Morphology and systematics of the genus Alopia H. & A. Adams (Gastropoda, Stylommatophora, Clausiliidae)

Hartmut Nordsieck (I.2016)

Systematic position

The genus Alopia belongs (together with the genera Herilla H. & A. Adams and Triloba Vest) to the subfamily Alopiinae, tribe Alopiini.
According to DNA analysis (Uit de Weerd & Gittenberger 2013: fig. 3) it is near to Herilla (and Montenegrina O. Boettger, but on morphological grounds the latter can be excluded as near relative).
The inner lamellae endings are developed like in other Alopiinae (Fig. 1): spiral lamella less deeply penetrating than inferior lamella, subcolumellar lamella ending on columella without an inner part.


Fig. 1. A. p. plumbea, Braşov, ex SMF 234001 (phot. S. Hof).
Shell opened, to show inner lamellae endings; shell height = H 17.8 mm.
Abbreviations: il = inferior lamella, sc = subcolumellar lamella, sp = spiral lamella.  

Diagnosis, distribution
Diagnosis: Shell left- or right-coiled; clausilial apparatus = CA like in other Alopiini (with clausilium plate notched), with middle palatal plica(e) instead of lunella, well-developed to strongly reduced.
Genitalia like in other Alopiini (with penial caecum instead of papilla); diverticulum of bursa copulatrix shorter than or about as long as bursa + proximal pedunculus, in one group also longer; penis mostly shorter than vagina, caecum well-developed or more or less reduced; in some groups male copulatory organs lengthened.
Distribution (Fig. 2): W., S. and E. Carpathians from Vl. Cernei and M. Bihorului to M. Vrancei and M. Ceahlău (one species also N. Carpathians near Turňa), including Transylvanian highlands, Carpathian mountains and Wallachian Carpathian borderland.


Fig. 2. Distributional range of Alopia, with subdivision (see text). 

Subdivision

The following subdivision into species is based on morphology; the COI analysis carried out by Fehér et al. (2013: fig. 2) is also considered.

A. (Alopia)
Transylvanian highlands:
A. bielzii (L. Pfeiffer 1849),
A. bogatensis (Bielz 1856),
A. meschendorferi (Bielz 1858).
Wallachian Carpathian borderland:
A. grossuana H. Nordsieck 1977,
A. mafteiana Grossu 1967.
S. Carpathian mountains from W to E:
A. subcosticollis (A. Schmidt 1868),
A. hildegardae R. Kimakowicz 1931,
A. hirschfelderi H. Nordsieck 2013,
A. glorifica (Charpentier 1852),
A. lischkeana (Charpentier 1852),
A. plumbea (Rossmässler 1839),
A. regalis (M. Bielz 1851),
A. straminicollis (Charpentier 1852),
A. livida (Menke 1828),
A. canescens (Charpentier 1852),
A. nefasta (Kimakowicz 1894),
A. helenae R. Kimakowicz 1928.
(Bucegi, higher parts):
A. nixa (Kimakowicz 1894),
A. fussi (Kimakowicz 1894).

A. (Kimakowiczia)
W., S. and E. Carpathians:
A. glauca (Bielz 1853),
A. maciana Bădărău & Szekeres 2001,
A. pomatias (L. Pfeiffer 1868).

Annotations:

1. The following enantiomorph forms, which are nearly indistinguishable, are provisionally classified within one species:
A. grossuana + A. nemethi Deli & Szekeres 2011,
A. helenae + A. zagani Szekeres 1969,
A. nefasta + A. mauritii R. Kimakowicz 1928.
A. helenae and A. zagani occur sometimes syntopically. A. nefasta and A. mauritii have slight morphological differences. The rank of these enantiomorphs should therefore be checked.
.
2. A. bogatensis angustata (Bielz 1859) is possibly an independent species, because its range overlaps that of A. b. bogatensis (central Perşani mountains) without transitions.

3. A. glorifica alpina R. Kimakowicz 1933 is morphologically like A. glorifica. The diffent position in COI analysis could be due to hybridization with the neighbouring A. nixa; its systematic position should therefore be checked.

