Corresponding author: Russell L. Minton ( email@example.com )
Academic editor: Matthias Glaubrecht
© 2017 Russell L. Minton, Phillip M. Harris, Ernest North, Do Van Tu.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Minton RL, Harris PM, North E, Tu DV (2017) Diversity and taxonomy of Vietnamese Pollicaria (Gastropoda, Pupinidae). Zoosystematics and Evolution 93(1): 95-104. https://doi.org/10.3897/zse.93.10794
Species in the genus Pollicaria (Gastropoda: Pupinidae) are conspicuous members of the southeast Asian land snail fauna. Originally erected in 1856, both the genus and its constituent species have been reorganized multiple times with the most recent treatment published in 2013. Collections of Vietnamese Pollicaria during 2014 and 2015 raised questions of the utility of currently used diagnostic shell characters and identification keys in species identification. An examination of the authors’ collections, combined with museum specimens, suggested that at least three species of Pollicaria occur or have historically occurred in Vietnam. It is suggested that P. rochebruni is a senior synonym of P. crossei and treat both taxa as conspecific. A second species, P. mouhoti, was believed to only occur in Cambodia, Laos, and Thailand. A possible third species, based only on previous karyotypic work, is discussed. Our data further suggest that shell features such as color and size lack consistent utility in species-level identifications in Pollicaria.
Pollicaria rochebruni, Pollicaria crossei, Pollicaria mouhoti, Vietnam, pupinid
The genus Pollicaria was erected by
While identifying Vietnamese land snails collected in 2015 by PMH and DVT, we found
Specimens collected by the authors were vouchered at the
We also searched the Internet for shell dealers selling Pollicaria specimens from Vietnam and surrounding areas. While we lacked the funding to purchase specimens outright, we examined shell images and locality information from the dealer websites. Requests to formally include images and additional information in this manuscript went unanswered. We accepted that this information was not equivalent to that of vouchered specimens, but could be important in determining the diversity and distribution (
Live Pollicaria specimens were collected in Vietnam by PMH, DVT, and local farmers in 2015, preserved in ethanol, and DNA was successfully sequenced from two of them. One individual collected south of Hoàng Liên National Park had a reddish-brown shell we identified as P. rochebruni; the other was collected from Cúc Phương National Park and had an orange shell that was consistent with P. crossei sensu
GenBank accession numbers for all taxa included in the phylogenetic analysis.
|Pollicaria cf. crossei||KY359073||KY359075||KY359077|
A review of the original descriptions of both P. rochebruni and P. crossei suggested that
Original illustrations and type material of Vietnamese Pollicaria. A. Pollicaria crossei from
Morphological character comparison taken from the original descriptions of Pollicaria rochebruni and P. crossei.
|P. rochebruni||P. crossei|
|Height||39 mm||39 mm|
|Diameter||21 mm||20 mm|
|Peristome||Thick, upturned, with a channel in the upper portion of the lip||White, circular, thickened, with a triangular air space at the lip.|
|Whorls||6.5 to 7 convex, flattened||7 convex, flattened on the upper part|
|Shell||Ovate-pupiform, striate, and distorted||Pupiform, striate, and distorted|
|Sutures||Impressed||Linear and impressed|
A total of 87 museum specimens (Figure
Vietnamese Pollicaria from museum collections. A and B.
Pollicaria specimens are advertised for sale at five websites: eBay.com, yhshells.com, femorale.com, conchology.be, and topseashells.com. Taken together, these specimens suggest that the known distribution of Pollicaria species should be expanded to include Guangxi autonomous region and Yunnan province in southern China. These two regions are adjacent to the northern borders of Vietnam, Laos, and Myanmar. Shells from these two regions were identified by their sellers as P. crossei, P. gravida, and P. rochebruni. All but two Chinese specimens possessed the interiorly shouldered perisotome; the other two possessed the flared lip and no shoulder seen in P. mouhoti and P. myersii. Shell sizes varied up to 45 mm in length, and shell colors varied from light tan through orange, reddish brown, dark brown, and dark purple. Vietnamese Pollicaria specimens varied similarly in color and size to the Chinese samples, and all possessed the interior shoulder in the peristome. These specimens were labelled as P. crossei and P. rochebruni.
DNA sequences from our putative P. rochebruni and P. crossei specimens (Figure
Pollicaria specimens sequenced in this study. A.
Based on museum, online, and our own data, we believe that at least two, and possibly three, species of Pollicaria occur or have historically occurred in Vietnam. We consider the first, P. rochebruni, to comprise both P. rochebruni sensu stricto and P. crossei pre-
Revised distribution map for North Vietnamese Pollicaria species. Pollicaria rochebruni is present at all sites shown. Black dots indicate the presence of P. mouhoti, while gray dots indicate the presence of the putative new species of
We identified the second Vietnamese Pollicaria species as P. mouhoti, based on
A possible third Vietnamese Pollicaria species is based on karyotype differences that
Our preliminary molecular evidence suggests that shell color and size may not be reliable for consistent species identification in Vietnamese Pollicaria. Sequences from one small, reddish-brown shelled snail (cf. P. rochebruni) and one large, orange-shelled snail (cf. P. crossei) were identical at three genetic loci. Our orange-shelled snail was larger than the nominal P. crossei in
Despite our best efforts and those of
Megalostoma gravidum Benson, 1856 (=Cyclostoma pollex Gould, 1856), designated by
– Kobelt 1902: 290;
All material from Vietnam / Tonkin Province. The number in parentheses is the number of shells from each lot assigned to the species. Locality names have been corrected wherever possible. –
(not examined). All from Vietnam, taken from
Pupoid shell, to 45 mm length and 20 mm diameter, color varying from tan to orange, reddish-brown, and dark brown, possibly dark purple. Old specimens are often finely pitted. Whorls 5-7, transverse growth lines present, sutures linear and slightly impressed, apex obtuse and occasionally distorted to the left (assuming standard anatomical position), spire short. Penultimate body whorl may appear inflated relative to whorls on either side. Aperture circular with a right posterior triangular breathing structure. Peristome thickened, white to shell colored, with a thin parietal declining shoulder inside; umbilicus narrow. Operculum concentric, thick, and calcareous.
Radula with teeth in a 2-1-1-1-2 arrangement, based on the figure in
Northern Vietnam south to Đà Nẵng (Figure
By synonymizing P. rochebruni and P. crossei, we suggest that all Pollicaria specimens from Vietnam that possess an interiorly shouldered peristome are a single species, excluding some smaller (< 35 mm) individuals with bright orange shells. We found live specimens of P. rochebruni at the bases of and in the valleys between karst outcrops in northern Vietnam. Reports from local farmers indicated that snails are more abundant during the spring rains, when native residents eat them as a delicacy. Some Chinese shells found for sale on the Internet are consistent morphologically with P. rochebruni but may represent a separate species.
RLM was supported by Faculty Research Support Funds through UHCL. PMH was supported in part by the UA Research Grants Committee, and a UA College Academy of Research, Scholarship, and Creativity award. Images of original figures (P. rochebruni and P. crossei) were downloaded from Biodiversity Heritage Library and are in the public domain. Images in figure 1 are reproduced from