Anyone familiar with bluegill occuring in the Yadkin River, in or near Roane Co., North Carolina?

Anyone familiar with bluegill occuring in the Yadkin River, in or near Roane Co., North Carolina?

I have never heard of Roane Co. NC, Rowan county maybe?

I have never heard of Roane Co. NC, Rowan county maybe?

My text (Gilbert, C.R. 1998. Type catalog of recent and fossil North American freshwater fishes; families Cyprinidae, Catostomidae, Ictaluridae, Centrarchidae and Elassomatidae. FLorida Museum of Natural History, Special Publication No. 1) does read Roane Co., but I think it is a miss-print and should say Rowan Co.

bluegill have been so widely stocked in farm ponds for so many years that its highly unlikley you'll find any "uncontaminated" native population in Rowan County. ive caught juvies by seine, but i guess the "coppernose" trait wouldnt be apparent in juvies. However, Rowan is just 2 counties SW from Greensboro (Guilford Co) if youre coming for our NC conferenec in June.

It is possible that most of the bluegill handled by state and private hatcheries have been native stocks from the eastern seaboard. I hope likely. Regardless, the possibility remains that even with contamination, the native alleles dominate in the existing populations. After seeing the animals from several locations in FLorida and the Savanah River drainage understandardized lab conditions I am becoming increasingly wary of calling bluegill stocks as one heads north along the eastern seaboard to be intergrades with northern bluegill. Speculation at this time but a cline may exist where the appearance of the coppernose / southeastern / Florida bluegill grossly approaches that of northern bluegill owing to convergense.

Here are two paragraphs from a book chapter coming out this summer. The book is on the diversity and biology of centrarchids. These paragraphs address bluegills in the Yadkin R, as it is a Cope type locality for Lepomis purpurescens.--Tom

The two valid subspecies of L. macrochirus present an interesting problem of nomenclature confusion, morphological and genetic divergence, an area of presumed secondary contact and introgression, and a biogeographic pattern and a timing of divergence seen in another centrarchid sister species pair. The nominal subspecies L. m. macrochirus Rafinesque is distributed across eastern North America except for the northern Atlantic Coast (Lee, et al., 1980), while the other subspecies is endemic to the Florida Peninsula (Felley, 1980). Initially, the subspecies found in Florida was designated as L. m. purpurescens Cope under the premise that this subspecies extended from the Atlantic Coast of the Carolinas to the Florida Peninsula (Hubbs and Allen, 1943; Hubbs and Lagler, 1958). The type locality for Lepomis purpurescens is in the Yadkin River Drainage in North Carolina (Cope, 1870). Subsequent morphological and molecular analyses demonstrate that this is far north of the range of the Florida subspecies (Avise and Smith, 1974a; Felley, 1980; Avise, et al., 1984), and as Gilbert (1998) has pointed out, Cope described a Bluegill from Florida, Lepomis mystacalis (Cope, 1877). Therefore, the appropriate name for the Florida Bluegill is L. macrochirus mystacalis.


Lepomis m. macrochirus and L. m. mystacalis are morphologically and genetically distinct, but there is a presumed area of introgression via secondary contact along most of southern Georgia and South Carolina (Felley, 1980; Avise, et al., 1984). Another sister species pair in Centrarchidae, Micropterus salmoides and M. floridanus, exhibit a very similar distribution and area of secondary contact and introgression (Bailey and Hubbs, 1949; Philipp, et al., 1983). Based on a fossil calibrated molecular phylogeny of Centrarchidae, the divergence time between M. salmoides and M. floridanus is approximately 2.8 million years ago (mya) (Near, et al., 2003; Near, et al., 2005b). Lepomis m. macrochirus and L. m. mystacalis exhibit a very similar divergence time. We found mtDNA cytochrome b gene sequences on Genbank for five individuals of L. m. macrochirus and a single L. m. mystacalis (accession numbers, AY115975, AY115976, AY225667, AY828966, AY828967, AY828968). The average genetic distance between these two subspecies was 4.5%, which translates to a divergence time of roughly 2.3 mya (Near, et al., 2003). Future work should aim towards gathering sufficient morphological and molecular data to more precisely determine the geographic distribution of these two forms and assess if L. mystacalis is a valid species.

Tom-

My interest do not lie directly with phylogeny but I will do my best to consider diversity and relationships as they affect my efforts with bluegill(s). You do not mention the southwestern bluegill L. m. speciosus (Baird and Girard 1854). Are you of the opinion it does not exist?

The markers (enzymes on gels) used during the 1970's and 1980's seem to me to be less than optimal for assessing stock structure of populations (subspecies) that are thought to have diverged > 2 mya. What evidence supports that native bluegill to the north of the Savanah river drainage on the eastern seaboard are L. m. macrochirus. Yes, they are darker with a very different color pattern and more elongate that bluegill of FLorida and genetically distinguishable from the latter but I need to know more. Did Avise or Felly compare their putative northern bluegill stocks of the eastern seaboard to northern bluegill of the Mississippi drainage? Mobile River bluegill are not good representatives of northern bluegill. How could northern bluegill get from the MIssissippi drainage to the eastern seaboard? During one of the glaciation advances they could have occupied drainages of Georgia and northern Florida? Stream capture seems unlikely since the low order streams affected are not what I consider to typical bluegill habitat unless eascapement from man made impoundments is involved.

