Identification of Ls and Books Available

[bigbird]

Hi,

Why is it, that all L ID books only have photos of L on the side and not from top ? The reason I am asking, is that in each request for ID, all forums also request a shot from above. I know there are varients, but why then in the L ID books do they not shold side and top shots ? Just a query....cheers jk :thumbup:

 

[Lornek8]

Most books are not geared to be ID books but rather simply a catalog or collection of photos. The sketchy part about L# ID is that L#s are not based on scientific data but rather simply "looks". DATZ assigns the original L# to a particular fish and then each additional look-alike is refered to by that same L#. Confusion comes about when various references interpretes what fish DATZ assigned & labels other fish as the same L#. This can be seen in some of the Aqualog books.

 

[bigbird]

good to know thanks and have a good day..cheers jk :thumbup:

 

[jacksonsjones]

Hey Lornek8,
Thanks for explaing how the L#s came about and some of the underlying cause of confussion in indentification.

My question would be, I have a few reference books etc etc that I use to compare what I have. Sure there are variants within the species, but lets assume you have just purchased a fish and it was sold to you as a particular species. When you receive it, say it looks similar to what you were expecting and you go through the reference books and you cannot ID it still.

What other places can you get your fish ID'ed if you were really interested?
I know forums like this is really useful, but do you suggest anything else?

I'd be interested to know as a scientist (not that I have any that I want to).

J

 

[Lornek8]

Books & forums are about you best options. As most L#s haven't been scientifically described, it makes no difference if a scientist does look at your particular fish as there is no species description to compare to in order to "properly" identify it. Furthermore, I believe, in order to scientifically describe a fish the fish must be destroyed.

 

[FF MkII]

Most photos that are taken from above the fish are for sexing purposes, width of head, abdomen area and pectoral hair growth.

Side one shots i think are better for ID purposes.

 

[dw1305]

Hi all,
Lornek wrote:

Books & forums are about you best options. As most L#s haven't been scientifically described, it makes no difference if a scientist does look at your particular fish as there is no species description to compare to in order to "properly" identify it. Furthermore, I believe, in order to scientifically describe a fish the fish must be destroyed.

Spot on, every new species that is named refers back to a "type" specimen that is retained and preserved and is known as the "holotype" <[ame="http://en.wikipedia.org/wiki/Holotype"]Holotype - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:AgriasPhlacidonBertradiF2.JPG" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/commons/thumb/3/38/AgriasPhlacidonBertradiF2.JPG/250px-AgriasPhlacidonBertradiF2.JPG"@@AMEPARAM@@commons/thumb/3/38/AgriasPhlacidonBertradiF2.JPG/250px-AgriasPhlacidonBertradiF2.JPG[/ame]>, this has some standard "metadata" with it, date, collecting location, latin description, name of collector, name of describer and where the holotype specimen is held (usually a museum somewhere).

We have a post here for those who don't want "too much" detail. <http://www.plecoplanet.com/forum/showthread.php?t=3857>

When scientists suspect that they have caught a new population of a known species (in which case the preserved specimen will become a "paratype" <[ame="http://en.wikipedia.org/wiki/Paratype"]Paratype - Wikipedia, the free encyclopedia[/ame]>), or a new species of a certain genera (like Hypancistrus) they can compare their specimen with all the existing holotypes to see whether it is an already described species or new to science.

With the L numbers we are in the strange situation where something like L66 is well known in the trade, but un described by science. A collected specimen which arrives in Europe or the USA can't be described, it doesn't have any "metadata".

Jonathon Armbruster <http://www.practicalfishkeeping.co.uk/content.php?sid=314>, Milton Tan etc from Auburn University <http://www.auburn.edu/academic/science_math/res_area/loricariid/fish_key/lorhome/index.html> (and quite a few European and Brazilian scientists are working on the un-described Loricariid catfish, and are going to S. America collecting where they are creating holotypes and scientifically describing them where ever possible.

Their species descriptions are based upon traditional morphological grounds - number of fin rays, dentition etc rather than on the DNA that is normally used these days. The reason for this is that you need to develop a library of DNA for any particular group of organisms and nobody has done this for Loricariids (one exists for Cichlids for example). It takes a lot of money and effort to develop the DNA libraries, but once they exist they can much more accurately tease out the relationships (phylogeny) of species, and how long ago they differentiated into species.

As an example of the difficulties of this the large and small Panaque species are classed in a single genus because of their unique teeth. There is some argument that this is convergent evolution, rather than due to their degree of relatedness. Because of this the genus name Panaqolus was suggested for the smaller species, along with the suggestion that they are more closely related to the, other than their teeth, morphologically similar Hypancistrus and Peckoltia spp, rather than their bigger brethren.

Needless to say any question without a definitive answer is likely to lead to
scientific argument. If you want the argument many of the scientists post on Planet Catfish, and I would recommend looking there: <http://www.planetcatfish.com/forum/viewtopic.php?f=14&t=3454>

cheers Darrel

 

[jacksonsjones]

Thanks all for your feedback. Like I said, unfortunately, I do not have such fish, but was interested to know. It is unfortunate that no DNA library exists for for these.

Cheers J

 

[dw1305]

Hi all,
I've had a bit of a dig in the Scientific literature and there are actually some phylogenetic papers based upon DNA for some of the Loricariidae, but not apparently for most of the "L numbers".

There seems to have been quite a bit of work on the "Loricariinae", Whiptails etc. This is from "The genera of the Neotropical armored catfish subfamily Loricariinae (Siluriformes: Loricariidae): a practical key and synopsis". The key looks quite interesting. I've got a copy, I can't post the link to it (due to copyright), but I could email a copy if any-one wants one:

"The subfamily Loricariinae belongs to the Neotropical mailed catfish family Loricariidae. Members of Loricariinae are recognized by their long and flattened caudal peduncle and absence of an adipose fin. Despite important studies conducted on this group, no comprehensive generic key is presently available. A Hill & Smith (1976) analysis and cluster analysis were performed on external morphological characters taken from specimens or borrowed from the literature. The two main groups recognized correspond to the tribes Harttiini and Loricariini. Within the Loricariini, four morphological groups were found: the Rineloricaria group, the Loricariichthys group, the Loricaria group, and the Pseudohemiodon group. Results of these analyses were used to construct a practical key to thirty genera, followed by a synopsis for
each genus."

I've also just found a 2011 one for the "Hypoptopomatinae" - Parotocinclus, Otocinclus etc.

cheers Darrel

 

[macvsog23]

" but I could email a copy if any-one wants one:"
The whips as you saw are one of my great loves

If you could old son?/

mail addy is macvsog_23@yahoo.co.uk

thanks

 

[dw1305]

Hi all,
Bob its posted to your email.

RAPHAEL COVAIN 1, 2 & SONIA FISCH-MULLER 1
"The genera of the Neotropical armored catfish subfamily Loricariinae
(Siluriformes: Loricariidae): a practical key and synopsis"
Zootaxa 1462: 1–40 (2007)