Research Article |
Corresponding author: Jozef Grego ( jozef.grego@gmail.com ) Academic editor: Oana Teodora Moldovan
© 2017 Jozef Grego, Peter Glöer, Zoltán Péter Erőss, Zoltán Fehér.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Grego J, Glöer P, Erőss ZP, Fehér Z (2017) Six new subterranean freshwater gastropod species from northern Albania and some new records from Albania and Kosovo (Mollusca, Gastropoda, Moitessieriidae and Hydrobiidae). Subterranean Biology 23: 85-107. https://doi.org/10.3897/subtbiol.23.14930
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During a field trip to the western part of the Balkan Peninsula in 2016, investigations of several caves and karstic springs revealed six new gastropod species living in subterranean waters and resulted in some noteworthy faunistic records. Five of the new species are assigned to the genus Paladilhiopsis Pavlović, 1913, namely P. prekalensis sp. n., P. lozeki sp. n., P. szekeresi sp. n., P. wohlberedti sp. n., P. falniowskii sp. n. and one to the genus Plagigeyeria Tomlin, 1930, namely P. steffeki sp. n. New Albania and Kosovo distribution records are given for Iglica illyrica Schütt, 1975, Plagigeyeria zetaprotogona Schütt, 1960, Vinodolia matjasici (Bole, 1961), and the first georeferenced record is given for Saxurinator schlickumi Schütt, 1960. The most important environmental factors influencing habitat selection of these subterranean freshwater gastropods are briefly discussed.
cave, spring, Kosovo, Paladilhiopsis , Iglica , Plagigeyeria , Saxurinator , stygobiont, interstitial water
It is known that the Balkan Peninsula is one of the most significant hotspots in terms of subterranean freshwater gastropod diversity (
The studied material was collected during a field trip in June and July of 2016 in northern Albania and Kosovo (Fig.
Distribution of the new species and faunal records mentioned in this paper. Red dots indicate type localities of new the species. 1 Prekal, Zhyla Cave (Paladilhiopsis prekalensis sp. n.) 2 Shoshan (Paladilhiopsis lozeki sp. n.) 3 Tamarë (Paladilhiopsis szekeresi sp. n. and P. wohlberedti sp. n.) 4 Krumë, Vrela Spring (Paladilhiopsis falniowskii sp. n., Plagigeyeria steffeki sp. n. and Paladilhiopsis szarowskae) 5 Novosellë, White Drin Spring (type locality of Plagigeyeria gladilini and Iglica illyrica) 6 Bajzë, Syri i Sheganit Spring (Plagigeyeria zetaprotogona) 7 Rrash, Vrak Spring (Plagigeyeria zetaprotogona) 8 Tamarë, Dverpte Cave (Plagigeyeria zetaprotogona) 9 Kosovo, Pejë, Rugova Gorge, (Saxurinator schlickumi) 10 Vau i Dejës (type locality of Paladilhiopsis gittenbergeri) 11 Kosovo, Decani Valley (Iglica illyrica).
Various habitats where subterranean gastropods were found: A Prekal, Zhyla Cave B Shoshan Spring C Tamarë, spring above the trout farm D Krumë, Vrela Spring E Novosellë, White Drin Spring F Bajzë, Syri i Sheganit Spring G Dverpte Cave south of Tamarë H sampling from sand and fine gravel by a sieve combined with polyamide pantyhose (photos: Zoltán Fehér, Maroš Grego, Dávid Murányi).
