Clathrocaspia brotzkajae (Starobogatov, 1992)

Anistratenko, Vitaliy V., Neubauer, Thomas A., Anistratenko, Olga Yu., Kijashko, Pavel V. & Wesselingh, Frank P., 2021, A revision of the Pontocaspian gastropods of the subfamily Caspiinae (Caenogastropoda: Hydrobiidae), Zootaxa 4933 (2), pp. 151-197 : 167

Clathrocaspia brotzkajae (Starobogatov in Anistratenko & Prisjazhnjuk, 1992)

Fig. 8

Pyrgula [(Caspia)] knipowitchi [sic] (Mak.)— Logvinenko & Starobogatov 1969: 379, fig. 367(8) [non Makarov, 1938]. Caspia (Clathrocaspia) brotzkajae Starobogatov sp. n. —Starobogatov in Anistratenko & Prisjazhnjuk 1992: 18–19, fig. 2a. Caspia brotzkajae Starobogatov in Anistratenko et Prisjazhnjuk, 1992— Kantor & Sysoev 2006: 87, pl. 41, fig. G. Clathrocaspia brotzkajae (Starobogatov in Anistratenko & Prisjazhnjuk, 1992)— Wesselingh et al. 2019: 69.

Type material. Holotype ( ZIN # 1 in systematic catalogue) and 74 paratypes ( ZIN collection). Four specimens labelled as paratypes of Caspia brotzkajae ( IZAN, unnumbered lot) from a late Holocene drilling borehole taken in the southern part of Odessa region, Ukraine ( Table 1 , locality 32), do not belong to that species but instead to C. knipowitschii (see there).

Type locality. Caspian Sea shores of Dagestan, Russia, at a depth of ca. 60–75 m (locality 10). The paratypes were retrieved from locality 12 close by the type locality .

Other material. 17 specimens in Starobogatov’s collection, marked as “ type material” of “ Caspia alighadzhievi ”, an unavailable catalogue name; collected in 1957 and 1960 near Derbent (Dagestan, Russia) at a depth of 60 m and in the eastern part of the middle Caspian Sea at a depth of 73 m (localities 6, 11) .

Description. Broadly ovoid shell with about 4 whorls and large body whorl (ratio of body whorl height/shell height approximately ¾). Protoconch consists of about 1.2 whorls that measure c. 400 μm, bearing irregular wrin-kles and faint spiral threads. Teleoconch covered by fine but distinct reticulate sculpture, with numerous spiral keels that are equally prominent across whorl profile and have interspaces that are approximately as wide as keels; only uppermost 1–2 keels are usually more prominent and slightly wider spaced; in some shells, uppermost keel forms weak subsutural ramp that results in slightly stepped outline. Aperture wide, sometimes laterally expanded; umbilicus covered in most shells, sometimes present as thin slit.

Remarks. Compared to other Clathrocaspia species, C. brotzkajae is more bulbous, has a larger body whorl and a more expanded aperture. Only C. logvinenkoi from the Black Sea Basin is even more bulbous but smaller.

Originally, four specimens from the Holocene of the Danube Delta, Ukraine, were attributed to that species (Anistratenko & Prisjazhnjuk 1992). These shells are more slender and have a smaller aperture; they rather resemble C. knipowitschii and are referred to this species herein. In turn, the specimen illustrated as “ Pyrgula knipowitchi ” in Logvinenko & Starobogatov (1969) from the Caspian Sea shows a very bulky shell that is highly reminiscent of and considered conspecific with Clathrocaspia brotzkajae .

In the collection of Starobogatov we found the “ holotype ” and 16 “ paratypes ” of a catalogue taxon Starobogatov named “ Caspia alighadzhievi ”. The material shows close similarities with the holotype of C. brotzkajae ( Fig. 8 g–j, m), described from the same region, and we consider Starobogatov’s material to belong to that species.

Distribution. Known only from the Caspian Sea shores of Dagestan, Russia. No living specimens have been encountered.

Figures

FIGURE 8. Clathrocaspia brotzkajae (Starobogatov in Anistratenko & Prisjazhnjuk, 1992) from the Middle Caspian Basin. (a, b) Holotype, locality 10 (ZIN #1). (c) Paratype, locality 12 (ZIN, no number). (d, k, l) Paratype, locality 12 (ZIN, no number). (e) Paratype, locality 12 (ZIN, no number). (f) Paratype, locality 12 (ZIN, no number). (g–i) Specimen labelled as “Caspia alighadzhievi, holotype”, locality 6 (ZIN, no number). (j, m) Specimen labelled as “Caspia alighadzhievi, paratype”, locality 11 (ZIN, no number). Scale bars = 1 mm (a–k), 100 μm (l, m).