4. According to COI analysis, A. grossuana and A. mafteiana are independent species. They have plesiomorphic shell charascters and are thus hardly distinguishable from A. subcosticollis and A. glorifica, respectively (which include subspecies with such characters); therefore until now they have been classified within these species.

5. A. hirschfelderi is an independent species (COI analysis by Hausdorf w. c.).

6. A. nefasta mauritii is not conspecific with A. canescens, as assumed until now. This result of COI analysis is confirmed by morphological differences (see diagnoses) and its range overlapping that of A. c. canescens (Valea Tigăile) without transitions.

7. According to COI analysis, A. regalis is an independent species. This is confirmed by morphological differences to A. plumbea (see diagnoses) and the presence of a basal form of A. regalis of its own (from Piatra Crinului).

8. The classification of farly disjunct forms recognized by COI analysis has been confirmed in all cases by shell morphology (in brackets direction of disjunction):
Two are known as disjunct forms since a long time:
A. bielzii clathrata (Bielz 1856) (NW),
A. livida julii A. J. Wagner 1914 (W).
Others have not been recognized as disjunct forms until now:
A. glorifica vranceana Grossu 1967 (E),
A. regalis petrensis H. Nordsieck 1996, A. r. nordsiecki Grossu & Tesio 1973 (both W),
A. straminicollis monacha Kimakowicz 1894 (peregrina R. Kimakowicz 1943) (W),
A. pomatias albicostata (soosiana Agócsy & Pócs 1961) (W).


Figs. 3-4. A. p. plumbea, Braşov, ex SMF 234001 (phot. S. Hof).
Characters of closing apparatus; shell height = H 19.7 mm.
Abbreviations: cp = clausilium plate, il = inferior lamella, lcp = outer lobe of clausilium plate, lpp = lower palatal plica, mpp = middle palatal plica(e), pr = principal plica, sc = subcolumellar lamella, sl = superior lamella, sp = spiral lamella, upp = upper palatal plica.
3. Body whorl partly removed, frontal;
4. Body whorl dorsal. 

Character analysis

Within the genus Alopia the following characters are regarded as plesiomorphic (Nordsieck 1997: 54, 2008: 7):
Shell (Figs. 3-4):
CA complete (palatal plicae long, middle palatal plica(e) distinct, clausilium not reduced, with protruding outer lobe).
Genitalia:
Diverticulum of bursa copulatrix short (shorter than bursa + proximal pedunculus), vagina long and penial caecum long.

A. (Alopia):
The species from the Transylvanian highlands have a fully developed CA and a long penial caecum (longer than third of penis).
The species from the Wallachian Carpathian borderland have a fully developed CA, but no long caecum (only genitalia of A. mafteiana examined).
The species from the Carpathian mountains have a fully developed or more or less reduced CA and a short or reduced caecum (except A. p. plumbea with relatively long caecum). In one group (livida group) the CA is strongly reduced (having only superior and inferior lamellae left).
The species correspond largely in genital morphology.
A. nixa and A. fussi (of livida group) from the high Bucegi mountains differ from the other species by the lengthened male copulatory organs (penis longer than or as long as vagina). In A. nixa the caecum is weakly developed, in A. fussi it is missing. Thus, these species are transitional to A. (Kimakowiczia).

A. (Kimakowiczia):
Shell: CA strongly reduced (only superior and inferior lamellae left), but in A. maciana CA fully developed.
Genitalia: Diverticulum lengthened (longer than or as long as bursa and proximal pedunculus); male copulatory organs lengthened (penis longer than vagina, epiphallus much longer than penis), caecum reduced or missing.
In COI analysis the subgenus is a group like others, but because of the morphological distance to the other species it is regarded as a subgenus.


Figs. 5-10. Alopia species, character states (phot. S. Hof).
Abbreviations: H = shell height (mm). 
5-6. A. p. plumbea, Braşov, ex SMF 234001.
Characters (except cervical sculpture) plesiomorphic: cervix densely ribbed; inferior lamella high; palatal plicae long; middle palatal plica(e) distinct; clausilium plate leaving no gaps, its outer lobe protruding.
5. H 19.7;
6. Body whorl partly removed, H 19.7.

