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Post by Chelmon on Feb 21, 2016 18:21:02 GMT -6
I really haven't noticed it with any of them. Although, I have to admit that I have never really looked.
But I would guess that the dark ones are the males as well?
Adrian
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Post by Mark~N on Feb 21, 2016 19:13:38 GMT -6
I don't know what made me question it really. I think I saw a couple really black ones amongst the light and put my opti visors on to get a closer look.. but, I do think they will turn out to be males myself.
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Hans
New Member
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Post by Hans on Feb 22, 2016 10:04:53 GMT -6
.... and put my optivisors on to get a closer look...
A while ago I was wondering about such an eye help (getting older is just so much fun... sigh...). Do you use it a lot and does that help a bit?
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Post by Mark~N on Feb 22, 2016 10:20:14 GMT -6
I seriously can't see fry or eggs without them Hans. you can see everything with these. plenty of different types out there . my work I have to use them most of the day so I'm used to them .
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Post by rainbowbratt on Mar 4, 2016 23:02:50 GMT -6
Found this video of p.mellis. While we were talking about the fins of other blue eyes,noticed how awesome the fin extensions on these guys are.
p.mellis video
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Post by Chelmon on Mar 5, 2016 16:35:44 GMT -6
Found this video of p.mellis. While we were talking about the fins of other blue eyes,noticed how awesome the fin extensions on these guys are.
p.mellis video
Yes, many blue-eyes have that long fin extensions in the wild. I remember some P.signifer I got from Lacey Creek (Mission Beach) in 1980 that were about 60 mm in size and a number of the males had long extended filaments on both the dorsal and anal fins, extending past the tail (like I. werrneri). For some unknown reason, these filaments are usually shed during capture or if not, once placed in the confines of an aquarium. From my experience, these fin extensions never re-grow or appear in captive populations? Adrian
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Post by rainbowbratt on Mar 6, 2016 1:17:25 GMT -6
That is interesting to know Adrian. Hadn't ever considered a shedding of the fin extensions when captured. I could understand a theory that they may do this, and not regrow them for some sort of survival reasons? The longer the extension, the more it can slow then down, or make them more prone to predators? So, in a captive setting, with wild caught fish, it could be a biological response, beneficial for the fish to not grow such long fins for the best survival....? (Efficient swimming)
Another thought is in a captive breeding situation, the males and females are so closely housed, the males do not have to compete as much to attract the females. So, why spend the energy growing those long fins if they don't have to?
I know from experience that many people underestimate the size of tank necessary when breeding them. That depth especially plays a role in the length of fin extensions. Which causes problems when people think they will see, or should expect the same results when growing fish out in a 10 gallon, versus a 30 gallon tank.
Considering your observations, I wonder if that is one reason we sometimes see better fins in blue eyes bred in outdoor ponds?
I have always considered the obvious things-- live foods, natural day/night cycle, sunlight, etc as benefits. But if you consider the predator stress idea behind shedding their very long extensions, and typical fishroom stressors versus living outdoors; along with the idea they do not have to work as hard at attracting mates for spawning....hmm.
I do wonder though why threadfins have kept their very long fin extensions, considering these thoughts and the fact of breeding many from limited genetic stock. Who knows how many generations from the wild most of the available threadfins are these days?
Thanks again. You always get my brain going
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Post by Mark~N on Mar 6, 2016 8:47:15 GMT -6
Great points made here. Let's not forget about foods. So many things lacking. Are our home cultured daphnia really getting the same nutrients that nature provides?. Same with worms.. Some culture them in paper and cardboard. Petroleum ,chemical products?. One of the many reasons why our bows lose their natural coloration down the generations or earlier.I am sure that has a lot to do with it also. Live, frozen or dry. Even the cultures we have or make cannot really reproduce what most absorb from a natural environment. e.g.bloodworms. What blood are they fed?. And from what?. Outdoor ponds may provide a better answer.Someday we need to rethink the whole processed food thing.Tank size is also key. most think that because they are a small fish 5 and 10 gal tanks are fine. for the most part they are. but not for growing long extensions. I am already seeing a difference from my Harvey creek sigs from a 29 gal to a 125 gal.Threadfins and gertrudae I think are the exception to the rule. In summary.I don't think they shed those extensions until later in captivity given the lack of proper food and true required space we give them.IMO
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Post by rainbowbratt on Mar 6, 2016 11:35:48 GMT -6
Good points Mark. I took Adrian's statement to mean the fish "shed" their extensions as in, the extensions broke off during capture, and never grew them back. Maybe they are not physically capable of regrowing? Or it is environmental? Because the extensions didn't show up in the next generation?
If we use our common sense with feeding our fish, obviously prepared/processed foods are not the best way to go for the long term health of the fish. Wanting them to look the same as wild fish is unreasonable. Just like when we feed ourselves and our other pets crap foods--it affects appearance and health. Many people think if their fish is large and fat, they are healthy. People are catching on as far as humans and other animals are concerned(how many fat cats and dogs do you see regularly? How many "diet" foods have been created recently?).
