Sperm drinking corydoras.

[Jens E]

I found this text on wikipedia:

A unique form of insemination has been described in Corydoras aeneus. When these fish reproduce, the male will present his abdomen to the female. The female will attach her mouth to the male's genital opening, creating the well-known "T-position" many Corydoras exhibit during courtship. The female will then drink the sperm. The sperm rapidly moves through her intestines and is discharged together with her eggs into a pouch formed by her pelvic fins. The female can then swim away and deposit the pouch somewhere else alone. Because the T-position is exhibited in other species than just C. aeneus, it is likely that this behavior is common in the genus.

They use a text called "Sperm drinking by female catfishes: a novel mode of insemination" as a reference. I havent read this text but i find this information totally strange and have never heard about it before.

Since wikipedia is known to be full of errors i am asking here, is this true? And how come this isnt more known?

Jens

[Suckermouth]

As the person that put that there, I can say that's what the reference says.

The method involved targeting dye at the fish right when they were forming the T-position. Following the T-posotion, the dye comes out the anus.

[MatsP]

Frank (Corylogist) posted on another forum that it's absolute rubbish, and I'd have thought so before I found that.

Here:
http://www.fishforums.net/index.php?showtopic=234372

If nothing else, it's pretty insane, since the female must have a really bad case of diarrhea for the sperm to come out only minutes after the male expelled them. And I've certainly seen a female place eggs on the glass/leaves within a minute from the T-position.

--
Mats

[Suckermouth]

Debunked? I'd like something to cite for that and I'll fix Wikipedia if that's the case.

[Coryman]

Although I cannot argue against the theory of female Corydoradinae catfishes ingesting the sperm of a male and passing it through her gut during the mating process. I would doubt on two counts that a dye being released at the mouth of a female when in the "T" mating position would be able to prove anything. Firstly anyone that has dealt with Methylene blue (This was the dye that was stated as being used by the Japanese students from Osaka University in 1995 that purportedly did the original experiments and wrote the paper "Sperm Drinking Corydoras") will know what happens as soon as it comes in contact with water, the whole body of water turns blue in an instant. The other difficulty in accepting this is the fact that at the point the dye was supposedly released the male had the female clamped across the mouth with his pectoral fin spine, making ingesting anything a very difficult proposition as the image below clearly shows.

Corydoras sterbai in typical "T" mating clinch.

Image courtesy Ian Fuller & Corydorasworld.com

However since that paper was first published there has be much discussion on the subject and more recently it has been discovered that male sperm are covered in a seminal fluid like gel, which is capable of protecting the sperm as it travels through the females gut.

The point at which the female would be able to take the males sperm packages would in my opinion be at the point just prior to their coming together, when the male is offering himself in the typical sideways on arched and quivering stance.

Ian