Editorial Type:
Article Category: Research Article
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Online Publication Date: 01 May 2005

A Solution to the Large Black Salamander Problem (Genus Bolitoglossa) in Costa Rica and Panamá

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Page Range: 227 – 245
DOI: 10.1643/CH-04-083R1
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Abstract

Several populations of large (adult standard length, 43–134 mm) black salamanders of the widespread neotropical genus Bolitoglossa (Plethodontidae) are known from the cordilleras of western Panamá and Costa Rica. These populations constitute at least seven species, including two recently described (B. anthracina, B. copia), one described long ago that remains poorly known (B. nigrescens), and three described herein as new. The long-recognized, wide-ranging B. robusta, which is distinguished by a pale, pigmented ring around the tail base and a unique combination of maxillary and vomerine tooth counts, may occur sympatrically with four of the other taxa. Differences in head and body form, adult size, cranial osteology, and maxillary and vomerine tooth counts separate all recognized taxa from one another. These results confirm and indeed increase the exceedingly high diversity of salamander species known from the Cordillera Talamanca-Barú of Costa Rica and Panamá, diversity that now rivals that found anywhere else in the tropics.

Resumen

En las cordilleras de oeste de Panamá y de Costa Rica, se conocen varias poblaciones de salamandras de color negro y de tamaño grande (longitud estandar del adulto, 43–134 mm). Estas salamandras son parte de Bolitoglossa (Plethodontidae), un género de amplia distribución neotropical. Estas poblaciones se incluyen en al menos siete especies, una descrita recientemente (B. anthracina, B. copia), una descrita desde hace tiempo y que permanece poco conocida (B. nigrescens) y otras tres nuevas que se describen aquí. La especie B. robusta conocida desde hace tiempo y de amplia distribución se distingue por la presencia de un anillo de color claro alrededor de la base de la cola y una combinación exclusiva de número de dientes maxilares y del vómer. Esta especie puede encontrarse en simpatría con cuatro de las otras especies. Todos los taxa reconocidos se diferencian entre sí por caracteres osteología del cráneo, asi como por la forma de la cabeza y del cuerpo, tamaño de adulto, y número de dientes maxilares y vomerinos. Estos resultados confirman y además incrementan la extremadamente alta diversidad de especies de salamandras conocidas en la Cordillera Talamanca-Barú de Costa Rica y Panamá, una diversidad que no es equiparable con la de ningún otro lugar de los trópicos.

Copyright: The American Society of Ichthyologists and Herpetologists
 Fig. 1. 
 Fig. 1. 

Type localities of the seven species of large black Bolitoglossa found in Costa Rica and Panamá. Bolitoglossa copia and B. obscura are known only from their respective type localities

 Fig. 2. 
 Fig. 2. 

Above: holotype of Bolitoglossa magnifica (MVZ 128619); scale bar, 1 cm. Below: live B. magnifica from the type locality (specimen number unavailable)

 Fig. 3. 
 Fig. 3. 

Maxillary tooth counts for large black Bolitoglossa. Total number of teeth is plotted against standard length (SL) for individual specimens of six species (legend; arrowheads point to holotypes). Ellipse encloses all values for B. robusta, which are not plotted individually. Linear regression lines are depicted for B. magnifica (solid) and B. anthracina (dashed)

 Fig. 4. 
 Fig. 4. 

Vomerine tooth counts for large black Bolitoglossa. Total number of teeth is plotted against standard length (SL) for individual specimens of six species (legend; arrowheads point to holotypes). Ellipse encloses all values for B. robusta, which are not plotted individually. Linear regression lines are depicted for B. magnifica (solid) and B. sombra (dashed)

 Fig. 5. 
 Fig. 5. 

Adult skulls of Bolitoglossa magnifica and B. robusta depicted in dorsal (left) and ventral views. Illustrations are drawn from cleared and stained whole mounts (B. magnifica, MVZ 128622; B. robusta, MVZ 183660); cartilage is stippled, bone is unshaded. The right posterior vomerine teeth (pvt) were removed earlier from the specimen of B. robusta. Scale bars, 2 mm

 Fig. 6. 
 Fig. 6. 

Holotype of Bolitoglossa obscura (UCR 2445), an adult female from Parque Nacional Tapantí, Prov. Cartago, Costa Rica. Dorsal (above) and ventral views; scale bar, 1 cm. Inset: close-up of head in ventral view; arrowhead points to the location of glandular openings in the roof of the mouth

 Fig. 7. 
 Fig. 7. 

Above: holotype of Bolitoglossa sombra (MVZ 225872), an adult male from Las Tablas, Prov. Puntarenas, Costa Rica. Below: holotype in life. Scale bars, 1 cm

 Fig. 8. 
 Fig. 8. 

Adult female Bolitoglossa nigrescens (UCR 1063) from 4 km S of Villa Mills, Prov. San José, Costa Rica, which is near the species' type locality. Scale bar, 1 cm

 Fig. 9. 
 Fig. 9. 

Adult Bolitoglossa robusta from Salto El Angel, Prov. Alajuela, Costa Rica, 4 February 1984 (specimen number unavailable). Scale bar, 1 cm

Contributor Notes

(JH) Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, Massachusetts 02138; (DBW) Department of Integrative Biology and Museum of Vertebrate Zoology, 3060 Valley Life Sciences Building #3140, University of California, Berkeley, California 94720-3140; and (JMS) Department of Biology, San Diego State University, San Diego, California 92182-4614. (JH) hanken@oeb.harvard.edu Send reprint requests to JH.

Accepted: 29 Nov 2004
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