Stegonotus aruensis ( Doria, 1874:352 ) Kaiser & Kaiser & O’Shea, 2018

Kaiser, Christine M., Kaiser, Hinrich & O’Shea, Mark, 2018, The taxonomic history of Indo-Papuan groundsnakes, genus Stegonotus Duméril et al., 1854 (Colubridae), with some taxonomic revisions and the designation of a neotype for S. parvus (Meyer, 1874), Zootaxa 4512 (1), pp. 1-73 : 32-34

Stegonotus aruensis ( Doria, 1874:352) n. comb.

Taxonomic status. Lycodon aruensis has heretofore been considered as a synonym of S. modestus . Having restricted that species to some of the central Moluccan islands, and combined with the lack of a neck band and a much higher value of SCR in aruensis , we hereby remove this species from the synonymy of S. modestus . This population therefore takes the name Stegonotus aruensis n. comb.

Synonyms. None.

Original name. Lycodon aruensis Doria, 1874:352 . Giacomo Doria (1840–1913; Fig. 17A ) was an influential Italian naturalist and founder of a natural history collection in Genoa, Italy. The species is named for the Aru Islands, and the description was presented in Italian.

Holotype. MSNG 30186 ( Fig. 18 ; Table 1), most likely an adult male (see below).

Type locality. “Wokan (Isole Aru)” [Wokam, Tanahbesar Island, Maluku Province, Indonesia]. There could be some confusion regarding the specifics of the type locality. A literal translation simply yields the place name Wokam and “Aru Islands.” It should be noted that Doria used the plural for island (isole) and not the singular (isola), referencing the reality that “Aru” is actually a complex of several islands, separated by narrow saltwater channels. Specifically, “Wokam” may refer to Tanahbesar, one of the four larger islands that make up the landmass of the Aru Islands, but also to a sparsely populated administrative area on the westernmost extreme of Tanahbesar. The voyage that resulted in the collection of this specimen originated on Ambon and the vessel arrived at the main port of the Aru Islands at Dobo ( Doria 1874). The administrative area called Wokam lies just across a saltwater channel from Dobo in the western region of Tanahbesar, and the short distance from Dobo makes it a very likely place for a landfall. Doria (1874) further recounted that the collector Beccari’s travels in the Aru Islands were restricted to the islands’ western coast. This is borne out by a map drawn by Beccari and reproduced in Gigliolo (1873:857), where Locality 1 is labeled as “Wokan.” We therefore restrict the type locality of S. aruensis to the Wokam administrative unit in western Tanahbesar (ca. 5.6636°S, 134.2509°E).

Collector. Doria (1874) reported on a collection of specimens made by Odoardo Beccari (1843–1920; Fig. 17B ), who traveled extensively in the Malay Archipelago and into Papuasia in the 1860s and 1870s. On this particular trip, Beccari departed Ambon for Dobo in the Aru Islands on 8 February 1872, where he arrived on 22 February 1872 ( Anonymous 2018a). On 6 July, Beccari departed Wokam for the Kei Islands ( Anonymous 2018a). Thus, the specimen must have been collected between 8 February and 6 July 1872. The photographs of Doria ( Fig. 17A ) and Beccari ( Fig. 17B ) are from Doria & Gippoliti (2006) and are used by permission of Giuliano Doria (in litt., 8 August 2018).

Key characteristics of the holotype. 560 (582) mm SVL + 240 (233) mm TL = 800 (815) mm TTL. V ♂ = 190 (190), SC ♂ = 100 (103), SCR ♂ = O (0.35), D = O-17-O (17-17-15), SL E = 3+4 (3+4), SL = 7 (7), IL = O (8), IL G = O (4). Based on the high value of SCR, we believe this specimen to be a male and treat it as such.

Key characteristics of the species. Other than the holotype, we were able to locate only one additional specimen of S. aruensis (SMF 18055). As a consequence, our assessment of the species-level characteristics is very limited. It appears that S. aruensis , just like S. modestus , is sexually dimorphic with respect to tail length. The putatively male holotype has a high SCR value of 0.35, whereas the second specimen, putatively a female, has an SCR of only 0.29. Beyond that, among the diversity of Stegonotus this species falls into the category of having SL E = 3+4, D = 17-17-15, the lower counts for SL and IL (7 and 8, respectively), as well as IL G = 4. Additional specimens would be needed to ascertain the variability of these characters, or to define the species more broadly.

Figures

FIGURE 17. Selected 19 th and 20 th Century authors and collectors of Stegonotus species. (A) Giacomo Doria (1840–1913), author of the species names aruensis and keyensis. (B) Odoardo Beccari (1843–1920), collector of the Stegonotus aruensis and S. keyensis type specimens. (C) William Macleay (1820–1891), author of the genus name Herbertophis and the species names darnleyensis and plumbeus. (D) John Archibald Boyd (1846–1926), collector of the Herbertophis plumbeus holotype. (E) George Albert Boulenger (1858–1937), author of the species names guentheri, heterurus, and reticulatus. Image licensed for use, © National Portrait Galley, London, United Kingdom. (F) The Reverend George Brown (1835–1917), collector of the Stegonotus heterurus syntypes from Duke of York Island. (G) Albert Stewart Meek (1871–1943), collector of the Stegonotus guentheri and S. reticulatus syntypes. (H) Wilhelm Adolfovich Lindholm (1874–1935), author of the species name diehli. (I) Nelly de Rooij (1883–1964), author of the species name florensis. (J) Franz Werner (1867–1939), author of the species names dorsalis and poechi. (K) Rudolf Pöch (1870–1921), collector of the Stegonotus dorsalis and S. poechi holotypes, and in whose honor the latter was named. (L) Lothar Forcart (1902–1990), author of the species name sutteri.

FIGURE 18. Holotype of Stegonotus aruensis (Doria, 1874) new combination, MSNG 30186, an adult male from Tanahbesar Island, Maluku Province, Indonesia. Shown are the entire specimen (TTL = 815 mm) in (A) dorsal and (B) ventral views, and its head in (C) dorsal, (D) right lateral, and (E) ventral views.