Sexing P. Cheni

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LES..
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Sexing P. Cheni

Post by LES.. » Thu Jan 12, 2006 3:05 am

Hi All,

I have recently been seeing a pair of p. cheni in my tank doing the ruffling dance which seems to be mentioned in the resources for breding these fish. The thought of having my fish spawn is very exciting but i am confused over why i am seeing this particular pair ruffling up together as i had assumed both fish were male.

Most of the information i have found for sexing p. cheni lists the depth of colour on the dorsal fin, shape of the nose and the size of the tubercules.

The ruffling pair both have a thick, deep red, line on their dorsal fins, the same shape of nose and similarly sized tubercules. This leads to the confusion.

I'll try and get some photos to post but has anyone got some good tips on how to distinguish male and female in this species?

Thanks
LES..

p.s. Thanks to all for the responses to my pervious question on my skinny hillstream, the fish seems to be doing better now.

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Graeme Robson
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Post by Graeme Robson » Thu Jan 12, 2006 6:46 am

Hopefully this should help you Les. http://aquaweb.pair.com/forums/archives ... read=86107


Graeme.

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LES..
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Feeling dim

Post by LES.. » Thu Jan 12, 2006 7:02 am

I have studdied this picture before but i'm completely stumped as to what exactly i'm supposed to be seeing.

It's like those spot the difference puzzles but because they are two different fish you are never sure as to what the differences are significant.

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Martin Thoene
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Post by Martin Thoene » Thu Jan 12, 2006 9:35 pm

Hey, how did I miss this thread?

Right LES, let's try this another way......

Image

You'll note that the female's belly is noticeably more full than the male's. It is convex and reflects the light back from it's centre. The female is broader in the belly at the point just behind the Pectoral fin rear origin.

Look at the nose of the fish. Sexually active male cheni have nasal tubercules increased in size. See them either side of the nose? Compare with the female. Females have very much smaller tubercules which do not increase in size when sexually mature. From underneath, you can only just see one pair.

A male looks like this:
Image

A female like this:
Image

Compare.....the upper fish is the dominant male in the tank....
Image

The other fish looks like a subordinate male. You can see it has tubercules, but they are somewhat smaller than the other fish. Females generally have a higher arch to the top profile of the body and are more full-bodied.
A male side on is pretty streamlined............
Image
Note this one has much reduced contrast between the light and dark body colours (see difference in dominant male above).
Females are generally this low contrast colour.
Note back contour..........
Image

The good news is that P. cheni are pretty good at working out who is who themselves :wink: . Now, I'm not sure what you mean by "ruffling". cheni courtship consists of the male dancing around the chosen female (often on the aquarium glass) and generally following her around. At some point the male will get accepted by her and then she will tend to follow him around.
Two fish squaring up to one another and trying to get on top of one another are generally males in territorial dispute. At these times colours will be intensified and may change to what we term "war paint". The upper area darkens and the sides go paler than normal. Males will raise their colourful dorsals as a display.......

Image

The dominant male will tend to be the one breeding in a tank where you have several. He will dig a pit under a stone by sliding backwards off it and wooshing substrate away with his tail.......

Image

The male and female then take turns in sliding backwards into the hole and eggs are layed and fertilized. The male then covers up the eggs. Several pits may be dug, but generally it appears they choose one only.
The eggs are quite large......

(Jim Powers photo)
Image

After a few days, tiny babies will emerge from the gravel. At that time they are around 4-5mm in length and will begin grazing on microorganisms on the tank surfaces........
Image

They grow quickly. At around 6mm they have a prominent caudal peduncle eye spot, probably to confuse predators.

Image

If you look for the clues, you may realize the behaviour you've seen is either fighting or courtship. If it's the latter and there are no other fish in the tank which might predate on tiny babies, there's a good chance they might breed successfuly. Both Jim Powers and I have bred them lots of times.

Good Luck! :wink:

Martin.
Last edited by Martin Thoene on Mon Oct 09, 2006 3:01 pm, edited 1 time in total.
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Well that told me!

Post by LES.. » Fri Jan 13, 2006 12:30 pm

Thanks Martin, this just sums up all that is so great about this forum.

Now i think i will have spend a good good couple of hours infront of the tank to work through that lot of information :-) Oh the suffering!

The dance i'm seeing involves turning around nose to nose on a stone then backing tail first into little scrapes under the stone which seems consistant with mating. Certainly the dominant loack in the tank will swim around looking for his partner who will then follow him back to the stone. There is little warpaint visible in these dances.

