The Bristlenose Pleco.
Genera include: Ancistrus Dolichopterus, Ancistrus temminckii, Ancistrus cirrhosus
If you are looking for a small, relatively peaceful algae eater, look no further than the Bristlenose Catfish. It is hardy, will tolerate a range of environments and will surprise you with its breeding habits. This fish will not get much bigger than 8-10cm. The male will display the characteristic bristles on his snout and round his mouth. The female (depending on type) may have one or two just around the top edge of her snout or none at all. Both fish have bristles on what can only be described as cheek extensions which they will flare occasionally!
Tank and water requirements:
Having being imported to the UK since the early 70's, this delightful little catfish originates from the fast flowing rivers of South America, and so it likes well oxygenated water. Literature has it that a 60cm length tank will be enough for one of these fish, but for breeding it is probably preferable to have at least 90cm. The ph can be anything from 5.8 to 7.5, temperature from 22-28c and the hardness range from 2-20dGH. As with all tropicals, ammonia and nitrite must be 0, and nitrate kept below 20ppm. The ancistrus also requires some bogwood or mopani wood in the tank and it will rasp away at it to obtain lignin, a substance that it requires to aid digestion. You will find that a lot of gravel cleaning is required under the usual resting place of your Bristlenose cat....
You may find if you read up on the Bristlenose Catfish that it is an algae eater, and yes, it will clean up your tank for you. However, please do not ignore the fish's dietary needs. Many people relegate this fish to the role of tank cleaner/scavenger and do not provide a range of food for it.
The Bristlenose will eat all of the following lightly blanched: peas (squeezed out of their skins); courgette (zucchini for those in the USA); lettuce; spinach; broccoli and cucumber. It is not by any means vegetarian and will eat bloodworm, sinking tablets and other protein rich foods. Like all fish, it is not averse to grazing on dead tankmates.