Sulawesidrobia dinersteini, Haase & Rintelen & Harting & Marwoto & Glaubrecht, 2023

Haase, Martin, Rintelen, Thomas von, Harting, Britta, Marwoto, Ristiyanti & Glaubrecht, Matthias, 2023, New species from a ‘ lost world’: Sulawesidrobia (Caenogastropoda, Tateidae) from ancient Lake Matano, Sulawesi, Indonesia, European Journal of Taxonomy 864 (1), pp. 77-103 : 93-95

Sulawesidrobia dinersteini sp. nov.

urn:lsid:zoobank.org:act:5AD928D7-232F-4D7E-AB84-FE9BA9D471F4

Figs 2E , 3I–J , 5D , 6G–H , 7I–J , 8H (all from type locality)

Diagnosis

In the new species, the penis tapering continuously from a broadened base with triangular lobe in about the middle on the right side is unique within the genus. Six diagnostic positions are of type 1 and three of type 3 ( Table 3 ).

Etymology

Sulawesidrobia dinersteini sp. nov. is named after the American conservation biologist Eric Dinerstein (born 1952) for his influential contributions in identifying representative and biologically important ecoregions which help to develop a global safety net aiming to at least protect 30 percent of Earth’s surface in order to save a considerable fraction of biodiversity.

Material examined

Holotype ( Fig. 2E )

INDONESIA • Sulawesi, Lake Matano , S shore, on rocks and macrophytes; 02°27.850′ S, 121°13.870′ E; 1 Aug. 2004; von Rintelen and Zitzler leg.; MZB Gst. 12124 .

Paratypes ( Fig. 3I–J )

INDONESIA • 40 specs; same collection data as for holotype; MZB Gst 12125 • 38 specs; same collection data as for holotype; ZMB 107092 • 11 specs; Sulawesi, Lake Matano , S shore, on rocks and macrophytes; 02°28.461′ S, 121°15.591′ E; 24 Jul. 2004; von Rintelen and Zitzler leg.; MZB Gst 12126 • 11 specs; same collection data as for preceding; ZMB 107094 .

Description

SHELL ( Figs 2E , 3I–J ). Short-conical, sutures very shallow, about 1.6 times as high as wide, shell and priostracum light brown; protoconch structure not verified, ca 0.8 whorls; entire shell with 3.500 to 4.250 whorls, teleoconch without structure apart from growth lines; umbilicus a narrow slit; aperture orthocline, only slightly higher than wide.

OPERCULUM. Light yellow and thin, paucispiral, nucleus eccentric.

EXTERNAL FEATURES. Epidermis entirely black except mantle edge, eventually pigment less dense over distal genital glands; tentacles with small, central field of cilia ( Fig. 5D ).

MANTLE CAVITY (N = 4 from each locality). 16–18 (type locality) and 14–17 (2 nd locality) ctenidial filaments, respectively; osphradium ovate-elongate, underneath middle or slightly behind middle of gill, half to two thirds of length of gill.

DIGESTIVE SYSTEM. The radula has the formula R 3-4 1 3-4/3-4 3-4, L 2 1 2-3, M1 15-20, M2 23-28, central denticle of lateral tooth with rounded tip ( Fig. 6G–H ); stomach without caecum, without pigment at type locality, pigmented at locality 2; intestine follows pallial genital glands, in females closer than in males.

FEMALE GENITALIA (N = 2 from each locality; Fig. 14I–J). Ovary starts ca 1.25 or slightly more whorls below apex, comprises ca 0.5 whorls, covers stomach chambers; renal oviduct first coiling 180° clockwise, then 270° counter-clockwise; no receptaculum seminis; bursa copulatrix more or less globular, bursal duct enters anteriorly; albumen gland with opaque-white anterior and milky-white posterior section, capsule gland with small opaque white and large yellow posterior portion.

