Eurycheilichthys

Taxobox
name = "Eurycheilichthys"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Loricariidae
subfamilia = Hypoptopomatinae
tribus = Otothyrini
genus = "Eurycheilichthys"
genus_authority = Reis & Schaefer, 1993
type_species = "Eurycheilus pantherinus"
type_species_authority = Reis & Schaefer, 1992
subdivision_ranks = Binomial name
subdivision =
"Eurycheilichthys limulus"
Reis & Schaefer, 1998"Eurycheilichthys pantherinus"
(Reis & Schaefer, 1992)

synonyms = "Eurycheilus"
Reis & Schaefer, 1992

"Eurycheilichthys" is a small genus of catfishes (order Siluriformes) of the family Loricariidae. It includes two species, "E. limulus" and "E. pantherinus".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]

Taxonomy

"Eurycheilus pantherinus" was first described in 1992 by Roberto Esser dos Reis and Scott A. Schaefer.cite journal|title="Eurycheilus pantherinus" (Siluroidei: Loricariidae), a New Genus and Species of Hypoptopomatinae from Southern Brazil|first=Roberto E.|last=Reis|authorlink=Roberto Esser dos Reis|coauthors=Schaefer, Scott A.|journal=Copeia|year=1992|pages=215–223|doi=10.2307/1446554|volume=1992] However, "Eurycheilus" was preoccupied in fossil cephalopods, and therefore was replaced by "Eurycheilichthys" in 1993.cite journal|title="Eurycheilichthys" nom. nov., a Substitute Name for "Eurycheilus" Reis and Schaefer, 1992 (Siluroidei: Loricariidae)|first=Roberto E.|last=Reis|authorlink=Roberto Esser dos Reis|coauthors=Schaefer, Scott A.|journal=Copeia|year=1993|issue=3|pages=894|doi=10.2307/1447263|volume=1993] "E. limulus" was described in 1998.

"Eurycheilichthys" has a sister group to the clade formed by "Pseudotocinclus", "Microlepidogaster", "Schizolecis", "Otothyris", and "Pseudotothyris".

Distribution

"E. pantherinus" was described from the upper reaches of the Uruguay River drainage of Brazil. "E. limulus" originates from the upper reaches of the Jacui River drainage in Rio Grande do Sul State.cite journal|url=http://digitallibrary.amnh.org/dspace/bitstream/2246/3154/1/N3254.pdf|title=New Cascudinhos from Southern Brazil: Systematics, Endemism, and Relationships (Siluriformes, Loricariidae, Hypoptopomatinae)|authorlink=Roberto Esser dos Reis|first=Roberto E.|last=Reis|coauthors=Schaefer, Scott A.|journal=American Museum Novitates|volume=3254|pages=1–25|date=December 21, 1998|format=PDF]

Description

The two species of "Eurychelichthys" are similar. The trunk and caudal peduncle are round in cross section. Males have a fleshy flap along the posterior margin of the thickened first pelvic fin ray. They lack a dorsal fin locking mechanism. Both species lack an adipose fin. Their bodies are almost entirely covered by plates. The body and head lack crests. The head and body plates are covered with odontodes; these are larger on the ventral face of pelvic and pectoral fin spines. Odontodes on the head and trunk are otherwise of uniform size and distribution, and not arranged in conspicuous rows. The lips are roundish, wide and papillose. The maxillary barbels are short.

"E. limulus" shares with "E. pantherinus" a single synapomorphy: the derived presence of seven branched pectoral fin rays. "E. limulus" is distinguished from "E. pantherinus" by a more narrow body, head and dorsal trunk with series of longitudinal light stripes (versus scattered dark blotches), and presence of an accessory ceratobranchial flange and filamentous gill rakers (versus absence of those features in "E. pantherinus").

Ecology

"E. pantherinus" inhabits shady, fast-flowing, shallow water, ranging from approximately 200–500 metres in elevation. The substratum is predominantly stones, with little or no macrophytes.

The habitat at the type locality of "E. limulus" is a small river about 3–5 metres wide with moderate water current, bottom comprising some rocks but mostly sand and a large amount of marginal vegetation. These fishes live among leaves and stalks.

References