Vol. 11(3/4): 103–114

CONFERENCE REPORT: THE 19TH POLISH MALACOLOGICAL SEMINAR

SEMINAR REPORT

The 19th Polish Malacological Seminar was held in reacted quite enthusiastically to our first circular (in- S³upsk (for those who do not know: a town temptingly cluding many of our Ukrainian neighbours), finally close to the seaside, about 30 minutes by bus), on Sep- did not appear but at least sent their summaries. tember 22nd–24th which is an unusual time, since we The range of problems discussed was as wide as usually have our seminars in spring. This year the Sem- during the last fewSeminars: terrestrial and aquatic inar was a bit of a “last-minute offer”: the person(s) ecology and faunistics, snail and bivalve physiology, who should have organised it, failed to do so, and we and variation, life cycles, bionomics and only realised in May that it was ALMOST too late to or- population biology of gastropods and bivalves, growth ganise anything. But fear not, no true malacologist patterns and variation, trematode effect on various as- would miss a chance of having a good time, and we or- pects of snail physiology and behaviour, karyology, in- ganised everything rather rapidly. The main organiser troduced and species protection. Contribu- was The President of The Association of Polish tions dealing with mollusc reaction to human impact Malacologists, ADAM WOJCIECHOWSKI (previously (radionuclides, heavy metals, biomonitoring) and based in Poznañ, nowin S³upsk, hence the location), with applied aspects of malacology: snails that we con- aided loyally by the very same people who begged him sume and slugs that consume cultivated plants (see to take the responsibility and finally bribed him with an also abstracts below) were many. The nomenclature offer to co-organise the meeting (TOMASZ K. MALTZ & adopted by the CLECOM was discussed in a rather BEATA M. POKRYSZKO). In spite of the rather short no- tempestuous manner (one of those situations when tice, the attendance was no poorer than during the last everybody agrees, but they are too emotional about it fewmeetings: there wereabout 60 people, most of to agree quietly), and duly criticised. The posters them with lectures, posters, short communications (about twenty) were all very beautiful, and the etc., and most either arriving after the Seminar began best-poster contest was won by AGNIESZKA MICHA- or departing before it ended. Some of the people who LIK-KUCHARZ from the Silesian University (congratu-

The Main Organiser during the General Assembly Malacologists at large 104 Seminar report lations, Agnieszka!). As usual there were many young tor we could go to places normally inaccessible to malacologists, doctoral students mostly, some with tourists. The weather was fine, though windy, and we very good posters/papers. Will they ever find jobs? sawthe famous and very spectacular wanderingdunes Will their jobs be malacological? (though we would have had to stay much longer to ac- During the General Assembly of The Association tually SEE them wander). of Polish Malacologists it was decided that for the next The Book of Abstracts, hastily produced two days – 20th!!! – Seminar we would go to Kroœcienko in the before the Seminar started, with a Eucobresia on the Pieniny Mts, where we had the 1st Malacological Sem- cover, includes abstracts ranging from a fewlines to inar very long ago. over two pages, most of them in Polish and some few in Most of us stayed in one hotel, only very fewpeople English. In accordance with my firm belief that other were stationed in another. Those who stayed in our malacologists should know what we do, the abstracts hotel had a lot of opportunities for unofficial discus- have been translated and in many cases edited and/or sion and small, unoffical banquets (though we had a abbreviated behind the authors’ back. The institution very good, big, official banquet as well). One evening names are given in Polish, like in the Abstract Book. ANDRZEJ WIKTOR showed us magnificent slides from his malacological trip to China – not only snails but BEATA M. POKRYSZKO lots of beautiful nature and architecture. Museum of Natural History, Wroc³awUniversity, There was an excursion to the S³owiñski National Sienkiewicza 21, 50-335 Wroc³aw, Poland Park. Thanks to the permission from the Park’s Direc- (e-mail: [email protected])

