Spixia martensii ( Doering 1874 )

Oroño, Eugenia Salas, 2007, Taxonomic review of the Spixia pyriformis species complex (Gastropoda: Pulmonata: Odontostominae), Zootaxa 1498, pp. 1-25 : 9-14

Spixia martensii ( Doering 1874)

( Figures 15–26 )

Odontostomus martensii Doering, 1874: 455 .

Odontostomus martensii Doering, 1875: 181 .

Bulimus (Odontostomus) martensii Kobelt, 1876: 8 . Bulimus (Odontostomus) martensii Pfeiffer, 1877: 8 . Odontostomus (Spixia) martensii Pilsbry, 1901 /2: 89. Odontostomus (Spixia) martensii Parodiz, 1942b: 323 . Cyclodontina (Spixia) martensii Parodiz, 1957: 26 . Scalarinella (Spixia) martensii Zilch, 1971: 201 . Spixia martensii Fernández, 1973: 131 .

Lectotype: SMF 9454 a

Paratype 1: MACN 23139 (the only paratype investigated)

Type locality: Argentina, Córdoba, Totoral.

Shell ( Fig. 15 ): Subpyriform elongated, 8 1/2 whorls, first ones convex, less convexity in last two ones. Color light brown slightly cupreous with irregular whitish axial bands. Protoconch with slim, axial ribs, parallel, slightly curved on superior edge, among ribs, ultraestructure surface consisting in perpendicularly micro bands cutting axial ribs ( Fig. 16 ). Second whorl from protoconch, smooth in appearance. Teleoconch sculpture with axial oblique wrinkles. From third whorl to sixth, three spiral major rows, elevated, not continuous, on each whorl. Triangular lamellae inserted on these major rows ( Fig.17–18 ). Between each major row, 4 to 6 spiral minor rows slightly undulated in zigzag, separated by regular spaces. Departing from each row, grow axial micro folds, not straight, connecting each other in the center; under them horizontal fine lines form a grillwork together with the previous ones ( Fig. 19 ). Suture simple, slightly pronounced. Aperture ovate, wide, peristome slightly reflex. Parietal callus present, of medium development. Aperture with one tooth, four lamellae. Suprapalatal tooth shallowly developed or absent. Palatal lamellae with concave sides and bulky edge, slightly oblique respect peristome. Basal lamellae narrow. Columellar lamellae concave in its superior side, perpendicular, oblique from peristome. Parietal lamellae stretched ( Fig. 15 ).

Shell Measurements: Paratype 1: H: 19; D maj: 7; H ap: 7; D ap: 5. FML 14785 (n=3): H: 20.7–22 (Median: 21.2); D maj: 6.5– 7.03 (Median: 6.8); H ap: 6.7–8 (Median: 7.2); D ap: 4.8–5.8 (Median: 5.2); Ang sp: 25º–34º (Median: 30.6º); Ang max: 131º–145º (Median: 135.2º). FML 14786 (n=3): H: 19–20 (Median: 19.4); D maj: 6–6.3 (Median: 6). H ap: 6.4–6.6 (Median: 6.5); D ap: 4.2–4.8 (Median: 4.5); Ang sp: 26º–37º (Median: 3.2º); Ang max: 130º–136º (Median: 132.7º). FML 2825 (n=3): H: 19–20.5(Median: 19.7); DM: 6– 6.5(Median: 6.2); H ap: 7–7.5(Median: 7.2); D ap: 4.3–4.8 (Median: 4.5); Ang sp: 27º–33º (Median: 29.3º); Ang max: 133º–136º (Median: 134.3º). FML 1158 (n=3): H: 19.5–24 (Median: 21.5); D maj: 6–7.5 (Median: 6.9); H ap: 7–7.7 (Median: 7.4); D ap: 4–5.2 (Median: 4.7); Ang sp: 28º–35º (Median: 32.2º); Ang max: 126º– 135º (Median: 131.2º).

Digestive System: Jaw arcuate, light brown, lustrous, formed by 16 imbricate plaques ( Fig. 20 ). Plaques show fine transversal irregular lines. Most external plaques double size respect to central ones. Inferior border of jaw with irregular outline due to projections of plaques. Radula identical with S. doellojuradoi . Central tooth tricuspid, lateral teeth bicuspid, marginal teeth tricuspid.

Pallial System: Idem to S. doellojuradoi . Kidney length 1/4 of pulmonary roof.

Reproductive System: ( Fig. 21 ) Ovotestis consisting of five bunches of acini. Each one fan shaped, digitiform, ramified, orange-yellowish homogeneous. Free oviduct short and narrow 1/6 of spermoviduct total length. Bursa copulatrix duct 1/4 longer than spermoviduct, with distal portion enlarged. Vagina 1/3 of penis length, inner wall consisting of folds with small irregular pustules.