NHMW Naturhistorisches Museum, Wien
H Shell height
W Shell width
WB Width of the body whorl
HA Aperture height
HB Height of the body whorl
The shells of the genus Bythiospeum and Paladilhiopsis are very similar and it is not possible to distinguish between these genera by shells only. An ongoing molecular study of the Moitessieriidae Bourguignat, 1863 following the earlier studies of
Can be compared to Paladilhiopsis szekeresi sp. n. (Albania, Tamarë), from which it differs by a blunter apex, more convex whorls, more elongated and more declined aperture from the columella and by upper aperture edge more prominent in the shell outline as well as by the narrower umbilicus. It differs from Paladilhiopsis lozeki sp. n. (Albania, Shoshan) by its smaller and less elongated shell, blunter apex, more tumid body whorl and by the shape of the aperture. P. wohlberedti sp. n. (Albania, Tamarë) and Montenegrospeum bogici Pešić & Glöer, 2012 (Montenegro, Podgorica) differ markedly by their larger more conical shells, more prominent body whorls and shape of their apertures. The shell shape of the news species is somewhat similar to that of Bosnidilhia vreloana Boeters, Glöer & Pešić, 2013 (Bosnia, Banja Luka) which differs from the new species by its more slender shape, narrower elongated aperture and more flattened whorls.
Albania, Shkodër district, Prekal, Shpellë e Zhylit (Zhyla Cave), 210 m, near junction of Kiri and Prroni i Cise, 205 m, 42.1782°N; 19.7200°E (Fig.
Holotype, Type locality: leg. Erőss, Fehér, Grego, Szekeres, 28.06.2016 (
H 1.7 mm; W 0.8 mm; WB 0.65 mm; HA/H 0.36, HB/H 0.26 (holotype). Paratypes have broken apices, measurements not provided.
Derived from the name of Prekal village, where the type locality is situated.
The whitish and silky shell has 5 tumid convex whorls with a deep suture and a blunt apex. The surface is smooth and shiny. The shell is elongated, slightly conical, and almost subcylindrical. Umbilicus is slit-like. In frontal view, the palatal side of the aperture protrudes laterally. Aperture is ovoid, slightly attached to the body whorl and slightly extended left of the columella line, its major diameter deviates by ca. 30 degrees from the plane of the columella. The peristome margin is sharp, slightly reflexed outwards. The evenly thick outer lip is sinuated and the lower part of the aperture protrudes forward in such a way, that in the lateral view the labral margin deviates ca. 13 degrees from the plane of the columellar axis.
The Zhyla Cave is a prominent spring cave acting as a temporary water overflow channel during high water outlets in the main spring (Burimi i Zhylës) situated underneath the cave close to bank of Kiri River. The approximately 70 m long cave is formed in a dark grey limestone by a single phreatic tunnel of 10 × 5 meters average diameter and ends in a terminal siphon. The underground water stream is acoustically detectable under the large boulders close to the terminal siphon. The cave is flushed by the frequent water outflows leaving only fine sandy sediment on the bottom. Empty and fragmented shells were found inside the cave, in a large sand sediment deposits close to the terminal siphon at the end of the hitherto known main dry cave passage. Therefore, it is supposed to live deeper in the cave as a typical underground species colonizing also the appropriate water caverns and cave habitats.
Only known from the type locality.
Most of the collected specimens were empty shells of white color, but it is likely that the shells of living specimens have translucent yellowish color like all other related species known from live-collected material.
Differs from Paladilhiopsis szekeresi sp. n. (Albania, Tamarë) and P. prekalensis sp. n. (Albania, Prekal) by its larger and more elongated shell, less tumid more flattened whorls, its more acuminate apex, its narrower umbilicus and the shape of the aperture. P. wohlberedti sp. n. (Albania, Tamarë) has a significantly more conical shape with fewer whorls and different proportions as well as its larger, differently shaped aperture. Montenegrospeum bogici (Montenegro, Podgorica) from family Hydrobiidae has a larger conical shell with more tumid whorls and proportionally larger aperture. Bosnidilhia vreloana (Bosnia, Banja Luka) has a similar shell shape with fewer whorls, more tumid apical whorls, blunter apex, and a proportionally smaller, more elongated aperture.
Albania, Tropojë district, Shoshan, Burimi i Shoshanit (Shoshan Spring), 270 m, 42.3862°N; 20.0795°E (Fig.
