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dollar sunfish


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#1 Guest_centrarchid_*

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Posted 08 September 2009 - 01:47 PM

Anyone know the proper subspecies names for the dollars sunfishes? Do not hesitate to tell me I am wrong.

Eastern Dollar Sunfish
Lepomis marginatus _________?
Western Dollar Sunfish
Lepomis marginatus marginatus (I think)

Critter in Florida?
Lepomis marginatus _________? (floridanus?)

#2 Guest_daveneely_*

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Posted 08 September 2009 - 03:27 PM

The type locality is St. Johns River, FL, so marginatus should be restricted to that form. I don't think any subspecies have been formally described, and there's no synonyms listed in the Catalog of Fishes...

Edited by daveneely, 08 September 2009 - 03:28 PM.


#3 Guest_centrarchid_*

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Posted 08 September 2009 - 04:04 PM

If St. Johns River is type locality, then L. marginatus marginatus, if subspecies to be considered will refer to the eastern form? I am not familiar with what occurs at the type locality.

#4 Guest_TomNear_*

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Posted 08 September 2009 - 09:17 PM

Dave is correct that there have been no other forms of L. marginatus described and St Johns is the type locality. Jim, I think that it is safe to say that if different populations of Dollars were deemed differnt, no systematist would describe them as subspecies, but would describe them as species. The subspecies is not often used for "new" fish descriptions, and as a concept has fallen out of favor among evolutionary biologists.

Dave, would you agree with this? (not a trick question...)

Tom

#5 Guest_daveneely_*

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Posted 09 September 2009 - 09:35 AM

If St. Johns River is type locality, then L. marginatus marginatus, if subspecies to be considered will refer to the eastern form? I am not familiar with what occurs at the type locality.


Sorry for not being clearer. In taxonomy, the type locality just refers to the place where the species (or at least the holotype, a single, name-bearing specimen) was originally described from. From a pragmatic standpoint, this helps to assure that that name will always be associated with that form, especially in freshwater fish where diversity is often tied to discrete watersheds.

Long story short, if somebody identifies a population of what we now consider "L. marginatus" that is diagnosably distinct from the type specimen and what occurs in the St. Johns, and describes it as a new species, it will require a completely new name. If you're really into this (or trying to fight insomnia) I'd recommend checking out the ICZN's Code of Zoological Nomenclature online...

http://www.iczn.org/...ection=contents

Tom, I'd agree with you 100% on that.

#6 Guest_centrarchid_*

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Posted 09 September 2009 - 12:25 PM

My original question pertains to Holbrook's type specimen. Was it most like those occuring along the eastern seaboard, or those occuring in the Gulf of Mexico drainage centered on the Mississippi River? Assuming no significant changes in the population from which the type speciman was derived, my best plan of action is to acquire some dollars from at or near the type locality.

#7 Guest_daveneely_*

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Posted 09 September 2009 - 01:31 PM

My original question pertains to Holbrook's type specimen...


{throws hands up in air and shrugs} Dunno. Holbrook's type lies in sweet repose in a dusty jar of ethanol on a dusty shelf at the Museum of Comparative Zoology at Harvard. Without visiting the MCZ and examining the specimen there's no way to be 100% sure, but the approach you suggest sounds reasonable.

Good luck!

#8 Guest_TomNear_*

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Posted 09 September 2009 - 04:23 PM

Jim, if you are going to do this by going out and gathering specimens, be sure to preserve tissues in ethanol for genetic work. I will be spending some time at the MCZ during my sabbatical year (started 1 July), I would be happy to take some counts for you. I should try and get a nice picture of the type. There is an idea, an illustrated type catalog for Centrarchidae. Carter Gilbert published an excellent catalog, but photos of the types would be interesting.

Dave, see after we get it out of our system, maybe we can find common ground.

#9 Guest_centrarchid_*

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Posted 09 September 2009 - 05:22 PM

Thanks Dave and Tom,

I did not set out to initiate a taxonomic description, but rather to simply make certain the appropriate name is used for the dollar sunfish we used in a larval feeding trial. We have seen with other sunfish taxa, what is considered to be only subspecific differences at the genetic level / morphological level can turn out to be whopping big differences at the growth trial level. I agree, some of what are considered subspecies should species based on what I do.

#10 Guest_gerald_*

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Posted 13 September 2009 - 11:28 AM

Hi Tom, Dave et al -- Aside from having "fallen out of favor", what's so inherently wrong about the subspecies concept? Obviously populations don't go from being genetically indistinguishable to discrete species in a single generation. In some cases it may happen relatively fast, but it's not instantaneous, and it seems to me there are valid reasons for tracking and naming divergent populations that might be in transition either toward species-hood or re-homogenization (if they were temporarily isolated). Botanists are still actively using the "variety" concept. Prestigious ecologists I'm sure would never stoop so low, but rejection of the subspecies concept kinda sounds like: "Hey, let's dump on the old theories so we can write papers and argue about it." Why exactly DO these guys reject any taxonomic distinction less than species level?

