MATERIALS TO THE KNOWLEDGE OF MOLLUSCS OF WIELKOPOLSKA ( WEST-CENTRAL POLAND ) . V . FAMILY : PLANORBIDAE ( GASTROPODA : PULMONATA )

The paper presents data on 20 freshwater snail species: Planorbis planorbis, P. carinatus, Anisus spirorbis, A. leucostoma, A. septemgyratus, A. vortex, A. vorticulus, Bathyomphalus contortus, Gyraulus albus, G. laevis, G. acronicus, G. rossmaessleri, G. riparius, G. crista, Hippeutis complanatus, Segmentina nitida, Planorbarius corneus, Menetus dilatatus, Ancylus fluviatilis and Ferrissia fragilis, recorded over the last fifty years in the Wielkopolska Province (W. Poland). Their distribution is shown on maps with UTM/MGRS grid; most typical habitats of each are described. Among the recorded species P. corneus (497 sites) and P. planorbis (465 sites) are the most frequent. Two species are known from more than three hundred localities, namely: A. vortex (362 sites) and B. contortus (330 sites). The next two species should be also regarded as very frequent in the region: G. albus (242 sites), S. nitida (230 sites). Among the three species with the smallest number of localities, two are introduced alien species – M. dilatatus and F. fragilis, recorded from five localities each; one, G. riparius, recorded from six sites, is native and endangered. key words: malacofauna, Wielkopolska province, distribution


INTRODUCTION
Part V is part of the series of papers by koralewska- Batura et al. (2010a, b), szyBiak & Jankowiak (2012) and czyż & Gołdyn (2013).Here, we present characteristics of a family of freshwater snails (subclass Pulmonata) -Planorbidae, found in Wielkopolska after 1957.Their distribution is shown on maps with UTM/MGRS grid.Most typical habitats of each of the species occurring in Wielkopolska are described.

METHODS
We followed methods described in koralewska- Batura et al. (2010a, b).Due to the common occurrence of most of the species, the data on their distribution are limited to the maps in the main text.Detailed data on particular localities are stored in the computer database of biodiversity created by the Natural History Collections and Department of General Zoology, AMU in Poznań and are available on request.The number of sites recorded in each UTM square is marked on the maps.We analysed only reports from the last 50 years; pre-1957 publications containing information on the past occurrences in Wielkopolska or the Wielkopolsko-Kujawska Lowland were listed earlier (urBański 1957, riedel 1988, koralewska-Batura 1992).We also include some previously unpublished localities bordering with the region but not enclosed in its administrative boundaries.The classification used follows welterschultes (2012).

RESULTS PLANORBIDAE O. F. MÜLLER, 1774
It is a widely distributed family of freshwater snails, suborder Basommatophora, order Pulmonata.They include three subfamilies: Plesiophysinae (Central and Southern America), Bulininae (Africa, Australia and Eurasia), and Planorbinae (worldwide).The last two subfamilies with 12 genera represented by 41 species have been reported for Europe (welter-schultes 2012); 20 species from eight genera are known from Poland and all of these occur also in Wielkopolska (Piechocki 1979(Piechocki , 2008)).
Planorbis planorbis (Linnaeus, 1758) P. planorbis typically occurs in small water bodies such as field ponds, swamps or turf pits overgrown by plants.The species inhabits also lakes and slow flowing rivers and streams.It is also characteristic of ponds and pools of river floodplains.P. planorbis is a Holarctic species.It is one of most common and widespread planorbids.Its range includes all the countries of mainland Europe and in Asia it extends as far east as Lake Baikal, Russia.In Poland it is common mainly in the lowlands, however there are some localities in the mountains (Western Sudety, and Eastern Beskidy; Piechocki 1979).

