Thursday, November 26, 2020

[Herpetology • 2020] Atlantihyla melissa • A Critically Endangered New Species of Polymorphic Stream Frog (Anura: Hylidae: Atlantihyla) from the Montane Rainforest of Refugio de Vida Silvestre Texiguat, Honduras


Atlantihyla melissa
Townsend, Herrera-B., Hofmann, Luque-Montes, Ross, Dudek, Krygeris, Duchamp & Wilson, 2020


The Chortís Highlands of Mesoamerica exhibit a high degree of in situ evolutionary diversification, exemplified by numerous endemic radiations of stream-dwelling treefrogs (Anura: Hylidae: Atlantihyla, Duellmanohyla, and Ptychohyla), which have been a source of ongoing taxonomic uncertainty. Recent evidence suggests that one species, Atlantihyla spinipollex, may conceal an unrecognized sister species found in Refugio de Vida Silvestre Texiguat. We applied an iterative integrative taxonomic framework to assess this population within the context of Chortís Highlands populations of Atlantihyla spinipollex sensu stricto, Duellmanohyla salvadorensis, D. salvavida, D. soralia, and Ptychohyla hypomykter, using both a single locus (mtDNA: 16S) and multilocus (mtDNA: 12S, 16S; nDNA: POMC, RAG-1, Rhodopsin) datasets accompanied by distance- and tree-based species delimitation methods to inform our taxonomy. Samples of A. spinipollex sensu lato formed two deeply divergent monophyletic lineages, suggesting that populations from the central and eastern Cordillera Nombre de Dios are conspecific, while the population from Refugio de Vida Silvestre Texiguat represents a previously undescribed species. We analyzed morphological and bioacoustic variation within and between the two lineages of A. spinipollex sensu lato and found support for recognition of two distinct taxa. We restricted the name A. spinipollex to populations in the central and eastern Cordillera Nombre de Dios, and formally describe the Texiguat population as a new species. We recommend the new species be considered Critically Endangered due to ongoing habitat loss within what remains of its highly restricted natural distribution. This new species joins 26 other endemic species of amphibians and reptiles at Texiguat.

Key words: Atlantihyla melissa sp. nov., Atlantihyla spinipollex, Chortís Block Highlands, Cordillera Nombre de Dios, Ptychohyla hypomykter, Refugio de Vida Silvestre Texiguat.

The known distribution of focal taxa in the Chortís Block. Filled shapes indicate localities with molecular (at least 16S) sequence data generated or utilized herein; additional historical records (with no sequence data) are indicated by white shapes. Numbers and grayshaded areas refer to relevant localities within the Cordillera Nombre de Dios as follows: 1 = Refugio de Vida Silvestre Texiguat; 2 = Parque Nacional Pico Bonito; 3 = Parque Nacional Nombre de Dios; 4 = Cerro Corre Viento; 5 = Parque Nacional Capiro y Calentura. TL = type locality.

Fig. 3. Multilocus Bayesian phylogram based on combined mtDNA (12S, 16S) + nDNA (POMC, RAG-1, RHO) dataset; maximum likelihood bootstrap support values (0– 100) and Bayesian posterior probabilities (0– 1.0) shown above corresponding branches.
Photos from top to bottom: D. salvavida from Río Jilamito, Dept. Atlántida, Honduras © JHT; D. soralia from Merendón, Dept. Cortés, Honduras © JHT; holotype of Atlantihyla melissa © JHT; A. spinipollex from Cerro Corre Viento, Dept. Colón, Honduras © Jason M. Butler; Ptychohyla hypomykter from Rio Negro de Comayagua, Dept. Comayagua, Honduras (© JHT).

Adult male holotype of Atlantihyla melissa (USNM 578679; SVL = 34.4 mm), shown in life (left) and in dorsal (top right) and ventral (bottom right) aspects after eight years in preservation (photos: Josiah H. Townsend).

Paratypes of Atlantihyla melissa in life: 
(a) adult female (USNM 578676), (b) adult female (USNM 578672),
(c) adult female (USNM 578665), (d) adult female (USNM 578686),
(e) adult male (USNM 578674), (f) adult female (USNM 578668)
(photographs: Josiah H. Townsend).

Atlantihyla melissa sp. nov.

