Open AccessEvolutionary insights into the North American Necturus beyeri complex (Amphibia: Caudata) based on molecular genetic and morphological analyses
Author(s) -
Chabarria Ryan E.,
Murray Christopher M.,
Moler Paul E.,
Bart Henry L.,
Crother Brian I.,
Guyer Craig
Publication year - 2018
Publication title -
journal of zoological systematics and evolutionary research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.769
H-Index - 50
eISSN - 1439-0469
pISSN - 0947-5745
DOI - 10.1111/jzs.12203
Subject(s) - necturus , biology , paraphyly , phylogenetic tree , evolutionary biology , lineage (genetic) , caudata , zoology , most recent common ancestor , range (aeronautics) , clade , genetics , gene , membrane , materials science , composite material
Necturus beyeri (Caudata: Proteidae), as conceived by some, contains paedomorphic salamanders distributed from the Ochlockonee drainage of Florida to the Angelina drainage of Texas. Because these salamanders differ in color pattern and karyotype across their geographic range, we performed a phylogeographic analysis that included representatives from all major drainages as well as of all congeners. The mitochondrially encoded ND 2 gene was used to infer phylogenetic relationships using Bayesian inference. Morphometrics of head shape were analyzed and included as an independent data set. Our work suggests that Necturus comprises 11 lineages. A basal split within the genus separates an ancestor of two Atlantic Coastal Plain species ( Necturus lewisi and Necturus punctatus ) from the ancestor of nine distinct Gulf Coastal Plain lineages. One lineage is consistent with Necturus alabamensis , a species currently recognized in the Black Warrior drainage of Alabama. Two lineages comprise Necturus maculosus , as historically recognized, and six lineages comprise N. beyeri , as recognized by some, each of which occupies a unique drainage. Both of these species are demonstrated to be paraphyletic. Head morphometrics show the same patterns as the mt DNA . Overall, lineages within Necturus exhibit an east‐to‐west progression of appearance on the phylogenetic trees. This pattern corroborates biogeographic hypotheses based on previous karyological work. Within N. beyeri , this progression separates a pattern class of two eastern lineages lacking bold spotting and possessing relatively small mean body lengths from a pattern class of four western lineages possessing bold spotting and larger mean body sizes. Thus, the two eastern lineages of N. beyeri are similar in color pattern and body size to N. punctatus either through retention of the ancestral color pattern and size for the genus or through convergent selection in eastern streams of the Gulf Coastal Plain.