Ammoglanis is a genus of pencil catfishes native to South America.

Ammoglanis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Trichomycteridae
Subfamily: Sarcoglanidinae
Genus: Ammoglanis
Costa, 1994
Type species
Ammoglanis diaphanus
Costa, 1994
Species

At least 5, see text.

Taxonomy

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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.[1]

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.[1]

Species

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There are currently five recognized species in this genus:[2][3][4]

Distribution

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A. amapaensis originates from three different drainages of the Amazon River, the Jari, Amapari, and Araguari River.[5] A. diaphanus originates from a stream tributary to the Javaés River of the Araguaia River basin in Tocantins, Brazil.[6] A. pulex originates from the Paria Grande River, the Pamoni River, and Caño Garrapata of Venezuela.[7] A. obliquus is only known from the Rio Preta da Eva drainage basin.[4]

Description

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Ammoglanis species grow to about 1.5–1.9 centimetres (0.59–0.75 inches) SL.[6][7] A. pulex is among the smallest known vertebrates.[1] 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.[1]

Ecology

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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.[6] A. pulex is a translucent light-pink fish that camouflages well in sand.[1] 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).[1] 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.[1]

References

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  1. ^ a b c d e f g "A New Species of Ammoglanis (Siluriformes: Trichomycteridae) from Venezuela" (PDF). Ichthyol. Explor. Freshwaters. 11 (3): 255–264. November 2000. Archived from the original (PDF) on 2006-09-13.
  2. ^ Froese, Rainer; Pauly, Daniel (eds.). "Species in genus Ammoglanis". FishBase. February 2012 version.
  3. ^ Henschel, Elisabeth; Lujan, Nathan K.; Baskin, Jonathan N. (November 2020). "Ammoglanis natgeorum, a new miniature pencil catfish (Siluriformes: Trichomycteridae) from the lower Atabapo River, Amazonas, Venezuela". Journal of Fish Biology. 97 (5): 1481–1490. doi:10.1111/jfb.14515. ISSN 0022-1112. PMID 32920863. S2CID 221672947.
  4. ^ a b Henschel, Elisabeth; Bragança, Pedro H. N.; Rangel-Pereira, Filipe; Costa, Wilson J. E. M. (2020-02-18). "A new psammophilic species of the catfish genus Ammoglanis (Siluriformes, Trichomycteridae) from the Amazon River basin, northern Brazil". Zoosystematics and Evolution. 96 (1): 67–72. doi:10.3897/zse.96.48952. ISSN 1860-0743.
  5. ^ Mattos, José L. O.; Costa, Wilson J. E. M.; Gama, Cecile de S. (2008). "A new miniature species of Ammoglanis (Siluriformes: Trichomycteridae) from the Brazilian Amazon". Ichthyol. Explor. Freshwaters. 19 (2): 161–166.
  6. ^ a b c Froese, Rainer; Pauly, Daniel (eds.). "Ammoglanis diaphanus". FishBase. July 2007 version.
  7. ^ a b Froese, Rainer; Pauly, Daniel (eds.). "Ammoglanis pulex". FishBase. July 2007 version.