Zospeum obesum (FRAUENFELD, 1854)
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https://doi.org/ 10.1007/s13127-019-00400-8 |
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https://treatment.plazi.org/id/300F1A79-B423-B74D-E780-FB01FEDAFDAD |
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treatment provided by |
Felipe |
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scientific name |
Zospeum obesum |
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Zospeum obesum View in CoL clade
Distribution Known from the northern Dinarides of Slovenia and Istria (Supplementary Fig. S10).
Within this clade there are two distinct groups ( Fig. 3 View Fig , brown part), which are recognized in the species delimitations B–E ( Table 3) as independent species.
Morphology: Shell conical, translucent when fresh; the last few whorls usually slightly to regularly expanded; shell surface often with spiral lines, otherwise smooth; aperture taller than wide, parietal shield not always well- differentiated from the lip; parietalis present, but not very strongly; columellaris beyond the aperture or absent; incidence of morphological overlap with other clades. Differing from the Z. spelaeum clade by the absence of the angularis and the palatalis; differing from the Z. pretneri clade by the shell height and the larger aperture; usually differing (though not always clearly) from the Z. alpestre and the Z. frauenfeldii clade by the expanded last whorl and the presence of spiral lines.
Differing in the LDA from the Z. spelaeum clade by the ratios aw/D1 ( Z. obesum : (1.718–)2.2–2.703, Z. spelaeum : 1.389 – 2.225) and sh/sw ( Z. obesum clade: 1.208 –1.455, Z. spelaeum clade: 1.338 –1.934); from the Z. alpestre clade by the ratios aw/ D1 ( Z. obesum clade: (1.718–)2.2–2.703; Z. alpestre clade: 1.437–2(− 2.202)) and sh/lh ( Z. obesum clade: 1.215 –1.448, Z. alpestre clade: 1.387 –1.739); from the Z. pretneri clade by the ratios lh/D1 ( Z. obesum clade: 2.531(outlier) –4.108, Z. pretneri clade: 1.845 –2.442), aw/lw ( Z. obesum clade: 0.743 –0.917, Z. pretneri clade: 0.517 –0.698).
The morphometric analyses were constrained by the paucity of specimens of Z. exiguum (n = 4). The PCAs (Supplementary Fig. S4 View Fig , top and middle) show some overlap between the two species in this clade, though only little in the measurement-based PCA. The CVA (Supplementary Fig. S4 View Fig , bottom) is able to separate the two species, but the changes in the position of the landmarks (most notably landmarks 1, 4 and 8) are fairly small.
Zospeum obesum ( FRAUENFELD, 1854)
Figures 7 View Fig (a–d), S15a–b, S18f–h
1854 Carychium obesum FRAUENFELD, Verh. zool-bot. Ges. Wien, Abh., 4 (1): 32, 33, 34, pl. [4] fig. 6 (shell) [Grotte von Obergurk (F.J. SCHMIDT leg.; Krška jama, Gorica)].
Type specimens Syntypes: NHMW 58043 View Materials ex coll. Schmidt 361 [ Frauenfeld 1856] syntype; NHMW 71832 View Materials /3 Obergurk in coll. Frauenfeld syntype; NHMW 71833 View Materials /2 ex coll. Schmidt [ Frauenfeld Von 1856] syntype; NHMW 71835 View Materials Obergurk in coll. Frauenfeld syntype.
Specimens examined Slovenia: NMBE 553284 View Materials /2, Krška jama, 1.9.2010, leg. Jochum ; NMBE 553409 View Materials /12, Krška jama, 1.9.2010, leg. Jochum.
Diagnosis Shell ca. 2 mm, ovate-conic in form, with spiral striae, transparent, last whorl expanded, large, oval peristome with a large, often rounded parietal shield, parietalis and columellaris present, the latter only weak.
Measurements (n = 12) sh: 1.84–2.08 mm (mean: 1.983 ± 0.076 mm); sw: 1.38–1.51 mm (mean: 1.439 ± 0.041 mm); ah: 1.11–1.29 mm (mean: 1.196 ± 0.052 mm); aw: 0.96– 1.04 mm (mean: 1.001 ± 0.027 mm); number of whorls: 4.5–5 (mean: 4.813 ± 0.155).
