FishForums.com - View Single Post - Elephant nose

Plums · 11-09-2005, 09:42 PM

Many thanks for the help. The more I've looked into this the more it's become a bit of a pipedream, it's still interesting but not very likely to happen.

I didn't know about the indentation that males have. From what I've read, they can be sexed by cutting them up with a knife, which is a little drastic, by their EODs (electric organ discharges), and by their anal fins. Radiography is also mentioned quite a bit, which I'm guessing is a bit like xrays and lets you look inside the fish.

This is what I had about the anal fins - "Adult and subadult males show bone expansion at the base of a select number of anal fin rays (Brown et al., 1996; pezzanite and Moller, 1998); this characteristic is lacking in females."
from - http://biology.uky.edu/Yan/N0.%2012,...ion_social%20i

I can't tell anything about the anal fins looking at the one I have.

I googled around and found this - "Males were identified by the distinct indentation at the dorsal margin of the anal fin."
from - http://www.anovascience.com/pdf%20fi...ivityModel.pdf

So there's your indentation. My EN does seem to have a small notch there compared to, well, almost all of the elephant nose pictures I've seen.

The article in that last link also shows a big problem like you said. The ENs in the wild use their electric fields to tell each other what sex they are and who's ready to mate etc. The study seems to show that this all falls down when they are brought into captivity which seems to stop them signalling what sex they are, and can even make males signal like females and females signal like males.

I haven't given up just yet though

If anyone has any thoughts/further information please let me know.

When I have some time I'll put together everything I can about breeding these guys.

Btw. OldSalt, how did you get to find out about the anal fins/indentations?

11-09-2005, 09:42 PM	#6
Plums Junior Member Join Date: Nov 2005 Location: UK Posts: 3	Many thanks for the help. The more I've looked into this the more it's become a bit of a pipedream, it's still interesting but not very likely to happen. I didn't know about the indentation that males have. From what I've read, they can be sexed by cutting them up with a knife, which is a little drastic, by their EODs (electric organ discharges), and by their anal fins. Radiography is also mentioned quite a bit, which I'm guessing is a bit like xrays and lets you look inside the fish. This is what I had about the anal fins - "Adult and subadult males show bone expansion at the base of a select number of anal fin rays (Brown et al., 1996; pezzanite and Moller, 1998); this characteristic is lacking in females." from - http://biology.uky.edu/Yan/N0.%2012,...ion_social%20i I can't tell anything about the anal fins looking at the one I have. I googled around and found this - "Males were identified by the distinct indentation at the dorsal margin of the anal fin." from - http://www.anovascience.com/pdf%20fi...ivityModel.pdf So there's your indentation. My EN does seem to have a small notch there compared to, well, almost all of the elephant nose pictures I've seen. The article in that last link also shows a big problem like you said. The ENs in the wild use their electric fields to tell each other what sex they are and who's ready to mate etc. The study seems to show that this all falls down when they are brought into captivity which seems to stop them signalling what sex they are, and can even make males signal like females and females signal like males. I haven't given up just yet though If anyone has any thoughts/further information please let me know. When I have some time I'll put together everything I can about breeding these guys. Btw. OldSalt, how did you get to find out about the anal fins/indentations? Last edited by Plums; 11-09-2005 at 09:53 PM.