Epactionotus

Taxobox
name = "Epactionotus"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Loricariidae
subfamilia = Hypoptopomatinae
tribus = Otothyrini
genus = "Epactionotus"
genus_authority = Reis & Schaefer, 1998
subdivision_ranks = Species
subdivision =
*"E. aky"
Azpelicueta, Casciotta, Almirón & Köber, 2004
*"E. bilineatus"
Reis & Schaefer, 1998
*"E. gracilis"
Reis & Schaefer, 1998
*"E. itaimbezinho"
Reis & Schaefer, 1998
*"E. yasi"
Almirón, Azpelicueta & Casciotta, 2004

"Epactionotus" is a genus of catfish (order Siluriformes) of the family Loricariidae.

Taxonomy

"Epactionotus" was first described in 1998 by Roberto E. Reis and Scott A. Schaefer, as including three species.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] "Epactionotus" is part of the tribe Otothyrini within the subfamily Hypoptopomatini. "Epactionotus" is sister to a clade including "Eurycheilichthys", "Pseudotocinclus", "Microlepidogaster", "Schizolecis", "Otothyris", and "Pseudotothyris". "E. aky" and "E. yasi" were both described in 2004.cite journal|url=http://www.pecescriollos.de/media/docs/azpelicueta_et_al_2004_epactionotus_aky_sp_nov_75_dpi.pdf|title=A new species of Otothyrini (Siluriformes: Loricariidae: Hypoptopomatinae) from the Río Uruguay basin, Argentina|first=María de las Mercedes|last=Azpelicueta|coauthors=Casciotta, Jorge; Almirón, Adriana; Körber, Stefan|journal=Verhandlungen der Gesellschaft für Ichthyologie|volume=4|year=2004|pages=81–90|format=PDF] cite journal|url=http://globiz.sachsen.de/snsd/publikationen/Zool_Abh/Zool_Abh_54_2004_137-144.pdf|title=A new species of "Epactionotus" (Siluriformes: Loricariidae: Otothyrini) from the río Iguazú basin, Argentina|first=Adriana Edith|last=Almirón|coauthors=Azpelicueta, María de las Mercedes; Casciotta, Jorge Rafael|journal=Zoologische Abhandlungen (Dresden)|volume=54|pages=137–144|format=PDF]

Distribution

The first three described "Epactionotus" species are each endemic to a very limited geographic area along the Atlantic coast of southern Brazil. "E. bilineatus" is endemic to the rio Maquiné, the rio Três Forquilhas and its tributaries in Rio Grande do Sul State, southern Brazil. "E. itaimbezinho" is endemic to two localities in the upper reaches of the rio Mampituba drainage, an isolated coastal stream situated along the border between Rio Grande do Sul and Santa Catarina States, southern Brazil. "E. gracilis" is endemic to the Araranguá River drainage, an isolated coastal drainage in southern Santa Catarina State. "E. aky" is known from the arroyos Garibaldi and Fortaleza. Both streams are headwaters of the arroyo Yabotí-Guazú, which flows into the Uruguay River, in the Misiones Province of Argentina. "E. yasi" is only known from the arroyo Lobo, a tributary of the Iguazu River in Argentina.

Description

These fish are small, none surpassing 4 centimetres (1.6 in) SL. The head have longitudinal light-colored stripe markings which may extend onto the body over a base green color. The body is covered by bony plates except for a few areas. "E. aky" is differentiated from the other species in that it has platelets on its abdomen. "E. yasi" is differentiated from the other species by a vent completely covered by platelets. The adipose fin is absent. The lips are small and round and form a suckermouth. Maxillary barbels are short. Odontodes are present on the head and trunk and are generally uniform in size and distribution.

Ecology

The habitats of most of these species are similar. These fish are found in shallow, small rivers or creeks with bottom composed of rocks, loose stones, and gravel (and may also include sand and mud) and clear water with slow to moderate current. The habitat of "E. aky" may become turbid due to rainfall. Water is usually very cold in the austral (southern) winter. Grass or other vegetation is always present on the stream margins. The fishes are usually found on leaves and stalks of marginal vegetation, frequently adhering by means of their pelvic fins. "E. aky" associate with "Echinodorus" plants and may be well hidden and difficult to see by eye. "E. yasi" lives among terrestrial vegetation that falls into the water.

References