Monday, November 26, 2012

[Herpetology • 2001] Batrachoseps luciae, B. minor, B. incognitus & B. gavilanensis | Molecular phylogenetic analysis of slender salamanders, genus Batrachoseps (Amphibia: Plethodontidae), from central coastal California with descriptions of four new species


Figure 2. Examples of nonadaptive radiations (i.e. collections of related ecologically similar species that are allopatric or parapatric replacements of one another, also known as allospecies). (a) Batrachoseps salamanders (Plethodontidae) of western North America (from top: Batrachoseps gavilanensis, B. luciae, B. incognitus, B. minor). Species are genetically different, and some of the illustrated taxa might be separated by >10 million years. Species recognition is possibly based on pheromones.

Plethodontid salamanders  of  the genus  Batrachoseps comprise  a clade  of  morphologically  similar, elongate  species  whose  great genetic  diversity is being  revealed  through molecular studies. We used  allozymes  and mtDNA  sequences  to study variation in 62 populations  from central coastal  California,  treated  most  recently  as  members  of  the  B.  pacificus  complex.  Analyses  of mtDNA  data identify  four lineages  that  are well  differentiated  from  each  other  and do  not form a monophyletic  group.  Instead,  the  central  coastal lineages  are multiply  paraphyletic  with  respect  to the  southern  California  members  of  the  pacificus  group.  Marked  allozymic  differences  show  that these  four lineages  are  strongly  differentiated,  although  some  limited gene  exchange  may  have occurred  in the  past.  Each lineage is  also morphologically  distinctive,  but  the  differences  between them  are subtle.  Because  these lineages  appear to  be  evolving  independently,  we  describe  them  as new  species:  B. luciae,  B. incognitus  and B. minor, distributed parapatrically from north to south in the  Santa Lucia Mountains  of coastal Monterey  and San Luis Obispo  Counties,  and B. gavilanensis, occurring  mainly inland  from  the  range  of B.  luciae,  centered  on  the  Gabilan  Mountains,  but  also extending  to  the  Pacific  coast  at  the  north  end  of  the  range  of  the  complex,  along  the  northern border  of  Monterey  Bay. Although  no sympatry is known  among  any of  the  new  species,  B. luciae and B.  gavilanensis  are narrowly parapatric. Furthermore,  all but  B.  luciae  occur  in sympatry with other  members  of the  genus in at least  a part of their  geographic  ranges. The  new species  may have arisen  vicariantly  with  respect  both  to  each  other  and  to  related  forms  in  southern  California,  in part as a result  of the  dramatic tectonic  movements  that have  characterized  the  last 15 million years of  geological  history in western  North  America.
Key words:  Batrachoseps;  Plethodontidae;  Systematics;  Allozymes;  Cytochrome  b;  California biogeography;  New  species


Batrachoseps minor Jockusch, Yanev & Wake, 2001 Lesser slender salamander
Batrachoseps gavilanensis Jockusch, Yanev & Wake, 2001 Gabilan Mountains slender salamander
Batrachoseps incognitus Jockusch, Yanev & Wake, 2001 San Simeon slender salamander
Batrachoseps luciae Jockusch, Yanev & Wake, 2001 San Lucia Mountains slender salamander


Jockusch, E.L., Yanev, K.P. and Wake, D.B. 2001. Molecular phylogenetic analysis of slender salamanders, genus Batrachoseps (Amphibia: Plethodontidae), from central coastal California with descriptions of four new species. Herpetological Monographs. 54-99.

Rebecca J. Rundell and Trevor D. Price. 2009. Adaptive radiation, nonadaptive radiation, ecological speciation and nonecological speciation 

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