Bakyietaia indrapura Zhang, Yen & von Rintelen, 2025

Bakyietaia indrapura Zhang, Yen & von Rintelen gen. et sp. nov.

urn:lsid:zoobank.org:act:

Figs 38–39 View Fig View Fig

Diagnosis

Shell medium in size (26.92 ± 2.45 mm), thin, sturdy, whorls inflated, with prominent primary keels at suture; columellar lip recurved, forming callus covering umbilicus completely; operculum with small nuclear region (around 1/5 of inner opercular region) with shiny grains or veins; outer marginal tooth of radula with 21–26 small sharp cusps; distributed in central Vietnam.

Etymology

Named after Indrapura, capital of the ancient kingdom of Champa, which is close to the type locality. Formed as a noun in apposition. The recommended Chinese name is aēṉ田ª.

Material examined

Holotype

VIETNAM • 1 spec. (preserved in ethanol); Phuoc Son, Kham Duc, Cai River drainage ; 21–31 Oct. 2006; Frank Köhler leg.; ZMB.114403.1 .

Paratypes

VIETNAM • 2 specs (preserved in ethanol); same data as for holotype; ZMB.114403 • 5 specs (preserved in ethanol); Nghê An, Tân Duong District, Tam Quang, Truong Son Mts , mountain creek; 21–31 Oct. 2006; Frank Köhler leg.; ZMB.114402.1 , ZMB.114402 • 3 specs (preserved in ethanol); same data as for preceding; ZMB.114406 .

Description

Adult shell ( Fig. 38A–F View Fig ) medium in size (26.92 ± 2.45 mm), thin but sturdy, conical, olive to greenish brown, with five to six whorls, apex acute; teleoconch whorls, especially body whorl, slightly inflated, sometimes forming shoulder, with three smooth primary keels, with one to two weaker smooth secondary keels located between suture and first keel, sometimes one additional weak keel located between first and second/second and third keels, base of shell with three to five weak keels, keels usually darker than rest of shell surface; aperture ovate, less than half of shell in height, inner shell surface bluish white, outer lip thin, always with a strong angular periphery, columellar lip covered with thick inner shell layers, white or orange, adult columellar lip recurved, forming a very narrow crescent-shaped callus or without this structure, columellar lip or this structure usually covering umbilicus, umbilicus sometimes narrowly open, bordered by a keel.

Operculum ( Fig. 38G–H View Fig ) corneous, ovate, thin, yellow to orange; exterior surface smooth; interior surface with small nuclear region, around 1/5 of inner opercular region, with shiny grains or veins.

Radular ( Fig. 39 View Fig ) (n = 4) central tooth with one broad central denticle and five small sharp cusps on either side; lateral tooth with one broad central denticle and five small sharp cusps on either side; inner marginal tooth narrow, about half width of lateral tooth, with one broad central denticle and five to six small sharp cusps on either side; outer marginal tooth wide, almost same width as lateral tooth, with 21 to 26 small sharp cusps.

Remarks

Bakyietaia indrapura gen. et sp. nov. can be distinguished from most congeners, especially Bakyietaia polyzonata , based on the medium-sized thin conical shell, more inflated whorls and stronger keel at suture. The distribution of Bakyietaia indrapura in central Vietnam is far from the distributions of other congeners. It is probably the southernmost non-introduced species of this genus.

Habitat and distribution

Rivers and mountain creeks of Central Vietnam.