Boiga ochracea (Theobald, 1868)

Köhler, Gunther, Charunrochana, Panupong Thammachoti, Mogk, Linda, Than, Ni Lar, Kurniawan, Nia, Kadafi, Ahmad Muammar, Das, Abhijit, Tillack, Frank & O’Shea, Mark, 2023, A taxonomic revision of Boiga multomaculata (Boie, 1827) and B. ochracea (Theobald, 1868), with the description of a new subspecies (Squamata, Serpentes, Colubridae), Zootaxa 5270 (2), pp. 151-193 : 154-159

Boiga ochracea

In 1868 the description of Dipsas ochraceus was published by the German zoologist Albert Karl Ludwig Gotthilf Günther (1830–1914), then an assistant at the British Museum (Natural History) tasked with identifying 2,000 snake specimens in the collection. In his brief description of this species Günther (1868: 425), wrote: “We have received this new snake from Mr. Theobald, who named it “, thereby attributing the authorship to William Theobald (1829– 1908), a naturalist attached to the British Geological Survey of India. To complicate matters, Theobald (1868:53) also published a description of Dipsas ochracea , in Latin and English, in the same year.

The Reptile Database ( Uetz et al. 2022) suggested that Theobald’s paper was published prior to Günther’s paper, pointing out that Günther referred to Theobald in his paper, but without providing a published source. The editors may have assumed that Günther had access to Theobald’s already published paper, thereby attributing authorship to Theobald, 1868. Wallach et al. (2014) were of the contrary opinion and proposed that the first description of D. ochraceus appeared in the Günther paper, and the authorship should therefore read “Theobald in Günther, 1868 ”.

This question over the priority of authorship can only be resolved by determining which of these two papers was published first. Günther published his description in the Annals and Magazine of Natural History, series 4, volume 1, number 6, which was published on 1st June 1868 ( Evenhuis 2003; F. Tillack unpubl. obs.). Theobald published his account in the Journal of the Linnean Society of London (Zoology), volume 10, number 41. The year of publication is often given as 1868 ( Smith 1943; Wallach et al. 2014; Uetz et al. 2022) but the situation is somewhat unclear. Following its title, Theobald’s paper reads “By W. Theobald. Jun., Geological Survey of India. Communicated by G. Busk, Esq., Sec. L.S. [Read November 7, 1867.]”. The paper was therefore presented orally at a meeting of the Linnean Society of London in late 1867, but that does not constitute “published” according to the Code. According to the title page of the journal, volume 10 was not published until 1870 ( Theobald 1868b) which would seem to give priority to Günther’s 1868 paper, but this was not the actual date of publication of Theobald’s paper. According to the archives of the Linnean Society of London “pages 4–67 of Volume 10 of the Journal of the Linnean Society of London (Zoology) were issued on 30 May 1868. The reason the front page is dated 1870 (May 20th) is because that is when the title and contents page were finished, ready for the rest of the journal to be bound” (Vida Milovanovic, Linnean Society of London, pers. comm.; F. Tillack unpubl. obs.). Therefore, Theobald’s description takes precedence over Günther’s paper, by two days, and the correct citation should be Theobald (1868).

Amongst the distinguishing characteristics of D. ochraceus, Günther documented 19 dorsal scale rows, 239–242 ventral scales, and 100 subcaudal scales. His description was based on the two specimens obtained from Theobald, the largest of which he measured at 44 inches (1.12 m), and both of which, he reports, were collected at Pegu (now Bago, 17°19′ N, 96°28 E), central Myanmar. Theobald’s description differs in a number of respects from that of Günther. He states that he personally collected the first specimen at Rangoon (now Yangon, 16°48′ N, 96°09 E), and that his second specimen was collected by Colonel David Browne, at Maulmain (=Moulmein, now Mawlamyine, 16°29′ N, 97°38′ E) in the Tenasserim Region (now Tanintharyi Region, southern Myanmar). He also measured the first specimen at fully nine inches (229 mm) shorter than the measurement provided by Günther, and finally, Theobald reports that both specimens exhibited dorsal scale counts of 19 on the neck, 17 on the body, and 15 near the tail, in contrast to the dorsal count of 19 provided by Günther, presumably taken at midbody, and a count supported by Boulenger (1896) and Stimson (see later). Given the reported differences in localities, collectors and description, there is no doubt that the two authors described their species using different specimens. However, regarding the reported differences in the number of dorsal scale rows at midbody, it has to be noted that many Boiga have a rather chaotic dorsal scale row reduction which can go up and down more than three times within a range of only 10 corresponding ventral scales “at midbody”. Furthermore, the measured midbody can be different from the midbody position determined by counting half the number of ventrals.

