Ancistrus sexing

[summer]

I have two ancistrus which were bought at the same time. They are approx 2.5 to 3 inches long. They were both clean shaven when they arrived, but now I've had them for about 2 months and one has started to grow some impressive bristles. The other has none at all. So I'm thinking I have a male/female pair.

the thing is, the 'male' chases the 'female' away whenever she gets too near, especially at feeding time.

I think this means they are both male and the other one is slow with his bristles, but my hubby says the male is just grumpy/greedy

I just wanted some opinions from here - would a male be territorial with a female? or only with another male? Is my male being territorial? or just grumpy?

thanks in advance

PS he chases the other fish away from his food too, but not as much as he chases this female. In fact he will chase her off her piece of courgette, even when he has his own piece, and the pieces are at opposite sides of the tank!

[MatsP]

It can be difficult to tell them apart at younger age. A photo of each fish would help (from above preferably, and with a contrasting background).

I wrote down a set of different sexing keys that is in the FAQ:
http://www.planetcatfish.com/faq/index. ... 7&catid=15

You can use that to "score" whether the fish is "mostly male" or "mostly female".

The chasing away from food is generally belligerence, I expect, not a sign of whether the other fish is male or female - in fact, part of the courting ritual is that the male chases the female.

--
Mats

[Carp37]

My original male bristlenose is a bad-tempered so-and-so- he's always trying to chase away his mate if there's any food about, although they produce copious amounts of fry. Most of his sons are much more placid, even allowing females to feed on the same piece of vegetable, so I think there's a fair bit of individual variation in their behaviour.

[Richard B]

My original male bristlenose is a bad-tempered so-and-so- he's always trying to chase away his mate if there's any food about, although they produce copious amounts of fry.

Same with mine...

[summer]

oooo thanks everyone, I shall try for photos, and do that scoring thing

[summer]

after much study I definately have one of each

[andywoolloo]

congratulations! I predict baby bristlies in your future.

[summer]

lol well the grumpy male had better be nice to the girlie one first ha ha

[summer]

well mister catfish has been hiding for two days - can't see him anywhere, so my guess is he's egg sitting lol. Mrs catfish is making the most of the free grub!

[summer]

two months later and our mister is catsitting his 4th batch and we have over 300 babies!! Our local maidenhead has taken 50 of them, he doesn't need any more tho - so anyone want baby BNs?

[MatsP]

This is indeed one of the "problems" with this fish - once they start breeding, they don't stop unless you ensure you only have one sex in each tank... And whilst shops are often happy to take a bag or two of small bristlenoses, if you have a good breeding setup, you soon saturate the local area.

--
Mats

[summer]

we've now taken the female out and put her in with the sturisoma. (They've stopped spawning now and we still have 20 juveniles to sell...)

I must have fertile water as we also have a cherry red shrimp population boom and I've noticed assassin snail eggs this morning!

we are taking one of the male ancistrus back to the LFS and hope to get another female (we could keep one of ours from the batches but I don't really want any inter-breeding)

I also have a theory that ancistrus prefer to have their breeding caves set at a 45 degree angle. We set one of the clay tubes at an angle and the 2nd male is in there all the time, yet he never went in it when it was flat.

[summer]

btw Mat the link you added above doesn't work anymore - please can you put up a link to the file's new location?

many thanks

[MatsP]

btw Mat the link you added above doesn't work anymore - please can you put up a link to the file's new location?

many thanks

Unfortunately, Jools is working on modifying the FAQ section to be more inline with the rest of the Planet Catfish structure. At the moment, it's neither working in the new form, or the old form, so I can't post a link to it.

--
Mats