Author: Darren Stevens
First published in Aquarium World February 2010

Red spots, gold spots, and common plecos are some of the most popular in the hobby. They are often called sailfin plecos due to their very large dorsal fins. Sailfin plecos are all species of Pterygoplichthys, and not Hypostomus as many people believe. This is because the original ‘common’ plecos imported in the 1960’s were species of Hypostomus, probably including Hypostomus plecostomus (the origin of the term pleco). From the 1980’s sailfins were the commonly imported plecos: in particular what is now known as the common pleco, Pterygoplichthys pardalis. Hypostomus species are now relatively rarely imported. These two groups are easy to tell apart. Sailfin plecos have a broad-based, high dorsal fin with 10–14 fin rays (+1 hard spine at the front), while Hypostomus species have a shorter dorsal fin base and 7–8 fin rays (+1 spine).

There are 14 scientifically described sailfin plecos, and at least one awaiting a scientific name. In the early 1990’s a review of sailfins suggested that they should be split into three groups: the originalPterygoplichthys, and two new ones: Glyptoperichthys, and Liposarcus. However, these new groups have not been widely adopted. Researchers still refer to them by calling them the ‘P. gibbiceps group’ (formerly Glyptoperichthys) and the ‘P. multiradiatus group’ (formerly Liposarcus). Red spots, gold spots, and ‘yellow sailfin plecos’ (the P. gibbiceps group) can be separated from common plecos (the P.multiradiatus group) by their more robust build and a pronounced hump in front of the dorsal fin (obvious in large specimens).

Sailfin plecos are widespread in South America and found in the Amazon, Magdalena, Maracaibo, Orinoco, Paraná, and São Francisco river systems, where they are often found in slow flowing streams, floodplain lakes, and marshes.

These plecos are hardy, adaptable, and generally peaceful when small. They are attractive and well priced but will eventually grow too big for most aquaria. Larger specimens can be territorial and aggressive towards other plecos, and need good filtration as they produce a large amount of waste. They are more active during daylight hours if plenty of cover is provided.

Sailfin plecos are largely vegetarian but will eat most prepared fish foods. Feed them on pleco algae wafers, veggies (courgettes, cucumber, silverbeet, shelled peas, etc.), and smaller quantities of high protein foods (shrimp pellets, shrimps, fish, blood worms, etc.).

Most species have not been bred in aquaria. This would be very difficult to achieve as in the wild males of many species are known to burrow into muddy riverbanks to lay and brood their eggs. However common plecos, red spots and gold spots are all bred in large numbers in ponds in commercial fish farms in Asia and North America.

The following sailfin plecos are likely to be found in New Zealand.

Common pleco (Pterygoplichthys pardalis, L021, L023)

The common pleco is a large (to 42 cm standard length, SL) light grey to brown pleco with dark spots on the body that often fuse together to form irregular twisted lines, and dark spots on the belly. Albino and chocolate varieties are available. The chocolate or chocolate albino variety is an amelanistic form, i.e. it lacks melanin (black pigment). Common plecos originate from the Amazon River system and have been established in the wild in parts of North America and Asia, presumably from aquarium releases. They are suited to larger tanks with pH’s of 6.0–7.5 and temperatures of 21–26oC.

It is likely that other sailfin plecos have been imported as common plecos; the most likely being the vermiculated sailfin pleco, P. disjunctivus, and possibly the Orinoco sailfin pleco, P. multiradiatus. When normally coloured (i.e. not albino or chocolate) they can be separated on patterning. Common plecos and vermiculated sailfin plecos have dark spots that often fuse together to form irregular twisted lines (vermiculated patterning) on the body and head. However, common plecos have mostly discrete (separate, not fused) dark spots on the belly whereas vermiculated sailfins have mostly dark vermiculated patterning on the belly. Orinoco sailfins have discrete dark spots over the back half of the body.

Red spot pleco (Pterygoplichthys gibbiceps, L083, L165)

The red spot pleco or gibby is a large (to 45 cm SL) pale brown/yellowish pleco covered with irregular large brown spots separated by a thin margin giving a honeycombed appearance. Albino varieties are also available. They originate from the middle and upper Amazon and Orinoco basin. They are suited to larger tanks with pH’s of 6.5–7.8 and temperatures of 23–27oC.

Gold spot pleco (Pterygoplichthys joselimaianus, L001, L022)

The gold spot pleco is a large (to 30 cm SL) dark brown pleco covered with golden spots, which often merge on the body to form irregular lines. They originate from the Rio Tocantins basin in Brazil and are suited to larger tanks with pH’s of 6.5–7.3 and temperatures of 24–29oC. This species was the first pleco to be given an L-number.

‘Yellow sailfin pleco’ (Pterygoplichthys weberi)

Pterygoplichthys weberi is a large (to about 25 cm SL) pale brown/yellowish pleco covered with relatively large dark brown to black spots. These plecos have been sold as ‘yellow sailfin plecos’, although there is no accepted common name for this species. They originate from the Rio Marañon, Rio Ucayali, and upper Rio Amazonas drainages of Colombia, Ecuador, and Peru. They are suited to larger tanks with pH’s of about 6.0–7.0 and temperatures of 22–26oC. They are rarely available in New Zealand.

I would like to thank Firenzenz and Krazy Geoff for their comments and improvements on earlier versions of this article, and the Pet Centre, Lower Hutt, for allowing me to photograph their sailfins.

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)
Seidel, I. (2008). Back to nature guide to L-Catfishes. Fohrman Aquaristik AB, Sweden. 208 p.
Armbruster, J. W.; Page, L.M. (2006). Redescription of Pterygoplichthys punctatus and description of a new species of Pterygoplichthys (Siluriformes: Loricariidae). Neotropical Ichthyology 4: 401–409.
Chavezi, J.M.; De La Pazi, R. M.; Manohari, S. K.; Pagulayan2, R. C.; Carandang VII, J. R. (2006). New Philippine record of south american sailfin catfishes (Pisces: Loricariidae). Zootaxa 1109: 57–68.

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