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Post by Jim Powers » Fri Jan 13, 2006 12:51 pm

Your description certainly sounds as if your fish are spawning.
Sometimes, particularly with younger pairs, it takes a bit of time and experience to determine the sex of the fish. The info Martin posted is very thorough and will certainly help in that regard.
As far as the lack of warpaint , the fish I have now don't seem to display that to the degree of that I experienced with my orginal chenis.
Keep us posted.

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Re: Well that told me!

Post by Martin Thoene » Fri Jan 13, 2006 7:42 pm

LES.. wrote:Thanks Martin, this just sums up all that is so great about this forum.

Now i think i will have spend a good good couple of hours infront of the tank to work through that lot of information :-) Oh the suffering!
Actually, Jim mailed me and said my post should be included as a page when we get into the big revision of LOL info that is planned to strart fairly soon. I had the same though actually just before I hit submit last night.

I see that you are in Surrey. Whereabouts? I lived in Wimbledon for nearly 30 years, North Cheam for 3 and Guildford for 4 years.

Martin.
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Post by Graeme Robson » Sat Jan 14, 2006 10:19 am

I agree! Soon as i saw your post, i thought thats a "Keeper" 8)



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Re: Well that told me!

Post by LES.. » Sat Jan 14, 2006 2:46 pm

Martin Thoene wrote:I see that you are in Surrey. Whereabouts? I lived in Wimbledon for nearly 30 years, North Cheam for 3 and Guildford for 4 years.
I'm currently living in Guildford. Not a bad part of the world if you can put up with the traffic :-)

LES..

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Still none the wiser

Post by LES.. » Mon Feb 20, 2006 4:28 pm

Well as Martin said it looks like the p. cheni are quite able to work out whose who!
Image

Yes, i had quite a shock when i saw this little critter zipping around the tank yesterday. We had seen some eggs two weekends ago but never suspected anything would come of them.

What should i be feeding this little guy?

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Jim Powers
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Post by Jim Powers » Mon Feb 20, 2006 5:33 pm

Congratulations, Les!!! Welcome to the club!!!

I bet that you have more than just the one baby. And, you will have many more as they continue to breed. That is, as long as nothing else in the tank find the fry tasty.
The nice thing about baby hillstreams is that they don't need much attention. They will find enough food on their own as they graze around the tank. As they grow they will begin eating pelleted food in addition to the algae and aufwuchs they find while grazing. I have also found that they enjoy parboiled spinach and kale leaves that are anchored under rocks.

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Post by Martin Thoene » Mon Feb 20, 2006 10:43 pm

Good stuff Les! :P Two weeks from spawning seems to be about the norm before you see babies like this. It would be around 4-5mm in body length now right? Jim's correct....where there's one, there's more.

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Poor choice of tank mates

Post by LES.. » Sat Feb 25, 2006 8:52 am

I have to admit to coming into owning p. cheni blind, when my partner and I first set up this tank it was to house a shubunkin and sarasa comet. My first p. cheni were bought on impulse and it's only thanks to LOL after the fact that i have a couple of big powerheads to keep them happy. I never really thought we would be able to breed fish in our tank so no thought was given to how these two ravenous monsters would react to little fry in the tank, it isn't looking good and i'm sure we have lost a number already. Hence the reason i'm looking at buying a second tank specifically for hill stream loaches.

In the mean time we have a breeding net in the tank and we are trying to catch the fry before they get eaten and place them in this net. So far we have caught one but have seen others in the tank.

Given this tank has been set up for less than a year it has been a very educational introduction to fish keeping :-)

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Post by Emma Turner » Sat Feb 25, 2006 8:59 am

Congrats, LES! This is wonderful news! :D

Emma
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New picture

Post by LES.. » Sun Feb 26, 2006 10:12 am

Well today's mission was to capture as many fry left in the tank and re-home them in the breeding net. So the shubunkin and comet were netted out into a bucket and all of the decor removed baring a few plants.
Well it seems like the monsters have been feeding well as there was just one lonesome loach of about 8mm left in the tank. However while rooting around the tank looking for more fry i noticed a little white wiggly thing in the gravel, curious i netted it out and had a closer look. Odd looking thing, too big to be a Planaria worm and i'd be darned if there weren't two little eye like dots. Taking another look i realised there were more and they were all from the area under a stone were we suspect the loaches spawned.

Could these be newly hatched p. cheni?
Image

I'd love to know what you guys think and if anyone else has seen fry at this stage of their development.

LES..
Last edited by LES.. on Sun Feb 26, 2006 10:20 am, edited 1 time in total.

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