Etymology. We name this species in honor of our friend and collaborator, Isis Melissa Medina-Flores, a feld biologist originally from Mangulile in the Department of Olancho, Honduras. Melissa participated in the discovery and description of this new species, two other Texiguat endemics: the palm-pitviper Bothriechis guifarroi Townsend, Medina-Flores, Wilson, Jadin & Austin, 2013, and the centipede snake Tantilla olympia Townsend, Wilson, Medina-Flores & Herrera-B., 2013; and two salamanders endemic to the Department of Olancho: Nototriton mime Townsend, Medina-Flores, Reyes-Calderón & Austin, 2013, and N. picucha Townsend, Medina-Flores, Murillo, and Austin, 2011. Melissa disappeared without a trace on 5 November 2016, after becoming separated from her companions while descending from the summit of the highest peak in Honduras, Cerro de Las Minas in Parque Nacional Celaque. Despite over a month of continuous searching by military and volunteer rescue teams supported by search dogs and aircraft, no evidence of Melissa’s fate has been found.



Fig. 9. a) Type locality of Atlantihyla melissa, the Río Jilamito, Departamento de Atlántida, Honduras, 1,030 m a.s.l.; holotype was collected on a palm frond in the vegetation on the left side of the image. b) Adult male Atlantihyla melissa (not collected) photographed in situ on vegetation directly overhanging a small tributary of the Río Jilamito, 1,060 m a.s.l.
(photographs: Josiah H. Townsend).
 
     

Large pool in the Río Jilamito, just above the type locality; tadpoles of Atlantihyla melissa. Duellmanohyla salvavida, and Plectrohyla chrysopleura were found here in April 2017, June 2010, and July 2010.


Josiah H. Townsend, Luis A. Herrera-B., Erich P. Hofmann, Ileana R. LuqueMontes, Ayla N. Ross, Daniel Dudek, Jr., Catherine Krygeris, Joseph E. Duchamp and Larry David Wilson. 2020. A Critically Endangered New Species of Polymorphic Stream Frog (Anura: Hylidae: Atlantihyla) from the Montane Rainforest of Refugio de Vida Silvestre Texiguat, Honduras.  Vertebrate Zoology. 70(4): 731-756. DOI: 10.26049/VZ70-4-2020-12

Description (es): Las tierras altas Chortís en Centro América presentan un alto grado de diversificación evolutiva in situ, demostrado por un numero de radiaciones endémicas de ranas arborícolas asociadas con ecosistemas lóticos (Anura: Hylidae: Atlantihyla, Duellmanohyla y Ptychohyla), y previamente han sido fuente de incertidumbre. Evidencia reciente sugiere que una especie, Atlantihyla spinipollex, podría ocultar un especie hermana no reconocida, en el Refugio de Vida Silvestre Texiguat. Aplicamos un modelo iterativo taxonómico integrativo para evaluar esta población dentro del contexto de las poblaciones de las Tierras Altas Chortís de Atlantihyla spinipollex sensu stricto, Duellmanohyla salvadorensis, D. salvavida, D. soralia, y Ptychohyla hypomykter, utilizando ambos, conjuntos de datos con locus génicos individuales (mtDNA: 16S) y conjuntos de datos con múltiple loci (mtDNA: 12S, 16S; nDNA: POMC, RAG-1, Rhodopsin), acompañados por métodos de delimitación de especies basados en distancia y arboles filogenéticos. Las muestras de A. spinipollex sensu lato formaron dos linajes monofiléticos profundamente divergentes, sugiriendo que las poblaciones del centro y Este de la Cordillera Nombre de Dios son conspecíficas, mientras que la población del Refugio de Vida Silvestre Texiguat representa un linaje a nivel de especie no descrito previamente. Analizamos la variación morfológica y bioacústica dentro y entre los dos linajes de A. spinipollexsensu lato y encontramos un fuerte soporte estadístico para el reconocimiento de dos taxones distintos. Restringimos el nombre A. spinipollex a las poblaciónes del centro y el Este de la Cordillera Nombre de Dios, y formalmente describimos la población del Refugio de Vida Silvestre Texiguat como una especie nueva. Recomendamos que la nueva especies sea considerada En Peligro Critico debido a la amenaza inmediata y continua de pérdida de hábitat dentro de su distribución natural altamente restringida. Esta nueva especie se une a otras 26 especies endémicas de anfibios y reptiles en Texiguat.