thing. The comb teeth have evolved precisely to scrape fresh greenery from surfaces, so try to facilitate that. If you can forego the pane of glass at the back of the tank, let algae flourish there and you’ll see your blenny heading over to graze on it. In absence of this, clown blennies may resort to scraping at algae growth on any nearby corals instead, causing polyps to retreat. The saddest feature of Ecsenius is that so few of them make it into the trade, and the hobby is dominated by a couple of easily caught ‘regulars.’ Many of the fish here you might never see in person, but it’s certainly worth keeping an eye out for them.
Midas blenny, Ecsenius midas
The Midas is one of the likelier species you’ll encounter, in part because (unlike many other clown blennies) it inhabits such a wide area — it can be caught from the eastern coast of Africa all the way across to French Polynesia. It’s up there as a larger species, able to reach somewhere around 13cm, and unlike its cousins it spends a lot of time out and about in the open water column. In the wild, it can even alter the intensity of its colours to mix in with shoals of Anthias, which it does so for security while feeding. Far from being an obligate herbivore, the Midas is a plankton feeder, and in aquaria it needs to be offered plenty of small meaty foods. Copepods, Artemia and Mysis are all appreciated. Note that this species is also up there as the likeliest to nip its tankmates, whether they are fish or invertebrates.
6Origin: Widespread throughout the Indo-Pacific
6Size: 13cm
6Feeding: Lots of small plankton foods as well as fresh algae. May refuse flake foods
Bicolor blenny, Ecsenius bicolor
Possibly the most common of all clown blennies in the trade, the Bicolor is another large species at around 10cm. In the wild it likes to make a home of abandoned tube structures, and in the aquarium it likes to perch itself on ‘peaks’ of rock and décor. This is one of two species most strongly implicated in coral nipping, with a taste for SPS in particular. If it does this, it could be an indication of insufficient feeding, so increase the amount of chopped Mysis and Artemia offered, while making sure that there’s a suitably large harvest of fresh algae available.
6Origin: Widespread throughout the Indo-Pacific
6Size: 11cm
6Feeding: Lots of small plankton foods as well as fresh algae and algae-based flake foods
Red Sea mimic blenny, Ecsenius graviera
The looker of the family, this is one of the most coveted species. The Red Sea mimic does what it says on the tin. Using Batesian mimicry it passes itself off as a Blackline fangblenny, Meiacanthus nigrolineatus — a fish with a venomous bite and avoided by many a potential predator. While they are still relatively scarce, captive breeding efforts are slowly boosting availability. If you do spot one, expect to pay through the nose for it. £100 or more isn’t unknown. Like the Bicolor blenny, this fish could be tempted to nip the occasional SPS coral.
6Origin: Red Sea to the Gulf of Aden
6Size: 8cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Dot dash blenny, Ecsenius lineatus
While not the most colourful fish in the genus, the Dot-dash is affordable and abundant, and gives good presence for the price at just shy of 10cm. Some individuals have been recorded as developing a taste for specific corals in aquaria, which can be managed to some degree by offering an ample diet. With a full belly, it tends to behave. You’ll find them from about £30.
6Origin: From Japan to Australia
6Size: 9.2cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Twocoat coralblenny, Ecsenius dilemma
6Origin: Philippines
6Size: 3.1cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Allen’s blenny, Ecsenius alleni
6Origin: Only known from a handful of reefs off of Western Australia 6Size: 3.4cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Fourline blenny, Ecsenius aequalis
6Origin: Australia’s Great Barrier reef as well as Osprey reef in the Coral Sea and the Trobriand Islands of Paupa New Guinea.
6Size: 4.3cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Clown blenny, Ecsenius axelrodi
6Origin: Centred around the Solomon Islands and Admiralty Islands, and Papua New Guinea 6Size: 6cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Kurt’s blenny, Ecsenius kurti
6Origin: Endemic to the Cuyo Islands, Philippines
6Size: 3.5cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Bath’s combt th, Ecsenius bathi
6Origin: Malaysia and Indonesia
6Size: 4.5cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Tiger blenny, Ecsenius tigris
6Origin: Bougainville, Holmes, and Osprey Reefs, Coral Sea. 6Size: 5cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Blue headed combt th blenny, Ecsenius lividanalis
6Origin: Northern Australia, Indonesia, Papua New Guinea, the Solomon Islands and the Philippines 6Size: 5cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Twinspot blenny, Ecsenius bimaculatus
6Origin: Borneo and the Philippines
6Size: 4.6cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Black combt th blenny, Ecsenius namiyei
6Origin: Taiwan to the Solomon Islands, Western Pacific 6Size: 11cm
6Feeding: Plenty of fresh algae and vegetable flake foods
Tailspot blenny, Ecsenius stigmatura
6Origin: Indonesia and the Philippines
6Size: 6.5cm
6Feeding: Requires lots of plankton feeding, offer Artemia, chopped Mysis and copepods
Striped blenny, Ecsenius pr culis
6Origin: Solomon Islands and Papua New Guinea
6Size: 3.8cm
6Feeding: Plenty of fresh algae and vegetable flake foods