Bristlenose Catfish (Ancistrus sp.)

Common Name:

Bristlenose catfish.

Other Name:

Bristlenose plec or Bushynose Plec .

Scientific Name:

Ancistrus sp.

Family:

Loricariidae.

Sub-Family:

Ancistrinae.

Distribution:

South America. Some have been found in Central America and Florida but are thought to have been introduced there from aquaria.

Size:

Adult males 4-6 inches. Females are smaller than males

Diet:

In the wild bristlenoses subsist mainly on algae, and they will graze on algae in the aquarium. However, in the aquarium their diet should be supplemented with vegetables such as cucumber, courgette(zucchini), lettuce, spinach, squash, boiled potato and shelled peas, along with sinking vegetable-based pellets, algae wafers and vegetable-based flakes. Bristlenoses also need to be able to chew at a piece of bogwood. High protein foods such as bloodworm, daphnia, mosquito larvae, peeled prawns or high protein sinking pellets may also be fed as a weekly treat. Bristlenoses will also eat the corpses of any fish that die in the aquarium, although this should not be encouraged.

Water Temperature:

78 - 90 degrees Fahrenheit, although most will prefer around 78 degrees.

Water Chemistry:

Will accept pH 5.5 - 7.8 and can be acclimatized to both hard and soft waters. Some species may require soft water to spawn.

Life Span:

15 years plus.

Housing:

29g minimum, must be supplied with some caves to sleep in during the day.

Sexing:

Females are smaller and less robust than males. Males generally have larger bristles on their noses, while those of females are either smaller and sparser or not present at all. Bristles generally start to appear when the fish is around 1.5 inches in length.

Requirements:

Bristlenoses like water with lots of movement and plenty of oxgenation. They need plenty of nooks and crannies to hide in. These can be constructed of pipes, stacked slate or rocks, but if using slate or rocks, ensure that the structure is stable and cannot collapse on them. They are most active at dusk and dawn, but will forage at most times of the day or night. However, they do not enjoy bright lighting, so if they are to be kept in a planted tank, select plants that can survive in low light, such as java moss. They will need a piece of bogwood to chew on, so this should be untreated and unvarnished.

Description:

A typical bristlenose is broad at the shoulders with the head narrowing in a triangular shape towards the nose. Their bodies are quite stocky, especially when compared with those of Hypostomus (common plec), for example and, except for the ventral surface, are armoured with scutes. Their eyes are located on the top of their heads and are of limited importance in the finding of food. However they have a papillary iris flap which they can expand to cut out light or contract to allow maximum light to reach their eyes. The mouth is adapted into a flat sucker, and has a distinctive shape which can be useful in determining whether a given fish is a bristlenose or from another lorcariid species. It is also equipped with barbels. The bristles, which all males and some females have, are soft and disappear when the fish is lifted out of water as they are incapable of supporting their own weight in air. Bristlenoses have evertible interopercular spines at either side of the head, which appear when the fish is upset. The spines are tipped with minute hooks, which can make it difficult to extract a bristlenose from a net. Bristlenoses also have the ability to lock their pectoral, ventral and adipose fins in the upright position, which forms a useful defense mechanism. Most bristlenoses are brown or black in colour, with a variety of lighter coloured spots in many species. The ventral area is paler. Sometimes it is possible to see a pattern of blotches on a bristlenose which may appear and disappear, but this does not appear to be related to stress. There are also gold marble ancistrus as well as albino and colour mutation varieties.

Behavior:

A bristlenose will tend to select a cave or cranny and adopt it as their home. They will not take kindly to their home being moved or invaded by other fish, and will use their powerful tails to evict unwanted guests. They like to rest upside down, especially when they are relaxed and tame. They are not good swimmers and will swim in short bursts. Males are territorial and may fight with other males, especially if there is more than one male in too small a tank. However, in larger tanks it is possible to keep more than one male providing there are enough caves and the like for them to establish a territory. Most aggression is related to males guarding eggs however. As a rule of thumb, a three-foot tank would be big enough for a male and two females or a breeding pair. Females do not establish a territory but simply move from one shelter to another.

Breeding:

Bristlenoses quite commonly breed in the aquarium, although the methods of inducing them to spawn are poorly understood. In the wild they will spawn in the winter months during the rainy season, and may still follow this pattern even though they have otherwise ideal breeding conditions all year round in the tank. To encourage breeding, ensure that there are plenty of crevices available as breeding sites and that the fish are well fed. Good water movement and extra aeration may also be beneficial, as these mimic that water conditions in the rainy season. When ready to breed, the male will take up residence in a suitable crevice. The female will then inspect both the breeding site and the male. There may be some chasing at this point, but no harm will be done. After a while the female will enter the crevice to lay her eggs. The male will then be seen to be half out of the crevice, his tail end inside and his head, complete with bristles, outside, ready to deal with any threats. The newly laid eggs will range from yellow to bright orange in colour and will be in a raspberry-like clump. Once laid, the female takes no further interest in the eggs. Instead the male will stay in the crevice guarding the eggs then the fry for up to two weeks. During that time he will fan the eggs by using his pectoral fins. The fry will escape parental care very shortly after hatching and will gather in the corners of the tank, looking like tiny yellow balloons. They are vulnerable to being eaten by other tank inhabitants, so should be removed to another tank for growing out. While the yellow yolk sacs are visible the fry should not be fed. Once these have gone the fry should be fed on plenty of vegetable matter.

Ideal Tank Mates:

All non-aggressive fish with similar requirements. However, because they like a lot of water movement and oxygen, they do not make good companions for anabantoids such as bettas that require relatively still waters.

Tank levels:

Bottom Strata.

Unsuitable Tank Mates:

Aggressive, territorial fish, especially those which are protective of their young.

Sources:

Sources: Bristlenoses (Catfish with Character) Kathy Jinkings.
www.planetcatfish.com
www.scotcat.com

Photo Credit:

Photos 1-3 supplied courtesy and ^©Molino
Photo 4 supplied courtesy and ^©Off-ice.