Both Günther’s syntypes, an adult female with an SVL 889 + 212 TL = 1101 mm total length and an adult male with an SVL 611 + TL 149 = 760 mm total length, are housed in the collection of the Natural History Museum, London (BMNH 1946.1.2.60–61).

As far as we are aware, the two types of D. ochracea Theobald are unlocated. They were not listed by Theobald (1868a), nor in Sclater (1891) or in Das et al. (1998). Some time ago one of us (AD) checked the collection in ZSI, Kolkata, but found no specimens marked as type for Theobald´s ochracea and none of the specimens examined by him agreed with Theobald’s description or locality.

During the late 19th Century the British Museum (Natural History) received five further specimens of D. ochracea from Myanmar, i.e., two specimens ( BMNH 74.4.29.1193–1194) from Myanmar, reportedly collected by the British army officer and naturalist Richard Henry Beddome (1830–1911), and three specimens ( BMNH 89.2.25.37–39) from Bhamo, in Kachin State, northern Myanmar, collected by the Italian naturalist Leonardo Fea (1852–1903) .

Ferdinand Stoliczka (1838–1874) was a Austrian paleontologist and naturalist who worked in India during the mid 19th Century, but died of altitude sickness during a Himalayan expedition. He exhibited a considerable interest in snakes and in 1870 he reported on five specimens from the Andaman Islands which he attributed to the taxon Dipsas hexagonotus Blyth, 1855 ( Stoliczka 1870) .

In the late 19th Century the Anglo-Belgian zoologist George Albert Boulenger (1858–1937), was Günther’s assistant at the British Museum (Natural History) and the person now tasked with the continued cataloguing of the herpetological collection. In 1890 he resurrected the genus Dipsadomorphus Fitzinger, 1843 , for the African, Asian, and Australasian cat snakes previously included in the genus Dipsas ( Boulenger 1890; Boulenger 1896) and he synonymised Günther’s Dipsas ochraceus with Blyth’s older Dipsadomorphus hexagonatus .

Adopting this new classification, the British physician and herpetologist Major Frank Wall (1868–1950) examined Blyth’s Dipsas hexagonotus type specimen (ZSIK 8048), from “Cherrapunji, Khasi Hills, Assam ” [= Sohra, East Khasi Hills district, Meghalaya state, India] and reidentified it as a juvenile Dipsadomorphus cyaneus , now Boiga cyanea (Duméril, Bibron and Duméril, 1854) ( Wall 1909) . He also examined the four adult specimens in Stoliczka’s Andaman Dipsas hexagonotus , which exhibited a dorsal scale count of 21, and included them in the syntype series of his new species Dispadomorphus andamanensis , now Boiga andamanensis . The remaining specimen from Stoliczka’s Andaman series reportedly possessed 19 dorsal scale rows, but Wall commented that its description was imperfect and the specimen itself appeared to be lost.

Further, Wall (1909) recognized that the mainland D. hexagonotus material he had available appeared to represent two different taxa. Five of the BMNH specimens (BMNH 1946.1.2.60–61, 89.2.25.37–39) from Myanmar, and a further nine specimens he had personally collected, all possessed 19 dorsal scale rows, 221–245 ventrals and 89–107 subcaudals which complied with the description of D. hexagonotus , and to which he applied that name, citing Stoliczka’s missing Andaman specimen as the holotype. It is curious that he sought to conserve the name “ hexagonotus ”, as Dipsadomorphus hexagonotus , by transferring it from Blyth’s holotype, now known to be a juvenile D. cyaneus , to Stoliczka’s missing and incompletely described juvenile. Fortunately, this move is illegal according to the Code ( Smith 1943), meaning the name is unavailable and D. hexagonotus remains synonymized with D. cyaneus . The Myanmar population with 19 dorsal scale rows should therefore be known as D. ochracea .

Two further Myanmar specimens available to Wall (BMNH 74.4.19.1193–94) exhibited a dorsal count of 21, which was more akin to that obtained from Himalayan specimens. These two specimens were reportedly collected in Myanmar, well within the range of those specimens attributed by Wall to D. hexagonotus . However, they were collected by Beddome, and Wall had already voiced criticism regarding the accuracy of Beddome’s record keeping. In the case of these two specimens he suggested that they could have easily come from “the hills to the west or north of Burma, the fauna of which closely agrees with that of the Eastern Himalayas”. Furthermore, Smith (1943) stated that Beddome never visited Burma, and therefore the long-accepted collection locality for these two specimens must be treated as extremely suspect. Similarly , a specimen of “ Boiga ochracea ” donated by Beddome to the Museum of Comparative Zoology (i.e., MCZ R-3886) is said to come from “Madras” [Chennai] at the southeast coast on India. However, the given locality is far outside the distribution limits of this group and our reexamination revealed that this specimen is a B. stoliczkae which very likely originated from the eastern Himalayas.

