Corydoras flaveolus IHERING, 1911

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.

flaveolus: from the Latin flaveolus, meaning ‘yellowish’.

Classification

Order: Siluriformes Family: Callichthyidae

Distribution

Known from several tributary drainages of the rio Tietê which is itself an affluent within the upper rio Paraná basin, São Paulo state, southeastern Brazil. These include the rios Piracicaba, Alambari, Corumbataí, Capivari, and Bauru.

Type locality is ‘Tributaries to Rio Piracicaba above Salto, 23°10’S, 47°16’W, Estado de São Paulo, Brazil’.

Maximum Standard Length

35 – 50 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: 20 – 25 °C

pH: 6.0 – 7.5

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 chironomid larvae (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.

NotesTop ↑

This species is exceptionally rare in the aquarium hobby.

Among congeners it is most similar to C. lacrimostigmata, but can be distinguished by possessing more serrations on the posterior margin of the pectoral-fin spine (27-36 vs. 16-19) and on the posterior margin of the dorsal-fin spine (15-22 vs. 7-10), and by the presence of well-developed (vs. weakly-developed) simple and bifid (vs. simple only) serrations on the posterior margin of the pectoral-fin spine. In C. flaveolus the snout is roughly rounded and the dorsal profile of the head is abruptly concave (vs. snout slightly pointed and dorsal profile of head gradually concave in C. lacrimostigmata), the outer mental barbel is long, reaching or extending slightly beyond the anteroventral limit of the gill opening (vs. short and distant from the gill opening), the overall body shape is robust (vs. slender), the anterior internal process of the basipterygium is relatively thick (vs. thin), the external anterior and the dorsal ischiac processes of the basipterygium are close together or even fused (vs. distant), dark spots are present from the snout tip to the dorsal-fin base (vs. restricted to the snout tip and dorsal surface of head in some specimens), the flanks, dorsal and caudal fins are densely-patterned with spots and bars (vs. weakly-patterned).

The genus Corydoras 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. Ihering, R. von, 1911 - Revista do Museo São Paulo 8: 380-404
   Algumas especies novas de peixes d'agua doce (Nematognatha) (Corydoras, Plecostomus, Hemipsilichthys).
2. 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.
3. Ferraris, C. J., Jr., 2007 - Zootaxa 1418: 1-628
   Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types.
4. Fuller, I. A. M., and H-G. Evers, 2005 - Verlag A. C. S. GmbH: 1-384
   Identifying Corydoradinae Catfish.
5. Tencatt, L. F. C., M. R. Brtto and C. S. Pavanelli, 2014 - Neotropical Ichthyology 12(1): 89-96
   A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the upper rio Paraná basin, Brazil.