Royal plec

Panaque
Panaque sp. cf. nigrolineatus in an aquarium
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Siluriformes
Family:	Loricariidae
Genus:	Panaque
Species:	P. nigrolineatus
Binomial name
Panaque nigrolineatus (Peters, 1877)
Synonyms
Chaetostomus nigrolineatus Peters, 1877

The royal plec, royal pleco, or royal panaque, Panaque nigrolineatus, is a herbivorous freshwater catfish from South America known for being one of the few fish that digest wood.^[1] It is the type species of its genus and a member of the Loricariidae. In its native habitat this fish is eaten as food.^{[citation needed]} This fish is also a popular aquarium fish.

Anatomy and appearance

Mouth and teeth of Panaque nigrolineatus

The royal plec is closely related to the popular plecostomus catfish kept in many aquaria as an algae eater. While the royal plec also eats algae, it is best known among biologists as being among the very few fish capable of eating and digesting wood. It does so using symbiotic gut bacteria. Royal plecs are light grey in colour patterned with dark grey squiggles. They have red eyes and the dorsal fins are edged with cream or gold. The body is encased in heavy armour, except for the belly, which is soft. This armour is made of strong plates of skin, not scales. Royal plecs can grow to 43 centimetres (17 in) in length. Because they are heavy and inflexible, they do not swim well, but they do have a strong sucker-like mouth that enables them to hold onto rocks and wood in fast flowing waters.

Distribution and habitat

The royal plec can be found in the Orinoco River as well as a number of tributaries of the Amazon River.^[1]

Varieties

There are several undescribed varieties of Panaque that are very similar to Panaque nigrolineatus and are commonly traded as aquarium fish [1]. These may be regional variations, subspecies, or closely related species. All share the same basic colouration but vary in the shape and distribution of the stripes and the amount of cream or gold on the fins. These varieties are:

• Panaque sp. cf. nigrolineatus 'Tapajos' (after the river from which it is collected)
• Panaque sp. cf. nigrolineatus 'watermelon pleco'
• Panaque sp. cf. nigrolineatus 'olive pleco'
• Panaque sp. cf. nigrolineatus 'Tocantins' (after the river from which it is collected)
• Panaque sp. cf. nigrolineatus 'Xingu' (after the river from which it is collected)

In the aquarium

The Royal plec is valuable as an aquarium fish. It is a very attractive aquarium fish which grows to a large size.^[2] Maintenance is as for other Panaque, with the fish needing plenty of space, well oxygenated water, and a regular supply of vegetables and wood on which to feed. Young are often imported in an undernourished state which requires dedicated attention to allow recovery.^[2] Primarily nocturnal, this fish is generally shy under the light and will keep in hiding during the day.^[3] This fish is territorial, so a suitable resting area for this fish is necessary.^[3] This species has not yet been bred in captivity.^[3]

References

1. ^ ^{a b} Froese, Rainer, and Daniel Pauly, eds. (2007). "Panaque nigrolineatus" in FishBase. Apr 2007 version.
2. ^ ^{a b} "PlanetCatfish::Catfish of the Month::May 1999". 2007-05-22. http://www.planetcatfish.com/cotm/cotm.php?article_id=74. Retrieved 2007-07-01. 
3. ^ ^{a b c} Axelrod, Herbert, R. (1996). Exotic Tropical Fishes. T.F.H. Publications.. ISBN 0-87666-543-1. 

External links

• "Panaque nigrolineatus". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=164365. Retrieved 19 March 2006. 
• Planet Catfish
• Panaque Research
• QuickTime movie of a Royal plec swimming and feeding in an aquarium