Holotype, Type locality, leg. Erőss, Fehér, Grego, Szekeres, 01.07.2016 (
H 2.00 mm; W 0.85 mm; WB 0.75mm; HA/H 0.30, HB/H 0.26 (Holotype).
Named after the well renowned Czech malacologist and an ever-helpful friend, Vojen Ložek (Prague, Czech Republic), who contributed significantly to the knowledge of Recent and Pleistocene mollusc fauna of Europe.
The whitish shell has 5 ½ convex, slightly flattened whorls with a smooth surface, a semi-deep suture and a blunt apex. The shell has slim, elongated, subconical shape with ovoid aperture and closed umbilicus. The left side of the aperture extends very slightly beyond the columellar axis, declining from it by ca. 25 degrees. Aperture is situated under the last whorl and is not prominent on the shell periphery outline. The slightly outward reflexed peristome is equally thick along its outline. The labral lip is sinuous with forward declining lower end by 13 degrees from the columellar axis. The aperture is detached from last whorl by a tiny gap at the suture.
Shoshan Spring is situated in a natural limestone amphitheatre close to left bank of the Valbona River, and it forms a prominent spring-fed lake supplied by water from multiple debris outlets at its southern side and from the adjacent waterworks outlet at its eastern side. A small side spring can be found at the northern side of the path to the waterworks building. An old watermill is located at the spring lake outlet to the Valbona River. The new subterranean species likely inhabits the interstitial water of the underground gravel sediment layer. Empty shell of the new species were collected in the sandy sediment of spring water outlet at the left side of the broad spring zone south of the waterworks building.
Only known from the type locality, where it was found together with a spring gastropod that most likely belongs to the genus Graeconatolica. The latter species could be described once representative material becomes available.
Differs from Paladilhiopsis lozeki sp. n. (Albania, Shosan) by its smaller and less elongate shell, more tumid whorls, less conspicuous apex, broader umbilicus, and the shape of the aperture. From Paladilhiopsis prekalensis sp. n. (Albania, Prekal) it differs by a more prominent apex, less convex whorls, less elongated and less declined aperture from the columella and by the broader umbilicus. The sympatric Paladilhiopsis wohlberedti sp. n. has a much more conical shell. Montenegrospeum bogici (Montenegro, Podgorica) from family Hydrobiidae has a slightly larger, more conical shell with more tumid whorls and proportionally larger aperture. Bosnidilhia vreloana (Bosnia, Banja Luka) has a somewhat similar shell with fewer, more tumid whorls, blunter apex, and a smaller, more elongate, oval aperture.
Albania, Malësia district, Tamarë, a spring above the trout farm at the right side of valley, north of the village, 360 m, 42.4745°N; 19.5693°E (Fig.
Holotype: Type locality, leg. Erőss, Fehér, Grego, Szekeres, and 27.06.2016 (
Holotype H 1.7 mm; W 0.8 mm; WB 0.65 mm; HA/H 0.34; HB/H 0.28; Paratypes H: 1.5–1.8 mm, W: 0.7–0.9 mm. WB: 0.6–0.7 mm. Paratypes have broken apices, measurements not provided.
Named after our colleague and friend, a prominent specialist of the family Clausiliidae, Miklós Szekeres (Szeged, Hungary), who accompanied us on the field trip in 2016
The shell is whitish, consisting of 5, slightly convex whorls with a semi deep suture and a blunt rounded apex. The rapidly expanding first apical whorl makes the shell shape oval-elongate. The aperture is ovoid expanded on its right side, and the umbilicus is semi-opened and deep. The left side of the aperture is situated slightly left of the columellar axis. The upper part of the aperture is slightly detached from the body whorl at the suture.
Empty shells of the new species were collected at sand among stones and inside a small concrete well-built directly on the spring zone. The only known locality is a permanent spring that arises at the junction of a large debris zone and the limestone massif (concrete well) with a second permanent outflow from a large debris about 30 m upstream the small valley. The lower active spring and well are connected to a pipeline and an aqueduct supplying a trout farm on the right bank of the Cem (Cijevna) River. A large temporary spring outlet is situated under a vertical limestone wall at the end of the deeply cut gorge about 100 m northwest of the two permanent springs, and the large oval boulders indicate a significantly higher temporary water flow during wet seasons and during the snow melting. The morphology of the gorge indicates its genesis by the collapse of a cave portal. The new species likely inhabits the interstitial water of the debris and the flooded caverns within a cave system present behind the debris.