Wall (1909) also examined 39 specimens from the Darjeeling area of West Bengal, India, which exhibited 21 dorsal scale rows, 218–252 ventrals, and 100–119 subcaudals. To this series he added a further three Darjeeling specimens in the British Museum (Natural History). Two of these (BMNH 72.4.17.119, 72.4.17.386) were collected by the British naturalist and physician Thomas Caverhill Jerdon (1811–1872), while the third specimen (BMNH 94.12.31.55) was collected by the British geologist and naturalist William Thomas Blanford (1832–1905). Finding this Eastern Himalayan taxon without a name, Wall (1909) proposed Dipsadomorphus stoliczkae , “the first reference of it having been made by Stoliczka”.

Annandale (1909) discussed Wall’s (1909) paper on the forms of Dipsadomorphus , and criticizes the, in his opinion, difficult delimitation of the species introduced by Wall, particular with regard to Boiga ceylonensis , but also to other species of this genus, and considered Wall’s new species merely as forms of one species, i.e., of B. ceylonensis .

Cope (1860) resurrected the name Boiga Fitzinger, 1826 and designated Coluber irregularis as type species. In 1902 the Norwegian-American zoologist Leonard Hess Stejneger (1851–1943) described a new species of rear-fanged snake from Taiwan (then Formosa), and in so doing also resurrected the genus Boiga Fitzinger, 1826 from obscurity as a senior synonym for Dipsadomorphus , the generic name it would replace for the remainder of the 20th Century. The two taxa under discussion here would therefore become Boiga ochracea (Theobald, 1868) , with 19 dorsal scale rows, from NE India south and east of the Brahmaputra valley across Bangladesh to Myanmar, and B. stoliczkae ( Wall, 1909) , with 21 dorsal scale rows, from the Eastern Himalayas, but including Beddome’s two “Burmese” specimens.

From all that we now know and have examined, B. ochracea does not occur on the Andaman or Nicobar Islands, that material being referred to Boiga andamanensis ( Wall, 1909) . This assumption is also confirmed by the recent studies of Chandramouli (2022: 321), who removes B. ochracea from the list of snake species occurring on the Andaman Islands. It has to be noted that B. andamanensis usually has 21 midbody DSR, rarely 19, but in preservation the coloration looks like “ ochracea ”, particular in the red color morph, a possible reason for the confusion.

The next author to take a look at this group of snakes was the British physician and herpetologist Malcolm Arthur Smith (1875–1958). In 1941 he used for the first time the combination Boiga ochracea walli (as a nomen nudum) and applied this name to populations from the Andaman and Nicobar islands, and Burma. A few years later Smith (1943) synonymized B. stoliczkae with B. ochracea , stating: “The name hexagonatus must become a synonym of cyanea , and the next one available is Günther’s ochracea . The type has 21 scale rows and is therefore the Himalayan form, and the locality (Pegu) from which it is said to have come is in no doubt an error. Beddome, from whom the specimen came, was never in Burma, and his localities have been shown to be incorrect on many occasions.” Smith (1943) defined his eastern Himalayan B. ochracea ochracea as exhibiting 21-21-17 dorsal rows, 223–252 ventrals, and 100–119 subcaudals, and described the populations of B. ochracea from “ Burma, south of lat. 25°; Tenasserim; the Andaman and Nicobar Islands.”, with 19-19-15 dorsal rows, 221–246 ventrals, and 89–107 subcaudals, as a new subspecies, formally named B. ochracea walli . On the BMNH ledger and on the jar labels, the BMNH specimens collected by Leonardo Fea at Bhamo, Myanmar, (i.e., BMNH 89.3.25.37–39) are declared as syntypes. However, this does not constitute a type selection according to the Code and is therefore not a valid syntype designation because it is not following the principles of typification. Smith (1943) did not cite any type material from his B. ochracea walli in its original description. Therefore, all specimens available to Smith at the time of the description of B. ochracea walli constitute the syntypes, not just the three specimens subsequently labeled as “ syntypes ” in the BMNH collection. The list of potential syntypes of Smith’s B. ochracea walli obviously includes specimens present at BMNH at the time but it is known that Smith travelled in South and Southeast Asia and visited all the main collections there in the preparation of his “Fauna of British India ” series, the third, Serpentes, volume of which was ready to go to print in 1938 (delayed until 1943 due to WWII). He examined material from the collections in Bombay, Calcutta, Paris ( Smith 1943:v–vi), Vienna ( Smith 1928) and Berlin (pers. data FT, he was in contact with Mell and arranged specimen loans with ZMB), and also loans from different US museums and from Leiden and Colombo ( Smith 1943). So it cannot be ruled out that specimens from these collections are also putative syntypes of Smith´s B. o. walli . Wallach et al. (2014) treated walli as full species and mentioned that this taxon is based on a single name-bearing type specimen, but they provided no inventory number for that specimen. According to Art. 72.4.1 of the Code (“The type series of a nominal speciesgroup taxon consists of all the specimens included by the author in the new nominal taxon (whether directly or by bibliographic reference) …”, we suggest that in the case of B. ochracea walli at least the following specimens belong to the original syntype series: BMNH 1946.1.2.60–61 from Pegu (at the same time syntypes of Dipsas ochraceus Günther ), BMNH 89.3.25.37–39 from Bhamo, and specimens from the Andamans and Nicobars, at least from the BMNH collection which were available to Smith.

