Stegonotus admiraltiensis Ruane et al., 2017:21

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 : 60-62

Stegonotus admiraltiensis Ruane et al., 2017:21

Taxonomic status. Valid.

Synonyms. None.

Original name. Stegonotus admiraltiensis Ruane et al., 2017:21 . The species name references the Admiralty Islands of Manus Province, Papua New Guinea, where the species is thought to be endemic. The description was presented in English.

Type specimens. Holotype: LSUMZ 93598 (Ruane et al. 2017: Fig. 8 ), an adult male ( Table 1) . Paratypes: LSUMZ 93597 , 93599–600 (all paratypes unsexed) .

Type localities. All type specimens were collected in Manus Province, Papua New Guinea. Holotype: Penchal Village, Rambutyo Island, elev. 58 m (ca. 2.3283°S, 147.77°E). Paratypes: LSUMZ 93597 , Peyon Village , Los Negros Island, elev. 10 m (ca. 2.0327°S, 147.43°E) ; LSUMZ 93599–600 , northeast of Penchal Village , Rambutyo Island, elev. 100 m (ca. 2.3405°S, 147.79°E) .

Collection. All type specimens were collected by Christopher C. Austin (Louisiana Museum of Natural History, Baton Rouge, Louisiana, USA) between 29 August and 3 September 2001.

Key characteristics of the type specimens. (1) Holotype, LSUMZ 93598 : 658 mm SVL + 185 mm TL = 843 mm TTL. V ♂ = 208, SC ♂ = 98 , SCR ♂ = 0.32, D = 17-19-15, SL E = 4+5, SL = 8 , IL = 10, IL G = 6. (2) Paratype, LSUMZ 93597 : 560 mm SVL + 174 mm TL = 734 mm TTL. V? = 214, SC? = 94, SCR? = 0.31, D = O-17-O, SL E = x, SL = 8, IL = 10, IL G = O. (3) Paratype, LSUMZ 93599 : 646 mm SVL + 190 mm TL = 836 mm TTL. V? = 206, SC? = 93, SCR? = 0.31, D = O-17-O, SL E = O, SL = 8, IL = 9, IL G = O. (4) Paratype, LSUMZ 93600 : 598 mm SVL + 110+ mm TL = 708+ mm TTL. V? = 202, SC? = O, SCR? = O, D = O-19-O, SL E = O, SL = 8, IL = 10, IL G = O.

Key characteristics of the species. According to their specimen list, Ruane et al. (2017: Appendix) included four specimens of S. admiraltiensis in their analysis. Of these, one male and two unsexed specimens were collected on Rambutyo, and one unsexed specimen on Los Negros. Given that most of the specimens were not sexed, it is not possible to draw conclusions regarding the distribution of characteristics by sex or about the presence of sexual dimorphism. The characteristics we list here are therefore somewhat limited in their overall description of the species. We consider S. admiraltiensis to be a species with a relatively high ventral scale count (V> 200) with a relatively high number of subcaudal scales (SC> 90; SCR> 0.30). The dorsal count of 17-19-15 is unique among the species of Stegonotus , and its occurrence in a species that also presents dorsal counts of O-17-O (most likely 17-17-15) is unusual. The SL E is most likely 4+5 for the species given that this character tends not to be rarely variable in Stegonotus species. The number of supralabials was eight for all specimens, and among infralabials three specimens had IL = 10, whereas one had SL = 9. Based on the ventral view of the holotype, the sixth infralabial scale barely touches the anterior genial, and we wonder whether this character can be consistently scored as IL G = 6 across all specimens. If so, then this is another unique characteristics of S. admiraltiensis among the species of Stegonotus .