Only known from the type locality, where it was found syntopticaly with the more abundant Paladilhiopsis wohlberedti sp. n.
Paladilhiopsis wohlberedti sp. n. differs from P. prekalensis sp. n. (Albania, Prekal), P. lozeki sp. n. (Albania, Shoshan) and P. szekeresi sp. n. (sympatric) by its more conical shell and proportinonately much larger body whorl. The new species can be compared by shell shape to Paladilhiopsis grobbeni Kuščer, 1928 (Slovenia, Sevnica), from which it differs by a more robust shell, more tumid whorls, blunter apex and by its differently positioned and shaped aperture. From Paladilhiopsis szarowskae it differs by its more conical shape, less (4 ½) and more tumid whorls, the more prominent body whorl and the larger aperture. Montenegrospeum bogici (Montenegro, Podgorica) has a more slender shell with more prominent and proportionally larger aperture situated more to the left of the columellar axis compared to the new species.
Albania, Malësia district, Tamarë, a spring above the trout farm at the right side of valley, north of the village, 360 m, 42.4745°N; 19.5693°E (Fig.
Holotype: Type locality, leg. Erőss, Fehér, Grego, Szekeres, 27.06.2016 (
H 2.0 mm; W 1.0 mm; WB 0.9 mm; HA/H- 0.39, HB/H 0.33 (holotype).
Named after Otto Wohlberedt (Triebes, Thüringen), who within his large work (1909) about Montenegro and northern Albania Mollusca (and Isopoda, Chilopoda, Diplopoda) contributed much to the knowledge of Invertebrate fauna of the Balkan peninsula.
The whitish smooth shell has 4 ½ slightly tumid whorls with a semi-deep suture and a blunt apex. The shell shape is elongate-conoid with proportionally large body whorl. The oval aperture does not deviate from the conoid shell peripheral outline and is reflected, attached to the body whorl by its upper left side and extends slightly over the columellar axis on ts left side. The umbilicus is narrow and deep. On the lateral view, the labral peristome is straight and deviates backward by ca 8 degrees by the plane of columella.
See P. szekeresi sp. n.
Only known from the type locality, where it occurs syntopicaly with P. szekeresi sp. n.
Easily distinguished from the sympatric Paladilhiopsis szarowskae (Fig.
Albania, Has district, Krumë, Vrela Spring, 450 m, 42.1921°N; 20.4166°E (Fig.
Holotype: Type locality, leg. Erőss, Fehér, Grego, Szekeres, 30.06.2016 (
Holotype, H 2.4 mm; W 1.0 mm; WB 1.0 mm; HA/H 0.37; HB/H 0.35. Paratypes H: 2.3–2.4 mm, W: 0.9–1.0 mm, WB: 1.0–1.1 mm
Named after the honored malacologist and friend, Andrzej Falniowski (Jagellonian University, Kraków), who has greatly contributed to the knowledge of the Balkan Hydrobiidae and Moitessieriidae.
The white translucent smooth shell has 4 convex whorls with a semi-deep suture. The shell is elongate-ovoid, and the tumid whorls are regularly tapering towards the blunt apex. The aperture is ovate with very slightly reflexed margins, its palatal side does not exceed the shell periphery, and its columellar side extends beyond the columellar axis. The peristome is detached from the body whorl by, the umbilicus is a tiny furrow. The labrum is straight-not sinuated laterally
The type locality is a karstic spring at the foot of a scree slope. It has a permanent outflow from within the right side of a shallow pond and an intermittent upper spring outflow, situated at about 5 m higher level, 50 m from active spring. The new species had been collected in the sandy sediment of the spring water outlet at bottom of the broad and shallow spring zone. There is a large communal waste deposit site near the spring zone, which poses a direct threat to the spring habitat and the fauna of the outflowing rivulet.