ABSTRACTS FROM THE 19TH MALACOLOGICAL SEMINAR

POPULATION STRUCTURE AND GROWTH RATE within a more extensive monitoring programme, in IN ANODONTA CYGNEA (L.) FROM THE 1993–1994 and 2000–2001, using Oekland method, in BACKWATER ZONE OF THE SULEJOWSKI an oak-hornbeam forest, a pine forest and on a humid RESERVOIR meadow. The numbers of snail species found in 1993/94 and 2000/01 were 45 of 15 families (41 ter- A. ABRASZEWSKA-KOWALCZYK restrial, 4 aquatic) and 48 of 16 families (44 terrestrial Katedra Zoologii Bezkrêgowców i Hydrobiologii, and 4 aquatic). The species numbers and densities in Uniwersytet £ódzki the studied habitats were: oak-hornbeam 29 species and 702 indiv./m2 in 2000/01, 27 species and 690 Results of the 1998 and 2003 studies on A. cygnea in indiv./m2 in 1993/94; pine 23 species and 775 a flow canal of the backwater zone of the Sulejowski indiv./m2 in 2000/01, 27 species and 750 indiv./m2 in reservoir were compared. The number of individuals 1993/94; meadow38 species and 946 indiv./m 2 in was found to have dropped (from 10 to 5 per m2), 2000/01, 30 species and 920 indiv./m2 in 1993/94. while the dominant age class shifted from individuals The number of species and the density were similar aged 3–4 to 5–7 years. Compared to the earlier study, between the study periods. The unusually high num- larger colonies of A. cygnea were found in the reser- ber of species and individuals in the pine forest may voir belowthe canal, and on the other side of the is - suggest its disturbed character. land separating the canal from the river bed. The density there reached 30 indiv./m2, and the lowmean age (2–5 years) indicates a recent origin of these col- ENZYMATIC ACTIVITY IN ZEBRA MUSSEL onies. SPERMATOZOA

J. BIA£KOWSKA1 &J.G£OGOWSKI1,2 THE EFFECT OF HABITAT ALKALISATION IN 1Katedra Ekologii Ewolucyjnej, THE ŒWIÊTOKRZYSKI REGION ON THE SNAILS Uniwersytet Warmiñsko-Mazurski, Olsztyn OF BIA£E ZAG£ÊBIE 2Zak³ad Andrologii Molekularnej PAN, Olsztyn