Phallic complex comprised by penis, epiphallus, and flagellum. Flagellum short, filiform. Epiphallus twice the length and diameter of flagellum. Inner wall of penial area I with small folds ( Fig. 22–23 ). Penial gland short, rounded. Penial area II with two ovate projections of numerous festoon shaped rows circularly arranged leaving circular small spaces. Within distal portion of area II a lateral pilaster running towards to area IV is present. Wall of penial area III with rows in zigzag, V shaped, becomes longitudinal towards area V. Penial area V smooth, with longitudinal folds, semi undulated, until atrium. Retractor muscle inserted externally at proximal portion of area II. Vas deferens short, stacked to retractor muscle; running independently parallel to epiphallus. Penial sheath short thin, located at distal portion of penis.

Habitat: Spixia martensii lives under rocks and among roots and basal portions of small shrubs

Distribution: Argentina, Cordoba Province, Punilla and Totoral departments. Area of distribution of the present species is part of the Chaco biogeographic area in Argentina delimited by Morrone (2006).

Remarks: Spixia martensii is highly variable in shell size. Due to the variability in the body whorl’s diameter within the present species, the subpyriform shell shape may not be so evident in some specimens ( Fig. 24 ). Shell wrinkles, that are characteristics of the body whorl in this species, are sometimes not conspicuous even when the periostracum is well preserved. Shell sculpture until 6 1/2 whorl on both adults and juveniles, is similar to that of Spixia tucumanensis . However, in S. martensii the spiral major rows are not continuous, whereas in S. tucumanensis complete rows are present. In the paratype of S. martensii studied, the periostracum is lost so the observations on the shell sculpture are limited. In some specimens of S. martensii collected alive, a marked change of shell sculpture at the level of the sixth whorl was observed. The spiral rows are replaced by grooves that combined with axial wrinkles give a network appearance to the last whorls surface. In some specimens, although having a complete periostracum, the spiral rows disappear at whorl six with vestiges of spiral grooves left ( Fig. 25–26 ). The change in sculpture described for S. martensii is not present in the other species of the complex studied except for S. tucumanensis . The shell sculpture described is present in juvenile specimen as well as in adult specimens. The structure of periostracum in S. martensii was not previously described or illustrated before by any author and the spiral rows and lamellae inserted on them where not mentioned either in previous descriptions. The pallial gland is usually smaller than in S. doellojuradoi .

Concerning the reproductive system, the penial gland is small, rounded, similar to S. pyriformis and different from the rest of the species complex where the penial gland is short and triangular. The inner sculpture of penial wall is different from the other species except for penial areas I and V, that are similar to the other species. The penial area II is completely different from the other species, because the present species has a different arrangement of the rows, ordered into two conspicuous projections festoon shaped. The penial area III and area IV in S. martensii is similar to the same area in S. doellojuradoi , but showing V-shaped rows more twisted and tighter. In the present species the insertion point of retractor muscle is at proximal portion of penial area II, similar than in S. pyriformis and different from the rest of species of the complex where the insertion of the retractor muscle is in the area I.

The type locality in Doering´s original description is not clearly specified. He indicated it as “Cordoba, Totoral”. However, Totoral is an entire political department of Cordoba Province in central Argentina. In Totoral department neither dead nor alive material was found by the author. Also, most of the material currently deposited at the Museums, except for the paratypes, is from Punilla, Ischilín, Tulumba and Calamuchita departments from Cordoba. Parodiz (1942b) reported that the distribution of S. martensii ranges from Cordoba, Catamarca to Tucumán. Nevertheless, no material of this species was yet found alive in field in Catamarca and Tucumán provinces. We now can extend the range of this species to Salta Province in north-western Argentina, where a group of specimens was found close to Juramento River. New field work and extensive collections are needed to precise the real distribution of S. martensii in Argentina.