Only known from the type locality. Within the type locality the new species co-occur with the subterranean Plagigeyeria steffeki sp. n., Paladilhiopsis szarowskae and several spring surface dwelling species: Radomaniola curta (Küster, 1852), Ancylus fluviatilis O.F. Müller, 1774, Pseudamnicola krumensis Glöer, Grego, Erőss and Fehér, 2015.
Iglica (Rhaphica) illyrica Schütt, 1975: 8, figs 26–27.
Iglica
illyrica
–
Kosovo, Gjakova (Đakovica) district, Deçan (Dečani), Deçani luginë valley (dolina Dečani) 2 km NW behind the Visoki Dečani Monastery, along the left bank of Lumbardh i Deçanit (Dečanska Bistrica), W of the trout farm. 710 m, 42.5533°N; 20.2492°E; leg. Angyal, Erőss, Fehér, Grego, 25.6.2014
This species is known only from the three locations, namely the spring of the White Drin River in Kosovo (Burimi i Drinit të Bardhë or Beli Drin Izvor, Fig.
Plagigeyeria
gladilini
–
Compared to the most closely related Plagigeyeria gladilini Kuščer, 1937 (Kosovo, Novosellë) (Figs
Albania, Has district, Krumë, Vrela Spring, 450 m, 42.1921°N; 20.4166°E (Fig.
Holotype: Type locality: leg. Erőss, Fehér, Grego, Szekeres, 20.06.2016 (
Same locality, leg. Erőss, Fehér, Grego, 02.07.2015 (coll. Grego and coll. Eross).
Holotype H 2.8 mm; W 1.7mm; WB 1.1 mm; HA/H 0.47, HB/H 0.28. Paratypes H: 2.2–3.1 mm, W: 1.5–1.9 mm., WB: 1.0–1.2 mm.
Named after our untimely deceased excellent friend Jozef Šteffek (Banská Štiavnica, Slovakia) whose multidisciplinary activities dominated in the fields of malacozoology, ecosozology and zoogeography of the Slovakian mollusc fauna.
The milky whitish, translucent shell has 4 convex whorls with a deep suture. The surface is smooth with fine axial growth lines. The shell is narrow-conical. The aperture is oval; the peristome expands widely outwards forming a wing-like structure at the columellar peristome. The lateral edge of the labrum is sinuated, and a characteristic sinuation is present on the wing shaped lower half of its columellar margin. The umbilicus is tiny, hidden behind the aperture and its reflected margins.
See P. falniowskii sp. n.
Only known from the type locality. Within the type locality the new species was found together with the subterranean Paladilhiopsis falniowskii sp. n. and Paladilhiopsis szarowskae.
The first specimens of the new species were collected in 2015 and were erroneously reported as P. gladilini (
Plagigeyeria steffeki sp. n. together with P. gladilini from Kosovo (
Plagigeyeria zetaprotogona Schütt, 1960: 148–149, fig. 3 (Zetaquelle bei Tunjevo)
Plagigeyeria zetadidyma Schütt, 1960: 149–150, fig. 4 (Zetaquelle bei Tunjevo).
