Ammoglanis

Taxobox
name = "Ammoglanis"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Trichomycteridae
subfamilia = Sarcoglanidinae
genus = "Ammoglanis"
genus_authority = Costa, 1994
type_species = "Ammoglanis diaphanus"
type_species_authority = Costa, 1994
subdivision_ranks = Binomial name
subdivision =
"Ammoglanis amapaensis"
Mattos, Costa & Gama, 2008
"Ammoglanis diaphanus"
Costa, 1994
"Ammoglanis pulex"
de Pinna & Winemiller, 2000

"Ammoglanis" is a genus of catfishes (order Siluriformes) of the family Trichomycteridae. It includes three species, "A. amapaensis", "A. diaphanus" and "A. pulex".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

The phylogenetic position of "A. pulex" is problematic. It seems to be closely related to "A. diaphanus" due to some derived characters of the internal anatomy, but a conclusive assessment of its relationships has not been prevented by its paedomorphic features and scarcity of study material. This generic placement seems to be well supported.

The relationships of the genus "Ammoglanis" are unknown; it is thought that this genus along with undescribed forms are the sister group to a large intrafamilial clade composed of several genera and subfamilies. In the interim, this genus is included within Sarcoglanidinae.

Distribution

"A. amapaensis" originates from three different drainages of the Amazon River, the Jari, Amapari, and Araguari River.cite journal|title=A new miniature species of "Ammoglanis" (Siluriformes: Trichomycteridae) from the Brazilian Amazon|first=José L. O.|last=Mattos|coauthors=Costa, Wilson J. E. M.; Gama, Cecile de S.|journal=Ichthyol. Explor. Freshwaters|volume=19|issue=2|pages=161-166|year=2008] "A. diaphanus" originates from a stream tributary to the Javaés River of the Araguaia River basin in Tocantins, Brazil.FishBase species|genus=Ammoglanis|species=diaphanus|year=2007|month=July] "A. pulex" originates from the Paria Grande River, the Pamoni River, and Caño Garrapata of Venezuela.FishBase species|genus=Ammoglanis|species=pulex|year=2007|month=July]

Description

"Ammoglanis" species grow to about 1.5–1.9 centimetres (.59–.75 in) SL. "A. pulex" is among the smallest known vertebrates. "A. pulex" can be distinguished from "A. diaphanus" by a number of characteristics, including the presence of a faint pattern of eight bands formed by internal chromatophores and the lack of teeth.cite journal|url=http://wfsc.tamu.edu/winemiller/lab/DePinna&W-Ammoglanis-IEFW00.pdf|title=A New Species of "Ammoglanis" (Siluriformes: Trichomycteridae) from Venezuela|journal=Ichthyol. Explor. Freshwaters|volume=11|issue=3|pages=255–264|date=November 2000|format=PDF]

Ecology

"A. diaphanus" inhabits shallow, narrow, clear water, moderately swift-flowing stream and is found buried in the sand. It feeds on Diptera larvae and a cladocerans. "A. pulex" is a translucent light-pink fish that camouflages well in sand. "A. pulex" is found in sand banks near the shorelines of clear water and slightly tea-stained streams. Apparently fossorial by daylight, it is found buried in coarse clear sand at the stream edge, in areas shaded by dense tropical rainforest. The waters are with slow current, pH varying between 5.5–6.2, and temperature between 27.5–28°C (81.5–82.4°F). "A. pulex" is thought to feed on microscopic fauna like protozoa, rotifers, and nematodes since it inhabits interstitial spaces among sand grains in nutrient-poor, clear-water and backwater streams.

References