please help sexing my new Chameleon Whiptails - Pseudohemiodon Apithanos

[racoll]

We are going rather off topic here (so apologies to OP, and mods feel free to move).

To me this phrase doesn't sound good because "not encouraged" can also be taken as "discouraged," and I would never want to discourage hobbyists from trying to take their interests to the next level. I presume you don't mean it this way either, but that's how it comes across to me.

Yes, it did sound negative. To clarify, aquarists should definitely not be excluded from the process, but they are better off collaborating with scientists rather than doing their own thing. Both will benefit from the process.

P.S. good points Larry

[bekateen]

Hi Larry, First of all, I hope you get well soon.

..."if it's going to be done, make sure it's done in a way which isn't going to decrease the value of the work done by those who work so hard to provide useable information."

To clarify, aquarists should definitely not be excluded from the process, but they are better off collaborating with scientists rather than doing their own thing. Both will benefit from the process.

Larry and Rupert, Thank you for voicing these concerns; I agree completely. Perhaps one of the benefits of this website is that it IS a mix of hobbyists and scientists (who also happen to be hobbyists ). In this social context, we are able to interact and work together, and perhaps we can make the most of the data that can be collected through all the reports and photos that can be compiled through this site. This way, we can avoid the free-wheeling that could lead to chaos.

There was a great deal of discussion on the old catfish-l mailing list, prior to the existence of this site but a lot of the same original members, about the description of this species from aquarium specimens. Even the current species listing in the catelog states the type locality as "Aquarium specimens said to be from near the town of Boa Vista, State of Roraima, Brazil [possibly from the Rio Branco]." This leaves no verifiable locality and, while not doubting the validity of the species, a huge hole of valuable information in any future study. There are a lot of individuals on this site which would be completely capable of the same type of description based solely on measurement/proportion, and a lot more which are not members of this site. If all of those decided to begin tackling L numbers, based on Rio Xingu, Tapajos, etc... which are considered understood collection locations, the quality of the entire family could easily be degraded.

Larry, this actually goes to my point. Your concerns about the potential proliferation of species (would this also include the misidentification of specimens to existing species?) as a result of hobbyists collecting morphometric and morphological data and compiling it into a database is exactly how I felt before I joined this site, when I first discovered the existence of the C, CW, L, LDA, etc., numbered fishes. From the outside, it seemed to me that anybody with a fish that didn't already have a known species label could give it a number and voila, a new fish is introduced to the hobby. Now of course these numbers don't really work that way, but what I still feel is lacking (and I've expressed this in another thread when I first joined) is solid morphometric and morphological descriptions for each of these cats, with details such as number of rays per fin, body proportions, etc., (the kind of data which would be found in a standard scientific paper describing a species). If this type of data can be collected, compiled and presented in a systematic fashion, it will at least make it easier for hobbyists (like myself when I bought my C141) to figure out what we have when we get an unidentified fish, since color patterns can vary with age, size, and geography. Moreover, if done right, this should tighten up the various C, CW, L, LDA numbered fish categories because we can have accessible standards for comparison. Thus, it might allow new fish to be lumped in with preexisting numbers rather than putting them into new numbers of their own.

As to the graph done above, I'd like to say thank you for that bit of work. I've considered the angle of the head from tip of the snout to the base of the head to be the most valuable sexual dimorphism feature of a large percentage of species for quite a while, and agree it needs to be taken from known mature specimens. This is a nicer representation of that, at least in method since I don't consider these fish to be of mature size, than I could've put together.

Thank you! Although honestly, the credit needs to go to @jamesleagas and @jac for their wonderful photos, to jamesleagas for getting this thread started, and to @jools for asking for the angle calculations (my head width/head length ratio provides an equivalent metric for head shape since it uses the same exact measures to calculate, but I can see how the snout angle calculation is more intuitively meaningful for anyone trying to describe the shape of the head and snout). I didn't know much about these fish before this thread, but I know more now!

With regard to the original poster, my advice would be to grow them out for another 6-12 months and post pictures when they are in a better condition and more mature.

Great advice. Moreover, if these fish are allowed to grow out for a year and if we can redo these measurements using the same morphological landmarks, then whether or not the proportions change we will have learned something: Either they change and these turn out to be females, or they don't change and the fish turn out to be males, or the numbers change for some of them and we get a mix of males and females in the bunch... or they don't change because the fish still aren't sexually mature ... or we get entirely different numbers and we can't make any inferences from the growth data. Obviously, I hope it's one of the first three options (all of these would validate the hypothesis that we can use these photographic measures to identify gender, and they would also help us know at what age (older vs. younger) the ratios can be applied reliably) and not one of the latter two options.

