Herpetologists' League A New Species of Subterranean Blind Salamander (Plethodontidae: Hemidactyliini: Eurycea: Typhlomolge) from Austin, Texas, and A Systematic Revision of Central Texas Paedomorphic Salamanders Author(s): David M. Hillis, Dee Ann Chamberlain, Thomas P. Wilcox, Paul T. Chippindale Source: Herpetologica, Vol. 57, No. 3 (Sep., 2001), pp. 266-280 Published by: Herpetologists' League Stable URL: http://www.jstor.org/stable/3893095 . Accessed: 04/08/2011 09:48 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. 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A NEW SPECIES OF SUBTERRANEAN BLIND SALAMANDER (PLETHODONTIDAE: HEMIDACTYLIINI: EURYCEA: TYPHLOMOLGE) FROM AUSTIN, TEXAS, AND A SYSTEMATIC REVISION OF CENTRAL TEXAS PAEDOMORPHIC SALAMANDERS DAVID M. HILLIS', DEE ANN CHAMBERLAIN', THOMAS P. WILCOX', AND PAUL T. CHIPPINDALE2 'Section of Integrative Biology, School of Biological Sciences, The University of Texas at Austin, Austin, TX 78712, USA 2Department of Biology, The University of Texas at Arlington, Arlington, TX 76019, USA ABSTRACT: We describe a new species of salamander (Eurycea) from the Barton Springs seg- ment of the Edwards Aquifer, Austin, Texas, USA. The new species is most closely related to Eurycea (Typhlomolge) rathbuni from subterranean waters around San Marcos, Texas, and like that species lacks external eyes and shows other morphological features associated with subterranean life. The new species is easily distinguished on the basis of morphology from all previously described species of salamanders, and in particular is easily distinguished from its closest relatives, E. (Ty- phlomolge) rathbuni and E. (Typhlomolge) robusta, as well as the sympatric E. sosorum. We used sequences of the mitochondrial cytochrome b gene to infer the phylogeny of described species of central Texas Eurycea, and these data support the major groups reported previously on the basis of other DNA and allozyme data. We also define names for the major clades of central Texas Eurycea. Key words: Caudata; Plethodontidae; Hemidactyliini; Eurycea waterlooensis new species; Blep- simolge new clade; Notiomolge new clade; Paedomolge new clade; Septentriomolge new clade; Ty- phlomolge clade definition; Eurycea clade definition; Endangered species; Texas; Barton Springs "[Eurycea neotenes] was described in Sep- tenes, was not discovered at Helotes until tember, 1937, on the basis of nine speci- 1936 (Bishop and Wright, 1937; see also mens taken in April, 1936, from Culebra quote above by L. T. Murray), and some- Creek, 5 miles north of Helotes, Bexar how herpetologists missed the abundant County, Texas .... This is a very interest- Eurycea nana (sympatric with E. rathbuni ing discovery; and surprising, since no at San Marcos Springs) until 1938 (Bishop, small area in Texas has been more care- 1941). Both of these localities were visited fully collected over than that about Helo- by numerous herpetologists for many years tes. Gabriel Marnock made of it an historic prior to the discovery of these common region that many herpetologists have vis- animals. Perhaps even more surprising is ited as a shrine; yet so evident an animal the case of Eurycea sosorum from Barton as this salamander had escaped notice un- Springs, in downtown Austin, Texas. De- til 1936." L. T. Murray (1939:5) spite the fact that dozens of herpetologists received the Ph.D. from the 1940s to the MANY distinct species of paedomorphic 1990s at The University of Texas at Austin, salamanders from the springs and caves of this species was not described until 1993 the Edwards Plateau in central Texas have (Chippindale et al., 1993). been overlooked by generations of herpe- For several years prior to the initial pe- tologists. The first member of this group titions to list Eurycea sosorum as a federal to be described was Eurycea (Typhlomol- Endangered Species in 1992, cleaning ge) rathbuni, which was collected from an practices at Barton Springs had reduced artesian well at the Federal Fish hatchery most of the observable population of sal- in San Marcos, Texas in the 1890s (Stejne- amanders to a small number of individuals ger, 1896). However, the first surface spe- around the main spring outlet (Parthenia cies of paedomorphic salamander de- Spring). Changes in cleaning practices scribed from central Texas, Eurycea neo- (elimination of the use of chlorine, and the 266 September 2001] HERPETOLOGICA 267 reduction in mechanical disturbance and Springs). Here we name the new species the use of high-pressure hoses) from from Barton Springs. 