Planorbis carinatus (O. F. Müller, 1774)
P. carinatus inhabits permanent water bodies.It typically occurs in lake littoral.Occasionally, it is found in slow flowing rivers, streams or oxbow lakes.The species most often occurs in densely vegetated, shallow waters with bottom sediments rich in organic matter.Its distribution covers most of Europe (except north Scandinavia), extending eastward to western Siberia (welter-schultes 2012).In Poland it is common in the Pomorskie and Mazurskie Lake Districts, Wielkopolsko-Kujawska Lowland and partly in Podlasie, although its populations are in decline and the species is listed as near threatened in the red list of threatened animals (Piechocki 2002).Single localities are known from Lower Silesia, Cracow and Eastern Beskidy (Piechocki 1979).
In 67% of its localities the species occurred in lakes.Ponds constituted 13% of the localities in Wielkopolska.It was rarely found in ditches (6%), rivers (7%) and channels (5%).P. carinatus was also found in one each: a stream, a swamp and a peat pit.
A. spirorbis is a Palaearctic species.In Poland it is common in the Pomorskie and Mazurskie Lake Districts, Wielkopolsko-Kujawska, Mazowiecka and Sandomierska Lowlands, Upper and Lower Silesia, and Western Sudety.In other regions of Poland it is rare or absent (Piechocki 1979).Due to the habitat loss and because of the poor state of knowledge of its habitats it is classified as data deficient in the red list of threatened animals in Poland (Piechocki 2002).
Most of the records come from ponds (45%) and ditches (21%).The species was also found in lakes, though rarely (16%), and in wetlands (13%; including flooded meadows and swamps) and occasionally in channels (3 sites) and rivers (2 sites).Anisus leucostoma (Millet, 1813) A. leucostoma inhabits small water bodies (flooded fields and meadows, drainage ditches, shallow ponds and swamps), often temporary ones.It rarely occurs in slow flowing streams, shallow lakes and puddles in river floodplains.A. leucostoma is a Palaearctic species.In Poland it is common in all the lowlands and in some of the mountain areas (Sudety and Beskidy) (Piechocki 1979).

Anisus septemgyratus (Rossmässler, 1758)
A. septemgyratus inhabits shallow forest and field ponds, oxbows, ponds and vegetated lakes, as well as drainage ditches.It occurs in Central and Eastern Europe and in Western Siberia.In Poland it was regarded as quite common in the Pomorskie and Mazurskie Lake Districts, Wielkopolsko-Kujawska, Mazowiecka and Sandomierska Lowlands (Piechocki 1979), although more recently it was red listed and classified as vulnerable due to the habitat loss (Piechocki 2002).It is also known from single localities in Upper Silesia, Lubelska Upland, Roztocze and Eastern Beskidy (Piechocki 1979).

Anisus vorticulus (Troschel, 1834)
A. vorticulus is rare and sparsely distributed.It inhabits small, densely vegetated water bodies: shallow ponds, oxbows, floodplains, swamps, drainage ditches, turf pits.It can be also found in lake littoral and in slow flowing waters.It prefers higher temperatures and thus occurs predominantly in well insolated, shallow water bodies.The range of A. vorticulus includes Central and Eastern Europe, and Western Siberia.In Poland it was reported from the Pomorskie and Mazurskie Lake Districts and Wielkopolsko-Kujawska Lowland.Single localities are known from the Baltic Coast, Mazowiecka Lowland, Białowieża Forest, Upper and Lower Silesia and Małopolska Upland (Piechocki 1979).It is protected across Europe as one of the species listed in Annex II of the EU Habitats Directive (zaJąc & Gołdyn 2012) and for Poland it is classified as near threatened in the red list of threatened animals (Piechocki 2002).
Bathyomphalus contortus (Linnaeus,1758) B. contortus inhabits flowing and standing waters.Most often it occurs in densely vegetated, shallow waters with bottom deposits rich in organic matter.A. contortus is a Palaearctic species.In Poland it is common and widely distributed in all the lowlands and highlands.It is also known form a few mountain areas (Western Sudety, Eastern and Western Beskidy) (Piechocki 1979).

Gyraulus albus (O. F. Müller, 1774)
G. albus inhabits both small and large, stagnant and running waters (turf pits, floodplains, oxbows, ponds, lakes, rivers).It is a Holarctic species.In Poland it is common and widely distributed in all the lowlands and highlands.It is also known from some mountain areas (Eastern and Western Sudety, Eastern and Western Beskidy, Pieniny) (Piechocki 1979).

