Sexing Hemiancistrus sp. L128

[Haavard Stoere]

I tried to press the abdomen hard against the glass to reveal the shape of the genital papillae. Unfortunately it seems to make little difference. What do you think? Are both sexes represented?

These are the 5 fish..

Fish nr 1 measures 14 cm:






Fish nr 2 measures 13 cm:






Fish nr 3 measures around 12,5 cm:






Fish nr 4 also measures atound 12,5 cm:






Fish nr 5 measures around 13 cm:

[Haavard Stoere]

I can see little difference.

It was easier with Hypancistrus zebra:
http://www.planetcatfish.com/forum/view ... hp?t=16551

[Haavard Stoere]

Maybe it is easier to compare like this:

[Haavard Stoere]

The distance to the camera was fixed, and scale is actual pixels in the following pictures. This should make comparison easier.

[MatsP]

I'd be hard pushed to say which is which, but it looks like you have two distinct forms - which is good, right?

--
Mats

[Haavard Stoere]

Absolutely Two forms are good

I have noticed that fish nr 3 has a little bit more curve in its pectoral fins. She also has less odontal growth in the nedher regions. Her pectoral main fins are slightly thinner.

I will make another comparison serie of the pectoral fins.

Why can´t some geek make some kind of program or device for sex determination? A hand held genital papillae scanner with a usb interface perhaps

[Haavard Stoere]

For some reason all the papillae pictures of fish nr. 1 were out of focus. Here is another one of fish nr 1 where she/he looks a little different.

[MatsP]

Why can´t some geek make some kind of program or device for sex determination? A hand held genital papillae scanner with a usb interface perhaps

You just wait

Actually, seriously, the reason no one has done such a thing is that it's a bit too hard for HUMANS to compare these things - never mind stupid computers.

--
Mats

[Haavard Stoere]

The organs are soft and changes form when under pressure from the outside or its own muscles on the inside. I can actually see this happen when I observe them. The profile of the head from above also changes as the fish grips or lets go with its mouth. The curvature of the fins increase or decreas when seen from above as they are angled upwards or downwards. All of this makes it rather difficult to determine sex. Despite of all this some people are much better then others to guess correctly. I find it very hard.

[Haavard Stoere]

Pectoral fins 1-5

[Haavard Stoere]

Do odonts rub off when the fish are in transit? It sure looks like it.

[MatsP]

Don't think it's mechanical rubbing, but yes, odontodes will be lost when the fish is under stress for some time, such as during shipping.

So it may be a good idea to let them settle a bit to see what happens.

--
Mats

[apistomaster]

Do odonts rub off when the fish are in transit? It sure looks like it.

I don't think so, Haavard, and I would say you have a nice balance of sexes based on overall appearances save genital papilla for which I don't have an expert's eye.

If these are the fish you recently described in your other thread they now look to be in excellent shape.

[Haavard Stoere]

If these are the fish you recently described in your other thread they now look to be in excellent shape.

These are the same fish I described:) They look and act very healthy at this point. They will be even better looking in 6 months and of course even further into the future. I feel that fish like these are long term projects.

Genital papilla on these fish seems to be non conclusive. In my eyes at least. Maybee it would be better not to press them against the glass when photographing. Not sure..

Do anyone of you dare to guess which ones are males and females? Looking at the last series of gill area/pectoral fins I would say that 1 and 2 are males simply because of the odontal growth from the gill area.

[Haavard Stoere]

This is fish nr 4 just one or two days after purchase. It was a little lethargic, and therefore easy to photograph.

[Haavard Stoere]

This fish seems to be a very good referance as a male:http://www.planetcatfish.com/forum/view ... hp?t=21028
Note the odontes on the left pectoral fin in picture nr. 2

I bet the odontes from the gill area and pectoral fins will grow longer on my males in a few months.

[Haavard Stoere]

This is a really good reference:
http://www.planetcatfish.com/catelog/im ... ge_id=6344

[Haavard Stoere]

I had a hard time telling the sexes apart one year ago, and I think the reason was that they are all males.

Today I pulled them out of the tank for a new measuring and photosession.

Fish1 152mm tl and 112mm sl:


Fish2 148mm tl and 113mm sl:


Fish3 159mm tl and 120mm sl:


Fish4 162mm tl and 120mm sl:


Fish5 167mm tl and 121mm sl:


Fish nr 6 and 7 are definite males. Didn`t bother to photograph them today.

