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Taxonomical clarification of the Iberian endemic Helicella (Xerotricha) mariae Gasull, 1972 (Gastropoda, Pulmonata Hygromiidae) PDF

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Preview Taxonomical clarification of the Iberian endemic Helicella (Xerotricha) mariae Gasull, 1972 (Gastropoda, Pulmonata Hygromiidae)

B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 147 BASTERIA, 72: 147-154, 2008 Taxonomical clarification of the Iberian endemic Helicella (Xerotricha) mariaeGasull, 1972 (Gastropoda, Pulmonata Hygromiidae) Alberto MARTÍNEZ-ORTÍ Departamento de Zoología. Facultad de Biología. Universitat de València. Av/ Dr. Moliner, 50. 46100 Burjassot (Valencia, Spain) and Museu Valencià d’Història Natural. [email protected] The type series of the Iberian endemic hygromiidHelicella mariae was studied conchologically, with the purpose of clarifying its taxonomic status. This study compares protoconch and teleo- conch microsculpture and hairs of Helicella mariae and the most similar hygromiid species Microxeromagna loweiand Xerotricha conspurcata. The study of dried specimens of Helicella mari- ae found inside some shells was inconclusive because of the specimens’ immaturity. Based on the conchological characters examined and on distributional data, Helicella mariaemust be con- sidered a junior synonym of Xerotricha conspurcata. The distribution map in the Iberian Peninsula for this species is shown. Key words: Gastropoda, Pulmonata, Hygromiidae, Helicella,Xerotricha, taxonomy, endemism, Spain, Portugal. INTRODUCTION Since its description by Gasull in 1972, the taxonomic status of the hygromiid Helicella (Xerotricha) mariaehas been considered uncertain. It was collected from a single locality in the southeast of the Iberian Peninsula in the province of Almería [“Sierra de Gata, Sabinal ravine, Mediodía summits (19-1-1973)”; UTM: 30SWF76]. The description and generic assignment of Helicella (Xerotricha) mariaewere based on conchological characteristics only. The reproductive system of three syntypes was studied by Dr. Edmund Gittenberger (in Gasull, 1972), but these were found to be sexually imma- ture. The subgenus was named with some doubts as shown by Gasull (1972: 72) when he wrote Helicella (Xerotricha?) mariae, in the lower part of the figure, with a question mark. This suggests that he assigned it uncertainly to Helicella (Xerotricha)for its conchological similarity, mainly its hairiness, which it shared with Helicella (Xerotricha) conspurcata. Currently, Xerotricha Monterosato, 1892 is a valid genus, different from Helicella within Hygromiidae according to Giusti & Manganelli (1989), who elevated it to genus. Puente (1994: 473) named it Helicella (?) mariaeand Arrébola (1995: 471) Xerotricha (?) mariae. Both authors indicate the necessity to know the genital anatomy of this taxon in order to con- firm its generic placement. Xerotrichacan be distinguished from Helicella by its dart-sac complex. The dart-sac complex of Helicellahas two reduced and externally invisible acces- sory sacs, which are somewhat visible in Xerotricha, and two dart-sacs are more developed in Helicellathan in Xerotricha. In addition, Helicella has an interior elliptic wall in the dart- sac complex, which is absent in Xerotricha, and there are two connected tongue-like struc- tures in Helicella, with independent apical in Xerotricha. Moreover, Arrébola indicates that the available conchological data on this taxon do not allow for a clear differentiation from other similar taxa, such as Xerotricha conspurcata (Draparnaud, 1801) (Arrébola, 1995) or Microxeromagna lowei (Potiez & Michaud, 1835) (pers. comm.). MicroxeromagnaOrtiz de Zárate, 1950 is characterized by having one dart- B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 148 148 BASTERIA, Vol. 72, No. 4-6, 2008 Figs 1-12, Some Spanish hygromiids. 1-3. Lectotype of Helicella mariae Gasull, 1972 (diameter (Ø)=5.8 mm). 4-6. Paralectotype of H. mariae(Ø=5.25 mm). 7-9. Xerotricha conspurcata(Muro d’Alcoi, river Serpis, Alicante province, Spain) (Ø=6.51 mm). 