Catfish, Bronze


Corydoras aeneus


Adult size is 2.5” (6½ cm) for males and a slightly larger 2.8” (7 cm) for females; body is yellow or pink with a white belly; head and back are blue-grey; fins are yellow or pink. In common with most Corydoras the dorsal, pectoral and adipose fins have an additional sharp barb that is mildly poisonous; a brownish-orange patch is usually present on the head, just before the dorsal fin, and is its most distinctive feature when viewed from above in the stream.

Family

Callichthyidae

Order

Siluriformes

Class

Actinopterygii

Range

Eastern side of the Andes, from Colombia and Trinidad to the Río de la Plata basin

Habitat

Quiet, shallow waters with soft bottoms that can sometimes be heavily polluted by clouds of disturbed mud from the bottom, but it also inhabits running waters

Life Expectancy

About 10 years in captivity

Sexual Maturity

Information not available

Diet

In the wild they eat worms, benthic crustaceans, insects, and plant matter; in the Zoo they are fed a variety of proprietary fish foods.

Status

Not listed

Behaviors

In its native habitat, bronze catfish inhabit waters with a temperature range of 25 °C to 28 °C (77 °F to 82 °F), pH 6.0-8.0, and hardness 5 to 19 DGH. It typically stays in schools of 20 to 30 individuals and forages at night. Reproduction occurs with the onset of the rainy season, which changes the water chemistry. Females spawn 10–20 egg-clutches with multiple males at a time, but an entire egg clutch is inseminated by sperm of a single male. Bronze catfish have a unique method of insemination. The male presents his abdomen to the female. The female attaches her mouth to the male’s genital opening, creating the well-known “T-position” many Corydoras exhibit during courtship. The female drinks the sperm, which then rapidly moves through her intestines and is discharged together with her eggs into a pouch formed by her pelvic fins. The female swims away and deposits the pouch somewhere else alone. In the wild, eggs are laid on waterweeds. The eggs gradually grow darker in color, and just prior to hatching (ranging from three days at 82.4°F (28°C) to a week at 68°F (20°C) they turn dark brown. In the aquarium the fry keep to the bottom of the tank, feeding on detritus and any fine foods available. The parents may spawn again within two to three weeks. Males do not form territories or compete over females; interference between males might only happen when two males present their abdomens simultaneously. On the other hand, females do not choose between males. Mating is more or less random; therefore, male reproductive success is directly related to courtship frequency.

Adaptions

Like most members of the Corydoras genus, these catfish have a unique method of coping with the low oxygen content that prevails in such environments. In addition to utilizing their gills like any other fish, they can come to the surface of the water and draw air in through their mouth. This air is then absorbed through the wall of the intestine and any surplus air is expelled through the vent. The eggs exhibit a unique surface pattern with small villi-like bumps which resemble attaching-filaments of teleost eggs. These structures allow the eggs to be adhesive and stick to a specific place or to each other. The presence of these structures may be related to the turbid habitat in which this species lives. Corydoras have a very sharp barb just under each eye, one in the adipose and a large one in the front of their dorsal fin. These barbs protect it from being swallowed by a larger fish. In the aquarium be prepared for the cory to become caught up in the mesh of the net and do not try to catch this fish in your hand. Bronze catfish are armored not scaled catfish. They have two rows of overlapping bony plates running down each side and large plates covering their head, great protection from predators. Known to ‘blink’ its eyes to the amazement of onlookers, the Cory has the ability to tilt its eye down to examine the nearby substrate.

Special Interests

The name Corydoras is derived from the Greek ‘kory’ (helmet) and ‘doras’ (skin). Other common names include green corydoras, bronze cory cat, aeneus cat, bronze cory, brown cory, albino cory, gold laser cory, and green laser cory. Scientific synonyms include Callichthys aeneus, Corydoras macrosteus, Corydoras microps, Corydoras venezuelanus, Hoplosoma aeneum. Bronze catfish are very popular amongst aquarists. They ceaselessly comb the bottom of the aquarium for food and therefore disturb it slightly, sending up detritus and waste material that has settled loosely on the bottom. Due to their social nature, they prefer being kept in groups of 5 or more and are ideal fish for a community tank. Other Corydoras species can be placed in the same aquarium, and despite the strong resemblance many species bear to one another, the species will tend to separate out and only move about among their own kind. In the aquarium, the ideal environment is freshwater with no salt added at a pH 6 – 8, temperature 72°F - 81°F (22°C - 26°C), and hardness 5dH – 19 dH. Corydoras aeneus has been selectively bred in captivity for many generations, and mutations of the standard type are common. An albino form is extremely widespread, more common in shops than most other actual species of Corydoras. Other existing manmade variants are longfin forms of the normal and albino colorations, squat and fat “balloon” fish, and artificially dyed or “tattooed” catfish. Wild variants include C. aeneus with gold, orange, green, or red neon shoulder stripes, and black or gold.

Folklore

Conservation

Bronze catfish are probably the most popular Corydoras species. It is annually bred and shipped in large quantities all over the world. It is easily bred and is produced in commercial quantities in the United States, Europe, and Singapore. Most of the available fish are therefore domestic strains. Wild imports are reported to be less easy to breed.

Jacksonville Zoo History

The Jacksonville Zoo held bronze catfish from 1992-2000 and then brought them back again in 2005.

Exhibit