Secondary Contact and Hybridization in the Texas Cave Salamanders Eurycea neotenes and E. tridentifera


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Publication Date

May 1984


Unusual levels of individual and populational variation and character discordance in three samples of troglobitic Eurycea from the Edwards Plateau of central Texas indicate hybridization between Eurycea neotenes and E. tridentifera. The two species are microsympatric but exhibit habitat segregation in one case, are contiguously allopatric in the same cave system in another, and appear to interact as vagrants in the third. E. neotenes and E. tridentifera seem to be evolving reproductive isolation at Honey Creek Cave, where hybrids are uncommon. Eurycea troglodytes and E. latitans are shown to be invalid taxa, the former consisting of a hybrid swarm of temporally variable composition and the latter being a troglobitic population of E. neotenes which episodically incorporates individuals of E. tridentifera. Variation in the interactions of the parental species on contact is ascribed to differences in the opportunity for ecological segregation permitted, the relative frequencies of incursion of the parental taxa through time, and differences in the escape behavior of intermediate and advanced troglobites in cave systems which periodically receive influxes of flood-borne epigean fish.


Caves, Sinkholes, Hybrid Species, Specimens, Salamanders, Taxa, Creeks, Farming Systems, Vertebrae, Discriminants

Document Type



Copeia, Vol. 1984, no. 2 (1984-05-01).