Plagigeyeria zetatridyma Schütt, 1960: 150, fig. 5 (Zetaquelle bei Tunjevo)
Plagigeyeria montenigrina Bole, 1961b: 207, fig. 3 (Obodska pećina bei Rijeka Crnojevića)
? Plagigeyeria pageti Schütt, 1961: 134–136, fig. 3 (Velika Spilja bei Risan)
? Plagigeyeria pageti minor Schütt, 1961: 136, fig. 3 (Velika Spilja bei Risan)
Plagigeyeria zetaprotogona vitoja Reischütz & Reischütz, 2008: 143, fig. 1 (Östliche Quelle in Vitoja am Ufer des Skadarsko Jezero):
Plagigeyeria
zetaprotogona
zetaprotogona
–
Plagigeyeria
zetaprotogona
zetadidima
–
Plagigeyeria
zetaprotogona
zetatridyma
–
? Plagigeyeria zetaprotogona pageti –
Plagigeyeria
zetaprotogona
montenigrina
–
Plagigeyeria
montenegrina
(sic!) –
Plagigeyeria
montenigrina
–
Plagigeyeria
zetaprotogona
–
? Plagigeyeria zetaprotogona pageti –
Plagigeyeria
zetaprotogona
vitoja
–
Plagigeyeria
zetaprotogona
zetadidyma
–
Plagigeyeria
zetaprotogona
zetatridyma
–
Plagigeyeria
zetaprotogona
–
Albania, Malësia district, Bajzë, Syri i Sheganit Spring by the Shkodër Lake, 10 m, 42.2722°N; 19.3963°E (Fig.
The taxonomic identity of this species is not clear.
We have found three populations that seem to belong to this taxon (or taxon group), which are the first records thereof from Albania. The Syri i Sheganit population is conchologically very similar to that of the Vitoja Spring (Podgorica, Montenegro, type locality of P. z. vitoja), and the other two populations further expand the known range of morphological heterogeneity. The specimens from Vrak spring have a more robust shape and could represent a new subspecies, while the single broken shell and few fragments from Shpelle Dverptes are more elongate. Until more material become available we will treat it as Plagigeyeria cf. zetaprotogona.
Figs
Iglica matjašiči Bole, 1961a: 59–60, fig. 1 (a small spring near Rijeka Crnojevića)
Anagasta
matjašiči
–
Iglica (Iglica) matjasici
–
Anagastina
matjasici
–
Vinodolia (Anagastina) matjasici
–
Vinodolia
matjasici
–
Vinodolia
matjasici
–
Albania, Malësia district, Bajzë, Syri i Sheganit Spring by the Shkodër Lake, 10 m, 42.2722°N; 19.3963°E (Fig.
Hitherto only three locations of this species were known, all in Montenegro: the type locality near Rijeka Crnojevića (
Saxurinator schlickumi Schütt, 1960: 148, fig. 2 (Rugovska klisura bei Peć).
Saxurinator
schlickumi
–
Kosovo, Pejë (Peć) district, Rugova Gorge, 3.5 km W of the Patriarchate Monastery, spring with travertine waterfalls at the left side of gorge near a resting station, 650 m, 42.6654°N; 20.2307°E; leg. Erőss, Fehér, Grego, Szekeres, 03.07.2016 (
This species was known only from the type locality, which was defined quite inaccurately as ”Rugovska klisura bei Peć” (=Rugova Gorge or Gryka e Rugovës, near Pejë) by
As before, little is known about how environmental factors influencing the living conditions of subterranean truncatelloid gastropods. Most of our knowledge is based on field observations and partly on intuition of the specific groundwater habitat characterization. We assume that the most important factors determining the appropriate habitat of the subterranean freshwater species include: 1.- the absence of daylight; 2.- the availability of food; 3.- oxygen and carbon dioxide concentrations of the water; 4.- water chemistry; and 5.- water flow velocity. Combinations of these factors within their optimal range for the snail species determine their living conditions directly and indirectly by influencing the composition of the biotic community (influence on the growth of food species, on predator species, and on the competitors, parasites, etc.) as well.
1. Absence of daylight: By the absence of light, photosynthesizing Cyanobacteria, algae and auxotrophic Labyrinthulomycetes are also absent in the subterranean habitats, while their strong presence on the surface spring zone has allowed the evolution of a wide range of daylight dependent food competitors, predators and parasites. We assume that the lower number of predators, parasites and competitors for food, together with the more steady environment was the main driving factor for gastropods inhabiting and adapting to underground habitats.