Gerald

Dave is correct that there have been no other forms of L. marginatus described and St Johns is the type locality. Jim, I think that it is safe to say that if different populations of Dollars were deemed differnt, no systematist would describe them as subspecies, but would describe them as species. The subspecies is not often used for "new" fish descriptions, and as a concept has fallen out of favor among evolutionary biologists.

Dave, would you agree with this? (not a trick question...)

Tom



#11 Guest_fundulus_*

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Posted 13 September 2009 - 07:04 PM

It's going to a simpler conceptual structure, with a species made up of a series of more or less linked populations. Subspecies is a squishy intermediate that is at best ill defined.

#12 Guest_centrarchid_*

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Posted 14 September 2009 - 01:34 PM

The lack of interest in the lower level taxonomic designations in my opinion has a lot to do with legal considerations / politics. The scientific community is largely in agreement on what qualifies as species level differences, but with subspecies level and population level a consensus is often not achieved. If environmental management efforts are contemplated / scrutenized by politicians and the taxon of greatest interest is difficult for the scientific community /environmental managers to repressent as unique, then it is difficult to develop political will for protection. Therefore, if your efforts as a biologist are not supportable (financially), then why do it? Some of the support can also be in the form of "thataboy with pats on back" and "yes, you can keep your job".

I think what I wrote is consistent with being a cynic.


cynic = somebody who believes that human actions are insincere and motivated by self-interest

#13 Guest_farmertodd_*

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Posted 14 September 2009 - 01:51 PM

Botanists are still actively using the "variety" concept. Prestigious ecologists I'm sure would never stoop so low, but rejection of the subspecies concept kinda sounds like: "Hey, let's dump on the old theories so we can write papers and argue about it." Why exactly DO these guys reject any taxonomic distinction less than species level?


Two thoughts...

One, plant genes travel in 360 degrees, while fish travel, for the most part, in 2. Thus, plants are sloppy and botanists are forever dealing with the exceptions. However, this simplifies our fish task at hand - Is 10% difference in base pairs different enough to call things different species? I hear lots of arguments FOR speciation over the 1.5% difference in humans and chimpanzees. Which gets to the scientific discussion...

Two, there never were theories at the genus level. There have only ever been hypotheses regarding species level distinctions. This is where these discussions run amok. People forget that there are morphologic, geographic and now genetic TESTS of HYPOTHESES related to these taxa. No one doing genetic work are dumping anything. They're retesting old hypotheses with new technology.

Todd

#14 Guest_centrarchid_*

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Posted 14 September 2009 - 02:09 PM

farmertodd,

I am not clear about your reasoning as to why subspecies designations are either ignored or go strait to species level. Even though many taxa can be distinguished consistantly at the molecular level, what is the level that serves as cutoff between species and differences that are not significant? Appears to me to be arbitrary at present time.

#15 Guest_farmertodd_*

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Posted 14 September 2009 - 02:39 PM

It totally is as we build that body of evidence. That's why we need reminders that species are hypotheses :)

Todd

#16 Guest_CATfishTONY_*

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Posted 14 September 2009 - 02:42 PM

Anyone know the proper subspecies names for the dollars sunfishes? Do not hesitate to tell me I am wrong.

Eastern Dollar Sunfish
Lepomis marginatus _________?
Western Dollar Sunfish
Lepomis marginatus marginatus (I think)

Critter in Florida?
Lepomis marginatus _________? (floridanus?)


It would seem this is the best ? of the month.

#17 Guest_megalotis1_*

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Posted 05 July 2010 - 06:21 PM

From my data on marginatus I am of the opinion that there are multiple taxa involved, peninsular FL specimens are very different than those in the St Johns system (type locality); in addition eastern seaboard populations differ from those of the Gulf outside of peninsular FL. Differences show up in coloration, as well as in morphometrics and to lesser degree meristics.

#18 Guest_fundulus_*

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Posted 05 July 2010 - 06:55 PM

From my data on marginatus I am of the opinion that there are multiple taxa involved, peninsular FL specimens are very different than those in the St Johns system (type locality); in addition eastern seaboard populations differ from those of the Gulf outside of peninsular FL. Differences show up in coloration, as well as in morphometrics and to lesser degree meristics.

I would guess that no comprehensive DNA data exist on the species across its range?



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