J. BARGA-WIÊC£AWSKA The activity of acrosin, acid and alkaline phospha- Instytut Biologii, tase, arylosulphatase and B-N-acetylglucosaminidase Œwiêtokrzyska Akademia Pedagogiczna, Kielce in zebra mussel spermatozoa was determined spectro- photometrically. The activity of acid phosphatase and Bia³e Zag³êbie is an area of intense rock exploita- B-N-acetylglucosaminidase was 0.56±0.31 and tion and cement industry. Since the beginning of the 0.7±0.32 U/106 spermatozoa; the activity of the re- sixties the alkaline dust from cement plants has been maining enzymes was below the sensitivity of the causing soil alkalisation. The snail fauna was surveyed method used. Cytochemical staining with the Gomori Seminar report 105 method in order to locate acid phosphatase resulted showed no activity (aestivation). No individuals were in an intense dark brown staining of the whole sper- active during daytime, even after intense rains. matozoon, indicating the presence of the enzyme in the acrosomal region, nuclear envelope and/or plasmalemma. PRELIMINARY OBSERVATIONS ON THE BIOLOGY OF AND DAMAGE CAUSED BY OXYCHILUS CELLARIUS (O. F. MÜLL.) DISTURBANCE OF CILIARY ACTIVITY IN UNIONIDAE FROM RADIONUCLIDE- E. DANKOWSKA -CONTAMINATED TERRITORIES Katedra Metod Ochrony Roœlin, Akademia Rolnicza, Poznañ T. V. CHERNOMAZ Uniwersytet Pedagogiczny w ¯ytomierzu, Ukraina In western Poland, Oxychilus cellarius lives in natu- ral habitats as well as in gardens, greenhouses and cel- Unionid bivalves in radionuclide-contaminated lars; when numerous it can seriously damage green- areas of Ukraine (zones II: 15–39.9 Êu/km2, and III: house plants. It lays batches of 4–12 eggs (mean 7.2). 5–14.9 Êu/km2), are subject to chronic internal and The eggs are smooth, white, 1.2 × 1.3 mm. At 18°C the external irradiation. Accumulation coefficients of incubation takes 28–32 days, at 5°C – 93–94 days. The 90Sr, determined for Batavusiana musiva, Unio conus, snails reach maturity at the age of 6–7 months. In the U. rostratus gentilis, Anodonta cygnea, Colletopterum laboratory O. cellarius preferred food, in the piscinale, Pseudanodonta complanata, ranged from 12.7 greenhouse where it appeared in masses, it caused to 137.5, and coefficients of bottom biological accu- much damage to ornamental plants. mulation – from 1.5 to 42.3. 137Cs was found in bodies of molluscs in lower quantities compared to 90Sr. In the unionids from the radionuclide-contaminated territories the beating frequency of ciliated epithe- MOLLUSCS OF SMALL MIDFIELD WATER lium was found to increase by 2.1–6.6% (increased BODIES OF THE REGION OF TARNOWO metabolic rate), while the duration of ciliary motion PODGÓRNE (W POLAND) decreased by 15.4–48.7%, compared to molluscs from unpolluted zones. The increase in beating frequency B. GO£DYN, E. KORALEWSKA-BATURA of the epithelium was correlated with the decreased Zak³ad Zoologii Ogólnej, duration of the periods of ciliary motion. There was a Uniwersytet Adama Mickiewicza, Poznañ positive correlation between the ciliary beating fre- quency and the radionuclide content in the body, and Thirty small ponds located in the upper section of a negative correlation between the duration of ciliary the Sama River valley were studied with respect to activity and the radionuclide content. their malacofauna. The ponds differed in characters that might affect their mollusc fauna: perma- nent/temporary character, degree of isolation, bot- tom sediments, vegetation etc. Benthological samples CIRCADIAN ACTIVITY OF HELICOPSIS STRIATA were taken in the summer 2002, with a 20 × 30 cm net of1×1mmmesh, towed along the bottom for 0.5 m. S. CHOLEWA Thirty samples, adding up to 3 m2 bottom, were taken Zak³ad Zoologii Ogólnej, from each pond. The samples were hand-sorted, and Uniwersytet Adama Mickiewicza, Poznañ physico-chemical parameters of water were analysed. A total of 13 snail and 3 bivalve species were found The activity of Helicopsis striata was studied in July (60,000 specimens). The mollusc communities varied and August 2003 in the steppe nature reserve from malacocenoses consisting of one or two Pamiêcin. The study included four 24-hour observa- planorbid species (Anisus leucostomus Mill., Segmentina tion sessions (2/3 July, 16/17 July, 1/2 August, 17/18 nitida O. F. Müll.) to ones comprising up to 14 spe- August), on a plot of 5×5m.Thetemperature and cies. The mollusc density ranged from a fewdozen to relative humidity were measured 15 cm above the several thousand indiv./m2. The species richness and ground. Active individuals were observed at a humidity abundance seemed to be affected mainly by the per- exceeding 81% and temperature of 8–21°C. The activ- manent/temporary character of the ponds and the ity reached its peak (over 80% observed specimens) in number of available microhabitats. the night and early morning hours (2.00–7.00) when there was dew. During long rainless periods a large proportion of individuals (72% adult, 37% young) 106 Seminar report

TERRESTRIAL SNAILS OF SELECTED HABITATS SELECTED ASPECTS OF LIFE HISTORY IN TOWNS OF MIDDLE POMERANIA OF VIVIPARUS VIVIPARUS L.

