Corydoras aurofrenatus EIGENMANN & KENNEDY, 1903

CW005

Etymology

Corydoras: from the Ancient Greek κόρυς (korus), meaning ‘helmet’, and δορά (dora), meaning ‘skin, hide of an animal’, in allusion to the rows of bony plates on the flanks of genus members.

aurofrenatus: not mentioned in the original description but possibly from the Latin auro, meaning ‘gold’, and frenatus, meaning ‘bridled’, in reference to the ‘broad, yellow band across the snout’.

Classification

Order: Siluriformes Family: Callichthyidae

Distribution

C. aurofrenatus is currently understood to occur throughout much of the Río Paraguay-Paraná system in Paraguay, and has also been recorded in Argentina and Bolivia.

It was described from Paraguay with type locality given as ‘Aguada near Arroyo Trementina’. The latter is stated to be a tributary of the ‘Rio Aquido Canigi’.

This refers to the Río Aquidabán (Axenrot and Kullander, 2003) which flows through the departments of Amambay and Concepción before entering the Río Paraguay north of Concepción city.

One of the major tributaries of the Aquidabán is the Río Trementina.

Maximum Standard Length

50 – 55 mm.

Maintenance

Ideally use a substrate of fine sand, although rounded gravel is an acceptable alternative provided it’s kept scrupulously clean.

Other décor is largely down to personal choice, but some cover should be provided to give the fish security.

Water Conditions

Temperature: 22 – 26 °C

pH: 6.0 – 8.0

Hardness: 36 – 268 ppm

Diet

Corydoras spp. are foraging omnivores and will accept most sinking dried foods, as well as small live and frozen varieties such as bloodworm, Tubifex, etc.

Feeding a varied diet will ensure the fish are in optimum condition.

Under no circumstances should they be expected to survive on ‘left-overs’ from other inhabitants of the aquarium or relied on to ‘clean’ the aquarium.

Sexual Dimorphism

Females tend to grow larger, and sexually mature individuals are noticeably rounder and broader-bodied than males, especially when gravid.

NotesTop ↑

This species has been traded as C. sp. ‘Corrientes’ and CW005 in the past.

It possesses 24-26 lateral scutes and a colour pattern comprising two dark blotches on each flank, the first below the adipose-fin and second behind the head, plus the dorsal-fin has 3-4 dark stripes and caudal-fin up to 8. The caudal-fin lobes are long with the upper more extended than the lower (Axenrot and Kullander, 2003).

The latter authors also considered C. ellisae Gosline, 1940 a junior synonym of C. aurofrenatus, although this decision appears not to have achieved wide acceptance.

The genus Corydoras is among the largest catfish groups and currently contains over 150 valid species.

It is included in the family Callichthyidae, of which members are often referred to collectively as ‘armoured’ or ‘mailed’ catfishes group due to the presence of bony plates in place of scales on the body.

Their taxonomy can be confusing, and numerous undescribed species are also thought to exist.

Fish of unconfirmed identification entering the aquarium hobby are therefore typically assigned a ‘C‘ or ‘CW‘ number for purposes of reference and organisation.

They are facultative air breathers and possess a modified, highly vascularised intestine which has evolved to facilitate uptake of atmospheric oxygen and aid survival in oxygen-deprived environments. In the aquarium you’ll occasionally see them rising to the surface to take in gulps of air.

The stiffened pectoral-fin spines are capable of piercing human skin and a ‘sting’ can be very painful indeed, so care should be exercised when handling them.

It is thought that secretions from the axillary glands at the base of each spine may even be mildly toxic or venomous.

References

1. Eigenmann, C. H. and C. H. Kennedy, 1903 - Proceedings of the Academy of Natural Sciences of Philadelphia v. 55: 497-537
   On a collection of fishes from Paraguay, with a synopsis of the American genera of cichlids.
2. Axenrot, T. E. and S. O. Kullander, 2003 - Ichthyological Exploration of Freshwaters 14(3): 249-272
   Corydoras diphyes (Siluriformes: Callichthyidae) and Otocinclus mimulus (Siluriformes: Loricariidae), two new species of catfishes from Paraguay, a case of minetic association.
3. Calviño, P. A. and F. Alonso, 2010 - Revista del Museo Argentino de Ciencias Naturales, n.s. 11(2): 199-214
   Two new species of the genus Corydoras (Ostariophysi: Siluriformes: Callichthyidae) from northwestern Argentina, and redescription of C. micracanthus Regan, 1912.
4. Ferraris, C. J., Jr., 2007 - Zootaxa 1418: 1-628
   Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types.
5. Fuller, I. A. M., and H-G. Evers, 2005 - Verlag A.C.S. GmbH: 1-384
   Identifying Corydoradinae Catfish.
6. Nijssen, H. and I. J. H. Isbrücker, 1980 - Bijdragen tot de Dierkunde 50(1): 190-220
   A review of the genus Corydoras Lacépède, 1803 (Pisces, Siluriformes, Callichthyidae).
7. Reis, R. E., S. O. Kullander, and C. J. Ferraris, Jr. (eds), 2003 - EDIPUCRS, Porto Alegre: i-xi + 1-729
   Check list of the freshwater fishes of South and Central America. CLOFFSCA.