Quantula doma, Deeprom & Tumpeesuwan & Tumpeesuwan, 2022

Deeprom, Kanchanog, Tumpeesuwan, Chanidaporn & Tumpeesuwan, Sakboworn, 2022, A new species of the genus Quantula Baker, 1941 (Eupulmonata: Dyakiidae) from the southern part of north-eastern Thailand, Raffles Bulletin of Zoology 70, pp. 519-533 : 527-530

publication ID	https://doi.org/ 10.26107/RBZ-2022-0029
publication LSID	lsid:zoobank.org:pub:800A7AAD-D76E-43E4-8001-6754CE3ECE57
DOI	https://doi.org/10.5281/zenodo.7502312
persistent identifier	https://treatment.plazi.org/id/E4BD56F7-BFE9-4C74-9601-8195A0B3AB79
taxon LSID	lsid:zoobank.org:act:E4BD56F7-BFE9-4C74-9601-8195A0B3AB79
treatment provided by	Felipe
scientific name	Quantula doma
status	sp. nov.

Treatment

Quantula doma View in CoL , new species

( Figs. 3B–C View Fig , 4B–C View Fig , 6A–J View Fig ; Tables 1 View Table 1 –3)

Quantula sp. – Jumlong et al., 2013: 71–72, 74–76, 78–79, fig. 3.

Quantula weinkauffiana View in CoL – Worachak, 2014: 40–42, figs. 4.1A–B, 4.2 A–C, 4.3 B–C.

Quantula sp. 1 – Worachak, 2014: 43–45, figs. 4.4A, 4.5A–E, 4.6A–B.

Quantula sp. 1 – Jirapatrasilp et al., 2021: 193 (1), 262–263. Quantula striata View in CoL – Hoompuay, 2016: 22–25, figs. 4.1–4.3. Quantula sp. 6 – Hoompuay, 2016: 43–45, figs. 4.21–4.24.

Material examined. Holotype: NHMSU-00048 ( Fig. 4B View Fig ) from Khao Sala, Buachet District , Surin Province; 14°25′50.5″N 103°56′15.6″E; 14 October 2017; SH = 18.69 mm, SW = 28.61 mm GoogleMaps . Paratypes: 47 shells (25 adults & 22 juveniles), 28 living specimens; same data as holotype; NHMSU-00049. GoogleMaps One shell (NHMSU-00050) from Phu Jor Kor , Nong Soong District , Mukdahan Province; (16°22′22.1″N, 104°22′32.2″E), 11 October 2017 ( Fig. 4C View Fig ); GoogleMaps Two adult and three juvenile shells, and nine living specimens (NHMSU-00051) same locality as NHMSU-00050; GoogleMaps One adult and one juvenile shells and two living specimens (NHMSU-00052); Pha Nam Yoi, Nong Phok District, Roi Et Province, Thailand; 16°19′22.3″N 104°19′33.4″E; 11 October 2017; GoogleMaps seven adult and three juvenile shells, and five living specimens (NHMSU-00053), same data with NHMSU-00052 GoogleMaps .

Diagnosis. Last whorl angular with peripheral keel, not descending in front. Amatorial organ duct longer than amatorial organ.

Etymology. The specific epithet is derived from the Latin word ‘domus’ meaning roof, referring to the fact that its shell shape is similar to a hemispherical roof.

Description. Shell (n=48, 26 adult & 22 juveniles from Khao Sala ( Fig. 4B View Fig ) and n=20, 11 adults & 9 juveniles from Phu Jor Kor and Pha Nam Yoi ( Fig. 4C View Fig )): Dextral, domeshaped to depressed-conic lenticular, with 6–6¼ whorls, suture shallow, growth line prominent. Last whorl angular with peripheral keel, but less sharp than Q. wienkauffiana . Shell height 14.8–21.9 mm, shell width 25.1–35.3 mm. Apex blunt, shell light brown, ventral side paler than dorsal side. Apertural lip simple and thick, and slightly expanded at columellar side in adult specimens. Umbilicus narrow and deep.