Ventral view..

Fish1:


Fish2:


Fish3:


Fish4:


Fish5:


If you all agree these are definite males I will auction them all away and use the tank for L. sp L240s.

[Haavard Stoere]

The dorsal view of fish nr.2 shows rather curved pectoral fins, and maybee a wider body?
What do you guys think?

[Janne]

If I would make a guess I would say 1 and 2 is defenitly males and 4-5 maybe not 100% but likely females, the third one something between

Janne

[Haavard Stoere]

Are you looking at the dorsal, or ventral view? I must be looking at the fish in a totally wrong way.

Is it the shape of the papilla, or the shape of the whole ventral area?

[Janne]

Are you looking at the dorsal, or ventral view?

Both, the overall look of their body shape, their thin pectoral fins and the shape of the pelvic fins together with a quite wide body. The genital papilla is different on the last two compared with the first two.
Males in this size should be quite simple to tell apart from females, special after such long time in your aquarium. Males develope quite heavy odontodes on their pectoral fins 1-2 cm and their gill odontodes should be almost as long that the pectoral fin is wide, why the first two not have developed such long odontodes could be that you already have two very well developed males that is dominating in your aquarium (my guess). Both sexes is similar and difficult to tell apart but small differencies like this may be the only thing to go for before they really are fully grown and in breeding conditions.

I dont say I am right, I just say what I think could be right

Janne

[Haavard Stoere]

Thank you Janne I was a bit bummed out yesterday, because I could only see males.

I made individual markings on the tips of the dorsal fins with scissors, so that I can sort out a group after reading your opinion on the sexes.
My strategy now will be to sell Fish 1 and 2, and possibly one of my fully developed males. I might keep it as a backup, but I really feel that these species don`t die in my tanks anyway, so one definite male should be sufficient. Getting a lonely male if needed is not really that difficult.

Thank you Janne:)

The last couple of days I have been moving some of my fish around, and taken the opportunity to measure and photograph them. I am eager to hear your opinion on my 7 Baryancistrus demantoides that I photographed and measured today. They will be posted in another old thread in a few minutes. They have been placed in a 100x50x40cm tank.

Thanks again

[pramirez]

Hi Haavard.

I'm not a specialist in H. L128. I only have a trio and I hope they are 1 male and two females. I was choosing them for more than two hours, them arrive one friend and in minutes he took a look and could choose and sex them. They are not bigger than yours but his experience in these was very "useful". He explain me I'd to look at five basics points that all of us in any measure consider: pectoral fins in size and odontodes develope, head size and form, gill odontodes long, the overall look of their body shape and the form of their odd fins. Oh! My god! the same we ever read about, but... he was right. In my opinion your n4 L128 is a female. And as MatsP said the gill odontodes develope only is reference for the dominat male of the colony but not if you have more than one there. As he said too I think you have good proportion m/f for a breedig colony 2/3 or 3/2. If you still having possibility to pic them, please try any profile photo, it's not necesary good ones only to see they odd fins.

Regads.

[edlund]

Ive got a trio of L128.I think this is 1 male and 2 females.Today im going to add some RO water and see what happends

[Haavard Stoere]

Thank you for posting those images Edlund:) Beautiful trio:)

May I ask what you feed them, how often, and how big they are?

[edlund]

Hi.The "females" are arounf 13cm and male 17cm.
I feed them once a day after the lights go out.
Food is Oat,white beans,hikari algae wafers,shrimp pellets,bloodworms pellets and some red parrots.
Yesterday they got some RO water and i took the cable out from the heather.
µs is around 140 atm but i want it down to around 100-110.
Ph is little under 7.
Tank size is 110 liters only.
Gonna try it and see if it works.

[Janne]

Food is Oat,white beans,hikari algae wafers,shrimp pellets,bloodworms pellets and some red parrots.

You mean red carrots because you would not have any fingers left if you tried to put red Parrots in the aquarium
Good luck, I am sure you will succed...just a matter of time

Janne

[Haavard Stoere]

Thank you for good information Edlund:) I found the thread on goc, and will follow it closely

[edlund]

Hi my male have started to fann again.I wonder what that really means.I know that ancistrus species is fanning when they want to spawn.

http://s52.photobucket.com/albums/g11/k ... 180457.flv