Thursday, March 1, 2018

[Herpetology • 2018] Homonota marthae • A New Species of Homonota (Squamata, Phyllodactylidae) from the central region of northern Paraguay

Homonota marthae
Cacciali, Morando, Avila & Koehler, 2018

   DOI: 10.3897/zse.94.21754 

Homonota is a gecko distributed in central and southern South America with 12 species allocated in three groups. In this work, we performed molecular and morphological analyses of samples of Homonota from the central region of northern Paraguay, comparing the data with those of related species of the group: H. horrida and H. septentrionalis. We found strong molecular evidence (based on 16S, Cyt-b, and PRLR gene sequences) to distinguish this lineage as a new species. Morphological statistical analysis showed that females of the three species are different in metric characters (SVL and TL as the most contributing variables), whereas males are less differentiated. No robust differences were found in meristic characters. The most remarkable trait for the diagnosis of the new species is the presence of well-developed keeled tubercles on the sides of the neck, and lack of a white band (crescent-shaped) in the occipital area, which is present in H. horrida and H. septentrionalis. Nevertheless, in our sample, we found three specimens (one juvenile and two young adults) that exhibit the white occipital band. Thus, this character seems only reliable in adults of the new species. The new species is parapatric to H. septentrionalis, both inhabiting the Dry Chaco of Paraguay.

Key Words: Dry Chaco, Gekkota, phylogeny, South America, taxonomy

Figure 4. Dorsal (A) and ventral (B) views of the holotype of Homonota marthae

Figure 6. Plate showing the difference in scalation among individuals of similar sizes and same gender, of Homonota marthae (A, C, E) and H. septentrionalis (B, D, F). Note the more developed keeled tubercles on the sides of the neck in the former species. 

Homonota marthae sp. n.

Diagnosis: A species of Homonota assigned to the horrida group given its relationship (based on molecular evidence) with H. horrida, and by the color pattern composed of a vertebral and five to seven transversal clear lines appearing as a banded Homonota smilar to H. horrida and H. septentrionalis. Homonota marthae has a robust body, and prominently keeled tubercles disposed in four to eight longitudinal rows on the dorsum.

Etymology: This species is named in honor of our indefatigable colleague Martha Motte, who is not only dedicated to safekeeping the herpetological collection of the “Museo Nacional de Historia Natural del Paraguay”, but also does a great job in providing selfless support to scientists that are striving to improve the knowledge of the Paraguayan herpetofauna.

Habitat and distribution: Homonota marthae is known from the central area of the Paraguayan Dry Chaco in the Department of Boquerón (Fig. 5). The environment is a xeric forest with abundance of thorny vegetation and almost absence of a herbaceous stratum. Nevertheless, a more detailed analysis of museum collections is advisable for a better knowledge of the distribution of this species.

This species is a dry forest inhabitant, but it is also frequently found in human dwellings. Talbot (1978) recorded the use of logs of Drunken tree (Chorisia speciosa: Malvaceae) as shelter by Homonota in the Dry Chaco, since the wood of this tree keeps high water levels. Additionally, Cacciali et al. (2007a) demonstrated the use of subterranean caves (usually armadillo burrows) by Homonota in several areas of the Paraguayan Chaco.

 Pier Cacciali, Mariana Morando, Luciano Javier Avila and Gunther Koehler. 2018. Description of A New Species of Homonota (Reptilia, Squamata, Phyllodactylidae) from the central region of northern Paraguay.  Zoosystematics and Evolution. 94(1): 147-161.  DOI: 10.3897/zse.94.21754

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