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how can you tell if a cory is a female or a male instead of there.. can you tell by their color? like one is darker than the other?? if anyone know plz help me here

Female corys are usually wider when you look at them from the top.

~elaine~

yea i kno that you can tell if a cory is a female or male jus by which one it wider.. but can you tell wether a cory is a female or male by looking at the color???

Only in certain species, and even then it's more color pattern than the actual color. Most Corydoras cannot be readily sexed without looking at the girth or length of the fish. Most of the species which can be sexed by pattern fall under the "elegans group", those cories that are similar to C. elegans.

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And when he gets to Heaven, to Saint Peter he will tell: "One more Marine reporting, Sir! I've served my time in Hell."

In addition, the venerable Innes book claims that it is possible to determine gender of Corydoras catfishes by looking at the angularity of the shape of the pelvic fins. However, whether this is a reliable diagnostic criterion, is open to question, as I've only ever seen it mentioned in that one source.

This is a quote from the Innes book (page 220):

In the majority of species the female is somewhat the larger. We are sure that in C. paleatus the ventral fins are slightly more rounded in the female. Our accompanying illustration shows this difference. Not having seen other species breed, we do not know whether this applies to them all, but it probably does. As breeding approaches, the belly of the female takes of a reddish hue. Also the strong first ray of her pectoral fin reddens and thickens. In addition to these indications we have the old rule to select the more round and full-bodied fish as the female. It has long been claimed that the males have more pointed dorsal fins. Our obervations do not confirm this.

Incidentally, in the case of wild-caught Corydoras paleatus, the fishes are sexully dimorphic. Males have much more elongated dorsal fins than the females, a trait which has been lost in commercially bred stock.

I would question the reliability of the above quote as a source of information, as no other authority on Corydoras catfishes (including the Derek Lambourne book and Ian Fuller) make mention of these alternative diagnostic characteristics to my knowledge. But, the Innes quote is interesting because it may prove to be reliable if someone performs the appropriate morphometric analysis on large numbers of individuals. However, this is a task that has yet, to my knowledge, to be performed.

Stick with the females being larger and fuller-bodied, especially when ripe with eggs, and if other criteria become available for your particular species, then post them here so we can see if those other criteria prove reliable.

Oh, there are some fishes that were formerly members of Corydoras that are sexually dimorphic too - Scleromystax barbatus exhibits bristles upon the preopercular region of the head. The same applies to scleromystax macropterus, whose males also have longer pectoral spines and extended soft dorsal rays when compared to the females.

Additionally, when Corydoras pygmaeus is breeding, the female's eyes dilate, and remain dilated until spawning is completed. This also occurs in Corydoras hastatus.


Panda Catfish fan and keeper/breeder since Christmas 2002

oh so the color of a cory cant help me to figure out if it is a male or a female.. i got to panda cories and one is darker than the other so i thought that one was a male and the other was a female.

thanks for all your help

"Incidentally, in the case of wild-caught Corydoras paleatus, the fishes are sexully dimorphic. Males have much more elongated dorsal fins than the females, a trait which has been lost in commercially bred stock."

Actually, the so called "long finned" paleatus is an undescribed fish that is considered, as of now, to be a separate species of corydoras.