mwp
In Memoriam
<a href=showthread.php?s=&postid=7726159#post7726159 target=_blank>Originally posted</a> by colby
MWP,
Again I appreciate your knowledge and experience....
Regarding hybrids...perhaps I should have been clearer, as far as we know ALL clownfish can cross breed to produce VIABLE progeny. As we have seen cases of hybrids producing young and do not know of any sterile clown hybrids, it is safe to assume that they all produce viable offspring.
This is where the burden of proof comes into the debate and my lack of intimate clownfish knowledge perhaps could cause problems. However this also bolsters one of my prior arguments. Let's just say that a breeder decides that crossing A. sebae and A. clarkii is a good idea...or for that matter A. frenatus and A. melanopus. Definition of a species aside, we can agree that the fish currently classified as such are indeed different. What happens when the A. sebae X A. clarkii or A. frenatus X A. melanopus hybrids are put out onto the open market. What happens if they LOSE their hybrid distinction, accidentally falling into another breeder's hands labeled with only ONE of the parental names?
This is where the danger lies in producing hybrids. Not so much in the case of the Indigo Dottyback, but in other, less "apparent" hybrids. No one is going to confuse a Blood Parrot with any other cichlid species. But this is not the case, perhaps as an example Hap. sp. "Ruby Green" vs. Hap. sp. "Flameback". Hybrids of the two species could easily throw a wrench into a well-intended breeder's plans. I keep coming back to this example because it is all too very real...it is IMPOSSIBLE to find really good quality Hap. sp. "Flameback" anymore because along the way they have been muddled with genes from other species. What happens when wild clownfish collection is banned, or simply becomes unfeasible, and all that's left is our captive broodstock? Do we want pure lines or will we be happy with muddle genetics in our future broodstock?
And regarding the "rule" that a species is an animal that can mate in the wild and produce fertile offspring, still even more incorrect. That would imply then the chrystoperus and sandaracinos would be of the same specie while Ocellaris and Percula are not (however there has been documentation of the two been found on the same reef...)...
Can you elaborate futher Colby? You may have more detailed information on these particular species, but I think you missed part of the "wild" scenario. Your implication is that Chystoperus and sandaracinos cohabitate (aka. are sympatric) on the reef, regularly mate with each other and produce living offspring that if mated together are capable of producing a 2nd generation of hybrid offspring? Even if this is the case, there must be a reason for them to interbreed regularly in the wild and it has to do with MATE selection. Furthermore, do these HYBRID OFFSPRING mate and produce 2nd generations of babies in THE WILD? Mate selection plays a vital role in speciation...even if a chrystopterusX sandaracinos was produced in the wild, WOULD it be able to mate again successfully or would the standard of mate selection eliminate a hybrid offspring from successfully mating? Are the hybrid offspring even capable of surviving to adulthood in the wild?
To take this to the next level, let's consider Orchids, another one of my passions. It is clearly demonstrated with regularity that you can mate two species together to produce offspring that are in turn viable and can often produce more offspring themselves. We're talking orchids that aren't even from the same GENUS. Why are these not then considered the same species? It all has to do with the natural barriers to reproduction in the wild, whether they are geographic, mate selection based or both.
Lets not forget that our concept of a species is a man-made construct designed to place order on the natural diversity around us. We've created certain rules that seem to apply fairly well in most circumstances in the natural world. What we're all starting to learn is that ALL of this breaks down once we enter into an unnatural environment, i.e. captivity. The odds of an "Indigo Dottyback" are pretty slim as far as a wild-occuring creature, yet there are probably a good handful running around in captivity due to an artificial set of circumstances.
furthermore that would mean that two humans of two different races from opposite sides of the earth are different species as the would never mate in the wild....
I would simply argue that NONE of us live in the "wild" or under "natural" circumstances at this point, so in most respects we are definitely an exception to our own rules when it comes to the definition of our own species. On the flipside, what is artificial to most other life on the planet IS our "WILD" environment.
You might also want to look into polymorphism, subspecies, races and varients. "Species" is not the end-all be-all in the discussion of "hybrids".
You should check out the various articles on Reticulate Evolution in the same issue as Mai's Mandarin breeding article in Coral Magazine....
FWIW,
Matt