Systematics of the Pseudemys Concinna-Floridana Complex

Systematics of the Pseudemys Concinna-Floridana Complex

COMME TARIES AND REVIEWS 329 A synopsis of Projeto TAMAR was presented in 1992 1have not conducted an exhaustive systematic analysis during the IV Encontro Brasileiro de Herpetologos and of the genus, nor have I examined specimens from through­ subsequently published (Baptistotte, 1994). One of out its range. I primarily address disagreements I have with TAMAR's consistent priorities has been to develop collabo­ Seidel's conclusions as they relate to cooters in northern rative arrangements with national and international organi­ Florida, an area where I have studied the taxa in question for zations, investigators, and conservationists, and this policy two decades. continues to prevail. Because he believes that cranial musculature and oste­ ology "are oflittle use in field identification or in evaluation Literature Cited of fluid-preserved material," Seidel quickly dismissed the analysis of Ward (1984), which relied heavily on these BAPTISTOTTE, C. )994. Tartarugas marinhas: Projeto TAMAR. In: characters. While not in complete agreement with Ward's Nascimento, L.B., Bernardes, A.T., and Cotta, G.A. (Eds.). findings, I nonetheless affirm the importance of such char­ Herpetologia no Brasil, I. (Artigos solicitados aos palestrantes acters in systematics. Surely Seidel would not deny the value do IV Encontro Brasileiro de Herpet610gos). Belo Horizonte: of such characters as karyotype, electrophoretic pattern, Pontificia Universidade Cat61ica de Minas Gerais e Funda~lio vocalization, and behavior in systematics, yet which ofthese Biodiversitas, pp. 19-24. MROSOVSKY, N., AND GODFREY, M.H. 1995. Manipulating sex is useful with preserved specimens? Based on years of ratios: turtle speed ahead! Chelonian Conservation and Biology observation of thousands of Pseudemys, I long ago con­ 1(3):238-240. cluded that theirhigh levels ofintraspecific variation in scute VOGT, R.C. 1994. Temperature controlled sex determination as a and shell proportions diminish the overall utility ofmorpho­ tool for turtle conservation. Chelonian Conservation and Biol­ metric relationships in systematic analyses, although certain ogy 1(2):159-162. characters (e.g., nuchal scute proportions) are diagnostic. It Accepted: 19 April 1995 is principally among largely homogeneous turtle groups (e.g., the genus Kinosternon, members of which are rela­ tively uniform in shape and coloration) that biologists have Chelonian Consen1otiofl and Biology, 1995, 1(4):329-333 been forced to rely extensively on such tools. Seidel (1994) © 1995 by Chelonian Research Foundalion noted that "many of the character states in Pseudemys are Systematics of the based upon continuous variables with considerable overlap." Pseudemys concinna-floridana Complex Nonetheless, despite extensive variation, color patterns do exhibit certain central themes that seem especially useful in (Testudines: Emydidae): discriminating species (e.g., Conant and Collins, 1991). An Alternative Interpretation Further, other generally used characters vary more than is typically appreciated. Forexample, the uppertomial notch DALE R. JACKSO I and bordering cusps, often used to distinguish the Pseudemys I Florida Natural Areas Inventory, The Nature Conservancy, rubriventris group, occur in the P. concinna line as well, not 1018 Thomasville Rd., Suite 200-C, just throughout such western taxa as P. texana and P. Tallahassee, Florida 32303 USA gorzugi, but even as an intrapopulational variant within [Fax: 904-681-9364] rivers of the Florida panhandle (e.g., the Wakulla and Apalachicola). The frequency of these characters in this lin­ The complex relationships among the many forms of eage may increase as one moves westward; they are seemingly cooters (i.e., thePseudemys concinna-floridana complex) in absentin peninsularFlorida, infrequently presentinthe Florida the southeastern United States have served as fodder for panhandle, and common in western forms such as P. texana. turtle systematists for decades (e.g., Carr, 1935, 1937, 1938, Additionally, I noted earlier (as cited by Seidel, 1994) the 1952; Crenshaw, 1955; Ward, 1984; Dundee and Rossman, unreliability of trophic structures such as these as taxonomic 1989). Unfortunately, several recent authors (Frost and characters for this group ofemydids (Jackson, 1978). Hillis, 1990; Collins, 1991; Seidel, 1994) may have de­ Below, I address my three principal disagreements pended at least in part upon inadequate information for their with Seidel (1994): the elevation of both P. concinna summaries or analyses, which I believe led them to errone­ suwanniensis and P. floridana peninsularis to specific ous conclusions. status and the combining of the remaining P. concinna and While I respect Seidel's (1994) innovative attempt to