Article © Julian Dignall, uploaded May 13, 2014.

What would you do with a time machine? Once I'd seen some dinosaurs, been to 01/01/01 and probably debunked a few conspiracy theories, I might like to travel to the discovery time and place of the then new catfish species and actually have a look at the specimens as they came out the water. Thinking about it, I'd probably need an invisibility cloak while I was at it — otherwise I suspect I'd stick out a bit. Given these flights of fancy, I might also (and this, even for me, is much further down the bucket list) visit the offices of a few American and German ornamental fishkeeping publishing empires and suggest different names for some fishes that they were writing about for the first time.

Or not even the first time.

Much has been made about the repeated misidentification of Ancistrus dolichopterus in the German hobby literature. I found this confusing and was not familiar with the Ancistrus hoplogenys misidentification introduced therein. Not because one fish was being mistakenly called another — that happens all the time — but because I was already familiar with it and using the right name. The UK (and, I think, US) fish press never made this mistake and so were a touch confused by all the fuss trying to correct the error. That is, except those that followed the error and some did. So, mostly, the Dolly Pleco, as it was sold locally to me in 1980s Scotland, was always A. dolichopterus. That common name however died with the advent of globalisation and the English transaltion of the German common name, starlight pleco, has won out.

Fortunately, and without the use of a time machine, the historical identification error has been corrected in recent publications and on the internet. Yet, with we've seen a lot of black with white spotted plecos and several of them are Ancistrus. Again, identifying A. dolichopterus is now known to be simple; this species is the only such coloured species that has 9 soft rays (excluding the leading thicker hard dorsal ray) up top in the dorsal. Less precise, but it is also useful to know, that the white seam has a bluish sheen; other species have pure white with no tint.

Despite being given the L-number L183 in 1994 (in an article featuring five black with white spots Ancistrus) this was both already a well-known species and was described by the Austrian Kner in 1854 in, again, a German language publication. The export trade route pioneered by the commercial value of the cardinal tetra from the Rio Negro river system was and is also the conduit for the supply of these fishes to the hobby. They, like the red and neon blue tetra are numerous and widespread in this, the largest blackwater river on the planet. The Rio Negro is a nutrient-deprived, typically plantless habitat with a pH from 3.5 to 6 and temperature range of 26°C to a decidedly warm 31°C.

However, it is the soft, acidic water that is the key to maintaining the species in the home aquaria. Get this right and it is straightforward to feed these omnivorous fishes and thus raise them to a breedable size. They are seasonally available and not too expensive and so are always sought-after species, as are captive bred youngsters, which have the advantage of tending towards increased hardiness.

This is a pretty pleco. I especially like the border of flesh around the deep blue eye. It is spotted with pinprick white spots like the rest of the fish but the spots move with the eye. Its similarly spotted head tentacles give it a mesmeric look. Not a fish that needs major water current, and not a large pleco: there are few reasons it shouldn't grace any soft water set-up.

Copyright information for the images used in this article can be found on the species' full Cat-eLog page.

Cat-eLog Data Sheet
Scientific Name	Ancistrus dolichopterus  Kner, 1854
Common Names	L183, Starlight Bristlenose Catfish Blå Antennmal (Sweden), Dolly Pleco, Hvidsømmet Antennesugemalle (Denmark), Starlight Bushymouth Catfish
Type Locality	Manaus, Brazil.
Synonym(s)	Hypostoma punctatum, Xenocara dolichoptera
Pronunciation	an SISS truss
Etymology	The name Ancistrus is derived from the Greek word agkistron, meaning hook, in reference to the interopercular odontodes that are hooked. This specific epithet refers to its long (dolichos=long) fins (pteron=fins).
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Species Information
Size	118mm or 4.6" SL. Find near, nearer or same sized spp.
Identification	Mature males and sometimes females have soft tentacles (bushy fleshy growths) on the snout - this is unique to the genus Ancistrus. The overall appearance of this species is not as useful for identification as you may think - there are many Ancistrus species which have a dark base with small white dots as colour pattern. There is however a key that differentiates this species from all other (currently known) Ancistrus species - it's the only species with one hard and nine soft dorsal rays (I,9). Also encountered under the name Ancistrus hoplogenys.
Sexing	Males have head tentacles, females do not.
Habitat Information
Distribution	South America: upper and middle Brazilian Amazon River basin and from the Negro, lower Trombetas, Tefé, Madeira and Tapajós River basins. Amazon, Middle Amazon (Solimoes), Negro, Lower Negro (click on these areas to find other species found there) Amazon, Lower Amazon, Trombetas, Lower Trombetas (click on these areas to find other species found there) Amazon, Tefé (click on these areas to find other species found there) Amazon, Middle Amazon (Solimoes), Madeira (click on these areas to find other species found there) Amazon, Lower Amazon, Tapajós (click on these areas to find other species found there) Amazon, Lower Amazon, Nhamundá (click on these areas to find other species found there) Log in to view data on a map.
IUCN Red List Category	Least Concern, range map and more is available on the IUCN species page. Last assessed 2020.
pH	5.0 - 6.5
Temperature	23.0-28.0°C or 73.4-82.4°F (Show species within this range)
Other Parameters	A blackwater resident that can be somewhat delicate if not kept in similar conditions in captivity.
Husbandry Information
Feeding	Ancistrus are omnivorous with something of a vegetarian bent. Vegetables and commercially prepared food are avidly taken. They also like to eat blood worms, gammarus and most frozen foods. You can also witness them eating dead fish when they find a carcass before you do. User data.
Furniture	Prefers wood to stone. Bamboo caves are best but will also take refuge in slate or PVC pipes.
Compatibility	Will defend their own territories, but these are small and so groups can be housed in relatively small aquaria.
Breeding	Reasonably straight forward once the correct (black water) parameters are attained. Spawning follows the typical pattern for the genus. The female lays around 50 eggs in a cave or hole that is guarded by the male.
Breeding Reports	There are 20 breeding reports, read them all here.
Further Information
Reference	Denkschriften der Kaiserlichen Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftliche Classe. v. 7, pp 274 [24], Pl. 3 (fig. 1).
Registered Keepers	There are 368 registered keepers, view all "my cats" data.
Wishlists	Love this species? Click the heart to add it to your wish list. There are 26 wishes to keep this species, see who wants what.
Spotters	Spotted this species somewhere? Click the binoculars! There are 109 records of this fish being seen, view them all.
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	Look up A. dolichopterus on Encyclopedia of Life
	Look up A. dolichopterus on Global Biodiversity Information Facility
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Last Update	2022 Jan 19 09:42 (species record created: 2014 May 13 12:53)

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