Corydoras arcuatus

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Corydoras arcuatus
Systematics
Order : Catfish (Siluriformes)
Subordination : Loricarioidei
Family : Armored and calloused catfish (Callichthyidae)
Subfamily : Armored catfish (Corydoradinae)
Genre : Corydoras
Type : Corydoras arcuatus
Scientific name
Corydoras arcuatus
Elwin , 1939
The streamlined armored catfish known in the aquarium hobby is not Corydoras arcuatus

Corydoras arcuatus is a small freshwater fish from the group of armored catfish (Corydoradinae), which occurs in the catchment area of ​​the central Rio Juruá in Brazil, in the Rio Javari on the border between Brazil and Peru and in somerivers and streams in Colombiaimmediately north of Leticia . Presumably the species also lives in the riverbasin ofthe Rio Purus and in the Peruvian Amazon.

features

Corydoras arcuatus can reach a standard length of about 5.5 cm. The body height is 36.5 to 44% of the standard length and the head length is 41 to 46% of the standard length. In cross section, the body is elliptical and increasingly flattened towards the tail. The head profile is triangular when viewed from the side. The snout is pointed. The anterior and posterior nostrils are close together. The back profile is slightly curved up to the adipose fin , then straight.

The basic color of the fish is whitish-gray and shimmers somewhat greenish or yellowish. However, there are also yellowish or reddish-brown tints, especially on the back. Characteristic of the species is a long, arched, continuous black stripe that runs parallel to the back profile on the sides of the body. However, Corydoras arcuatus shares this characteristic with Corydoras gracilis , C. granti , C. narcissus and C. urucu . Corydoras arcuatus can be distinguished from these species by the direction of the teeth on the serrated hard ray of the dorsal fin, which in Corydoras arcuatus point downwards, while in the other species they point upwards.

habitat

Corydoras arcuatus has so far only been caught in small, relatively shallow black water rivers and streams with sandy bottoms. The species lives there individually or in small groups, sometimes together with Corydoras granti , Corydoras leopardus and Corydoras urucu .

Systematics

The armored catfish was first scientifically described in 1938 by the British ichthyologist Margery Graves Elwin. Of the two type specimens examined for the description , the first, larger specimen and at the same time the holotype were obtained from an aquarium dealer, while the place of origin of the second, smaller specimen was given as "Teffe, Amazonas" (probably the municipality of Tefé or the Rio Tefé river ). In the following 80 years, a species of armored catfish known in the aquarium hobby as streamlined armored catfish was identified as C. arcuatus and named as such in numerous aquarium and scientific publications. In 2014, the aquarist and amateur ichthyologist Steven Grant expressed doubts that this species is C. arcuatus , as this species has a rounded snout, whereas the holotype of C. arcuatus is sharp-snouted and in August 2019 the error in A scientific publication by three Brazilian ichthyologists and the armored catfish identified as C. arcuatus after the first description of C. arcuatus were described as a new species ( Corydoras granti ) and named after Steven Grant.

supporting documents

  1. ↑ a b c d e f g h Tencatt, LFC, Lima, FCT & Britto, MR (2019): Deconstructing an octongeneric misconception reveals the true Corydoras arcuatus Elwin 1938 (Siluriformes: Callichthyidae) and a new Corydoras species from the Amazon basin. Journal of Fish Biology, 95 (2): 453-471. doi: 10.1111 / jfb.13980 , PDF
  2. ^ Glaser, U, F. Schäfer and W. Glaser, 1996. Aqualog - all Corydoras . ACS, Germany. 142 pp
  3. ^ Fuller, IAM and HG Evers. 2011. Identifying Corydoradinae catfish. Supplement 1. Ian Fuller Enterprises, Worcestershire, 141p
  4. ↑ Britto, MR, WB Wosiacki and LFA Monday, 2009. A new species of Corydoradinae catfish (Ostariophysi: Siluriformes: Callichthyidae) from Rio Solimões Basin, Brazil. Copeia 2009 (no. 4): 684-689.
  5. ↑ Castro, DM, 1987. The fresh-water fishes of the genus Corydoras from Colombia, including two new species (Pisces, Siluriformes, Callichthyidae) . Boletin Ecotrópica. No. 16: 23-57, Pls. 1-11.
  6. ↑ Nijssen, H. and IJH Isbrücker, 1986. Review of the genus Corydoras from Peru and Ecuador (Pisces, Siluriformes, Loricariidae) . Studies on Neotropical Fauna and Environment v. 21 (no. 1-2): 1-68.
  7. ^ Grant, S. (2014). On the identity of Corydoras arcuatus Elwin, 1938 and some similarly patterned species (Siluriformes: Callichthyidae). Journal of the Catfish Study Group, 15: 24-29 PDF