10-12. Microxeromagna lowei (Ayora, Meca, Valencia province, Spain) (Ø=5.16 mm). sac, with one dart, and an accessory sac partially joined on one side of the vagina. Both Xerotricha conspurcata and Microxeromagna lowei are also present in the province of Almería. Arrébola (1995) also indicates that, according to Gasull (1972), H. mariaediffers from X. conspurcata, because it has more depressed shells with an incipient keel and more B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 149 Martínez-Ortí: Taxonomical clarification of Helicella (Xerotricha) mariae 149 Figs 13-21, Shell details of Helicella mariae. 13-16. Protoconch. 13. Lectotype (bar (b)=400 µm). 14. Paralectotype (b=200 µm). 15. Sculpture (b=30 µm). 16. Hairs (b=30 µm). 17-21. Teleoconch hairs (17-18. b=200 µm; 19. b=70 µm; 20. b=70 µm; 21. b=30 µm). B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 150 150 BASTERIA, Vol. 72, No. 4-6, 2008 Figs 22-29, shell sculpture of some Spanish hygromiids. 22-25. Xerotricha conspurcata. 22. Protoconch sculp- ture (bar (b)=300 µm). 22-24. Hairs and sculpture of teleoconch (21. b=100 µm; 22. b=200 µm). 25. Protoconch sculpture (b=50 µm). 26-29.Microxeromagna lowei. 26-28. Hairs and sculpture of teleoconch. (26. b=300 µm); 27. b=100 µm; 28. b=80 µm). 29. Detail of the protoconch (b=80 µm). B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 151 Martínez-Ortí: Taxonomical clarification of Helicella (Xerotricha) mariae 151 regular ribs. Recently, Ruiz, Cárcaba, Porras & Arrébola (2006) named it Xerotricha mariae and indi- cate that it has never again been found in its type locality nor in the rest of the Sierra de Gata, in spite of detailed sampling. Thus both its presence and its taxonomical validity must be confirmed. Finally, Martínez-Ortí & Uribe (2008) listed the type series of Helicella (Xerotricha) mariae, as well as the number of syntypes. Besides the lectotype, which corresponds to the specimen figured by Gasull (1972: 72), there are 10 paralectotypes (shells), in the Museu de Zoologia of Barcelona, and three paralectotypes (shells) in the Nationaal Natuurhistorisch Museum-Naturalis in Leiden (The Netherlands). Martínez-Ortí & Uribe (2008) also indicate that both their taxonomical validity and their generic placement in the Family Hygromiidae, are yet to be confirmed. In this work, conchological characteristics of Helicella mariae, such as protoconch and teleoconch hairs and microsculpture, are compared with those in X. conspurcata and M. lowei, to verify if it can be assigned to either genus and/or species. Furthermore, I have tried to obtain information about the genitalia of the dried specimens, extracted from two of the shells of the type series, which could support the generic assignment of H. mariaein the Family Hygromiidae. MATERIAL AND METHODS The type series deposited in the Museu de Zoologia of Barcelona has been revised. [lectotype nº84-8396A (shell) and paralectotypes nº84-8396B (10 shells)] (Martínez-Ortí & Uribe, 2008). This sample contains two labels. One of them indicates that the collected date is 14-II-1962, which is considered correct, and the other label 19-I-1973, can be considered a mistake, for the paper’s publication date is 1972. In the type material microphotographies of H. mariae, realized in the HITACHI S-4100 Scanning Electron Microscope, the habitual coat with gold-palladium was not used in order not to alter the characteristics of the shell, whilst it was used on the specimens of M. loweiand X. conspurcata. The extracted dried specimens from inside the shell of the lecto- type and of one paralectotype were softened with sodiumphosphate and permanent slides were made, in the case of the lectotype, whereas the paralectotype was preserved in ethanol 70%. The localities of the photographed specimens of X. conspurcatain this manuscript cor- respond to Muro d’Alcoi, river Serpis (Alicante) (Figs. 7-9), Benissa, Cala Baladrar (Alicante) (Fig. 25), l’Alcudia, Magro river (Valencia) (Figs. 23-24) and the vineyards of the Pobla del Duc (Valencia) (Fig. 22), and the ones of M. loweicorrespond to Ayora, la Meca (Valencia) (Figs. 10-12) and the vineyards of the Puebla del Duc (Valencia) (Figs. 26-29). RESULTS AND DISCUSSION Shell morphological data. -- The shell of H. mariaeshows periostracal hairiness on the pro- toconch (figs. 13, 14 and 16) as well as on the teleoconch (figs. 17-21). This