Four Reverse-Coiled Snail Shells from Romania (Gastropoda: Pulmonata)
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North-Western Journal of Zoology Vol. 5, No. 2, 2009, pp.357-363 P-ISSN: 1584-9074, E-ISSN: 1843-5629 Article No.: 051131 Four reverse-coiled snail shells from Romania (Gastropoda: Pulmonata) Barna PÁLL-GERGELY Department of General and Applied Ecology, University of Pécs, Ifjúság útja 6., H-7624 Pécs, Hungary, E-mail: [email protected] Abstract. This paper deals with recent records of reverse-coiled shells of three snail species in Romania: a dextral specimen of Pseudalinda fallax (Rossmässler, 1836) from the mountain of Raru, two sinistral specimens of Alopia livida bipalatalis (M. Kimakowicz, 1883) from the Bucegi Mountains (Gaura Valley), and a sinistral shell of Pyramidula pusilla (Vallot, 1801) from the Apuseni Mountains (Bogha Valley). The dimensions of the reverse-coiled shells lay within the range of variation of normal shells. The frequency of reverse coiling in the family Clausiliidae is evaluated. Key words: Gastropoda, Pulmonata, reverse-coiled shells, chirality, sinistral shell. Introduction proportions in most species. Schilthuizen et al. (2007) suggested the potential for sexual Reverse-coiled specimens and taxa always selection for dimorphism in chirality. In this arouse the interest of malacologists. Several genus matings between dextral and sinistral articles have reported records of unusual individuals occur more frequently than inverse individuals (e.g. Gittenberger 1963, expected by chance. Janssen 1966). Reverse-coiled specimens are The shape of the shell can be of a great not only interesting samples in collections, importance (see Asami et al. 1998). Accord- but they can help us to understand the evo- ing to Gittenberger (1988), more sinistral lution of shell chirality. Species and indi- species are found in high-spired than in viduals of opposite coil, with ranges of vari- low-spired groups. Preece & White (2008) ous sizes, are known in many different taxa mentioned that they have never encounter- of terrestrial pulmonates. They are not ran- ed sinistral specimens of either Carychium domly distributed taxonomically (Gitten- (slender-shelled) or Vallonia (flatshelled), berger 1988). perhaps the most abundant genera found as An important evolutionary feature of fossils in the regions discussed by them the occurrence of coil polymorphism is that (Britain, Ireland and Siberia). in some species it appears stable whereas in Reverse-coiled individuals can be found others it may be extraordinarily rare. In among prosobranch snails as well. Inverse Amphidromus, dextral and sinistral indivi- terrestrial prosobranchs are very infrequent; duals occur sympatrically in roughly equal a sinistral specimen of the cyclophorid ©NwjZ, Oradea, Romania, 2009 North-West J Zool, 5, 2009 www.herp-or.uv.ro/nwjz Oradea, Romania 358 Páll-Gergely, B. Neocyclotus prominulus (d’Orbigny, 1835) re- measurements for the normal specimens occurring ported by Nunes & dos Santos (2007) is a with it. rare example. During field trips in Romania in the last Results three years, I have found four reverse-coiled shells belonging to three taxa: one shell of Family Clausiliidae Pyramidula pusilla (Vallot, 1801) (family Alopia livida bipalatalis (M. Kimakowicz, Pyramidulidae), two shells of Alopia livida 1883) (Fig.1) bipalatalis (M. Kimakowicz, 1883) and one specimen of Pseudalinda fallax (Rossmässler, Collection data: Romania, Munii Bucegi: 1836) (family Clausiliidae). The concho- Valea Gaura, on small limestone and metrical data of these inverse shells are here conglomerate rocks along the tourist path, compared to normally coiled specimens. 2045 m a.s.l. GPS: 45°26'25.6''N, 25°25' 46.0''E, 19/07/2006. Two sinistral shells were found among Material and methods 142 dextral (normal) shells. In total, 952 dextral specimens were collected in the The clausiliids were collected alive by manual sampling, whereas the empty shell of the reverse- valley during the sampling tour, between coiled Pyramidula pusilla was found in a soil sample. altitudes of 1560 m and 2240 m. The living snails were killed after the field trips, so Alopia livida novalis (M. Kimakowicz, there are no data on their soft bodies. 1894) is known from the northern part of the In 2005 I did not have the possibility to measure Bucegi Mountains (“Wald an der Ostseite the precise elevation above sea level of the collected Pseudalinda fallax population. Therefore the data is an des Bucsoi an herabgerollten Felsblöcken” = estimate. Bucoiu). It differs from A. livida bipalatalis, The number of normally coiled specimens which was originally described from ‘Verfu collected from the same precise locality together with Cziganest’ and ‘Val. Czerbului’, only by the the reverse-coiled ones is reported below. The site sinistral shell. Thus, the sinistral specimens names are given in Romanian (Judeul = country, Munii = Mountains, Valea = valley, Vârf = peak). of A. livida bipalatalis looked like A. livida I cannot be sure that the reverse-coiled shells are novalis. However, the dimensions of the the same shape and size as normal shells. Sinistral dextral