Description Shell ovate-conical, translucent when fresh; tall compared to most of its congeners; weak spiral lines, and sometimes also weak ribs on the upper part of the whorl, are visible on fresh shells; the last two whorls are rapidly expand- ed; aperture relatively large, vaguely oval, taller than wide; parietal shield less pronounced than the lip, its margin a continuation of the lip and thus rounded; parietalis present in the aperture, though small compared to the size of the aperture, extending one whorl into the shell; columellaris usually present in the aperture, disappearing after half a whorl into the shell. Protoconch densely covered with striae of interconnect- ed pits (Supplementary Fig. S15a); teleoconch covered with spiral lines, their number increasing with each whorl (Supplementary Fig. S15b). Radula: The tricuspid rachidian
Pećina kod sela Puhari, sh: 1.524 mm; (q) ditto, sh: 1.436 mm. —(r–t) Zospeum tholussum , (r1–2) NMBE 553334, Lukina jama – Trojama, sh: 1.475 mm; (s) ditto, sh: 1.556 mm; — (t) SMF 341633, Lukina jama – Trojama, sh: 1.502 mm. —(u1–4): Zospeum troglobalcanicum, NMBE 553414, Taleža pećina, sh: 1.327 mm. —(v–x) Zospeum manitaense , (v1–3) Holotype, NMBE 554401, Manita peć, sh: 1.292 mm. — (w) NMBE 549731, Paklenica National park, sh: 1.432 mm. — (x) NMBE 553405, Draženova puhaljka, sh: 1.287 mm. — All phot. × 20; (d, g2, j, t M). Kampschulte, G. Martels, University of Giessen; e, f K. Jaksch-Mason, NHMW; (u3–4), (v1) B. Ruthensteiner, ZSM
tooth of Z. obesum (Krška Jama) is thick and flanked by an equally long endocone and ectocone whereby the endocone does not separate from the mesocone as does the ectocone (Supplementary Fig. S 18g). The left lateral teeth bear a small nub-like ectocone but no endocones. The right laterals bear a reduced and tightly attached endocone and a thick, partially disattached ectocone. Both cusps are the same size, reaching half the length of the mesocone. Some of the right laterals have one endocone and one and a half ectocones. The lateral teeth of Z. obesum show no signs of a median groove. The bicuspid tongue-like lateral teeth are rounded and smooth in appearance. Many cusps are broken. Overall, the laterals imply either an aged or stressed individual or a very old part of the radula (Supplementary Fig. S 18g). The basal plates supporting the lateral crowns are concave directly under the crown. They are long and sinuous and have a concavity on the lower righthand side, resembling those of Pedipes ovalis ( Martins 1996) (Supplementary Fig. S 18g). The crown is as wide as the basal plate and does not extend beyond it in width. The transitional teeth show 3–5 subequal cusps of varying width with partially detached endocones and an occasional detached ectocone. The cusps forming the transitional crown are otherwise melded into each other and do not extend further than the edge of the basal plate. The basal plates are concave directly under the crown. The transitional teeth show general wear and tear via erosion and breakage (Supplementary Fig. S18h). The radula ribbon is long and attenuates to both a comparatively pointed anterior and basal end (Supplementary Fig. S18f). The entire radular ribbon of Z. obesum is comparatively broader than that of Z. exiguum .
Differing from Z. exiguum through its larger size; differing from Z. robustum from Markov ponor through its lack of ribs at the top of the whorl. Differs from Z. exiguum through the ratio ah/D1 being over 2.68, though individuals with a ratio close to that number should also be tested with the ratio ah/aw (range: 1.13–1.26), which should allow a unanimous determination in combination with the ah/D1 ratio.
Distribution (Supplementary Fig. S10) Endemic to central, southern Slovenia, where it is known primarily in the upper parts of the Krka and Kolpa river catchment areas ( Bole 1974).