7-8. A. g. glorifica, Piatra Craiului Mare (near to refuge), ex SMF 84163.
Characters (except cervical sculpture) apomorphic: cervix with several ribs; inferior lamella moderately high; palatal plicae short; middle palatal plica(e) missing; clausilium plate leaving gaps, its outer lobe forming right angle.
7. H 15.3;
8. Body whorl partly removed, H 15.3.

9.-10. A. c. canescens, Ciucaş: Chiruşca, ex SMF 59055.
Characters (except cervical sculpture) apomorphic: cervix with several ribs; inferior lamella very low; CA strongly reduced = only superior and inferior lamellae present.
9. H 13.3;
10. Body whorl partly removed, H 11.6. 

Diagnoses of species based on shell morphology

The following diagnoses are based on a thorough analysis of the shell morphology of about 500 samples, more than three fourths of them collected by myself.

Characters (Figs. 3-10) used, with defined character states:
Coiling direction: left-coiled = L, right-coiled = R;
CA: complete to reduced, in some species strongly reduced = only superior and inferior lamellae present;
sculpture of lower whorls: nearly smooth to ribbed;
cervical sculpture: densely ribbed, with several ribs;
peristome: detached, adnate, attached;
inferior lamella: high, moderately high, low, very low;
The following characters could only be examined in the normally developed CA:
superior and spiral lamella: superior lamella not reaching, reaching, surpassing spiral lamella;
subcolumellar lamella: visible in front view, not visible;
(main) palatal plicae: long, moderately long, short;
middle palatal plica(e): distinct, lunella-like, missing;
clausilium plate: not reduced to reduced = leaving no gaps, moderate gaps, large gaps;
outer lobe of clausilium plate: protruding, forming right angle, missing.

Diagnoses:
Besides coiling direction (L, R) and development of CA only four of ten characters have revealed to be useful for species diagnoses: cervical sculpture, development of inferior lamella, palatal plicae, and clausilium plate. Within the species of the Carpathian mountains, the latter three are reduced in concert.
In the following diagnoses hybrid forms are not considered.
A. (Alopia):
A. bielzii:
R; cervix with several ribs; inferior lamella high; palatal plicae long; clausilium plate not reduced.
A. bogatensis:
L; cervix with several ribs; inferior lamella high; palatal plicae long to moderately long; clausilium plate not reduced.
A. canescens:
L; CA strongly reduced; cervix densely ribbed or with several ribs; inferior lamella very low.
A. fussi:
R; CA strongly reduced; cervix densely ribbed; inferior lamella high to moderately high.
A. glorifica:
L; cervix with several ribs; inferior lamella high to moderately high; palatal plicae long to short; clausilium plate not reduced to more or less reduced.
A. grossuana:
L (nemethi R); cervix with several ribs; inferior lamella mostly high; palatal plicae mostly moderately long; clausilium plate not reduced.
A. helenae:
R (zagani L); cervix with several ribs; inferior lamella high to moderately high; palatal plicae moderately long to short; clausilium plate not reduced to more or less reduced.
A. hildegardae:
R; cervix with several ribs; inferior lamella high to moderately high; palatal plicae long to short; clausilium plate not reduced to more or less reduced.
A. hirschfelderi:
R; cervix with several ribs; inferior lamella mostly moderately high; only lower palatal plica present or palatal plicae missing; clausilium plate reduced.
A. lischkeana:
R; cervix with several ribs; inferior lamella high to moderately high; palatal plicae long to short; clausilium plate not reduced to more or less reduced.
A. livida:
R; CA strongly reduced; cervix densely ribbed; inferior lamella high to moderately high.
A. mafteiana:
L; cervix with several ribs; inferior lamella high; palatal plicae moderately long; clausilium plate not reduced.
A. meschendorferi:
R; cervix with several ribs; inferior lamella high; palatal plicae long; clausilium plate not reduced.
A. nefasta:
R (mauritii L); CA strongly reduced; cervix more densely ribbed than in other species; inferior lamella moderately high to low.
A. nixa:
L; CA strongly reduced; cervix densely ribbed; inferior lamella high to moderately high.
A. plumbea:
L; cervix densely ribbed; inferior lamella high to moderately high; palatal plicae long to short; clausilium plate not reduced to more or less reduced.
A. regalis:
L; cervix densely ribbed or with several ribs; inferior lamella high to moderately high; palatal plicae moderately long to short; clausilium plate not reduced to reduced.
A. straminicollis:
L; cervix densely ribbed or with several ribs; inferior lamella high to moderately high; palatal plicae moderately long to short; clausilium plate not reduced to reduced, outer lobe on average more reduced than in other species.
A. subcosticollis:
L; cervix with several ribs; inferior lamella high to moderately high; palatal plicae long to short; clausilium plate not reduced to more or less reduced.
A. (Kimakowiczia):
L; cervix with several ribs; CA in A. maciana normally developed, in the remaining species strongly reduced; inferior lamella high to low.
A. glauca;
A. maciana;
A. pomatias.

