Ancistrus triradiatus
Horned Bristlenose Pleco, Hirschgeweihantennenwels (DE)
Etymology
Ancistrus: etymology not explained, but understood to be derived from the Greek άγκιστρο ágkistron (Gr. ἄγκιστρον), meaning ‘fish hook, hook of a spindle’, in reference to the hooked interopercular odontodes possessed by genus members.
triradiatus: from the Latin tri-, meaning ‘three’ and radiatus, meaning ‘rayed’, possibly in reference to the number of soft anal-fin rays possessed by this species.
Classification
Order: Siluriformes Family: Loricariidae
Distribution
Colombia and Venezuela.
Habitat
Inhabits flowing streams and tributaries, where it lives among the rocky substrates.
Maximum Standard Length
4.8″ (12cm).
Aquarium SizeTop ↑
A pair could be kept in a tank measuring 30″ x 12″ x 12″ (75cm x 30cm x 30cm) – 67.5 litres. Larger quarters would be required for a group.
Maintenance
A stream-type setup with a gravel or sand substrate and rounded stones and rocks would simulate its natural biotope, but it’s equally at home in a planted tank. It does require well-oxygenated water, however, and live plants tend not to do so well under these conditions. It also prefers a degree of current running through the tank.
Water Conditions
Temperature: 75-86°F (24-30°C)
pH: 6.6-7.6
Hardness: 5-15°H
Diet
Mainly vegetarian, so the bulk of the diet should be composed of vegetable matter in both fresh (cucumber slices, blanched spinach etc.) and dried (algae wafers, Spirulina tablets etc.) forms. It will also accept small live and frozen foods such as bloodworm or daphnia and these should be offered fairly regularly.
Behaviour and CompatibilityTop ↑
Peaceful and due to its small size is suitable for most communities of peaceful species. Ideal tankmates include characins, peaceful South American cichlids and catfish such as Corydoras and other small Loricariids. It’s territorial with conspecifics, with this behaviour being particularly pronounced among males, but due to its relatively small size several can be kept in most tanks.
Sexual Dimorphism
Only the males develop the full, bushy growth of tentacles covering the head. Females may have some tentacles, but they are few in number.
Reproduction
Easy once the fish reach maturity. It will sometimes spawn in the community tank if conditions are to its liking, but if you want to raise a full brood of these (and control when the fish spawn) it’s best to set up a separate spawning tank. The best way to obtain a pair is to buy a group of at least 6 fish and grow them on together. A tank around 30″ x 12″ x 12″ will be needed, to allow the males to develop territories. Furnish the tank with plenty of caves and refuges, as like other Ancistrus, this is a cave spawner. The caves can be formed from rock piles, small flowerpots with a piece chipped from the rim, hollow logs etc. What is important is that the entrances must be only slightly larger than the fish. Provide well-oxygenated water, with lots of movement, a pH of 6.0-6.5, and a temperature of 75-80°F. There’s no need to use a substrate.
Condition the fish with plenty of greenstuffs, algae wafers and occasional feeds of live or frozen foods. Once the fish sex out you may wish to leave just a single male in the tank with 2 or more females, or much fighting can occur, and the fish might not breed.
There exist many theories regarding the best way of initiating spawning in Ancistrus (see below), but a good place to start is by conducting a large (50-70%) water change with cool water, simulating the infux of colder water the rainy season brings in nature. If this works (it often does if the fish are in good condition), the males will choose caves and defend them vigorously against other males, whilst conversely trying to entice females inside. A successful male will be ejected from his cave briefly, whilst the female goes inside to lay her eggs. When she’s finished, the male re-enters the cave and fertilises them.
The female plays no further part in broodcare, the male assuming sole responsibility for defending the cave against intruders, and tending to the eggs. This he does almost constantly, fanning them vigorously with his fins. He may also allow more females to deposit their eggs in the cave, and will care for all diligently. In fact, it’s been suggested that females are more likely to spawn with a male that is already guarding eggs or fry, and some have even hypothesised that the characteristic tentacles on the head of male Ancistrus are
lures to prospective mates, being designed to resemble juvenile fish.
The eggs are large and orange, and hatch in 4-5 days. The fry then remain in the cave, under the protection of the male for another few days, until they’ve used up their yolk sacs. At this point brood care usually, though not always, ceases and the fry will need heavy feedings of greenstuffs, such as blanched spinach, cucumber slices and algae wafers. Ensure that food is available at all times, as the fry are voracious feeders and can easily starve if not provided with a constant supply of food. They can be left in the spawning tank if you wish, as the adults will not harm them, or they can be moved to a separate rearing tank containing identical water. Brood size can vary, but expect at least 40-50 fry. Be prepared to move some of them to separate tanks if differences in growth rate become apparent, as the larger fish will outcompete the smaller for food.
If you’re having trouble spawning these (unlikely), try conducting a large (50-70%) water change with cool water, simulating the infux of colder water the rainy season brings in nature. Repeat every few days until the fish spawn.
NotesTop ↑
Often confused with the common bristlenose, Ancistrus sp. (3) and some other members of the genus. This species is imported quite often, but unlike sp. (3) is almost always wild caught. So similar are some of these species that a definite id is sometimes impossible without knowing the collection locality of the fish.
When buying Loricariids always check that the fish has a rounded belly and that its eyes aren’t sunken, as these are classic signs of emaciation in newly imported specimens. One final point to note is that extreme care should be taken when netting Ancistrus, as the cheek odontotes (spines that can be raised in aggression or defence, found on either side of the head) and pectoral spines can easily become entangled in the mesh of aquarium nets.