We are going rather off topic here (so apologies to OP, and mods feel free to move).

Ditto.

Cheers, Eric

[racoll]

what I still feel is lacking (and I've expressed this in another thread when I first joined) is solid morphometric and morphological descriptions for each of these cats, with details such as number of rays per fin, body proportions, etc., (the kind of data which would be found in a standard scientific paper describing a species). If this type of data can be collected, compiled and presented in a systematic fashion, it will at least make it easier for hobbyists (like myself when I bought my C141) to figure out what we have when we get an unidentified fish

Great discussion Eric. Actually in my opinion, from the hobbyists it would be much more valuable to have tissue samples for DNA analysis than morphometric data. Collecting accurate morphometric data is not easy at all, and the fish needs to be dead and preserved of course (you cannot collect this data from live fishes). You also need decent microscope and calipers, which are not cheap.

With minimal training, anybody can collect some DNA, and the fish does not have to be sacrificed.

Moreover, if these fish are allowed to grow out for a year and if we can redo these measurements using the same morphological landmarks, then whether or not the proportions change we will have learned something

Yes! These are exactly the kind of data that are not readily available to scientists.

[bekateen]

If it helps I Dnt suspect that my fish are in tip top condition as the Lfs would not of been feeding them correctly if they are like most Lfs

Probably lived on occasional prima feedings for the last 6-8 weeks that they've been there.

Hi Jamesleagas, Although the fish in your photo look really good, I suspect you're right. My experience is that most fish at LFS are at least minimally fed to maintain size, if not underfed. Regardless of the sex of your fish, I predict that they will fill out nicely after even a short time in your tanks, with good care and nutrition.

Actually in my opinion, from the hobbyists it would be much more valuable to have tissue samples for DNA analysis than morphometric data. Collecting accurate morphometric data is not easy at all, and the fish needs to be dead and preserved of course (you cannot collect this data from live fishes). You also need decent microscope and calipers, which are not cheap.

With minimal training, anybody can collect some DNA, and the fish does not have to be sacrificed.

Rupert, excellent point. Since I'm not a molecular biologist, I don't think of that option as a first choice, but you really nailed this - a DNA database would be invaluable.

I think it's funny that you mention the expense of the tools needed for morphometrics and then you jump from there to "we should collect and analyze DNA" (okay, I paraphrased you), because in my mind I think the same way about DNA analysis (that it is expensive to work with and therefore morphometrics are cheaper and better). I've dabbled in cDNA work using my frogs, and I'm blown away by the expense of the reagents, so my first inclination is to imagine that DNA analysis would be expensive. But I'm sure that certain DNA tests are not so pricy.

As for the tools needed for morphometrics and the need to kill the fish, that might be addressed depending on how such a data collection system was set up. For example, instead of making hobbyists collect the actual measurements, perhaps they could simply submit photographs of their fish, following a set of rules that could be prescribed in advance (in terms of angle, lighting, zoom, fish position, tank setup, etc.), and fish wouldn't have to be killed (some might need to be sedated or cold-stunned on a species-appropriate basis in order to get them to sit still for photography). (And as a side note, I'm sure you're aware that preservation itself can introduce artifacts to certain measurements due to effects such as dehydration - Of course preserved specimens are measured for "hard" features (skeletal features typically) that don't distort, but these should also be fairly measureable in photographs of well-positioned live fish too I would think. And oh my, don't get me started on that "Color in alcohol" section that we have to use in scientific papers when describing preserved specimens; Oy!).

Once submitted, one or more willing biologists could do the morphometrics using a preselected software and defined landmarks, so that that the measurements are taken in a predictable and repeatable fashion. That way, the hobbyists wouldn't need to shoulder the expenses. This would be no different than your DNA sampling idea because some biologists would still have to analyze the DNA samples; we wouldn't expect the hobbyists to do so or to pay for it. I don't say this to minimize the DNA collection over morphometrics data collection, because the DNA idea is, as I said before, wonderful.

I guess I would summarize my position by saying that efforts to collect both morphometrics and DNA would be wise. The DNA would help with the scientific analysis and efforts to establish things like relatedness (and maybe extend that to species identification or definition), and the morphometrics could be used even by hobbyists to accomplish tasks like the one before us- are these fish boys or girls?