2. Availability of food: Subterranean truncatelloids are presumably feeding on the chemolithotrophic prokaryotes gaining the energy for their biochemical processes (structural proteins, lipids and sugar synthesis) under the absence of light from the oxidation of inorganic cations, in most cases Fe2+ or Mn2+. In similar some thermal and mineral waters (and deep sea vents) could host ecosystems based on biological oxidation of sulphurous compounds and H2S by chemoautothropic microorganisms (Falniowski at al. 2008). The organic material accumulated by the chemolithotroph/chemoautotroph assemblages is thus a fundament for specific underground ecosystems. The precipitated inorganic residua of chemolithotropic process (hydroxides/oxides of Fe3+ or Mn 4+ can be frequently found accumulated on the outer shell surface of underground gastropod species as a brown or black overlay indicating the likelihood of our assumption. We have also an indication that some underground valvatiform species (Carpathian populations of Hauffenia) can feed on the dense net of soft tiny tree roots penetrating the interstitial water among debris within the spring zone. Likely the flat valvatiform shell shape could better trap those species in the net of roots. Future genetic investigations of gastropod intestine content could most likely prove the above theories.
3. Oxygen and CO2 saturation: Dissolved oxygen is necessary for gastropod breathing and also to oxidative reactions important for the chemolitotrophic processes within its feed chain, while the dissolved CO2 is essential as the main carbon source for the feed bacteria. Both saturations are strongly dependent on temperature (saturation increasing by lower temperature) and thus the environment temperature has a secondary effect on optimal saturation range for the gastropod as well as food microorganisms. Furthermore, the CO2 saturation coupled with dissolved hydrocarbonate equilibrium are the key factors driving the corrosive/accumulation character of the karstic water. Some underground gastropod species are also adapted to thermal extremes and waters with high CO2, H2S content, and low oxygen saturation (
4. Water chemistry: The dissolved ions are important for reactions driving the biomass growth (Fe2+, Mn2+) of the food species. The calcium content is important to the secretion of the gastropod shell and other water-soluble growth factors are essential for the gastropod as well for the food substrate, in addition it stabilizes the pH value (hydrocarbonate equilibrium). As all the underground species are narrowly specialized to their steady chemical habitat, even slight anthropogenic pollution or other environment alternation could have a severe impact on water chemistry and could cause irreversible damages on the whole underground ecosystem.
5. Water flow velocity: The water flow velocity influences the oxygen and CO2 saturation and distribution. We assume it is also important for the species motility within the habitat. Stagnant water has lower oxygen saturation and higher CO2 content coming from decaying organic material. Low flow allows better animal motility towards food and to sexual partners and the opposite for high. High flow also challenges the adhesive strength of gastropod musculature and slime important for attachment of the animal to the substrate. The seasonal very high water flow likely detaches live animals from the substrate and washes them out where they accumulate in the sedimentation zones. The underground species must have adapted to withstand the flowing water within their habitat. We are convinced that the average water flow velocity could also determine the shape of the shell: more slender shells can stand higher velocities of water due to lower hydrodynamic resistance and the more robust forms evolved in habitats with slower or steady water velocity.
Although they are often referred to as cave-dwellers, the subterranean truncatelloids (those discussed in this paper and Bythiospeum, Paladilhia, Hauffenia, Islamia, Lanzaia etc.) are not restricted only to the caves and cave waters. Based on our two decades of field experience from the Carpathian mountains, the Carpathian basin, Dinarid Alps and southeastern Asia (
Some facultative cave-dwelling species (
Considering the above discussed very specific range of habitats the discussed gastropod species cannot be called as “troglobiont” species, as this term is preferably used for mostly air breathing species inhabiting the cave areas above the water level. The term “freshwater troglobiont” suggested by
While the neighboring former Yugoslavian territories have been recognized for their large subterranean freshwater gastropod species diversity for a long time, no data had been reported from Albania before the end of the millennium (
We would like to express our thanks to Andrzej Faniowski, (Jagellonian University, Krakow) for his support by consultations, to Maroš Grego (Horná Mičiná, Slovakia) and Dávid Murányi, (