Comparatively, the fish industry still has a ways to go. There are some good people working hard on recipes for live food replacement....but to me, processed fish food should be just that. Live foods supplementation, not the main diet. If people looked at it like we do our own diets, it is similar to expecting us to survive on all processed foods, with the occasional fresh food as a treat. Lol. Even the so called health foods available to us, are highly processed, and should not be our main diet. The better commercially available foods for fish still contain many fillers, binding agents, preservatives, extracts, colors, etc that wild fish would never have in their diets. The live and frozen foods are not regulated, so there is a question of the benefits of shelling out big bucks for these items, when you do not know what the live critters were fed, or their growing conditions. The idea that people can produce live foods in cardboard, sewage, etc is alarming. Not only for the fish' health, but our own. We are what we eat--this goes for fish too. If the live foods are poorly cultured, what's the point? Plus it could cause more problems by possibly bringing in unwanted things like disease for us and the fish, unwanted contaminants in the culture, on and on.
I wish there was not so much misinformation put out there to overcome. But people are educating themselves more and more these days. It's just a matter of getting good info out there, readily available and easily accessible to everyone.
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Post by Mark~N on Mar 6, 2016 15:07:39 GMT -6
I agree Lori.Still a lot to learn about foods and some progress and attention has been payed by some.I have been trying some new things I like already and some of my own things which I think might make a difference.Also been staying away from other things I used a lot of
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Post by Chelmon on Mar 6, 2016 17:47:43 GMT -6
That is interesting to know Adrian. Hadn't ever considered a shedding of the fin extensions when captured. I could understand a theory that they may do this, and not regrow them for some sort of survival reasons? The longer the extension, the more it can slow then down, or make them more prone to predators? So, in a captive setting, with wild caught fish, it could be a biological response, beneficial for the fish to not grow such long fins for the best survival....? (Efficient swimming)
Another thought is in a captive breeding situation, the males and females are so closely housed, the males do not have to compete as much to attract the females. So, why spend the energy growing those long fins if they don't have to?
I know from experience that many people underestimate the size of tank necessary when breeding them. That depth especially plays a role in the length of fin extensions. Which causes problems when people think they will see, or should expect the same results when growing fish out in a 10 gallon, versus a 30 gallon tank.
Considering your observations, I wonder if that is one reason we sometimes see better fins in blue eyes bred in outdoor ponds?
I have always considered the obvious things-- live foods, natural day/night cycle, sunlight, etc as benefits. But if you consider the predator stress idea behind shedding their very long extensions, and typical fishroom stressors versus living outdoors; along with the idea they do not have to work as hard at attracting mates for spawning....hmm.
I do wonder though why threadfins have kept their very long fin extensions, considering these thoughts and the fact of breeding many from limited genetic stock. Who knows how many generations from the wild most of the available threadfins are these days?
Thanks again. You always get my brain going
You are more astute than you give yourself credit for Mark
There has been a number of research papers published on the type of remarks you mentioned above. Mostly on other species of fishes. However, there is even one on I. werneri.
"Extravagant ornaments of male threadfin rainbowfish (Iriatherina werneri) are not costly for swimming"
"Exaggeration of male sexual ornaments should be costly, in terms of metabolic expenditure, resource allocation or even locomotor function. For example, many male ornaments are predicted to affect the aerodynamics, drag or biomechanics of movement and thus inhibit the speed or manoeuvrability of individuals; but empirical support for this is equivocal."
You can download the paper from this link:
onlinelibrary.wiley.com/doi/10.1111/1365-2435.12097/full
click on the PDF icon and then pick the "load the basic PDF" link down the bottom, otherwise you have to wait until the "enhanced version" loads which takes forever. There are similar papers available for some other rainbowfishes that talk about similar thing like body size , colour, etc., etc. Its just a matter of finding these papers. I do have some and will see if I can find them somewhere.
Adrian
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Post by Mark~N on Mar 6, 2016 18:59:20 GMT -6
I can't even believe such an amazing detailed study existed. thanks Adrian. Tremendous reading!.Fascinating they found no optimum length for swimming that was greater than the length of those experimentally manipulated. I see my Harvey creek sigs in my 125 with some nice long extensions and they are so much faster than I thought.They can out burst 5 inch pagwi's. I can't imagine even with long extensions that they would be more prone to predatory attacks with the speed they display. Again thank you for this article!
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Post by rainbowbratt on Mar 6, 2016 20:32:56 GMT -6
Well that article just made my day lol.
Thanks Adrian for the great info. Had no idea you all were already experimenting with things I've wondered about for quite a while
~Lori
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Post by Mark~N on May 30, 2016 11:56:09 GMT -6
I absolutely love this little blue-eye species !
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robm
New Member
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Post by robm on Aug 15, 2016 16:22:05 GMT -6
Another little experiment I wanted to try was separating the light/dark fry I see hatching out. Often wondered if this is an early sex determination sign or something else. I did leave a few in the container for a couple days to see if they would change.But they stayed the same. Could be interesting. Counting light/dark as they hatch. Will see later if this tells me anything.So far it is 8-5 dark. Did you come to any conclusions with this?
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