Skunk Cory Fish Breed Profile

Characteristics, Origin, and Helpful Information for Hobbyists

Corydoras arcuatus
Pia Helminen

The skunk cory is a peaceful and hardy armored catfish that can help keep the bottom of your tank clean while also living sociably with other members of your tank community. A bottom-dwelling schooling fish, it prefers to live in groups of six or more. But do not be alarmed when individuals pop up to the surface. The skunk cory possesses an ability to supply at least part of their oxygen needs by gulping air at the surface of the water. As the air passes through its specialized intestinal tract, oxygen is absorbed into the bloodstream.

Species Overview

Common Names: Skunk cory, arched cory

Scientific Name: Corydoras arcuatus

Adult Size: 2 inches

Life Expectancy: 5 years

Characteristics

Family Callichthyidae
Origin Brazil, Columbia, Ecuador, Peru
Social Peaceful schooling fish
Tank Level Bottom
Minimum Tank Size 10 gallons
Diet Omnivore
Breeding Egglayer
Care Easy
pH 6.8 to 7.5
Hardness 2 to 25 dGH
Temperature 72 to 79 F (22 to 26 C)

Origin and Distribution

Corydoras arcuatus originated in the upper Amazon River basin in Brazil, Colombia, Ecuador, and Peru. Although some wild-caught specimens are available, most skunk corys sold to hobbyists are captive bred on commercial farms.

Colors and Markings

Like other members of the Cory family, the skunk cory is an armored catfish; instead of scales, they possess overlapping bony plates, as well as sharp spines on their fins. This "armor" offers them some measure of protection from predatory fish. Owners also should exercise care when netting them, as the spines can get caught in the net. Frequently confused with Corydoras narcissus, the skunk cory has a much shorter nose. The fins are transparent; however, the tail has a smattering of very tiny dark spots.

The body of the skunk cory is cream-white colored, sometimes showing an attractive yellow-gold sheen. A black stripe begins at the mouth, runs through the eye, and then arches along the back, thus giving rise to both of its fitting commons names: arched cory and skunk cory. This stripe continues on to the beginning of the tail where it turns sharply downward. Whether in alarm or at rest, all parts of this black stripe can turn so pale that it almost disappears.

Tankmates

In nature, this species lives in large schools and does not do well alone. Groups of a half dozen or more are recommended. Skunk corys are quite peaceful, making them suitable for community aquariums made up of other small- to medium-sized peaceful species.

Examples of suitable tankmates might be other small peaceful catfish, dwarf cichlids, danios, small gouramis, rasboras, and small tetras. Avoid keeping skunk corys as well as others in the Corydoras genus with any large or aggressive species.

Skunk Cory Habitat and Care

The skunk cory does best in a planted tank, preferably with driftwood or similar decor that provides hiding places. Open swimming areas should also be provided, as well as small, smooth-surfaced gravel to preserve their sensitive barbels from chafing and becoming infected. Sand, which is found in their native Amazonian habitat, is superior to standard gravel substrates. Dim lighting, as well as blackwater conditions, are ideal for this species.

Good water conditions are key to the health of the skunk cory; elevated ammonia, nitrites, and nitrates are more stressful for this species than other fish. Very acidic water conditions should be avoided. Frequent water changes are important, as well as good filter maintenance. Also avoid using salt in the aquarium, as skunk corys are not tolerant of salt. This is true of most scaleless species.

Skunk Cory Diet and Feeding

Skunk corys are omnivorous and will accept a wide range of foods. Because they are primarily a bottom dweller, it is important to include sinking foods in their diet. Live foods, such as bloodworms and brine shrimp are gobbled up. But if live foods are not available, frozen foods are an acceptable substitution. Sinking pellets are a good staple food for this species. Make sure that your skunk cory gets enough food by delivering and lodging foods at the bottom with tongs.

Gender Differences

In general, female corydoras are larger and rounder than their male counterparts. These differences are subtle.

Breeding the Skunk Cory

Corydoras arcuatus is one of the more challenging of the cory species to breed. Begin by preparing a breeding tank with a sand bottom and plenty of hiding places. Anubis and java moss are good plant selections for the breeding tank. Filtration should be robust, as corys prefer strong currents for spawning. The pH of the water should be close to 7.0, with a hardness of no more than 10 dGH and initial water temperature in the range of 72 to 79 F (22 to 26 C).

Introduce the breeders to the tank, at a ratio of two males per female. Condition the breeders with a variety of live foods, such as brine shrimp, daphnia, mosquito larvae, Tubifex, and whiteworms. If live foods are unavailable, frozen foods may be used. Perform a 10 to 15 percent water chance twice a week to ensure that water quality remains pristine. When performing water changes, use water that is two or three degrees cooler than the aquarium water; this lower water with stimulate breeding by mimicking the start of the rainy season.

Females will become noticeably plumper as they fill with eggs, and they will begin cleaning possible spawning locations within the tank. Meanwhile, males will also become more active, swimming nervously about the tank. At times they will stop and remain stationary in the water, extending their fins and shaking their entire body. As spawning nears, the males assume a T position in front of the head of the female, grasping her barbels between his pectoral fins and body.

The female cups her pectoral fins to form a basket into which she releases several eggs. It is believed that in this species, the female passes the sperm through her gills to subsequently direct the sperm toward the eggs she is holding. Once fertilized, she places the adhesive eggs onto the areas in the tank she previously cleaned. It is not unusual for the males to chase the female in an attempt to be chosen to fertilize the next batch of eggs she releases. This process will continue until a hundred or more eggs are laid.

At this point, the parents should be removed from the breeding tank, as they will consume the eggs once spawning is complete. Another option is to move deposited eggs to a rearing tank. Place a few drops of methylene blue in the egg tank to prevent the formation of fungus. Some breeders have found that cherry shrimp are an excellent means to prevent the fungus from spreading. They will eat any diseased eggs but will leave healthy eggs unharmed.

In three to five, days the eggs will hatch and the fry will subsist on their own yolk sack for several days. After that, they will need to be fed freshly hatched brine shrimp, microworms, or commercially prepared fry powders. Frequent water changes are important to maintain good water quality. It is important that the tank is well oxygenated, using a sponge or box filter so that hatchling fry are not sucked into the filter intake. Many losses at the fry stage are due to improper water conditions.

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