Smith appears to have made a number of errors that had a considerably impact on the nomenclature and proposed distributions of these taxa. 1) It was Theobald, not Günther, who first described ochracea in 1868. 2) The ochracea type specimens (plural not singular) were recorded by Günther, as having come from Pegu (= Bago), but Theobald’s syntypes were collected from Rangoon (= Yangon) and Maulmain (= Mawlamyine ). Regardless of any confusion over precise localities, the two syntypes described by Theobald and the two other described by Günther were collected in southern Myanmar, not the eastern Himalayas or northern Myanmar. 3) Günther recorded the dorsal scale rows of these two specimens as 19, while Theobald reports 19-17-15 rows, but neither author reported a count of 21 for these specimens. 4) Beddome was responsible for collecting the two specimens reported as from “Burma”, not the two specimens from Pegu, and it is this locality that is now doubted by most authors, and it was these two specimens that exhibited 21 dorsal scale rows at midbody.

Not all authors accepted Smith’s synonymy of stoliczkae with B. ochracea , i.e., Kramer (1977) who reported that Andrew Stimson (BMNH) had checked the syntypes of Günther´s D ochraceus (BMNH 1946.1.2.60–61) and confirmed their dorsal scale counts as 19, and that they were collected in southern Myanmar and therefore he did not synonymise stoliczkae with ochracea , but rather recognized it as the eastern Himalayan-northern Burmese subspecies B. ochracea stoliczkae . It has to be noted here that all material examined by Kramer and determined by himself as B. o. stoliczkae was misidentified. Our re-examination (by FT) revealed that FMNH 131957 is Boiga multifasciata and FMNH 152584 is Boiga trigonata . Gruber in Schleich & Kästle (2002) recognized all three subspecies: B. o. ochracea from Darjeeling, Sikkim, Assam, Bhutan and Bangladesh; B. o. stoliczkae from Nepal, and B. o. walli as characterized by Smith (1943) from southern Myanmar and the Andaman and Nicobar Islands, but they did not provide any characteristics to distinguish between the three taxa.

Therefore, there appears to be a great deal of confusion over the nomenclature and distribution of the various populations of B. ochracea , largely caused by Smith’s misinterpretation of the data and some recent authors (e.g., Das 2010; Wallach et al. 2014) largely followed Smith’s (1943) erroneous concept of this group.

As a consequence of what is stated above, we consider Boiga walli to be a synonym of B. ochracea , and we elevate B. stoliczkae again to species level, distinct from B. ochracea . To summarize the current situation, Boiga ochracea should be the taxon with 19-19-15 or 13 dorsal scale rows, cream to beige color without any pattern, from NE India south and east of the Brahmaputra valley across Bangladesh to Myanmar. Boiga multomaculata should be the taxon with 19-19-15 or 13 dorsal scale rows and a bold pattern of ocellated dark blotches, definitely known from Myanmar and southern China across Thailand, Laos, Vietnam, and the Sunda Archipelago. Boiga stoliczkae should be the taxon with 19 or 21-21-15 or 17 dorsal rows that has been reported from Nepal, northeast India north and west of the Brahmaputra valley, and Bhutan.

In this work, we evaluate the genetic variation in the populations related to Boiga multomaculata , B. ochracea , and B. stoliczkae , respectively, based on the mtDNA markers 16S, ND4, and CYTB as well as the nuclear marker c-mos. We also analyze the variation in external morphology of these three taxa. Finally, we designate lectotypes for Boiga multomaculata , B. ochracea walli , and B. stoliczkae , and a neotype for Boiga ochracea respectively, and provide redescriptions of the primary types from these taxa.