shells were within the range of Cerion specimens observed by Gould et al. (1985) variation of A. livida biplalatalis (Fig. 4), differed in features of size and coiling from normal whereas the shells of A. livida novalis shells. In contrast, the measurements of a dextral (reverse-coiled) specimen of Albinaria cretensis (paratypes, leg: F. Deubel, 1886) are, on (Rossmässler, 1836) reported by Örstan & Welter- average, larger. Schultes (2002) were found not to differ significantly Dimensions of the sinistral shells: from the group means obtained from sinistral specimen 1: 16.30 mm (height) and 4.46 mm (normal) A. cretensis shells. Therefore, it was (width), specimen 2: 16.83 mm (height) and worthwhile to compare the reverse-coiled clausiliids against measurements of the shell height and width 4.46 mm (width). of one hundred randomly chosen specimens of each taxon. These shells were chosen from the same Pseudalinda fallax (Rossmässler, 1836) (Fig. 2) sample as the reverse-coiled individuals. The sinistral Pyramidula pusilla specimen had a damaged Collection data: Romania, Jud. Suceava, outer whorl. Hence, its size was not compared to Munii Raru, near the path to Hotel Raru North-West J Zool, 5, 2009 Reverse-coiled snails from Romania 359 in a mixed forest of Fagus, Abies and Picea, Family Pyramidulidae on and under decaying wood, south of Pyramidula pusilla (Vallot, 1801) (Fig. 3) Câmpulung Moldovenesc, about 1300 m a.s.l., 25/06/2005. Collection data: Romania, Munii Apuseni, One dextral shell was found among 312 Valea Boghii, near the waterfall, 580 m a.s.l., sinistral (normal) shells. The dimensions of 46º 36' 36.6'' N, 22º 39' 32.5'' E, 9/8/2007 the dextral shell (height: 16.5 mm, width: One sinistral shell with a width of 1.9 4.65 mm) were within the range of variation mm was found among 29 dextral (normal) of the normal shells (Fig. 5). shells. Figure 1. Inverse (right) and normal (left) shell Figure 2. Inverse (left) and normal (right) of Alopia livida bipalatalis (M. Kimakowicz, shells of Pseudalinda fallax (Rossmässler, 1883) (photo by Z. Fehér) 1836) (photo by Z. Fehér) Figure 3. Inverse (left) and normal (right) shells of Pyramidula pusilla (Vallot, 1801) (photo by J. Grego) North-West J Zool, 5, 2009 360 Páll-Gergely, B. The reverse-coiled clausiliids were not taxa, which could have evolved from single isolated from the normal specimens, but reverse-coiled mutants. Examples of dextral were found together. We cannot be sure that taxa from the subfamily Phaedusinae the normal and reverse-coiled specimens of (including Serrulininae) are Hemiphaedusa Pyramidula pusilla belonged to the same inversa (Heude, 1886) and Tsukatosia population. The shells found in a soil Gittenberger, 2000; similar examples from sample could be transported to the the Alopiinae are Albinaria voithii (Ross- collecting site by wind and rainwater from mässler, 1836) and several Alopia H. & A. the surrounding higher mountains. Adams 1855 forms; and from the subfamily Neniinae (including Garnieriinae) Incaglaia dextroversa (Pilsbry, 1947) is a dextral spe- Discussion cies. On the other hand, there are no des- cribed dextral species or subspecies from Of the four reverse-coiled specimens in the the subfamilies Mentissoideinae, Laminife- present, study three (one specimen of rinae and Clausiliinae (including Baleinae). Pseudalinda fallax and two of Alopia livida From this point of view, the record of bipalatalis) have high-spired shells, and one Pseudalinda fallax (subfamily Clausiliinae) (Pyramidula pusilla) has a low-spired shell. may be of significant importance. The lack Gittenberger (1988) argued, on the basis of a of dextral taxa in the above-mentioned three literature survey, that more sinistral subfamilies might be explained by the re- (=reverse-coiled) species are found in high- latively few species. According to Nordsieck spired than in low-spired groups, perhaps (2007) and some other papers published because of greater interchiral mating recently, Phaedusinae consists of 560, success in high-spired species (see also Alopiinae 365, and Neniinae 170 living Davison et al. 2005, Schilthuizen & Davison species, whereas Mentissoideinae has 120, 2005). However, after the review of the Clausiliinae 100 and Laminiferinae 2 recent current literature, Jordaens et al. (2009) species (Nordsieck [2007] classified the showed that our knowledge on gastropod recent members of the family within nine mating behaviour is too limited to detect subfamilies). This does not mean the total general evolutionary trajectories in mating absence of reverse coiled individuals in behaviour of snails. these three minor subfamilies. For example The results of Örstan & Welter-Schultes Degner (1952) reported a dextral Alinda (2002) match my observations: the dimen- biplicata (Montagu, 1803) (as Laciniaria sions of the reverse coiled shells were with- biplicata, subfamily Clausiliinae) and László in the range of dispersion of the normal Németh collected a dextral specimen of shells (A. livida bipalatalis: Fig.4; P. fallax: Roseniella sobrievskii (Lindholm, 1913) Fig.5). (subfamily Mentissoideinae) in Turkey (L. Several reverse-coiled individuals have Németh, pers.