Comment. Ruane et al. (2017) compared S. admiraltiensis to S. modestus and S. parvus at length, but without the benefit of having examined the holotype of the former or using the original description of the latter (characteristics of S. admiraltiensis in parentheses): S. modestus has a light neck band (absent), a subcaudal count <90 (> 90), SL E = 3+4 (4+5), and IL G = 4 (6). Stegonotus parvus has a ventral count <180 (> 200), SL E = 3+4 (4+5), and IL G = 4 (6). Furthermore, Ruane et al. (2017) referenced two additional Manus specimens but did not include them in their analysis. We have examined an additional 38 specimens from the Admiralty Islands, which include 15-15-15 (n = 3), 17-17-15 (n = 30), and 17-19-17 (n = 5) dorsal counts, with SL E = 3+4 (n = 16) or 4+5 (n = 20), with subcaudal counts that differ from S. admiraltiensis as defined above. Two specimens have aberrant counts of SL E, with 3+4 on one side of the head and 4+5 on the other. It therefore appears to us as if S. admiraltiensis is not the only species of Stegonotus present in the Admiralty Islands and further research will be needed to ascertain the taxonomy of groundsnakes there.

Specimen Type SCR SubC Species Synonym Sex SVL TL TTL V SC Dorsals SCE SL IL ILG Number Status (%) Condition BMNH heterurus LT M 393 89 482 179 80 31 single 17-17-15 3 +4 7 9 4 1946.1.14.95 MZB iridis HT M 713 238 951 201 88 30 paired 17-19-15 4 + 5 8 10 10 Ophi.3306 MSNG keyensis HT M 651 164 815 200 73 27 paired 17-17-15 4 [phone] RMNH lividus LT F 444 123 567 197 67 25 paired 17-17-15 3 +4 7 9 4 RENA.325A AMS melanolabiatus HT M 615 192 807 197 92 32 paired 17-17-15 3 +4 7 8 8 R115343 RMNH modestus HT M 656 158 814 200 83 29 paired 17-17-15 3 +4 7 8 4 RENA.324 BMNH modestus greineri HT M 552 162 714 206 86 29 paired 17-17-15 3 +4 7 8 4 1946.1.13.74 BMNH modestus holochrous HT M 537 182 719 195 83 30 paired 17-17-15 3 +4 7 8 4 1946.1.11.40 RMNH modestus rosenbergii HT M 582 178 760 203 80 28 paired 17-17-15 3 +4 7 9 4 RENA.4066 MNHN muelleri HT F 1006 302 1308 217 97 31 paired 17-17-15 4 +5 8 9 4 848 ZMB 9R muelleri samarensis HT M O O O 236 98 29 paired 17-17-15 4 + 5 10 4 4294 8L MTKD parvus ST c O O O O 177 100 36 paired O-17-O 3+ 4 7 O O 876A MTKD parvus ST c O O O O O O O O O 3+4 O O O 876B RMNH parvus NT F 217 75 292 173 87 33 paired 17-17-15 3 +4 7 8 4 RENA.46844 NMW 164 poechi HT F 860 O 200 55+ O paired 19-19-17 4 +5+ 6 9 10 4 23406 + BMNH reticulatus LT F 880 238 1118 201 78 28 paired 17-17-15 4 +5 8 9 4 1946.1.14.87 NMBA sutteri HT M 567 144 711 230 83 27 single 21-21-19 3 +4+ 5 9 10 5 14872 a MTKD 573 is definitely a type specimen of Lycodon magnus Meyer, 1874 , which was destroyed in 1945. b ZMB 8794 may be a syntype of L. magnus , but its status is inconclusive at this time. c MTKD 876A and 876B were destroyed in 1945. Values given are from the original description by Meyer (1874).

Figures

FIGURE 8. Jars and labels related to Stegonotus muelleri and Lycodon muelleri at the MNHN. (A) A tall glass jar (numbered C684) holding two snake specimens (MNHN 848, 1320). (B) A second tall glass jar (numbered C684/1), also holding two snake specimens (MNHN 5764 and 5764A). (C) Close-up of the label affixed to the jar shown in (A), identifying the specimens as Stegonotus mulleri [sic] and providing the correct citation for S. muelleri with an incorrect locality of Java. (D) A label from inside the jar shown in (B), listing the specimens correctly by their number but in the wrong genus. Both specimens are representatives of Lycodon muelleri. (E) Close-up of the external label from the jar shown in (B), listing the correct genus and locality.