E. GÓRSKA, B. PAKU£A B. JAKUBIK Zak³ad Zoologii i Fizjologii Zwierz¹t, Katedra Ekologii i Ochrony Œrodowiska, Pomorska Akademia Pedagogiczna, S³upsk Akademia Podlaska, Siedlce The snail fauna of Ko³obrzeg, Ustka, S³upsk, The following life cycle parameters of Viviparus Lêbork, Koœcierzyna and Barwice was surveyed in viviparus were determined based on an over 10-year 1993–2003. The material was collected in parks, allot- study: life span and its correlation with adult size, ment gardens, cemeteries, forests and meadows growth rate in mature and immature snails, duration within town boundaries (total: 74 sites), as well as in of reproductive period, copulation mode, number of cellars, rubbish dumps and hedges. A total of 49 spe- embryos per female and per lifetime, their develop- cies were found, representing 17 families; the highest ment rate and ways of their protection, energy expen- numbers of species were found in Lêbork (38) and diture on further growth versus reproduction, mortal- Ustka (36); only 23 species were present in each of ity. In a population of V. viviparus from a dam reser- the remaining towns. Ten species were common to all voir, at a high mortality, the snails matured at a the towns (Succinea putris, Cochlicopa lubrica, Vallonia smaller size and started reproducing earlier, com- pulchella, Oxychilus draparnaudi, Limax maximus, pared to the snails from the adjacent section of the Bradybaena fruticum, Trichia hispida, Cepaea hortensis, C. river. nemoralis, Helix pomatia) while six species were found in one town each (Succinea elegans, Limax cinereoniger, Clausilia bidentata, C. dubia, Laciniaria plicata, EFFECT OF LIGHT ON BEHAVIOUR strigella). The most common species were OF DREISSENA POLYMORPHA Cepaea nemoralis (65 sites), Trichia hispida (54 sites) and C. hortensis (39 sites). J. KOBAK Zak³ad Zoologii Bezkrêgowców, Instytut Biologii Ogólnej i Molekularnej, DIGENETIC TREMATODE INFECTION Uniwersytet Miko³aja Kopernika, Toruñ IN LYMNAEA STAGNALIS (L.) FROM SELECTED WATER BODIES The effect of light intensity and wave length on the behaviour of zebra mussel was studied in a dark room, B. GRYGON-FRANCKIEWICZ, E. ¯BIKOWSKA on Petri dishes with half of their lids covered with Zak³ad Zoologii Bezkrêgowców, black paper. The bivalves (10 per dish) were placed Instytut Biologii Ogólnej i Molekularnej, on the border between the light and dark zones, and Uniwersytet Miko³aja Kopernika, Toruñ illuminated with a dark room lamp (bulb 40W, 0.5 m above the dish) with an appropriate filter. The posi- The water bodies studied in 1998–2002 in the re- tion of bivalves was checked after 24 hrs. In experi- gion of Toruñ, Konin and in the I³awsko-Ostródzkie ment1–white light of intensity 0 (control), 0.6, 1.2, Lakeland differed in their abiotic and biotic condi- 6, 16 and 115 l× – the bivalves reacted at a light inten- tions. A total of 1,546 L. stagnalis from 15 lakes and 5 sity of 1.2 l× or higher. Blue (300–500 nm, maximum ponds were examined. The extensity of infection was 400 nm), green (450–650 nm, maximum 530 nm), red the highest (65–90%, mean 77%) in snails from small, (>650 nm, maximum 700 nm) and white light (16 lx) shallowponds whilein lakes it ranged from 4% to 49% were used in experiment 2. All the colours evoked a (mean 28%). The reasons for the high extensity of in- distinct reaction. The intensity of locomotion in fection in ponds were the high population density and various light conditions was estimated based on the easy access to ultimate hosts: water birds and frogs. length of traces left on the sandy substratum. At a uni- Less abundant snail populations in the lakes made the form light (16 l×) or in total darkness the bivalves transmission of parasites more difficult; besides, other covered an average distance of 221 mm in 24 hrs. snail species – though infection-resistant – could limit When they could choose between the light and dark the density of infected Lymnaea. In much polluted wa- halves of the dish, their mobility was twice smaller (109 ters the extensity of infection was higher compared to m) and almost completely limited to the dark zone. snail populations from waters of high quality. Seminar report 107

SETTLING AND DISTRIBUTION OF DREISSENA SENSITIVITY OF VARIETIES OF RAPE TO SLUG POLYMORPHA ON SUBSTRATA OF VARIOUS DAMAGE SHAPE AND ORIENTATION J. KOZ£OWSKI, T. KA£USKI J. KOBAK Instytut Ochrony Roœlin, Poznañ Zak³ad Zoologii Bezkrêgowców, Instytut Biologii Ogólnej i Molekularnej, The rape Brassica napus L. var. oleifera is often dam- Uniwersytet Miko³aja Kopernika, Toruñ aged by slugs; its commonly cultivated newvarieties of a lowcontent of erucic acid and glucosinolanes may Settling and distribution of the zebra mussel were be more palatable to slugs and thus more sensitive to studied in the dam reservoir of the power plant damage. The most common pest in rape plantations W³oc³awek, on substrata exposed at ca. 5 m depth, is Deroceras reticulatum, accompanied by other species from July till October of 2000–2002. In experiment 1 of the same genus, and by members of the genus the bivalves settled on glass substrata of convex, con- Arion. The aim of the study was to determine the sen- cave or flat surface; all the substrata were used indis- sitivity of young plants of various varieties of rape to criminately in places sheltered from water current. damage by D. reticulatum and Arion lusitanicus. The When the current was strong (up to 1200 m3/sec) the conditions of the experiment were: day temperature density of bivalves on concave substrata was signifi- 19°C, night temperature 16°C, RH 95%, day length cantly higher. Experiment 2 was aimed at determin- 15 hrs. Seedlings of 16 varieties of rape were sown in ing the effect of the position of the substratum (plas- plastic containers. For each slug species 30 young tic plates). There were no significant differences in plants (2–3 leaves) of each variety were tested, in 6 the density of bivalves between vertical and horizontal trials of 5 plants each. Damage to the tissue was esti- plates, with their surface or edge exposed to the cur- mated daily based on a 4-degree scale. The results rent. The bivalves were more numerous on the side were subject to variance analysis and Fisher test, a = sheltered from the current and on the upper surface 0.05. The differences in the slug preferences to vari- of horizontal plates. The distribution was clustered ous varieties became significant on the 13th day. De- (Lloyd index >1); the bivalves preferred the vicinity of pending on the variety, D. reticulatum damaged plate edges (all edges of horizontal and upper edges 33–63%, and A. lusitanicus 35–45% plant mass. D. of vertical plates). The most probable reason for such reticulatum caused the strongest damage to var. Ber- a distribution was movement of settled individuals muda, and the smallest to var. Marita; in the case of A. which then stopped having arrived at the edge. The lusitanicus var. Lirajet was the strongest damaged, and bivalve density on substrata of different outline varieties Bristol, Rasmum and Kana the least dam- (round and square) and size (100 and 56.25 cm2)was aged. Both species considerably damaged var. Baldur. similar.

