Sunday, July 9, 2023

[Herpetology • 2023] Cyrtodactylus gonjongCommon but Ignored: A New Species of Cyrtodactylus (Squamata: Gekkonidae) from lowland Sumatra Barat, Indonesia

Cyrtodactylus gonjong  
 Nugraha, Ahda, Tjong, Kurniawan, Riyanto, Fauzi & Lin, 2023

The lowland region of Sumatra Barat has received little attention in previous biodiversity studies. Past studies have mainly focused on highland habitat and conservation areas. However, many populations of Cyrtodactylus in the lowland habitats of Sumatra Barat were not correctly identified. A phylogenetic tree based on the NADH dehydrogenase subunit 2 (ND2) gene showed that the lowland Sumatran population is the sister group of the Malaysian lowland species, C. semenanjungensis, together nesting within the agamensis group. The genetic divergence within the Sumatra Barat population is 0–4.2% and 18.3–20% to C. semenanjungensis. Further examination of morphological characters revealed that they differed from the sister clade and other Sumatran Cyrtodactylus members by a unique combination of characters such as absence of tubercle on brachium, presence of tubercle on ventrolateral fold, 32–41 paravertebral tubercles, 38–46 ventral scales, enlarged femoral scales, presence of precloacofemoral pores and 22–23 subdigital lamellae under fourth toe. Based on the morphological and molecular evidence, the lowland Sumatran population is herein described as a new species, increasing the number of species in Sumatra to seven. More comprehensive and intensive sampling efforts would most likely yield further discoveries in the group of Sumatran Cyrtodactylus in the near future.

Key words: Bent-toed gecko, diversity, morphology, ND2 gene, phylogeny, Sumatra, taxonomy

Cyrtodactylus gonjong sp. nov.
The holotype (UNP193, adult female, SVL 65.1 mm)
A rostral view B gular view C precloacal scales D dorsal E ventrolateral F ventral view. A–D, F were taken after 1 month preservation E is a live individual.

Cyrtodactylus gonjong sp. nov.
Variation of labial color, stripe between eye and nostril and body bands in lateral view
A UNP167 B UNP165 C UNP196.

The representative paratypes of Cyrtodactylus gonjong sp. nov.

 Cyrtodactylus gonjong sp. nov. 
Recommended English common name: Gonjong Bent-toed Gecko 
Recommended Indonesia common name: Cicak Jari Lengkung Gonjong
Diagnosis: Cyrtodactylus gonjong sp. nov. is assigned to the C. agamensis group on the basis of its recovered phylogenetic position (Fig. 2). This species can be differentiated from all congeners within the C. agamensis group by having the following combination of characters: (1) a medium-sized Cyrtodactylus, 54.1–77.7 mm in adult males, 65.1–76.7 mm in adult females; (2) 10–13 enlarged supralabial and 9–13 enlarged infralabial scales; (3) 3–5 internasal scales; (4) antebrachium tuberculated, brachium not tuberculated; (5) 32–41 paravertebral tubercles; (6) 16–19 longitudinal rows of dorsum tubercles; (7) 38–46 ventral scales; (8) 22–24 subdigital lamellae on the fourth toe; (9) 34–46 enlarged femoroprecloacal scales; (10) femoroprecloacal pores present in both sexes, 13–36 in adult males, 0–18 in adult females; (11) precloacal groove or depression present; (12) enlarged median subcaudals absent; (13) distinct ventrolateral folds; (14) subconical prominent tubercles on body that extend to the base of the tail; (15) 2–3 postcloacal tubercles; (16) two postocular stripes fused to a U-shaped mark on occiput; (17) postocular stripes extended beyond the arms; (18) 7–8 dark bands on trunk; (19) tail ringed by beige and black; and (20) labials yellow or dark with yellow/beige spots.

Etymology: The specific ephitet gonjong is taken from the name of the roof style of the typical house in Sumatra Barat created by its ethnic people, called Minang. The house itself, called Rumah Gadang, and the unique style of the roof shape was inspired by the horn of buffalo, the most respected animal in Minang ethnology. The gonjong has become a symbol used by the Minang people to show their ethnic identity outside Sumatra Barat and now is used not only for the house but also for government buildings, restaurant buildings, hotels or other public venues. This name is given as an honour to the Minang people because they were helpful during our survey.

Fitra Arya Dwi Nugraha, Yuni Ahda, Djong Hon Tjong, Nia Kurniawan, Awal Riyanto, Muhammad Alif Fauzi and Si-Min Lin. 2023. Common but Ignored: A New Species of Cyrtodactylus (Chordata, Reptilia, Squamata, Gekkonidae) from lowland Sumatra Barat, Indonesia. ZooKeys. 1169: 47-64.  DOI: 10.3897/zookeys.1169.98681