This isn't so much a what is my catfish as opposed to a what form is my catfish. I'm trying to find out the difference between these two terms both used to describe fish with no pigmentation and black eyes.
My best guess is amelanistic means without black (pigmentation? lack of melanin?) and leucistic might just mean white form. Anyone know for sure?
Jools
What is the difference between amelanistic and leucistic?
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Jools
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Yes, amelanistic is albino.
I beg to differ on the other ones - though I must say the terms can be confusing, especially as you will see them misused all over the place.
Leucistic - means that all melanin is removed from the body but NOT from the retina. Thus the animal appears to be pure white with black eyes. Interestingly, albinos are not pure white as people would think. To be pure white an albino would have to have not one bit of melanin in its body - but melanin (even a tiny bit) is essential for life. So in order to have enough melanin to be alive, albinos actually have small traces of melanin in their body. Leucistic animals have the melanin in their retina, it's enough to survive so they are able to get away with a pure white body with no melanin. Bird breeders use the term "black-eyed clear" for leucistic, the term is also used for other animals such as ferrets.
Leucistic really should be reserved for white animal/black eyes, but is often used for animals which have reduced melanin (the "dilute" looking ones) Technically though, these dilute forms should be called hypomelanistic.
Xanthic - refers to increased amount of the yellow pigment xanthin, so a xanthic form of an animal is one which looks more yellow than it would normally. Technically xanthism should have nothing to do with removal of melanin (so it does not refer to a white animal/black eyes).
Don't get xanthic confused with lutino though - lutino refers to those albinos that have red eyes and are a clear yellow colour. Since the yellow colour has nothing to do with melanin if the animal is albino but has xanthin producing cells in its skin any black colour will be taken away and you are left with a bright yellow (or even red or orange as these are also not produced by melanin) animal. Good examples are the popular lutino indian ringneck, also you'll see plenty of snakes that have red eyes and white and yellow patterning on them.
Most people think of albinos as having red eyes and being completely white - but actually an albino can have any colour on it so long as that colour is not produced by melanin.
Hope this helps (colour mutations are a little pet thing for me)
Cheers,
Jess
I beg to differ on the other ones - though I must say the terms can be confusing, especially as you will see them misused all over the place.
Leucistic - means that all melanin is removed from the body but NOT from the retina. Thus the animal appears to be pure white with black eyes. Interestingly, albinos are not pure white as people would think. To be pure white an albino would have to have not one bit of melanin in its body - but melanin (even a tiny bit) is essential for life. So in order to have enough melanin to be alive, albinos actually have small traces of melanin in their body. Leucistic animals have the melanin in their retina, it's enough to survive so they are able to get away with a pure white body with no melanin. Bird breeders use the term "black-eyed clear" for leucistic, the term is also used for other animals such as ferrets.
Leucistic really should be reserved for white animal/black eyes, but is often used for animals which have reduced melanin (the "dilute" looking ones) Technically though, these dilute forms should be called hypomelanistic.
Xanthic - refers to increased amount of the yellow pigment xanthin, so a xanthic form of an animal is one which looks more yellow than it would normally. Technically xanthism should have nothing to do with removal of melanin (so it does not refer to a white animal/black eyes).
Don't get xanthic confused with lutino though - lutino refers to those albinos that have red eyes and are a clear yellow colour. Since the yellow colour has nothing to do with melanin if the animal is albino but has xanthin producing cells in its skin any black colour will be taken away and you are left with a bright yellow (or even red or orange as these are also not produced by melanin) animal. Good examples are the popular lutino indian ringneck, also you'll see plenty of snakes that have red eyes and white and yellow patterning on them.
Most people think of albinos as having red eyes and being completely white - but actually an albino can have any colour on it so long as that colour is not produced by melanin.
Hope this helps (colour mutations are a little pet thing for me)
Cheers,
Jess
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CommonPl*co
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So, to clarify: (if I understand correctly)
Albino=amelanistic, but must still have some melanin hidden on the body somewhere, just (in general usage) not the eyes.
Leucistic has that melanin in the eyes, so the body is a more pure white (or even yellow) than in the normal albino.
Lutino is an albino form with heightened yellow/red and red eyes.
Xanthic is not actually albino at all, but may look much like a lutino with its increased yellow.
So a leucistic will be the cleaner looking one with black eyes, while the lutino will have red eyes and more of a yellow cast.
Am I getting close?
Albino=amelanistic, but must still have some melanin hidden on the body somewhere, just (in general usage) not the eyes.
Leucistic has that melanin in the eyes, so the body is a more pure white (or even yellow) than in the normal albino.
Lutino is an albino form with heightened yellow/red and red eyes.
Xanthic is not actually albino at all, but may look much like a lutino with its increased yellow.
So a leucistic will be the cleaner looking one with black eyes, while the lutino will have red eyes and more of a yellow cast.
Am I getting close?
re: albinos etc
Yep, you've got it!
One thing I forgot to say above - a good example of xanthism is the good 'ol Electric Yellow (Labidochromis caeruleus). The nominate form of this fish is actually white or pale blue (hence the caeruleus in the latin name which refers to pale bule) with the same black markings as the yellow form. The Electric Yellow that we are familiar with all over the world is actually a xanthic form with extra yellow in the body. There's only a very small population of these xanthic L caeruleus in the wild - the ones we see in aquariums everywhere are descended from only a handful of fish - it is rumoured that they came from only one pair!
Cheers,
Jess
One thing I forgot to say above - a good example of xanthism is the good 'ol Electric Yellow (Labidochromis caeruleus). The nominate form of this fish is actually white or pale blue (hence the caeruleus in the latin name which refers to pale bule) with the same black markings as the yellow form. The Electric Yellow that we are familiar with all over the world is actually a xanthic form with extra yellow in the body. There's only a very small population of these xanthic L caeruleus in the wild - the ones we see in aquariums everywhere are descended from only a handful of fish - it is rumoured that they came from only one pair!
Cheers,
Jess