Specimen Record: FML 661(DM): Córdoba, Ischilín dept. Ischilín, Sierra Chica, M.I. Hylton Scott, 1962 leg. FML 706 (DM): Córdoba, Punilla dept. Near Villa Carlos Paz, 700 m, savanna with shrubs, small hills of rocks, 23/03/1967, W. Weyrauch leg. FML 708 (DM): Córdoba, Punilla dept. Capilla del Monte, 1000 m, 26/ 02/1967, W. Weyrauch leg. FML763 (DM): Córdoba, Ischilín dept. Ischilín, Sierra Chica, 1962, M.I. Hylton Scott leg. FML 950 (DM): Córdoba, Punilla dept. Near Capilla del Monte, 1050 m, 24/12/1967, W.Weyrauch leg. FML 1158 (DM): Córdoba, Punilla dept. Capilla del Monte, 1050 m, 24/11/1961, W. Weyrauch leg. FML 2001 (DM): Córdoba, Sierras de Córdoba, W.J. Ejerdam leg. FML 2441(DM): Córdoba, Punilla dept. 2 km south of Capilla del Monte, on the road to La Cumbre, 950m., 04/04/1969, W.Weyrauch leg. FML 2825 (DM): Córdoba, Punilla dept. Calabalumba River, north of Capilla del Monte, 10/02/1970, W. Weyrauch leg. FML 14784 (DAM): Córdoba, Punilla dept. Capilla del Monte, 4 km on the road to Los Cocos, over a wall of rocks near route, 30º 53’20’’S 64º 32’ 04’’W, 1028 m, 12/07/2005, E. Salas Oroño leg. FML 14785 (DAM): Córdoba, Punilla dept. Los Cocos near La Cumbre, road parallel to the route, 30º 56’ 30’’S 64º 29’ 33’’W, 1225 m, 12/07/2005, E. Salas Oroño leg. FML 14786 (DAM): Punilla dept. Casa Grande near Vaquerías River East of route 38, 31º 08’ 53’’S 64º 28’ 34’’W, 810 m, 13/07/2005, E. Salas Oroño leg. FML 14787 (DAM): Córdoba, Punilla dept. Capilla del Monte, rocks at 100 m of route 38, 30º 51’ 10’’S, 64º 31’ 53’’W, 973 m, 12/07/2005 alive specimens under rocks, E. Salas Oroño leg. FML 14790 (DAM): Córdoba, Punilla dept. 1 km north of Capilla del Monte, on a hill with rocks, 30º 51’ 09’’S 64º 31’ 55’’W, 900 m, 16/01/2006, E. Salas Oroño leg. FML 14791 (DAM): Córdoba, Punilla dept. Casa Grande near Vaquerías River East of route 38, 31º 08’ 53’’S 64º 28’ 34’’W, 810 m, 17/01/2006, E. Salas Oroño leg. FML 14792 (DM): Salta, road to Cabra Corral, road parallel to route 9, margins of Juramento River, 25º 14’ 40’’S 65º 12’ 59’’W, 850 m, 28/ 02/2000, M. G. Cuezzo leg. FML 14797(DAM): Córdoba, Tulumba dept. 3 km from San José de La Dormida on the road to Tulumba, 30º 22’ 36’’S 63º 58’ 82’’ W, 488 m, 16/03/2006, M. G. Cuezzo and E. Salas Oroño leg.

Figures

FIGURE 24. Spixia martensii: Size and shape variation of shells, scale bar: 10 mm.

FIGURES 15 – 20. Spixia martensii. 15. Paratype MACN 23139.16. Dorsal view of protoconch and next whorl smooth, scale bar: 100 Μm. 17. View from protoconch to sixth whorl of a juvenile shell. Note spiral rows and lamellae, scale bar: 1 mm. 18. Third and fourth whorl with spiral major rows with lamellae and minor files, scale bar: 1 mm. 19. Detail of sculpture in fourth whorl, spiral major row with lamella and minor rows with micro folds, arrow points to horizontal fine line, scale bar: 100 Μm. 20. Jaw with central plaques, scale bar: 100 Μm.

FIGURES 21 – 23. Spixia martensii. 21. Reproductive system dissected out, scale bar: 5 mm. 22. Phallic complex inner wall, scale bar: 5 mm. 23. Detail of constriction and widening area II and part of area III, scale bar: 2 mm. Abbreviations: A: atrium; Ag: albumen gland; Bc: bursa copulatrix; Bcd: bursa copulatrix duct; Ca: constriction area ;; Ep: epiphallus; F: flagellum; Hd: hermaphroditic duct; Lf: longitudinal folds; Ov: oviduct; P: penis; Pg: penial gland; Pi: pilaster; Piw: penis inner wall; Pr: prostate; Pro: projections; Ps: penial sheath; Piw: penis inner wall; Rm: retractor muscle I: proximal portion; II: widening area; III: proximal medial portion; IV: distal medial portion; V: distal portion.

FIGURES 25 – 26. Spixia martensii. 25. Shell with and without periostracum, arrow points to spiral row, scale bar: 1 mm. 26. Detail of shell with and without periostracum showing the grooves left by spiral rows, arrow points to groove, scale bar: 1 mm.