I have brood animals from three source populations of nominal L. m. mystacalus of pennisular Floriada and animals from the proposed introgression zone in Savanah River dr (SC / GA). Animals from all those locations are distinguishable even to the untrained eye. We will be lab rearing animals from those populations simultaneously for an ongoing project and will get a handle on enviromental effects for those differences.

I also have northern bluegill from several wide ranging localities of the Mississippi river drainage and for the characters of interest to me they very consistent although if a standout northern bluegill population exist among the samples I have, it is from the Mobile River drainage.


I am guessing you are also considering for your book the other sister taxa pairings possibly of the same nature which includes redspotted/spotted sunfishes and maybe the mess involving the eastern and western dollar sunfishes. The warmouth of FLorida look a bit odd relative to those in the Mississippi River drainage.

Tom, do you have a title for this book and the name of the author? Thanks.

Here is the citation for the book. It looks like November is the new release date. This is good, because it will allow me to update my chapter!

Cooke, S.J. and D. P. Philipp (editors) In press. Centrarchid fishes: diversity, biology, and conservation. Blackwell Publishing.


I think that the evidence for L. m. speciousus is weak. An allozyme analysis in 1986 did not find fixed allelic differences, or any differences in allele frequency. I think it is nomenclatural confusion. Again from the forthcoming chapter.

"There is a degree of uncertainty as to how many subspecies of Lepomis macrochirus are recognized. The problem centers on Pomotis speciosus described from Brownsville, Texas by Baird and Girard (1854). This species was subsequently synonymized with L. macrochirus by Hubbs (1935). At a later date, Hubbs and Lagler (1958) treated Pomotis speciosus as a subspecies of L. macrochirus, concluding that the geographic range is throughout Texas and northeastern Mexico. Allozyme analyses did not detect genetic differentiation between L. m. macrochirus and L. m. speciosus (Kulzer and Greenbaum, 1986), and subsequent treatments of centrarchid species diversity have not recognized L. m. speciosus (Gilbert, 1998)."

My professional opinion is that the concept of subspecies is bankrupt and provides little utility for understanding biodiversity. This may illicit some ire; however, the presence of contact zones where there is limited introgression is no reason to loose species status.

Regarding the sampling in Felley and Avise, I am not sure. However, I do know that Avise tended to sample centrarchids only as far west as the Mobile and not too far north. If you would be interested in getting some genes sequenced on your bluegills, send me a message and we can discuss the details.

My professional opinion is that the concept of subspecies is bankrupt and provides little utility for understanding biodiversity. This may illicit some ire; however, the presence of contact zones where there is limited introgression is no reason to loose species status.

You're right about subspecies as a concept. A species can be many different populations, but subspecies is meaningless phylogenetically.

In respect to the problem at hand here with blugill sunfishes, even the species concept is a bit fuzzy if it is applied to northern and coppernose populations if they are both to be recognized as species. Maybe the stock or population concept is more appropriate. I am willing to put a little money on that stocks of coppernose bluegill (within drainage populations) are as unique relative to each other as some the emperiled salmonid stocks of the northwest are from each other. Maybe overlooked since bluegill are lowly panfishes rather than preferred catch of the well healed and they do not support large commercial fisheries.

The subspecies concept as used here does lump together similar populations (based on color pattern). At least part of taxanomy is to lump and divide presumably based at least impart on relatedness.

You're right about subspecies as a concept. A species can be many different populations, but subspecies is meaningless phylogenetically.

Here's that ire you asked for: So, if not "subspecies", then what functional term should we use to talk about populations that are somewhere along that continuum between being just a geographically isolated pop of the same gene pool versus an ecologically/evolutionarilly isolated species ? Seems to me that "subspecies" is a very nice concept for describing populations that have diverged significantly and may in time become "distinct species" (whatever that means). If its just the word "subspecies" you dont like I'm open to other words (Evolutionarilly Significant Unit ?) but the basic concept seems valid: an isoltaed or semi-isolated population that's not yet distinct enough to call a species. To me "subspecies" is only slightly more ambiguous as a concept than "species" is.

Gerald, Good points; however, as different as species concepts may be they all have some operational criteria for recognizing species-level diversity. The problem with subspecies is that they are often not diagnosable, and they almost never correspond to clades identified with morphological or molecular characters. The growing trend in many taxonomic disciplines is to determine of subspecies are monophyletic (or exclusive) relative to other species and subspecies. If so, we should treat them as species. The problem with the "on their way to becoming species" is that there is no specific time scale on which speciation occurs.

So to sum up. If the lineages are diagnosable, reciprocally monophyletic (exclusive), and has a distinct geographic distribution treat them as species.