hairiness can be partially lost when shells become older. However, Helicellalacks hairs and hair-pits on the protoconch and the teleoconch, both in its young and older stage (Arrébola, 1995; Martínez-Ortí, 1999). The protoconch sculpture of H. mariae (fresh or older shells) consists of thin parallel spiral lines (fig. 15), that disappear on the teleoconch, which has an irreg- ular reticulated surface (figs. 19-21), as in X. conspurcata and M. lowei (Giusti & Manganelli, 1989; Giusti, Manganelli & Schembri, 1995). B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 152 152 BASTERIA, Vol. 72, No. 4-6, 2008 Fig. 30. Distribution map of Xerotricha conspurcata in the Iberian Peninsula based on Puente 1994, Martínez-Ortí, 1999; Ruiz et al., 2006 and new data (dot: Locus typicusof Helicella mariaeGasull, 1972). In the description of H. mariae, Gasull (1972) only points out that the hairs are thin, without giving further information about them. However, in my detailed study I show that the hairs are long and curved in their distal half portion (figs. 17-21), where they are much thinner, even creating a loop (fig. 19), as Gasull (1977) already indicated for X. con- spurcata. The hairs of the X. conspurcataand M. loweito which H. mariaehas been compared, show a different morphology. According to different authors such as Gasull (1977), Giusti & Manganelli (1989), Puente (1994), Arrébola (1995), Puente & Altonaga (1995), Martínez- Ortí (1999, 2000), Ruiz et al. (2006), amongst others, the hairs of X. conspurcataand M. lowei differ in length and density. In M. loweithey are shorter and more abundant whilst in X. conspurcatathey are longer and less abundant (figs. 22-14; 26-28). This is most evident in both species’ younger specimens. With respect to the density, distribution, abundance and morphology of the proto- and teleoconch hairs, Helicella mariae (fig. 17-21) is similar to Xerotricha conspurcata(figs. 22-24) and different from Microxeromagna lowei(fig. 26-28). Besides, the colour patter in H. mariae(figs. 1-6) is much more similar to X. conspurca- tathan M. lowei, for the presence of many white flecks (figs. 7-9). The protoconch and teleoconch sculpture (figs. 15, 16, 25, 29) (figs. 21, 23, 27) in the three taxa is very similar, with the presence of numerous parallel thin spiral lines. This protoconch morphology is common in many other hygromiids, such as in Helicella Férussac, 1821 (Martínez-Ortí, 1999, 2006), Microxeromagna Ortiz de Zárate, 1950(Giusti & B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 153 Martínez-Ortí: Taxonomical clarification of Helicella (Xerotricha) mariae 153 Manganelli, 1989), Trochulus Chemnitz, 1786 (Martínez-Ortí, 2006), Xerocrassa Monterosato, 1892 (Martínez-Ortí, 1999, 2000, 2006) or Xerotricha Monterosato, 1892 (Giusti & Manganelli, 1989; Giusti et al., 1995). Hence, it is not a valid character to assign to one of these genera. Other morphological characters pointed out by Gasull (1972) for H. mariae, such as size, thin and regular ribbing in the dorsal area, small umbilicus, a discontinuous cutting and non-reflected peristome, the nearly imperceptible presence of incipient keel and almost round and somewhat oblique aperture, can be also valid for X. conspurcataand/or M. lowei (figs. 1-12). Later Gasull himself (1977) and Puente & Altonaga (1995) indicate the conchological similarity between the last two taxa, and consequently with H. mariae. Data about the reproductive system morphology. —The two dried bodies studied of H. mariae, from the lectotype and from one paralectotype, showed neither dart-sacs nor darts, due to the fact that the examined specimens had not reached sexual maturity, as was also the case with the other three paralectotypes examined by Gittenberger (in Gasull, 1972). Therefore the genital-anatomical study does not allow me to assign H. mariaeto either the genus Xerotrichaor the genus Microxeromagna. Distribution. — Helicella mariae is known from only one locality of the Natural Parc of Cabo de Gata in Almería (fig. 30), where it has never been found again (Ruiz et al., 2006; Arrébola, pers. comm.), despite intense prospecting realized in this area in the last years. On the other hand, both M. lowei and X. conspurcata are