Tatia

[Waldo]

I'm curious as CAT-e_LOG and Fish base haven't been a plethora of knowledge in the case of "Tatia". Does the entire genus fertilize internally?

[Marc van Arc]

Good question. One should say yes, because all Tatias have modificated genital pores, which enable internal fertilization. Yet Ferraris (catfish in the aquarium, 1991), who's an authority on Auchenipterids, states that "they are thought not to undergo internal fertilization" and that "the genital pore of the male may help to clasp the female during reproductive activities".
He even puts Tatia, Centromochlus and Glanidium in a seperate family (Centromochlidae) because of that fact, plus the fact that their dorsal spine doesn't change while sexually active (which is the case in all other Auchenipterids).
I have seen matings of T. aulopygia, T. galaxias and T. perugiae and I do believe that they have internal fertilization. FishBase has 1 record on T. perugiae too.
I've never seen the family of Centromochlidae anywhere else and perhaps Dr. Ferraris has changed his opinions over the years.
So in answer to your question: I think it's a yes.

[pturley]

This was debated on an old catfish listserve several years ago (perhaps over a decade ago).

The long and short of it (the closing arguement in the discussion long ago): The location of the genital pore doesn't matter in the Gladulocaudine tetras, then it doesn't matter in Tatia.

Stan and Marilyn Weitzmann proved the internal insemination in the Glandulocaudines decades ago.

So to goes my limited experiences with Tatia spp. and several other Auchenipteriids as well.

I too have witness copulations in three separate species of Tatia (two unidentified). The behaviour is very similar to that in Auchenipterichthys coracoideus which I have also witnessed on several occasions.

I believe we are just lacking sound documentation of the behaviors.