Results:

Comparison of species:
There are nearly no specific species characters, thus the species are largely corresponding. This is unique within the Clausiliidae.
Besides those of coiling direction the species differences are only gradual.
The species from the Carpathian mountains include corresponding series of subspecies in which the characters gradually change: inferior lamella from high to low, palatal plicae from long to short, middle palatal plica(e) from distinct via lunella-like fused to missing, clausilium plate from leaving no gaps to large gaps, its outer lobe from protruding to missing.
An exception are two groups with strongly reduced CA (livida group, two species of Kimakowiczia); the species belonging to are thus separated from the remaining ones by a morphological gap.

Taxa with plesiomorphic characters:
The species from Transylvanian highlands and Wallachian Carpathian borderland have plesiomorphic characters.
The species from Carpathian mountains include subspecies with plesiomorphic characters = basic subspecies, nearly all occurring in low border regions of the mountains (relative occurrences within the species range in brackets) :
A. glorifica: g. boettgeri (Kimakowicz 1883) (N), g. magnifica R. Kimakowicz 1962 (S), g. vranceana Grossu 1967 (disjunct);
A. hildegardae: h. fortunata R. Kimakowicz 1931 (S);
A. lischkeana: l. obesa (Kimakowicz 1883) (N), l. sarkanyi Szekeres 2007 (S), l. livens (Bielz 1853) (E);
A. plumbea: p. plumbea (N and W);
A. regalis: r. regalis (form from Piatra Crinului, SW);
A. straminicollis: s. straminicollis (N), s. monacha (Kimakowicz 1894) (form from Vinturiş, SE);
A. subcosticollis: s. occulta R. Kimakowicz 1931 (S), s. tamasorum Szekeres 2007 (SW).
Within the livida group
A. livida: l. hypula Sóos 1928 (N) and l. bipalatalis (Kimakowicz 1883) (form from Ţiganeşti-Malaeşti, N), but these forms may have been originated by hybridization with A. straminicollis (Nordsieck 2016).
A. canescens: c. striaticollis (Kimakowicz 1894) (form from Babarunca, SW).
Within A. (Kimakowiczia) A. maciana has plesiomorphic characters.

References

Fehér, Z., Németh, L., Nicoară, A. & Szekeres, M. (2013): Molecular phylogeny of the land snail genus Alopia (Gastropoda: Clausiliidae) reveals multiple inversions of chirality. – Zoological Journal of the Linnean Society, 167: 259-272.

Nordsieck, H. (1997): Phylogeny of and within the Albinaria-Isabellaria group (Gastropoda: Pulmonata: Clausiliidae). – Heldia, 4, Sonderheft 5: 53-61.

Nordsieck, H. (2008): The system of the genus Alopia H. & A. Adams 1855 (Gastropoda: Stylommatophora: Clausiliidae). – Mitteilungen der deutschen malakozoologischen Gesellschaft, 79/80: 7-18.

Nordsieck, H. (2016): Interspecies hybridization in the genus Alopia (Gastropoda, Stylommatophora, Clausiliidae) from southern Carpathians, Romania, demonstrated by shell examination.– Conchylia, 46 (1-4): 3-15, 3 pls.

Uit de Weerd, D. R. & Gittenberger, E. (2013): Phylogeny of the land snail family Clausiliidae (Gastropoda: Pulmonata). – Molecular Phylogenetics and Evolution, 67: 201-216.


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