Gyraulus laevis (Adler, 1838)
G. laevis inhabits ponds, lakes and oxbows and is a Holarctic species.In Poland it is rare and is often mistaken for G. acronicus, G. rossmaessleri and G. albus.It is often found in Quarternary sediments.At present it is known from a few localities in Poland (Piechocki 1979) and is classified as endangered in the red list of invertebrates (Piechocki 2002).
G. laevis was found in six lakes and two ponds.
Gyraulus acronicus (Ferussac, 1807) G. acronicus inhabits ponds, lakes and oxbows.The species occurs in alpine-boreal zone in the Holarctic.In Poland it is rare and is probably a glacial relict.It is known from only a few localities (see Piechocki 1979) and is classified as endangered in the red list of invertebrates (Piechocki 2002).
Lakes accounted for half of the localities of G. acronicus.The remaining sites were three ponds and one small river at its outflow from a lake.(Auerswald, 1851) G. rossmaessleri inhabits mainly astatic water bodies (forest and field ditches, ponds, puddles, floodplains).Sometimes it is found in permanent water bodies such as lakes, turf pits, oxbows.G. rossmaessleri occurs in Central, Eastern and Northern Europe.In Poland  (Piechocki 1979).Due to the habitat loss it is classified as near threatened in the red list of invertebrates (Piechocki 2002).
This species was most often found in ditches (42%) and ponds (30%).It was rare in rivers and lakes (3 localities each); it was also found in one peat pit, a clay pit and a stream.(Westerlund, 1865) G. riparius inhabits ponds, lakes, turf pits, oxbows, forest and field ditches and floodplains.The species occurs in Northern Europe and Siberia.In Poland it was found in single localities on the Baltic Coast, in the Pomorskie and Mazurskie Lake districts, Mazowiecka, Sandomierska and Wielkopolsko-Kujawska Lowlands, Białowieża Forest and Małopolska Upland (Piechocki 1979) and is classified as vulnerable in the red list of invertebrates (Piechocki 2002).

Gyraulus riparius
Only six localities of G. riparius were found during the last 50 years in Wielkopolska, in four UTM/ MGRS 10×10 km squares (Fig. 13) (BerGer & dzięczkowski 1977, szczePanik 1980).Five of the sites were lakes, one a river.(Linnaeus, 1758) G. crista inhabits various types of standing and flowing waters, however it avoids astatic water bodies.It occurs in Europe, Siberia and Western Asia.In Poland it is common in the lowlands.It is also found at lower mountain altitudes (Eastern and Western Sudety, Western Beskidy) (Piechocki 1979).
In Wielkopolska H. complanatus was mainly found in lakes (51%) and ponds (28%), occasionally in riv-ers (8%) and streams (5%), as well as in two ditches, two peat pits, a clay pit, a wetland, a channel and an oxbow lake.
Segmentina nitida (O. F. Müller, 1774) S. nitida inhabits shallow, astatic water bodies: swamps, floodplains, turf pits, astatic ponds.It is also found in deeper permanent water bodies: lakes and oxbows.S. nitida is a Palaearctic species.In Poland it is common and widespread in the lowlands and highlands.It is also found in some mountain localities (Western Sudety, Western Beskidy) (Piechocki 1979).
The species was frequent in ponds (37%) and lakes (28%).It was also found in ditches (12%) and wetlands (including flooded meadows and swamps; 7%).S. nitida was rarely recorded from rivers (12 sites), channels (7 sites), peat and clay pits (6 and 3 sites, respectively), streams (3 sites) and oxbow lakes (3 sites).(Linnaeus, 1758) P. corneus inhabits turf pits, ponds, lakes, oxbows and slow flowing waters.It is a Euro-Siberian species.In Poland it is one of the most common and abundant freshwater snails; it occurs in all the lowland and highland areas.It is also found in some mountain localities (Sudety, Beskidy) (Piechocki 1979).
P. corneus was frequent in ponds (29%), lakes (26%), rivers (14%) and ditches (13%), and less so in streams (7%), wetlands (4%) and channels (3%).It was also reported from nine oxbow lakes, seven peat pits and two clay pits.(Gould, 1841) Within its original range (North America), M. dilatatus inhabits a range of freshwater habitats, including lakes, ponds, streams and rivers.It was accidentally introduced in Europe in the 19th century and has been gradually spreading since then.The current European range of M. dilatatus covers localities in England, France, Germany, in the Netherlands and the Czech Republic, in Ukraine and Poland.In Poland it is known form heated lakes of the Konin Power Plant (Piechocki 1979) and since recentlyfrom the middle Odra River (Piechocki & szlauer- Five localities of M. dilatatus were found within the last 50 years in three UTM/MGRS 10×10 km squares in Wielkopolska (Fig. 18) (Piechocki 1986, BerGer & dzięczkowski 1977).

Menetus dilatatus
In all of its localities the species occurred in lakes heated with hot water from the Power Plants near Konin.

Ancylus fluviatilis (O. F. Müller, 1774)
This snail occurs in various types of flowing waters, including temporary streams.It also occasionally inhabits the rip current zone of lakes.It is a West Palaearctic species.In Poland it is one of the most common species in flowing waters.The snail is frequent in the whole of Poland from the Baltic Coast to the Tatra Mts (Piechocki 1979).
More than half (53%) of the records come from rivers.The snail was also found in streams (6 sites, 35%) and in lakes (2 sites).