1992-1997 (when the species was formally listed as Endangered) resulted in some re- METHODS covery of the population. The biggest We sequenced copies of the mitochon- threat to the continued existence of this drial cytochrome b gene from individuals species now comes from development of of all the described species of central Tex- the recharge zone of the Barton Springs as Eurycea (except for Eurycea robusta, segment of the Edwards Aquifer, which which is known only from the holotype; has resulted in some new decline of the see Appendix I for a listing of specimens). population (especially from increased sil- We amplified a 1026-1141 bp fragment of tation of the aquifer and springs). None- the mitochondrial cytochrome b gene us- theless, efforts to protect Eurycea sosorum ing the forward primer MVZ15 (GAAC- allowed some recovery of the species in TAATGGCCCACACWWTAC GNAA; the mid-1990s from the extremely small Moritz et al., 1992) and the reverse primer population sizes that resulted from earlier HEMTHRREV (CTTTGRCTTACAAG- cleaning practices in the pool area. The GYCAATG) or EURCB9 (GATTGAG- City of Austin has protected one of the GAYRCTTGTCCAATTTC). We used outlets of Barton Springs (Sunken Gar- standard PCR conditions (Palumbi, 1996) dens Spring) as a salamander refuge since with annealing temperatures of 45-52 C 1998, and the city plans to restore another and extension times of 1-1.5 min, and outlet (Eliza Spring) to a more natural standard automated sequencing protocols state that is expected to benefit salaman- (Li-Cor and PE Biosystems). Phylogenetic der populations. Prior to its protection, analyses were performed using the Sunken Gardens Spring was heavily af- MVZ15-EURCB9 fragment (1026 bp). fected by humans, who often used the Phylogenetic analyses (parsimony and spring for bathing and even washing maximum-likelihood criteria) were con- clothes, and most of Eliza Spring was en- ducted using PAUP* (v4.b4, Swofford, cased in concrete in the early 1900s. 1998). An exact solution for the parsimony Since the description of Eurycea soso- analysis (with equal character weighting) rum, there have been occasional sightings was found using the branch-and-bound of juveniles of a morphologically distinct search algorithm. The maximum-likeli- paedomorphic salamander at Barton hood analysis was based on the GTR+F+ Springs that resembles E. (Typhlomolge) INV model of sequence evolution (Swof- rathbuni more than E. sosorum. However, ford et al., 1996). Rate heterogeneity was given the Endangered status of Eurycea modeled using four evolutionary rate clas- sosorum, collection of salamanders at Bar- ses, including an invariant class. For the ton Springs has been closely regulated and maximum likelihood analysis, we per- restricted. Combined with the fact that formed heuristic searches (TBR branch this second species is only very rarely seen swapping) on five stepwise addition trees at the surface, and typically only juveniles based on random taxon addition. We con- are seen in the spring outlets, obtaining ducted 500 bootstrap replicates for parsi- sufficient material for its description has mony and 100 bootstrap replicates for been difficult. However, we have now ver- maximum likelihood analyses (Felsenstein, ified that a parallel situation exists between 1985). Barton Springs and San Marcos Springs. Measurements were made with digital In each case, there are two species of sal- calipers to the nearest 0.1 mm. Measure- amanders: one surface species with func- ments used to compare species included tional image-forming eyes (E. sosorum at total length (TL: tip of snout to tip of tail), Barton Springs and E. nana at San Marcos standard length (SL: tip of snout to pos- Springs) and one blind subterranean spe- terior margin of cloaca), axilla-groin cies (an undescribed species at Barton length, trunk width (at maximum point be- Springs and E. rathbuni at San Marcos tween axilla and groin), width of the upper 268 HERPETOLOGICA [Vol. 57, No. 3 ,2 ~ ~ ~ ~ ~ ~ B B D ji~~~~ ~Scale 2 cm (Aand B); 1 cm (Cand D) FIG. 1 Comparison of the dorsal and lateral aspects of the heads and forelimbs of (A) Eurycea rathbuni (TNHC 51175, from Rattlesnake Cave, Hays Co., Texas); (B) E. robussta (TNHC 20255, holote); (C) E. sosorum (TNHC 51184, holotype); and (D) E. waterlooensis (TNHC 60201, holotype). Note that (A) and (B) are at 0.5x scale compared to (C) and (D).