Suitable Aquarium Blennies by Gerald Jennings and Terry Hall More and more aquarists are beginning to discover the great attraction of keeping cold-water marine life, for though the colours and shapes of tropical marines are outstanding, those of our native fishes are not to be despised. In addition there is a lot to be said for learning the different techniques of managing marine aquariums with less expensive fishes which you can collect for yourself. The blennies of our coast are excellent subjects for keeping in a cold-water marine aquarium, but do make sure that it is kept cold, for though some blennies frequent rock pools that heat up considerably between tides, they cannot stand too much heat and live far better in the cold. Use plenty of rocks and weeds for a blenny aquarium, and try to arrange an above-surface ledge of rock onto which the blenny can climb. The pectoral fins and ventral fins of some blennies are used like hands and feet for crawling about, and while this is mainly when they are in the water - and thus lighter - they are sometimes used to drag the fish onto an above-surface ledge. This is not to "sun" themselves as some folk think, for to expose themselves to the sun for any length of time would be fatal to any blenny as they must keep their gills damp. Therefore, if you do arrange a rock ledge at or above water level; be sure to drape wet seaweed over it to form a dank cave. Inside this your blenny will often conceal himself. Then it is just a matter of obtaining your blenny and that, fortunately, is not at all difficult if you have access to the coast anywhere, and who hasn't nowadays? Choose a beach where there are some rock pools and a time when the tide is out. Search each pool carefully, looking under the bladder wrack where it hangs in festoons down the side of the pool. Most likely the first fish you find will be a "Shanny". This is one of the most common of our blennies for it is present all around our coast. It is an interesting fish because of the variation in its colouring and blotchy markings. In length it can be up to six inches, while the colour is greenish-yellow, darkened with blotches of black, brown, or grey. Many blennies have a small filament sprouting from just above the eyes. The Shanny does not, so this feature can be used to distinguish it from others of a similar appearance. Although the food of the Shanny is mainly small water creatures of many kinds and some fishes, it does also eat some seaweed. In captivity it is easy to keep and soon learns to eat scraps of raw fish, pieces of mussel, and similar foods. With a similar taste in food, the Butterfly Blenny, Lipophrys ocellaris, is very much harder to find, for it has now become fairly rare. Nevertheless, it may occasionally be found among thick masses of seaweed in the larger pools towards the lower tide marks. It is up to 7 inches long. This blenny is easy to recognise, for it has the first spine in its dorsal fin extended beyond the others and there is a large "eye-spot" on the dorsal composed of a round black spot surrounded by a thin white line. In addition the Butterfly Blenny has a filament above its eves.
Montagu's Blenny, Lipophrys montagui, is a smaller fish than the first two mentioned, being only 3 inches long. This one also has the filament on the head above the eyes, but in addition, this filament is of an orange colour and it is connected to the dorsal fin by a series of small tentacles which sometimes show clearly and at other times are hardy discernible. The Montagu's Blenny lives in the tide edge among rocky pools and seaweeds and is somewhat more colourful than the first two described. It is brownish-grey with darker bands, but over this colouring is a series of bluish-white spots. The caudal is of an orange-red colour like the filaments over the eyes. Being smaller it is sometimes more convenient to keep in an aquarium, but always remember that all blennies have powerful jaws and teeth so that smaller living creatures are rarely safe from them. The Montagu's Blenny is inclined to skulk under rocky ledges, keeping out of sight for long periods. Looking something like the others but a larger size, is the Tompot Blenny, Paralipophrys gattorugine. This reaches a length of nine inches and has acquired its name of "Tompot" because it is so often found in lobster pots which it has entered to steal the bait. It will not normally be found in rock pools because its normal haunts are in slightly deeper water among rocks. The simplest way to catch one of these is with a hoop net baited with any kind of fish, or crushed-up shore crabs. Lower this to the bottom near rocks and after five minutes haul it up very smartly. Belonging to a slightly different group, though still with the name of blenny: Blennius ascanii or Yarrell's Blenny. This fish is up to 7 inches long, and lives in similar places to the Tompot, so may also be found in lobster pots or the hoop net. In colour the Yarrell's Blenny is reddish-brown, marked with blotches of lighter and darker colours. It is a longer, more slender fish than those already described; The filament over the eyes is supplemented by smaller ones farther forward, and by quite large ones on the first spines of the dorsal.
An extremely interesting fish is the Viviparous Blenny, Zoarces viviparus. Although this fish is reputed to reach a length of two feet, such big ones are rarely seen and a more normal size would be less than a foot. It would need a much larger aquarium but would be worth the extra trouble. The females mate in winter and carry their young about inside themselves for 3-4 months. When released, the babies are 1 to 1.5 inches long, perfectly formed and well able to fend for themselves. A large female can give birth to about two hundred at a time. This fish should be sought among seaweed lying on tumbled rocks near the lower tide marks, while the young ones may be almost anywhere in that sort of region. All these blennies have been kept in captivity and all are good feeders, so that they are most suitable for a first attempt at keeping salt-water fishes. |
