Aulacospira tekavongae, Dumrongrojwattana & Tanmuangpak, 2020

Dumrongrojwattana, Pongrat & Tanmuangpak, Kitti, 2020, The terrestrial microsnail genus Aulacospira Moellendorff, 1890 (Eupulmonata, Stylommatophora, Hypselostomatidae) in Thailand with key to Thai species, ZooKeys 980, pp. 23-42 : 23

Aulacospira tekavongae sp. nov. Figure 5A-D

Type material.

Holotype. ZRCBUU 0610; Thailand, Khao Chakan, an isolated limestone hill of Srakeo Province; 240 m a.s.l.; 13°48'02"N, 102°12'49"E; 5.v.2019; leg. Kamtuptim, C. and Dumrongrojwattana, P. Paratypes. ZRCBUU 0611 (15 shells); ZRCBUU 0420 (10 shells); 19.v.2014; leg. Dumrongrojwattana, P. THNHM-Iv-18803 (5 shells); MNHN IM-2014-7122 (5 shells); 5.v.2019; location same as holotype; leg. Kamtuptim, C. and Dumrongrojwattana, P.

Measurments.

Holotype H = 2.32 mm, W = 2.08 mm. Paratypes H = 1.94-2.35 mm, W = 1.95-2.21 mm.

Diagnosis.

Shell minute, conical. Protoconch smooth, body whorl with a very short projecting downward tuba; peristome expanded; aperture lacking teeth.

Aulacospira tekavongae sp. nov. is very similar to A. khaobote , but the shell is a conical and with a high spire, while that of A. khaobote shell helicoid and with a low spire.

Description.

Shell minute, conical, brownish, with 4- 4½ whorls. Tuba very short, projecting downward. Protoconch consisting of 1 ¼ whorls, with granulose wrinkles. Teleoconch smoothish, sculptured with uneven, oblique growth striae. Suture deep. Shell narrowly umbilicate. Spire high; first two whorls rounded, penultimate and body whorl with two distinct spiral sulci continuously to peristome. Peristome expanded; aperture round and lacking teeth (Fig. 4A ).

Radula.

As in A. depressa (Fig. 5B ).

Genital system.

Atrium longer than vagina. Penis shorter than epiphallus, with anterior portion a short tube and bulging. Epiphallus connected to distal end of penis. Epiphallus longer than vas deferens, with anterior portion slender and cylindrical, central portion slender and more bulging than anterior and posterior portion. Epiphallic flagellum absent. Epiphallic retractor caecum rather bulging, attached to posterior portion of epiphallus. Vas deferens long, slender, entering epiphallus apically. Vagina and free oviduct cylindrical, with vagina shorter than free oviduct. Gametolytic sac long and cylindrical, with anterior and central portion bulging, posterior portion slender and curved knob. Uterus long and large, with very thin prostate gland adhering to it. Hermaphroditic duct loosely convolute. Albumen gland large and yellowish. Dart apparatus absent (Fig. 5C, D ).

Type locality.

Thailand, Khao Chakan, an isolated limestone hill of Srakeo Province, eastern Thailand; 13°48'02"N, 102°12'49"E; ca 240 m a.s.l.

Etymology.

We name this species in the hornor of Ms Rattanawadee Tekavong, a research collaborator, who has worked extensively on the eastern microsnail diversity.

Distribution.

This species is known only from the type locality (Fig. 1 ).

Figures

Figure 1. Distribution map of Aulacospira spp. in Thailand: 1 A. depressa 2 A. khaopratun 3 A. panhai 4 A. khaobote 5 A. lampangensis 6 A. smaesarnensis 7 A. pluangtong 8 Aulacospira tekavongae sp. nov. 9 Aulacospira nudtadhirai sp. nov. 10 Aulacospira vanwalleghemi sp. nov.

Figure 4. A-D Aulacospira pluangtong (ZRCBUU 357) A shell B radula C, D genital system E-H Aulacospira nutadhirai sp. nov. E holotype (ZRCBUU 0391) F radula G, H genital system.

Figure 5. A-D Aulacospira tekavongae sp. nov. A holotype (ZRCBU 0610) B radula C, D genital system E-H Aulacospira vanwalleghemi sp. nov. E holotype (ZRCBUU 732) F radula G, H genital system.