Matt Clarke on the L-number Flyer plec, Pseudolithoxus anthrax, better known to catfish fans as L235.
Common name: L235, Flyer plec
Scientific name: Pseudolithoxus anthrax
Origin: Museum specimens have been collected from the Rio Orinoco drainage in Venezuela, and in the
Rio Caura and Rio Aro, which are tributaries of the Orinoco.
Size: Museum records state a size of 10cm/4", although some other sources say that the fish can reach twice this size.
Diet: Not known. Probably
a detritivore that feeds on decaying plant material. However, related Exastilithoxus and Lithoxus feed exclusively on insect larvae.
Water: Ideally soft and acidic with a pH of 6.0 or so, but probably quite adaptable to harder, more alkaline waters, like other loricariids.
Aquarium: This fish has similar requirements to other loricariids, so should do well in a South American biotope tank or simple community tank.
Sexing: Females are probably fatter with smaller odontodes than males.
Breeding: No reports of aquarium spawnings.
Notes: This species was originally described as Lasiancistrus anthrax in 2000 by Armbruster and Provenzano. It has recently been moved to a new genus, Pseudolithoxus, as it did not fit in well with other Lasiancistrus species.
Identification: According to Armbruster, P. anthrax should have two dorsal spines and seven to eight branched dorsal rays; one anal spine and four branched anal rays; 24-26 lateral line plates; seven to eight dorsal plates; seven to eight adipose-caudal plates and 12-14 post-anal plates. The fish is usually dark grey or black with white spots.
Similar species: Three other fish from Venezuela were also placed in Lasiancistrus when anthrax was first described - dumus, tigris and nicoi. These form a monophyletic group and are now also in the Pseudolithoxus genus.
P. nicoi, from the upper Rio Negro, is most similar (dumus is brown with black spots, tigris is brown with black stripes), but this species has a white edge to the caudal, while P. anthrax does not. (It's been imported into Germany and possibly also the UK).
There is also a further undescribed black species with white spots. This
fish is flatter than both nicoi and anthrax, but Armbruster thinks it doesn't fall in with the anthrax species-group.
Availability: Quite rare in the shops. This one was on sale at Wharf Aquatics in Pinxton, Nottinghamshire.
Price: Expect to pay around 35.