P. floridana into a single species with two subspecies, P. address one of chelonian systematics' most vexing ques­ concinna concinna and P. concinna floridana. tions, years of personal field observations of these turtles, mostly in northern Florida and adjacent states, as well as The suwanniensis Problem knowledge of their osteology as a result of conducting an extensive study oftheir fossils (Jackson, 1977), have led me Although he was not the first to do so (see Frost and to different conclusions. An examination of Seidel's mor­ Hillis, 1990; Collins, 1991), Seidel's elevation of P. c. phometric data, based on museum specimens, has notcaused suwanniensis to specific status was based on limited and me to alter these conclusions. inaccurate information. Seidel admitted that "few characters 330 CHELONIAN CONSERVATION AND BIOLOGY, Volume 1, Number 4 -1995 (!) 40 80 '20 K!tl Figure 1. Minimum known distribution ofPseudemys concinna (sensu lata) in Florida; shading indicates segments ofrivers known to be inhabited by the species. Rivers named in text: 1) Apalachicola, 2) Ochlockonee, 3) Wakulla-St. Marks, 4) Wacissa-Aucilla, 5) Econfina, 6) Fenholloway, 7) Steinhatchee, 8) Suwannee, 9) Withlacoochee. Specimens from the Ochlockonee River eastward conform generally to the definition of P. c. suwanniensis, which intergrades with other forms from the Apalachicola River westward. separate the recognized forms of river cooters." Further, banded water snakes to represent allopatric taxa simply despite noting that "morphometric analysis (PCA) did not because there may presently be 30-40 km of uninhabitable separate [suwanniensis] from other populations of P. dry land between occupied wetlands? I should hope not. concinna," he nonetheless recommended that it be consid­ Clearly, no riverine species is likely to occur where there are ered a distinct species, largely because cluster analysis no rivers, and, in the case of river cooters in Florida, a river separated it from otherforms, and it "appears to be allopatric may need to be of some minimum size to support cooters. to other P. concinna." As I will show, the latter contention is Between the Apalachicola and Ochlockonee rivers on incorrect. Seidel tried to strengthen his case by listing presum­ the west and the Suwannee River on the east (i.e., the alleged ably unique ecologicalcharacteristics (limited terrestrial activ­ gap separatingsuwanniensis from concinna) are a numberof ity, cryptic nesting behavior, migrations) that he gleaned from rather small river systems draining directly into the Gulf already conjectural literature. However, to my knowledge, (Fig. 1). The Wakulla-St. Marks River system, the first terrestrial activity is limited in all P. concinna (principally drainage east of the Ochlockonee, supports a substantial restricted to basking and nesting), the nesting habits of population of river cooters (Fig. 2) whose reproductive suwanniensis are not exceptionally cryptic (I have marked biology I have studied for several years (Jackson, 1987, nearly 300 nesting females in one population!), and there is 1989, 1994). River cooters also are abundant in the next no documentation ofdirected "migrations" to sea water. drainage eastward, the Wacissa-Aucilla River system (these The misconception that suwanniensis is allopatric with data are readily available from the state Natural Heritage other river cooters (i.e., P. concinna; Frost and Hillis, 1990; Program; Iverson and Etchberger, 1989, also note speci­ Collins, 1991; Seidel, 1994) stems principally from general­ mens from these rivers). Differences between turtles in ized, and not altogether accurate, range maps, such as those these two systems and those in the Suwannee and found in standard field guides (e.g., Conant and Collins, Withlacoochee to the south are so slight that even subspe­ 1991, which fails to include a substantial inhabited por­ cific separation would not bejustified. Ten depredated adult tion of the Suwannee River basin). Better depictions of female specimens from the Wakulla River, the shells and the species' range throughout Florida are presented by bones of which are currently in my collection pending Auffenberg (1978) and Jackson (1992; note: published map completion ofmy studies, match Seidel's characterization of inadvertently omittedthe Wacissa-AucillaRiver), who high­ P. c. suwanniensis (interestingly, carapaces ofturtles in this light only rivers inhabited by P. concinna. Application ofthe population, and potentially others, appear much blacker and concept ofallopatry to aquatic organisms requires the infu­ less patterned in life, perhaps suggestive of a response of sion ofcommon sense. Are we to consider isolated popula­ melanin to sunlight). Furthermore, cooters in all of these tions of largemouth bass, bullfrogs, greater

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