MALE GENITALIA (N = 2 from each locality; Fig. 8H ). Testis lobate, starts 0.75 (type locality) to 1 whorl (locality 2) below apex, comprises ca 1.25 whorls, covers stomach; vesicula seminalis coils along distal half to 0.75 whorls of testis; vasa deferentia insert close to middle of kidney-shaped prostate, which is much longer (almost twice as long) in locality 2 than at type locality; penis tapering continuously from broadened base, with triangular lobe in about middle on right side, can be considerable longer than in Fig. 8H , distal end subterminally grey.

Remarks

In the phylogenetic trees, S. dinersteini sp. nov. received high support. Its penis is unique as it is considerably shorter than the similar one of S. megalodon (see Zielske et al. 2011). Some similarity of the radula with that of S. ehrlichi sp. nov. has already been mentioned above. Sulawesidrobia dinersteini had the highest number of diagnostic alignment positions ( Table 3 ) among the new species which clearly reflects the well-supported position in the phylogenetic analyses (see below, Figs 9–10 , Supp, file 1).

Figures

Fig. 2. Holotypes. A. Sulawesidrobia wilsoni sp. nov. (MZB Gst. 12116). B. S. carsonae sp. nov. (MZB Gst. 12118). C. S. ehrlichi sp. nov. (MZB Gst. 12120). D. S. crutzeni sp. nov. (MZB Gst. 12122). E. S. dinersteini sp. nov. (MZB Gst. 12124). Scale bar = 1 mm.

Fig. 3. SEM micrographs of paratypes, all from type localities. A–B. Sulawesidrobia wilsoni sp. nov. (MZB Gst. 12117). C–D. S. carsonae sp. nov. (MZB Gst. 12119). E–F. S. ehrlichi sp. nov. (MZB Gst. 12121). G–H. S. crutzeni sp. nov. (MZB Gst. 12123). I–J. S. dinersteini sp. nov. (MZB Gst. 12125).

Fig. 5. SEM micrographs of cephalic tentacles. A. Sulawesidrobia wilsoni sp. nov. (ZMB 191842). B. S. carsonae sp. nov. (ZMB 107079). C. S. crutzeni sp. nov. (ZMB 191838). D. S. dinersteini sp. nov. (ZMB 107092). Arrows indicate field of cilia. Scale bars: A–B, D = 20 µm; C = 50 µm.

Fig. 6. Radula. A–C. Sulawesidrobia wilsoni sp. nov. D. S. carsonae sp. nov. E. S. ehrlichi sp. nov. F. S. crutzeni sp. nov. G–H. S. dinersteini sp. nov. Note different shapes of denticles on central and lateral teeth across species. Arrows indicate enlarged denticle on marginal tooth 1 in S. wilsoni sp. nov. Scale bars: A, C–G = 10 µm; B, H = 5 µm.

Fig. 7. Distal female genitalia. A–B. Sulawesidrobia wilsoni sp. nov. C–D. S. carsonae sp. nov. E–F. S. ehrlichi sp. nov. G–H. S. crutzeni sp. nov. I–J. S. dinersteini sp. nov. Abbreviations: aa = anterior albumen gland; ac = anterior capsule gland; bc = bursa copulatrix; bd = bursal duct; od = oviduct; pa = posterior albumen gland; pc = posterior capsule gland; vc = ventral channel.

Fig. 8. Penis. A–B. Sulawesidrobia wilsoni sp. nov. (ZMB 191842). C–D. S. carsonae sp. nov. (ZMB 107079).E–F. S. ehrlichi sp. nov. (ZMB 107095).G. S. crutzeni sp. nov. (ZMB 191838).H. S. dinersteini sp. nov. (ZMB 107092). Arrow indicates lobe in H. Scale bars: A–F, H = 50 µm; G = 100 µm.

Fig. 9. Bayesian phylogenetic analysis. Outgroup pruned from tree. Taxa represented by “species name_ZMB catalogue number and specimen_abbreviation of lake”. Numbers at nodes are posterior probabilities> 0.50. Scale in substitutions per site.

Fig. 10. Maximum likelihood phylogenetic analysis. Outgroup pruned from tree. Taxa represented by “species name_ZMB catalogue number and specimen_abbreviation of lake”. Numbers at nodes are bootstrap support values> 50. Scale in substitutions per site.