About the Spotfin Cory
Species Type: Freshwater Fish
Care Level: Easy. Does well in a slightly more narrow range of water parameters and shouldn't be used to cycle an aquarium. Will eat most prepared foods. May have some specific care requirements in terms of particular water parameters, social behaviors, food items etc.
Origin: Suriname River basin in Suriname and Iracoubo River basin in French Guyana. Occurs upstream in small moderately-sunny shallow creeks with sandy-muddy substrates, and on the edges of stagnant zones of flooded forest such as lakes.
Compatibility/Temperament: Very peaceful bottom fish, well suited to any community aquarium of non-aggressive fishes. Must be kept in a group, minimum three but preferably five or more. A group of three can be kept with other cory species, but given this species uniqueness, rarity and smaller size, a group of five would be ideal.
This species was the very first Corydoras to be described. It is one of four very similarly-patterned corys that are frequently confused and will often be seen in stores under incorrect names. Corydoras julii, C. leopardus, C. punctatus and C. trilineatus all share a large black blotch in the dorsal fin, a barred caudal fin, and usually a horizontal stripe along the body at the juncture of the dorsal and ventral lateral plates; the body is spotted. However, all these species are highly variable in their pattern, and the horizontal stripe may be absent in C. julii and always absent in the subject species.
Corydoras punctatus is rare in the hobby. In its lighter variant, it bears a very close similarity to C. julii; both have a spotted pattern on the head and body, and like some forms of C. julii, this species has no lateral stripe along the body. The spots are larger and more numerous on fish that occur over dark substrates (mud) compared to those over sandy substrates. The two attached photos illustrate both these variations. Also like C. julii, this species is somewhat smaller and more compact-looking in size than C. trilineatus.
The aquarium should be well-planted with pieces of bogwood, a dark substrate (small gravel or sand, provided it is smooth-edged) with some open areas. This species occurs in moderately-sunlit streams but its colouration will be paler under bright light. Females are rounder when viewed from above and slightly longer than males, and the pectoral fins of the male are markedly longer and thicker due to the presence of a number of spikelets.
The Corydoras are quite sensitive to water parameters and quality, and highly intolerant of salt, chemicals and medications. Signs of stress usually begin with rapid respiration, then lethargy (often just "sitting" on plant leaves, wood or the substrate respirating heavily, sometimes near the surface) and sometimes rolling onto one side. At such signs, a partial water change of at least 50% with a good water conditioner should immediately be made, and appropriate steps taken to remove the cause. Any sudden fluctuation in water chemistry or temperature often induces shock, causing the fish to "faint" and fall over on its side. Corydoras introduced to new aquaria will settle in better if the tank is established; Cory's do not adjust well to a new aquarium with still-unstable water conditions and fluctuations.
The dorsal, pectoral and adipose fins are each preceded by a spine which is actually a hardened and modified ray; the pectoral fin spine can be "locked" into position by the fish; care must be taken when netting Cory's not to entangle these spines, which can also give the aquarist a nasty jab. They are believed to be a defense adaptation, to lodge the fish in the throat of a predator.
All species in the genus will periodically and fairly regularly swim quickly to the surface for a gulp of air. The fish swallows the air and blood vessels in the hind gut extract oxygen from the air; it is then expelled through the vent the next time the fish breaks the surface for another gulp of air. This adaptation is believed to have evolved so that the fish can survive in poorly-oxygenated water such as drying pools during the dry season. It is however essential to the fish's well-being that it regularly swallows air.
The genus name is derived from the Greek "cory" meaning helmet, and "doras" meaning skin, incorrectly used here for "armour"; it refers to the dual row of overlapping plates (instead of scales) along the body, comparable to a suit of armour. This species was described by M.E. Bloch in 1794 as Cataphractus punctatus; it was reassigned to the genus Corydoras by Nijssen & Isbrücker in 1980. The species name is Latin for a small hole, dot or spot.
Spotfin Cory Diet
In its habit, feeds on worms, crustaceans, insect larvae. Readily accepts prepared foods that sink such as tablet and pellet; frozen bloodworms and live worms are relished as treats.
Attains 2 inches.
Minimum Tank Suggestion
24 inches in length.
Ideal water parameters for Spotfin Cory
Soft (hardness up to 12 dGH) acidic to very slightly basic (pH to 7.2) water, temperature 22-26C/72-79F but not warmer. Given that available fish will be wild-caught, soft and acidic water is recommended for long-term health.