well known species in the Iberian Peninsula; and both are widely distributed in Andalusia as well. X. conspurcatais scarcer in the province of Almería (fig. 30) (Puente, 1994; Puente & Altonaga, 1995; Arrébola, 1995; Martínez-Ortí, 1999; Ruiz et al., 2006; own data). CONCLUSIONS The conchological results obtained confirm that Helicella mariae does not belong to genus Helicella, as this genus lacks hairs and hair-pits, on the protoconch and the teleo- conch. Therefore, H. mariae must be reassigned to another genus in the Family Hygromiidae. The morphological characteristics of the shell in general, and especially the morphology and density of the hairs observed in H. mariae coincide with those present in Xerotricha conspurcata. Finally the locus typicusof H. mariaeis situated within the distribu- tion area of Xerotricha conspurcata in Andalusia and in the Iberian Peninsula (Fig. 30). Therefore, I conclude that Helicella (Xerotricha) mariaeGasull, 1972 must be considered a junior synonym of Xerotricha conspurcata(Draparnaud, 1801). ACKNOWLEDGMENTS To Professor Dr. Edmund Gittenberger who taught me, among many other things, the technique of dried specimen re-hydration. Also to Dr. Francesc Uribe who loaned the type material of Helicella mariae, Wim J. M. Maassen for the information on the syntypes deposited in the Natuurhistorich Museum-Naturalis of Leiden and Dr. José Ramón Arrébola for the information on the non-successful findings of this species in the last years in the type locality. Finally, to the “Sección de Microscopía Electrónica del S.C.S.I.E.” of the Universitat de València for their help using the SEM. B72(4-6)_totaal-backup_corr:Basteria-basis.qxd 15-9-2008 10:35 Pagina 154 154 BASTERIA, Vol. 72, No. 4-6, 2008 REFERENCES ARRÉBOLA, J.R., 1995. Caracoles terrestres (Gastropoda, Stylommatophora) de Andalucía con especial referencia a las provincias de Sevilla y Cádiz. — PhD. Universidad de Sevilla, 589 pp., Sevilla. GASULL, L., 1972. Una nueva Helicella de la provincia de Almería, Helicella (Xerotricha) mariaen. sp. — Boletín de la Sociedad Española de Historia Natural de Baleares, 17: 71-72. GASULL, L., 1977. Presencia de la Helicella Cernuella (Microxeromagna) vestita(Rambur) (Mollusc. Pulm.) en la isla de Mallorca. — Boletín de la Sociedad de Historia Natural de Baleares, 22: 179-182. GIUSTI, F. & G. MANGANELLI, 1989. Notulae malacologicae, XLIV. A new Hygromiidae from the Tyrrhenian islands of Capraia and Sardinia with notes on the genera Xeromicra and Xerotricha (Pulmonata: Helicoidea) (Studies on the Sardinian and Corsican malacofauna, VIII). — Bolletino Malacologico, 25(1-4): 23-62. GIUSTI, F., G. MANGANELLI & P.J. SCHEMBRI, 1995. The non-marine molluscs of the Maltese Islands. Monografie XV, Museu Regionale di Scienze Naturali, 607 pp., Torino. MARTÍNEZ-ORTÍ, A., 1999. Los moluscos terrestres testáceos de la Comunidad Valenciana. — PhD. Universitat de València. 743 pp., Valencia. MARTÍNEZ-ORTÍ, A., 2000. Descripción de Trochoidea (Xerocrassa) roblesi spec. nov. (Mollusca, Gastropoda, Hygromiidae) de la Comunidad Valenciana (España). — Iberus, 18(2): 31-39. MARTÍNEZ-ORTÍ, A., 2006. Descripción de un nuevo higrómido ibérico: Xerocrassa edmundispec. nov. (Gastropoda, Pulmonata). — Iberus, 24(2): 61-68. MARTÍNEZ-ORTÍ, A., & F. URIBE, 2008. Los ejemplares tipo de las colecciones malacológicas del Museu de Ciències Naturals de Barcelona y del Museu Valencià d’Història Natural. — Arxius de Miscellànea Zoològica, vol. 6: 1-156. PUENTE, A.I., 1994. Estudio taxonómico y biogeográfico de la Superfamilia Helicoidea Rafinesque, 1815 (Gastropoda: Pulmonata: Stylommatophora) de la Península Ibérica e Islas Baleares. — PhD. Universidad del País Vasco, 970 pp, Bilbao. PUENTE, A. I., & K. ALTONAGA,1995. Estudio morfológico y corológico de dos especies conquiológi- camente similares, Helicella conspurcata(Draparnaud, 1801) y Microxeromagna armillata(Lowe, 1852), en la Península Ibérica e islas Baleares (Pulmonata: Helicoidea: Hygromiidae). — Zoología baetica, 6: 121-148. RUIZ, A., A. CÁRCABA, A.I. PORRAS & J.R. ARRÉBOLA, 2006. Caracoles Terrestres de Andalucía. Guía y manual de identificación. — Junta de Andalucía ed., 303 pp., Sevilla.

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