Remarks Video of CT scans (ESM video) of Z. obesum showing the long intestinal string in relationship to the columella and the inner whorls is viewable via the link. Subsequent investigation of the MHNG 7904 Z. obesum material mentioned in Jochum et al. (2015b) Fig. 6D View Fig ) clarifies that it can not be syntype material as there is no evidence (i.e., no orthographic similarity) that it originated from Frauenfeld nor evidence that it derived from the type locality. However, there is evidence that it derived from Freyer and subsequently was deposited in the Bourguignat collection in Geneva.
Figures 7e–h, S View Fig 15c–d, S17a–d
1932 Zospeum obesum exiguum KUŠČER, Arch. Moll. , 64 (2): 60–61 [Höhle Križna jama^ (= B Kreuzberghöhle^)].
Type specimens Paratype (if not the holotype ( Jochum et al. 2015b Fig. 6h View Fig )): NHMW Edlauer 32,008, original label of Kuščer with the number 2010 (2010a being fixed as Holotype in Kuščer 1932) present.
Specimens examined Slovenia: NHMW Edlauer 49,752/1, Veliki iz Krkinc jama ; NMBE 553384 View Materials /1, Križna jama, 22.6.2009, leg. Jochum. — Croatia: NMBE 548798 View Materials /1, Borušnjak 3 Jama, 25.6.2009, leg. Bedek ; NMBE 548774 View Materials /1, Borušnjak 3 Jama, 25.6.2009, leg. Jalzic.
Diagnosis Shell ca. 1.7 mm, transparent, with some spiral striae, with an ovate-conic form, last whorl expanded, large peristome, parietalis and, sometimes, columellaris present, the latter only weak.
Measurements (n = 4) sh: 1.56–1.82 mm (mean: 1.702 ± 0.102 mm); sw: 1.19–1.33 mm (mean: 1.267 ± 0.056 mm); ah: 0.93–1 mm (mean: 0.961 ± 0.027 mm); aw: 0.79– 0.97 mm (mean: 0.886 ± 0.069 mm); number of whorls: 4.25–5.25 (mean: 4.813 ± 0.427).
Description Shell conical, translucent when fresh; weak spiral striae visible in all populations; smaller than Z. obesum ; the last few whorls expanded in those from Slovenia, but not that strongly in Istria; parietalis present, but not very prominent; columellaris present in specimens from Slovenia, visible in the aperture, disappearing half a whorl into the aperture; columellaris completely absent in Istrian material; protoconch densely covered with pits (Supplementary Fig. S15c), some at the top of the whorl aligned into striae; pits disappearing on the teleoconch (Supplementary Fig. S15d); spiral striae never as prevalent on the teleoconch as in Z. obesum . Radula: The radula of Z. exiguum (Križna jama) shows dense rows of strongly hooked, pointed teeth arching over long slender basal plates (Supplementary Fig. S17c). The bicuspid crowns bear semi-detached endocones on the left side of the long, pointed mesocone (Supplementary Fig. S17b). No ectocones are present. The endocones extend about 1/2–3/4 the length of the central tooth. The transitional teeth bear 4 pointed cusps of uneven lengths per crown (lower lefthand side) (Supplementary Fig. S17d). The upper section of the basal plates is concave directly under each crown. The mesocones are very long in this species (Supplementary Fig. S17d) as is the slender radular ribbon (Supplementary Fig. S17a). The radula is tapered at the anterior end while the proximal end is not visible here. The apparently robust, well-formed teeth suggest a healthy Z. exiguum individual in the prime of life.
Differing from Z. obesum by its smaller size; the Istrian population distinguishable from many smooth-shelled species from the Z. frauenfeldii clade by lacking a columellaris. Differing from Z. obesum by the ratio ah/D1 being over 2.65, though individuals with a ratio close to that number should also be tested with the ratio ah/aw (range: 1.02–1.18), which should allow an unambiguous determination in combination with the ah/D1 ratio.
Distribution (Supplementary Fig. S10) Occurs in the upper parts of the Lubljanica and Kolpa river catchment areas, sometimes together with Z. obesum ( Bole 1974) . Also occurring at a few sites in Croatia ( Slapnik and Ozimec 2004, this study).
Remarks This species is occasionally found in springs, where it apparently can stay submerged for a period of time ( De Mattia 2003).
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Naturhistorisches Museum, Wien |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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