PlanetCatfish.com

who know what is this?

Mega Crown Zebra Pleco (Hypancistrus sp. (1))
http://www.planetcatfish.com/common/spe ... es_id=3607

thank you!
is it LXXX?

Hypancistrus Hybrid.

It could be a form of L236: http://www.planetcatfish.com/cotm/cotm. ... cle_id=495. A lot of the plecos can have offspring with inverted colors.

It is a hybrid from Japan L333xL236

Technically, it can't be a hybrid as no described species are involved - unless someone wants to tell me which species were crossed... It is a selectively produced colour form of an undescribed single species of Hypancistrus as far as we know.

Jools

Well spoken. We talk so much about L Numbers even I forgot the numbers are place holders until described. (No matter how long it takes)

Jim

New species color morph, hybrid, or frankenpleco...no matter, it sure is pretty.

Hi Jools,

Jools wrote:Technically, it can't be a hybrid as no described species are involved - unless someone wants to tell me which species were crossed...

it depends how you define "hybrids", in Wikipedia it is defined like this:

In biology a hybrid is an offspring of two animals or plants of different breeds, varieties, species or genera

Following this definition it is a hybrid.

Cheers,

A little quick with the copy and paste as 'the devil is in the details.' Since this forum tends to be more detail oriented I have copied from Wikipedia note 3 under taxonomic which is most accurate for this situation.

The third type of hybrid consists of crosses between populations, breeds or cultivars within a single species. But it is actually crossbreeding and not hybrid. This meaning is often used in plant and animal breeding, where hybrids are commonly produced and selected because they have desirable characteristics not found or inconsistently present in the parent individuals or populations. This flow of genetic material between populations is often called hybridization.

I generally don't use Wikipedia but this submission was not bad.

Jim

You absolutely can have intraspecific hybrids, which is why in most scientific research the term "interspecific hybridisation" is used to distinguish the more commonly studied case of interbreeding between different species.

But Jools is still correct. If you don't know what the parents were, then how can you know it's a hybrid of anything?

He,

I think I remember the picture from fb, and if I am right the breeder said the parents are L 66 and L 333.
However, they look nice.

racoll wrote:You absolutely can have intraspecific hybrids,

We are at the limits of my knowledge and, I suspect, well within yours (thankfully). I did have subspecies in my mind as being "allowed" to be hybrids, but not anthing else. Are intraspecific hybrids when one sub species crosses with another? If so, then there are not a lot of catfishes with subspecies...

However, if not so, then what is the definition used to draw the line when dealing with individuals within a species?

Cheers,

Jools

Hi Jools,

Please allow me to provide an example of intraspecific hybrids, using plants and catfish as examples.

Typically, intraspecific hybrids are only possible when the parents represent true-breeding, distinct morphs. If the differences are not distinct (e.g., if you have two parents with different versions of a trait that varies along a continuum and the parents are also a blend of multiple genes that produce their phenotype, such as height in humans), you wouldn't usually bother to call their offspring hybrids.

Going back to plants - think of Gregor Mendel's classic experiments with peas: At that time, gardeners had different "true-breeding" genetic lines of pea plants. Some produced purple flowers and some produced white flowers. If you crossed a true-breeding purple flower pea plant with a true-breeding white flower pea plant, you would have produced an intraspecific hybrid. Since flower color is the result of a single gene with two alleles and a purple-dominant / white-recessive relationship, the "hybrid" offspring are nothing more than heterozygotes for flower color, all purple.

I suppose a similar example in catfish would be to cross an albino with a pure-breeding wild-type bronze Corydoras aeneus. The resulting heterozygous bronze offspring would be intraspecific hybrids.

You might make the same example with albino and brown/black BNs (), but that would be a poor example because, as has been so often explored on this website, it is not known if common BNs are even a species unto their own right, or if they are themselves a product of interspecific hybridization to begin with, right? LOL.

Cheers, Eric

Jools wrote:Are intraspecific hybrids when one sub species crosses with another? If so, then there are not a lot of catfishes with subspecies...

Try to remove all memory of subspecies from your mind (these are not the subspecific nomenclatural categories that you are looking for ...). I could talk all day about why I hate the subspecies rank, but I'll try to keep it as brief as possible.

Essentially, most of the variation we see in the natural world can be accommodated into two frameworks: species and populations (i.e. evolution on the macro and micro scales respectively). Species represent the groups that can be consistently diagnosed from others, and each member should be more closely related to its own species than another (reciprocal monophyly). Generally, species are reproductively isolated, either spatially, physically, temporally, or ecologically, and this causes the segregation and accumulation of traits that can tell them apart.

Populations within species form genetic clusters, and can often be told apart to some degree, but it is not possible to do so consistently. This allows for clines/grades of variation, and lots of mixing of genes between groups*. There obviously can be grey areas between species and populations, as the process of speciation does not happen overnight. Sometimes populations are on the path to speciating but get thrown back together, and then they can "de-speciate". If enough time elapses, however, this process cannot occur. I'd imagine even if you were really desperate you wouldn't mate with a chimp, and if you did, incompatibilities are too great to result in any offspring.

Despite what some taxonomists might say, species are simply convenient partitions for us to understand and communicate about the natural world. There is no magical definition of a species, as it is simply a process of nature diversifying, but the rules of thumb I mentioned above work in most cases. As you know, sorting out these problems is bad enough between species, without having an additional set of names for the even murkier world of what happens within species.

Subspecies were a terrible idea. It started with the infamous biological species concept, i.e. a two groups demand species status if they cannot produce viable offspring. With groups like butterflies and some other insects you can examine the structure of the genitalia, and this actually be demonstrated simply from the specimens, but of course for other groups in the real world, this is an almost untestable hypothesis. Generally people just started assuming that if two things were morphologically very different overall, then they could not breed with each other and were species. But then there were populations that had smaller, more subtle differences, and simply because these differences were deemed less significant, then they probably could breed with each other, and so they should be subspecies. See how ludicrous and arbitrary this is! Many subspecies have been since shown to be good species in their own right, or simply attributed to the population-level variation with a species.

Jools wrote:However, if not so, then what is the definition used to draw the line when dealing with individuals within a species?

So, to answer your question finally, there are no really hard and fast rules for what comprises an intraspecific group that can hybridise. Really any population with different allele frequencies, as bekateen said already, but I would probably say that for our purposes we are really talking about groups showing some degree of geographical genetic or phenotypic structure.

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*a somewhat relevant issue was a raised in a very recent article in the Graun (here). The author claimed human races do not scientifically exist, which drew a barrage of criticism from everyday folks who can see that they clearly do exist. This can largely be explained by fact that he seems to view race in the way I view species, as discrete entities that can be diagnosed with simple characters. However, the general public instinctively views race as more like amorphous clusters of loosely similar groups with significant gene flow and clines of variation between them (i.e. the way biologists view populations, as described above). So, here is a good example of why adding extra terminologies such as "race" and "subspecies" is really hindering our efforts at communicating biological diversity.

Racoll,

Well said; thank you. (I've never been a fan of the subspecies category - it's a meaningless taxonomic distinction, even WITHIN the definition of the Biological Species Concept)

Cheers, Eric