all theillei clowns infertile?

No that is not true. All clownfish species are able to interbreed and produce fertile offspring.
The high school biology definition of "species" is not all that accurate in real life.
We either need to redefine "species" or re-classify clowns as many different subspecies within the same species.
 
Phil,

Who says that the "possibility" of hybridization is a defining factor in speciation? What about geographic and environmental partitioning? Wild clown hybrids are much rarer than their ability to cross in captivity would lend one to believe - because the fish are so isolated behaviorally, geographically and environmentally.

Even "species flocks" such as the Haplochromine cichlids of Lake Vcitoria are considered valid species, and they can hardly be visually differentiated from one another, to the point where the males cannot even tell females apart. In captivity, you almost can't keep them from hybridizing - what makes them valid species is that they live in different habitats and have different behavoirs so that they don't come across each other in the wild.

You wrote -
"We either need to redefine "species" or re-classify clowns as many different subspecies within the same species."

- actually neither is appropriate.

Jay
 
I understand your point that geographic isolation and even behavioral isolation (fish that could produce fertile offspring but one breeds in the spring and the other in the fall) are included in the definition of species.
However, in the case of clownfish as in flickers (birds). The geographical/behavioral (occupying different anemones, or different reef zones perhaps) has broken down in the wild and we are seeing fertile hybrids. Theillei, leukocranos and probably A. chagosensis are examples of fertile hybrids who's parents are likely not even in the same complex.

So, since A. chrysopterus and A. sandarcinos breed in the wild to produce white cap clowns and white cap clowns breed freely with A. chrysopterus, A. sandaracinos and other white caps in the wild and produce fertile offspring, by our current definition of species, are chrysopterus and sandaracinos the same species. If they are not, please explain why?

I am writing in a hurry, I know my question sounds terse. It isn't meant to be. I know that you have more knowledge in taxonomy than I do. I am truely interested as this come up in my biology class quite often.
 
Phil,

I'll admit that I have not seen these hybrids in the wild myself, and clownfish taxonomy is not my speciality, but my understanding is that while these crosses are fertile, they are still very rare (as evidenced by their rarity in the trade). Clownfish, due to their localized habits, can have partitioned populations very near to that of other species. In some cases, it is obvious that when suitable mates are not present, these fish do hybridize naturally. But, these very hybrids are also isolated, and therefore remain rare. This by itself does not mean that they should be elevated to species status. I'm struggling to think of any valid fish species that can be seen to be a result of hybridization of two well-known species - I think that mechanism is rarely, (if ever) the route taken for new species to develop. As for lumping all clownfish (or even certain groups of clownfish) into the same species simply based on their ability to hybridize, my understanding is that this alone is not sufficient to elevate them to species status - even for the most avid taxonomic "lumper". And of course, there is the idea that the definition of "species" is a totally human artifact - the fish could care less what pigeonhole we feel they should belong to.

Jay
 
<a href=showthread.php?s=&postid=8612960#post8612960 target=_blank>Originally posted</a> by JHemdal
Phil,

I'll admit that I have not seen these hybrids in the wild myself, and clownfish taxonomy is not my speciality, but my understanding is that while these crosses are fertile, they are still very rare (as evidenced by their rarity in the trade).

Jay

I am afraid this is too much of an assumption to be a strong factor in your thinking.

Just because you do not see tons of these hybrids does not mean they are not a significant part of the overall population in a given area. You have to keep in mind the situation in which most marine fish are collected...

The typical collector is a local that is not there to id fish or collect something rare (they might not even know that all those cap clowns are rare), they are there to get what will bring them in money on a daily basis. They are living hand to mouth, they are collecting what they know will result in a sale at the best price.

Also consider that most wholesalers can not even tell the difference between A. percula and A. ocellaris or A. clarkii and A. Saebe and you have your answer as to why fish like caps are not regularly collected... "Oh great! More of those damn skunks with the funky head bar that always dies in a couple days! Why are you bringing me fish I can not even keep alive long enough to sell! Got some more of those percs? I can sell those!".
 
I am not of the opinion that leucokranos, thiellei, or chagosensis should be given species status. That is why I usually refer to leucs as white caps when I write.

I do think that the definition of species is a human artfact that is useful as a tool in studying organisms but not as some sort of scientific law, which makes me feel a little silly that I am even having this discussion.:D

So, let me redo my original answer.
Yes, thiellei are fertile. All clownfish species are able to interbreed and produce fertile offspring. (period)
 
JHardman,

Just because I admitted that I have not done actual population studies on these fish does NOT invalidate my assumption that these fish are rare in the wild. Besides, you try to invalidate my assumption with your own assumption - have *you* done population studies?

I do have 35+ years experience in the pet trade, wholesale and retail. If the collectors find 'em, and if they are common enough, they will be in the trade. Look at Pterapogon kaudnerii - first ones out of Indonesia were $50 each wholesale. That soon dropped once collectors began working that region (actually habitat - they were already collecting nearby, just not in the seagrass area). That has not happened with the hybrid clowns - because they are rare in the wild.

I do know tha white cap clowns are targeted by collectors in the Solomons, and they are paid more for them. This is not the case where a bunch of fish come in, and the wholesaler sees that some are different, and jacks the price up accordingly. These fish are invoiced as such from at least the exporter's level.

Jay Hemdal
 
Phil,

You wrote: "Yes, thiellei are fertile. All clownfish species are able to interbreed and produce fertile offspring. (period)"

Good enough, I've only bred and raised four species of clowns myself (none of them hybrids) so I have no basis for commenting on your revised answer (whew!)

Jay
 
Back
Top