Size?

[urbanfarmer]

To some extent though....all species have natural hydrization. I mean really, what is a "pure" strain? A pure bred dog, is still a compilation of other breeds at one point that was selectively and even line bred for specific traits. Take a look at the Jamaican Red Tilapia....or the White's. I find a lot of places claim a strain based on geographics....much in the same way the aquarium industry has gone with the Discus fish. Everyone with a slight color variance thinks they have a new strain. While some are in deed new/improved strains that will breed true....other's aren't, a great many are nothing more than diversity of the same gene pool. And so when bred you get a pot luck.

The Jamaican Red Tilapia is in fact a hybdrid. The are not pure strain. Pure strain refers to the purity of the genetic lineage specific to the genetics of that species.

The White Nile Tilapias are pure bred. They are not white because genetics from another species was introduced.

HOWEVER, in reality hybridization occurs in nature. We can draw distinctions by doing DNA tests on mitochondrial DNA and comparing other evidence at well, but selectively breeding vs. hybridization are totally different things.

[urbanfarmer]

I myself have a collection of tilapia, quite a pot luck. Some grow longer and not as thick fillets which are nice for a suchi like fillet that rolls right up. Others grow super short and thick ones. Some are natural colored, some are near black, others are bright orange/red....some look like dalmations, and like the paint horses. IS one better than the other? Depends on what you are trying to do with them I guess. University of HI and UVI have been working for more than a decade now on the genetics, temp tolerance, and salinity in the hopes of trying to breed them to be more salt tolerant. In hopes of being able to cage culture, etc.

I haven't seen any specific research from those 2 organizations (I'm sure it exists), but they have been cage culturing tilapia in cages in brackish waters to full strength seawater for decades. Some species are very capable of doing this with ease whereas others have limits to the salinity. If you look at the histology of tilapia you will see they are in fact built for such a thing. Have you ever wondered why your chlorinated water doesn't kill tilapia whereas it kills other types of fish???

[foodchain]

Tilapia can tolerate sea water, it doesn't mean they like it. Trout tolerate it too, in the case of the sea run trout. In fact most salmonoides do. However in those cases, some species come and go like the steelhead, with no apparant changes. Most actual salmon though go through a metomorphic change, and the end result is that the return spawning runs reult in it being a one way trip. I remember this from highschool in the Northwest and seeing first hand in the river "living dead" salmon. Still swimming around, but the flesh decaying on them. Easy prey for eagles and bears. I agree that hyrbization and line breeding are different processes, but I disagree that the end result is much different. The end result is an "improved" organism. "Pure" is relative and subjective. I am curious though, IF the white tilapia is of a mix of genes that are NOT pure. What did it cross with? Let's compare to sunfish here in the states. There are several "hybrid" sunfish, but those are sunfish that are crossed back to other types of sunfish to attain size/growth/etc. But they are still sunfish. They aren't taking a bass and crossing it. I understand what you are saying and please don't misunderstand me. I am agreeing with you. My point is, is that the terms are used interchangably when often times they shouldn't be...as hybridization and line breeding are two completely different processes. These terms are all too often used, when one meaning is meant, and the other is intended.

[foodchain]

I have to watch myself, as I do this sometimes...usually when I am in a hurry.

[urbanfarmer]

Tilapia can tolerate sea water, it doesn't mean they like it. Trout tolerate it too, in the case of the sea run trout. In fact most salmonoides do. However in those cases, some species come and go like the steelhead, with no apparant changes. Most actual salmon though go through a metomorphic change, and the end result is that the return spawning runs reult in it being a one way trip. I remember this from highschool in the Northwest and seeing first hand in the river "living dead" salmon. Still swimming around, but the flesh decaying on them. Easy prey for eagles and bears. I agree that hyrbization and line breeding are different processes, but I disagree that the end result is much different. The end result is an "improved" organism. "Pure" is relative and subjective. I am curious though, IF the white tilapia is of a mix of genes that are NOT pure. What did it cross with? Let's compare to sunfish here in the states. There are several "hybrid" sunfish, but those are sunfish that are crossed back to other types of sunfish to attain size/growth/etc. But they are still sunfish. They aren't taking a bass and crossing it. I understand what you are saying and please don't misunderstand me. I am agreeing with you. My point is, is that the terms are used interchangably when often times they shouldn't be...as hybridization and line breeding are two completely different processes. These terms are all too often used, when one meaning is meant, and the other is intended.

They are not used interchangeably in science.

The white niles were not crossed with other species to produce a white. They are albino. For instance, if we have a recessive trait [ww] then we can get it after selective breeding in this fashion:

Ww x Ww => 25% ww

Breed ww x ww => 100% ww (all white)

It's THAT easy!

[foodchain]

Then they are not a hybrid, they are line bred. I am confused:

"The While Nile Tilapias are pure bred. They are not white because genetics from another species was introduced."

A wolf hybrid...is just that a hybrid. A yellow lab crossing with a poodle is not.

[foodchain]

Either way, I apologize for getting off topic.
My tilapia are tilapia, they are tasty. They do what I want. So they are good enough for me.

[urbanfarmer]

Then they are not a hybrid, they are line bred. I am confused:

"The While Nile Tilapias are pure bred. They are not white because genetics from another species was introduced."

A wolf hybrid...is just that a hybrid. A yellow lab crossing with a poodle is not.

oops, WHITE nile, with a T

Why are you confused?

[urbanfarmer]

Either way, I apologize for getting off topic.
My tilapia are tilapia, they are tasty. They do what I want. So they are good enough for me.

Oh, we do it all the time it's okay. It's your thread anyway! lol

[foodchain]

Maybe a typo, or I am reading wrong. But your two statements appear to be in contradiction. White tilapia by definition are tilapia...you stated that they are not "pure" as they were crossed and genes added. So what where they crossed with? I believe it's Miami Aqua-culture, Inc that claims to have the white one, from line breeding. Not hybridizing. Hybridizing would be between two species....I don't think mine are albino, as they have color in the fins. True albino would have abcense of color pigment wouldn't it? Or am I forgetting my biology.