Body (n=28 from Khao Sala ( Fig. 3B View Fig ) and n = 11 from Phu Jor Kor and Pha Nam Yoi ( Fig. 3C View Fig )): Living snail orange brown, with two lateral light brown or dark stripes running from base of each upper tentacle backward to pneumostome.

Genitalia (n=13, comprising three specimens from Khao Sala (one specimen from Hoompuay, 2016) ( Fig. 6A–E View Fig ), three specimens from Phu Jor Kor, and seven specimens from Pha Nam Yoi (five specimens from Hoompuay, 2016) ( Fig. 6F–J View Fig ): Penis short, cylindrical, inner wall with robust longitudinal penial pilaster alternating with 1–2 thin longitudinal pilasters ( Fig. 6D View Fig ), whereas specimens from Phu Jor Kor sculptured with irregular undulate penial pilasters arranged in inclined and longitudinal rows ( Fig. 7D View Fig ). Epiphallus shorter than penis. Vas deferens longer than penis. Gametolytic duct connecting to basal part of amatorial organ, basally bulbous, distally with short and small duct. Tapering gametolytic sac long, robust ( Fig. 6A View Fig ). Amatorial organ elliptical, with inner wall smooth. Papilla of amatorial organ strong, long, reaching junction of gametolytic duct. Corneous spike present ( Fig. 6B–C View Fig ). Amatorial organ duct longer than amatorial organ. Vagina and free oviduct shorter than penis. Inner wall of vagina smooth, with 3–4 thin longitudinal pilasters on median part ( Fig. 6E View Fig ). Specimens from Phu Jor Kor has gametolytic duct connecting to middle part of amatorial organ. Gametolytic sac cylindrical, long. Amatorial organ long, cylindrical, with inner wall sculptured with irregular undulated short pilasters. Papilla of amatorial organ robust, cylindrical, distally finger-shaped, without terminal corneous spike. Vagina longer than penis, internally with four to five longitudinal pilasters. Amatorial organ duct nearly as long as, or slightly longer than amatorial organ.

Radula (n=13, comprising three specimens from Khao Sala (one specimen from Hoompuay, 2016) ( Fig. 7A–B View Fig ) three specimens from Phu Jor Kor, and seven specimens from Pha Nam Yoi (five specimens from Hoompuay, 2016) ( Fig. 7C–D View Fig ): with 83–90 rows of teeth. Each row with 83–123 teeth, formula: (24–42) + (17–19) + 1 + (17–19) + (24–42) in specimens from Khao Sala, and approximately 70–82 rows of teeth, each of which comprises 91–123 teeth. Fomula: (31–43) + (14–18) + 1 + (14–18) + (31–43) in specimens from Phu Jor Kor and Pha Nam Yoi. Central and lateral teeth lanceolate, tricuspid. Marginal teeth bicuspid and gradually changing to unicuspid and sword shaped.

Distribution. Quantula doma , new species, is found in sandstone mountains of the southern part of north-eastern Thailand, in the Surin, Roi Et, and Mukdahan Provinces.

Remarks. According to the genetic distance and phylogenetic analysis, Quantula “sp. 1” from Khao Sala in Jirapatrasilp et al. (2021) (specimen no. H60, COI and 28s accession numbers MT803088 View Materials and MT741936 View Materials ) is clustered with the Q. doma , new species (specimen no. KSH and KSL). Genetic distances within the Khao Sala population are around 0.5% ( Table 2 View Table 2 ), and all specimens have rather strong support ( Fig. 2 View Fig ) (BI posterior probability of 1.00 and 100% for ML, and 99% for NJ bootstrap replicate), based on which we conclude that specimen H60, KSH and KSL represent the same species as Q. doma , new species. Although conchologically this new species looks similar to Q. simonei Thach & Huber 2018 from Laos (see Thach, 2018: plate 49, figs. 580, 581 top), in Q. doma , new species, the last whorl is angulate with weak peripheral keel and has an open umbilicus, whereas in Q. simonei , the last whorl is well-inflated without peripheral keel, and the umbilicus is mostly covered by the columella portion of the apertural lip.