@Jools, I'm sorry because we really have strayed far afield from the OP topic, even if our discussion here is born from our efforts to help Jamesleagas figure out what sex his fish are.

Cheers, Eric

[racoll]

my first inclination is to imagine that DNA analysis would be expensive.

Yes, it is expensive, but I was not imagining that the hobbyist pays for that. The scientists would do the sequencing, and then share the results back. There are also organisations that can sequence for free if you send them the samples.

instead of making hobbyists collect the actual measurements, perhaps they could simply submit photographs of their fish, following a set of rules that could be prescribed in advance (in terms of angle, lighting, zoom, fish position, tank setup, etc.)

In my view this is a great idea, but for live colour pattern rather than morphometrics. Live colour pattern is something rarely reported in scientific work (although it's improving a lot now), as the specimens are usually long dead. Unless they collected the thing themselves, and took the time to photograph it in the field (which is a real PITA), then this data is lost to them, and along with DNA, is where hobbyists can really contribute.

[bekateen]

In my view this is a great idea, but for live colour pattern rather than morphometrics.

Yes, the value for live color is obvious, when compared to the historic reliance on preserved materials. But IME this doesn't minimize its value for morphometrics. I've done photographic morphometrics on frogs, mosquitoes, and microscope samples. In fact, most metrics taken from microscope slides are done from photographs these days rather than from the actual slide while being viewed in real time; it's simply a lot easier to take a quick photo, or many photos of different specimens all at once, and go back later to analyze it at your own pace and convenience.

[racoll]

I think it would be difficult with fishes, but species like the Pseudohemiodon lend themselves nicely to a pilot study; the landmarks are readily identifiable, and the fish are easy to photograph from above.

[bekateen]

Yes, indeed; there would certainly be some spp. that are more easily studied using this technique, and plenty of spp. that wouldn't be easy to work with.

Cheers, Eric

[jamesleagas]

With regard to the original poster, my advice would be to grow them out for another 6-12 months and post pictures when they are in a better condition and more mature.

Larry

i will do exactly that thank you

[jamesleagas]

If it helps I Dnt suspect that my fish are in tip top condition as the Lfs would not of been feeding them correctly if they are like most Lfs

Probably lived on occasional prima feedings for the last 6-8 weeks that they've been there.

Hi Jamesleagas, Although the fish in your photo look really good, I suspect you're right. My experience is that most fish at LFS are at least minimally fed to maintain size, if not underfed. Regardless of the sex of your fish, I predict that they will fill out nicely after even a short time in your tanks, with good care and nutrition.


@Jools, I'm sorry because we really have strayed far afield from the OP topic, even if our discussion here is born from our efforts to help Jamesleagas figure out what sex his fish are.

Cheers, Eric

thanks again guys, i find this post really interesting so please feel free to discuss how you will, i will do my best efforts with these fish and hopefully they grow on nicely, any tips on diet requirement or specific prepared foods which have brought good results for others would be great. atm I'm feeding them white worms (live) freeze dried tubifex, brine shrimp, new era catfish pellets, prima all varyingly of course

[jamesleagas]

What's peoples opinions now, these two clearly imo have different shapes (one has fuller body and shorter snout)

They look very different now they have settled and eating well

[bekateen]

Hi jamesleagas,

They really look nice, and clearly they are gaining weight. I'm inferring that these three photos are of the same two fish, yes? Compared to your first photos, I can see the thicker bodies in both fish, and I do see some visual difference in the snouts of the two fish. But using the mathematical calculations we did before, both of these fish are still well within the "male" values which I measured using jac's fish.

This time I calculated the value for each fish using measurements from both photos and averaging the values; I assumed that the dark fish in the solitary photo is the same as the dark fish in the photo of both fish together.

From your photos here, head width/body width ratios are 1.38 in both fish, and the average snout angles are 69.2 degrees for the dark fish and 72.2 degrees for the light fish.

From the first photos of jac's fish, the average head width/body width ratios were 1.21 for females and 1.39 for males; the average female snout angle was 78 degrees and the average male angle was 72 degrees.

Your fish are still only about 4 inches long, and they certainly have to mature more. But there is already a slight difference in the snout of these two fish, so perhaps with time the differences will be reinforced, and maybe the lighter fish is a female. But at this age, I am unable to tell using the measurements here.

