Aspredinidae

Taxobox
name = Banjo catfishes


image_width = 250px
image_caption = "Bunocephalus verrucosus"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Aspredinidae
familia_authority = Adams, 1854
subdivision_ranks = Subfamilies and generacite book|title=Fishes of the World|last=Nelson|first=Joseph S.|publisher=John Wiley & Sons, Inc|year=2006|isbn=0-471-25031-7]
subdivision = "incertae sedis" "Pseudobunocephalus"
Subfamily Aspredininae
"Aspredinichthys"
"Aspredo"
"Platystacus"
"Pterobunocephalus"
Subfamily Bunocephalinae
"Acanthobunocephalus"
"Amaralia"
"Bunocephalus"
Subfamily Hoplomyzontinae
"Dupouyichthys"
"Ernstichthys"
"Hoplomyzon"
"Micromyzon"
"Xyliphius"

The Aspredinidae are a small South American family of catfishes (order Siluriformes) also known as the banjo catfishes.

Distribution

Aspredinids are found throughout the major tropical rivers of South America (e.g., Magdalena, Orinoco, Amazon, São Francisco, Paraguay-Paraná, and Uruguay). "Bunocephalus" is the only genus found in rivers west of the Andes including the Atrato, San Juan, and Patia Rivers.cite paper|url=http://www.cumv.cornell.edu/pdf/Friel_Ph.D._Thesis_1994.pdf|title=A Phylogenetic Study of the Neotropical Banjo Catfishes (Teleostei: Siluriformes: Aspredinidae)|author=Friel, John Patrick|publisher=Duke University, Durham, NC|date=1994-12-13|accessdate=2007-08-07|format=PDF]

Taxonomy

There are 13 genera in the family Aspredinidae. A few of these genera have been described relatively recently, including "Acanthobunocephalus" in 1995, "Micromyzon" in 1996, and "Pseudobunocephalus" in 2008. [cite journal|last=Friel|first=J|year=1995|title="Acanthobunocephalus nicoi", a new genus and species of miniature banjo-catfish from the upper Orinoco and Casiquiare Rivers, Venezuela. (Siluriformes: Aspredinidae)|journal=Ichthyological Explorations of Freshwaters|volume=6|issue=1|pages=89–95] [cite journal|title="Micromyzon akamai", Gen. et Sp. Nov., a Small and Eyeless Banjo Catfish (Siluriformes: Aspredinidae) from the River Channels of the Lower Amazon Basin |first=John P.|last=Friel|coauthors=Lundberg, John G.|journal=Copeia|volume=1996|issue=3|date=Aug. 1, 1996|pages=641–648|doi=10.2307/1447528] These genera are categorized into three subfamilies.cite journal|url=http://silurus.acnatsci.org/ACSI/library/biblios/2007_Ferraris_Catfish_Checklist.pdf|title=Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types|first=Carl J., Jr.|last=Ferraris|journal=Zootaxa|volume=1418|pages=1–628|year=2007|format=PDF] "Pseudobunocephalus", the most recently described genus, is the most basal genus in the family; it was not assigned to any of the three subfamilies.

Aspredinidae is often recognized as a part of the primarily Asian superfamily Sisoroidea as the sister group to the family Erethistidae. However, other authors find that they are sister to the superfamily Doradoidea, which includes Doradidae, Auchenipteridae, and perhaps Mochokidae.cite journal|journal=Mol Phylogenet Evol.|year=2006|volume=41|issue=3|pages=636–62|title=A phylogenetic analysis of the major groups of catfishes (Teleostei: Siluriformes) using rag1 and rag2 nuclear gene sequences|last=Sullivan|first=JP|coauthors=Lundberg JG; Hardman M|doi=10.1016/j.ympev.2006.05.044]

Description

The common name of the family "banjo catfishes" refers to their overall body shape, with a depressed head and slender caudal peduncle, that in some species gives the appearance of a banjo. Banjo catfishes lack an adipose fin. Most species lack the dorsal spine-locking mechanism. Though their bodies are scaleless, their skin is completely keratinized and is covered by large, unculiferous tubercles arranged in longitudinal rows; the entire outer layer of skin may be shed. Size ranges from less than 2.0 centimetres (.79 in) SL in "Hoplomyzon papillatus" to "Aspredo aspredo" at about 38 centimetres (15 in) SL, though most are less than 15 cm. Most species exhibit cryptic coloration. Aspredinids have a loss of alarm cells and the fright reaction that is present in other ostariophysans.

Sexual dimorphism is exhibited in most species in that mature females are typically larger than males; this is, however, reversed in "Hoplomyzon sexpapilostoma". Also, in "Aspredo" and "Platystacus" the dorsal fin spine is much longer in males than in females.

Ecology

Aspredinids live in a variety of habitats ranging from shallow backwaters to deep river channels to tidal estuaries. Some aspredinids appear to be semi-fossorial, during the day often resting slightly buried in leaf litter or other soft substrates.cite journal|journal=Neotropical Ichthyology|volume=6|issue=3|pages=293-300|year=2008|title="Pseudobunocephalus", a new genus of banjo catfish with the description of a new species from the Orinoco River system of Colombia and Venezuela (Siluriformes: Aspredinidae)|first=John P.|last=Friel] Members of the subfamily Aspredininae inhabit coastal rivers and brackish water habitats such as mangrove swamps.Sands D.: South American Catfishes, Interpet 1988, ISBN 0-86101-348-4] [Monks N. (editor): Brackish Water Fishes, TFH 2006, ISBN 0-7938-0564-3]

In general, most species are cryptically pigmented, benthic, and rather sluggish unless disturbed. Like most fish, they are able to swim by undulating their bodies; however, they also propel themselves by pumping water through their gill openings to skip along the substrate. Some species are able to produce sounds by moving their pectoral fin spines back and forth when they are agitated. Most aspredinids are generalized omnivores that feed on aquatic and terrestrial invertebrates and organic debris; however, members of "Amaralia" appear to specialize in feeding on the eggs of other catfishes.

A peculiarity of the catfishes in the subfamily Aspredininae is that after the female's eggs are fertilised by the male, she attaches them to her belly and carries them to shallow water to hatch. In "Pterobunocephalus", the eggs are directly attached to the body, while in the other three genera of the subfamily, the eggs are attached to cotylephores, which are fleshy stalks that develop seasonally on the underside of the body that may function in exchange of materials between the mother and her developing embryos. It has been hypothesised that because these catfish live in muddy environments, this behaviour gives the eggs better access to oxygenated water.FishBase species|genus=Platystacus|species=cotylephorus|year=2007|month=Aug]

Accounts of reproduction in "Bunocephalus" vary; some sources state that they are egg-scatterers without any parental care, while others note them to build a depression for a nest and guard the eggs.

In the aquarium

A few banjo catfishes are kept as aquarium fish, predominantly the smaller members of the subfamily Aspredininae. Their requirements are similar to those of other tropical South American fish, preferring slightly acidic, not too hard water maintained at 20–25°C (68–77°F). Since these species are nocturnal burrowers, they need an aquarium with a soft, sandy substrate into which they will hide during the daytime and forage in at night. Sharp sand or coarse gravel will damage their whiskers. Although not schooling fish they are tolerant of their own kind and also get along with other small aquarium species. [Editore, Arnoldo. Freshwater and Marine Aquarium Fishes. Simon and Shuster 1976, ISBN 0-6712-2809-9]

ee also

* List of fish families
*List of freshwater aquarium fish species

References

Further reading

* Editore, Arnoldo. "Freshwater and Marine Aquarium Fishes". Simon and Shuster, New York, NY, 1976.