Author: Darren Stevens
First published in Aquarium World May 2011

The common bristlenose catfish and the GBA (golden black-eyed Ancistrus) are two of the most commonly available plecos in the hobby. They are small, growing to about 12 cm, tolerate a wide range of aquarium conditions, and breed freely. Both are types of Ancistrus and along with other similar relatives they are commonly called bristlenose or bushynose catfish, after the large fleshy ‘tentacles’ found on the front half of the head of adult males. The function of these large bristles is not known but it has been suggested that they imitate young bristlenose that are ready to leave the nest, as females prefer to lay their eggs in the nests of males that are already guarding young because this shows they are good parents.

There are over 60 scientifically described Ancistrus species, and many more awaiting a scientific name. The name Ancistrus comes from the Greek word agkistron which means hook in reference to the hooked odontal spines on their cheeks. Bristlenose catfish are widespread in rivers and floodplains throughout the Amazon River system.

The common Ancistrus species, such as the common bristlenose and GBA’s, are relatively hardy and peaceful, although adult males are territorial and do squabble. Most Ancistrus are suitable for community tanks, but they do need plenty of cover, in particular bogwood which is thought to be an essential part of their diet. However, some Ancistrus species such as the medusa plecos (Ancistrus ranunculus L034 andAncistrus sp. L255) are sensitive and are only suitable for experienced aquarists. All bristlenose appreciate good water flow and high dissolved oxygen levels.

Along with bogwood, feed your bristlenose on a varied diet of veggies, pleco algae wafers, and the odd meaty treat (shrimps, bloodworms, etc.). Most people feed bristlenose on courgettes and cucumber, but also try them on other veggies such as shelled peas, green beans, broccoli, silverbeet, spinach, etc. Sometimes they take a while to get used to a new veggie so try them on it a few times before giving up. Meaty foods should only be fed occasionally and in small quantities. A protein rich diet may result in the early death of your bristlenose.

Common bristlenose and GBA’s are easy to breed, although other species are more difficult. There are excellent articles on how to attempt this on Planet Catfish (www.planetcatfish.com).

There are many very similar looking Ancistrus species and as a result there is often confusion over their identity. It also appears that some species will hybridise if given the chance. Therefore, the identity of most Ancistrus species available in New Zealand is not well known and should be regarded as tentative. The following species are some of the more commonly available bristlenoses, along with their tentative identifications.

Common bristlenose (Ancistrus cf. cirrhosus)

The common bristlenose catfish is a small (to about 12.5 cm standard length, SL) light to dark brown fish with light brown spots. There are a number of man-made colour varieties overseas including albino, piebald, calico, green dragon, and super red forms and all are available as long-finned veiltails. In New Zealand we have standard, albino, and calico colour varieties. Recently standard, albino, and calico long finned veiltails have been imported. Common bristlenose are of unknown origin. For decades they were wrongly calledAncistrus dolichopterus, the scientific name for the starlight bristlenose. More recently they were referred to as Ancistrus sp (3). Recently, pleco guru Ingo Seidel, concluded that they closely resemble Ancistrus cirrhosus from the Paraná River, Argentina, one of the first Ancistrus species imported into Europe. Given these similarities it is now referred to as Ancistrus cf. cirrhosus, meaning that common bristlenose are very similar to Ancistrus cirrhosus, and possibly the same species. Common bristlenose have been captured in waterways in Central America and Florida, presumably from aquarium releases. They are suited to most community tanks with pH’s of 5.8–7.2 and temperatures of 21–26.5ºC. Common bristlenose are easy to breed.

Golden black-eyed Ancistrus (GBA) (Ancistrus sp. (4))

Golden black-eyed Ancistrus (or GBA’s) are a small (to about 12.5 cm SL) golden, black-eyed pleco. They are amelanistic, i.e. they lack black pigment (melanin), and are of unknown origin, although they are thought to have been derived from the common bristlenose. They are often incorrectly referred to asAncistrus sp. L144, a Paraquan species which has a blotchy look and is apparently very rare in the hobby. Regardless of their origin they can be kept in the same conditions as common bristlenose and are easy to breed. They are also available as long-finned veiltails.

‘spotted’ Ancistrus (Ancistrus sp.)

The ‘spotted’ Ancistrus is a light brown species with small pale brown spots. It is a recent import of unknown identity, although it has been tentatively identified as Ancistrus ‘Rio Ucayali’, a PeruvianAncistrus from the Rio Ucayali. This species grows to about 15–20 cm, and they are suitable for most aquarium conditions. They have been bred many times in New Zealand.

Starlight bristlenose (Ancistrus dolichopterus, L183)

Starlight bristlenose are a beautiful little (to 10 cm SL) dark brown pleco covered with very small white spots and a thin white margin to the dorsal (top) fin and tail. starlight bristlenose used to be very rare in New Zealand. However, recently a major New Zealand pet store chain has imported starlights in good numbers and at reasonably prices.  

There are several similar patterned Ancistrus species but apparently only the starlight bristlenose has one hard and mainly nine (sometimes 8–10) soft dorsal fin rays. other similar patterned Ancistrus have 7, rarely 8, soft dorsal rays. Prior to these recent imports most new Zealand 'starlights' had 8 soft dorsal rays and they lose most of their white fin edging with age, only retaining it on the outer tips of their caudal fin. these plecos are likely to be peppermint plecos (Ancistrus sp. L071, L181, L249) which are reportedly easier to keep and breed. 

True starlight bristlenose originate from the upper and middle Amazon River basin and the Negro, lower Trombetas, Tefé, Madeira and Tapajós River basins. They are a relatively delicate species that does best in blackwater tanks (the tank water is stained dark by tannins released from plant material) with pH’s of 6.0–7.0 and temperatures of 23–28ºC. 'Starlights' have been breed occasionally in New Zealand.

Gold-marbled bristlenose (Ancistrus claro, LDA08)

The Gold-marbled bristlenose is a beautiful small (to 7 cm SL) dark brown pleco covered with a network of irregular pale brown spots and stripes. Gold-marbled bristlenose originate from the Rios Claro and Coxipo in Brazil. They are suited to most community tanks with pH’s of 6.2–7.6 and temperatures of 24–28ºC. They have been bred occasionally in New Zealand but have not been imported for many years and they are now very rare.

There are other Ancistrus species that have been imported, including the Jari blue Ancistrus (L325). However many species look very similar and it is often difficult to get an accurate identification. One of the most distinctive Ancistrus is the medusa pleco (Ancistrus ranunculus L034) with a very broad and flattened body. It is almost identical to the spotted medusa pleco (A. sp., L255) but is covered with fine white spots. These beautiful species are delicate and not recommended for beginners.

I thank Firenzenz and Krazy Geoff for their comments and improvements on earlier versions of this article.

References:
Planet catfish (www.planetcatfish.com)
ScotCat (www.scotcat.com)
Wikipedia (en.wikipedia.org)
Jonathan Armbrusters Loricariidae website
(http://www.auburn.edu/academic/science math/res_area/ loricariid/fish_key/lorhome/index.html)
Sabaj, M.H.; Armbruster, J.W.; Page, L.M. (1999): Spawning in Ancistrus (Siluriformes: Loricariidae) with comments on the evolution of snout tentacles as a novel reproductive strategy: larval mimicry. Ichthyol. Explor. Freshwaters 10 (3): 217–229.
Seidel, I. (2008). Back to nature guide to L-Catfishes. Fohrman Aquaristik AB, Sweden. 208 p.

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