Cheers, Eric

[jamesleagas]

Hi jamesleagas,

They really look nice, and clearly they are gaining weight. I'm inferring that these three photos are of the same two fish, yes? Compared to your first photos, I can see the thicker bodies in both fish, and I do see some visual difference in the snouts of the two fish.

thanks for the reply eric, yes they are eating very well and have filled out a little over the last 2 weeks, I'm happy for now that i have a decent chance of having both sexes from the 4 i have, i have a mixture of head shapes and body thickness' so gives me hope.

hopefully over the next few months differences further develop ill keep this post update every now and then with pictures of progress

[jac]

For me they are still female. Let's see in a about 6-12 months

[jamesleagas]

For me they are still female. Let's see in a about 6-12 months

What makes u think both females out of interest. I think from what I've seen one male one female maybe I'm blinded by wishful thinking lol

[nvcichlids]

For me they are still female. Let's see in a about 6-12 months

What makes u think both females out of interest. I think from what I've seen one male one female maybe I'm blinded by wishful thinking lol

i would agree.. blinded by the wishful thinking. I see 2 females based on Jac's topic/post/thread of sexing them.

[bekateen]

For me they are still female. Let's see in a about 6-12 months

What makes u think both females out of interest. I think from what I've seen one male one female maybe I'm blinded by wishful thinking lol

i would agree.. blinded by the wishful thinking. I see 2 females based on Jac's topic/post/thread of sexing them.

For me, I am eager to find out how these fish develop. I restate my disclaimer that I've not owned these fish, and that my suspicions (all males in the earlier photos and both male in these latest photos, or too immature to tell) are based on mere mathematical measurements from the pictures rather than on personal experience. And as good as all these photos are, they are still not taken in a manner that assures reliable and accurate morphometric comparison. And this is a significant point, because in jac's other thread, she has posted an updated photo of one of her males, and based on my measurements, this male's snout angle has widened since its original photo, from 73 degrees to 75.4 degrees (by comparison, her original photos of 2 males had an average angle of 72 degrees, and her original photos of 4 females had an average angle of almost 78 degrees). If this happens with age and nutritional status, or if this is the result of slight differences in camera angle and photographic setup, then obtaining this angle using routine photographs won't be a meaningful calculation.

So I am fascinated by jac's opinion (and now nvcichlid's), and I am inclined to trust their opinion more than my own. The problem with math is that if you don't know the proper measurements to take, then you may be measuring a dimension that is not diagnostic of gender, and you might be missing a measurement that is. From jac's earlier posts, it is something about the head shape that is critical here (body girth is also a factor). So if these are all females, then it's not the snout angle that I'm measuring that matters but something else - perhaps the curvature of the head along its leading edge. And of course there's still the maturity issue - if these are females, their body widths at the leading edge of the pelvic fins are not the diagnostic measurement to collect - so far, all of jamesleagas' fish are thin like males at that point in the body.

The frustrating thing is this - if it turns out that jamesleagas has either all females or all males, he still doesn't have a breeding group. Thus, if males and females end up being more similar (morphometrically) than we expect, it will only be clarified if he has a mixed sex group and he gets them to spawn.

Oh, I can't wait to see them grow up! Hurry, hurry!

Cheers, Eric

[jamesleagas]

Believe me I can't wait either, I will be doing my best to obtain another 2-4 of similar size to increase my changes.

[parrot1974]

Hi James. I've only just read this. I had exactly the same problem when I bought two Chameleon Whiptails from my local Maidenhead Aquatic 6 months ago. There were two larger ones and one smaller one. I spent hours researching differences on all Whiptails, just to gain some idea of the possible differences. In fact, there is a rather long thread from 6 months ago - I'll see if I can find it. The main differences I was looking for were body shape, head shape (including a more 'bulbous' nose), pelvic girdle patterning, genital differences and finally 'whisker' length. After half an hour of staring at them in the shop, I picked the two largest, as they were the two with the most differences.
After 6 months of leaving them alone, I have just taken some pictures of them. I will post the ventral views on here so you can see the differences. From above, there are slight differences with head shape, with a blunter look to the head, but for me it is much easier to see the differences from underneath and these are the same differences that I spotted when they were young, so it would appear that you can sex Chameleons from their ventral view, as with many whiptails.

[jamesleagas]

one I've mine always remains jet black and the others go all shades of white/ grey, is that anything to go by also? maybe clutching straws lol

tomoz ill fish em out and take ventral photos