BOTTOM MACROFAUNA OF SINK-HOLE PONDS LITHOGLYPHUS NATICOIDES (C. PFEIFFER, 1828) WITH SPECIAL REFERENCE TO IN LAKE MIKO£AJSKIE A. KRÓLCZYK A. KO£ODZIEJCZYK Zak³ad Hydrobiologii, Katedra Ekologii, Zak³ad Hydrobiologii, Instytut Zoologii, Wydzia³ Biologii i Ochrony Œrodowiska, Uniwersytet Warszawski Uniwersytet Œl¹ski, Katowice Lithoglyphus naticoides, originally a Pontic species, Five sink-hole ponds in the eastern part of the Up- has spread considerably to the north and west since per Silesian Industrial region were studied from may the thirties of the 19th c. In Lake Miko³ajskie it was 2001 till April 2002. Quantitative samples were taken first found in 1997, in one site, depth 2.5 and 5.5 m, in shallow littoral, with Ekman grab of working area and was present there during the next four years. In 225 cm2. Qualitative samples were taken with bottom July 2003, when samples of fauna were taken in 11 scraper. High concentration of chlorides, sulphates, sites, from depths of 0.5 or 1.0 to the maximum depth phosphates and high electrolytic conductivity make of occurrence of submerged plants, it was found in such reservoirs a specific habitat for aquatic fauna. four sites adjoining one another and located at the Twelve snail species were found, dominants (D>20%) western shore, in its mid part. Live specimens were being Gyraulus crista and Segmentina nitida. Menetus found at 1.0–3.5 m, shells down to 5.5 m. Such an in- dilatatus, previosuly known only from the Konin lakes, sular occurrence provides no clue to the way of ex- was found in one reservoir. Six to ten species were pansion of the species into the lake. found in each site. The presence of some common species was found to depend on the quality of bottom sediments: Radix peregra on muddy sediments with 108 Seminar report carbonaceous shales, G. albus on sandy-muddy bot- macrophyte tissues. There was no significant correla- tom with thick layer of plant debris, and G. crista with tion between the density of molluscs and the muddy-detritus bottom with carbonaceous shales. physico-chemical properties of water. Changes under human impact observed in 1993–2002 involved quali- tative and quantitative composition of malacocenoses TENDENCIES OF CHANGES IN THE UNIONID and appearance of the introduced P. antipodarum. FAUNA IN LAKE MIKO£AJSKIE WITHIN 30 YEARS

K. LEWANDOWSKI BIVALVES – COLONISERS IN THE LOWER Katedra Ekologii i Ochrony Œrodowiska, DANUBE Akademia Podlaska, Siedlce A. V. LIASHENKO1,O.O.SINICYNA2, The 2002 study in Lake Miko³ajskie was an exact E. V. VOLOSHKEVICH2 repetition of the 1972 and 1987 studies. Samples were 1Instytut Hydrobiologii NAN Ukrainy always taken in the same 10 sites, at the same depth 2Dunajski Rezerwat Biosfery NAN Ukrainy and with the same methods. Two unionid species were found in 2002: Unio tumidus and U. pictorum. The Two new bivalve species appeared in the Danube number of species was smaller than on the previous and adjacent bays in Ukraine: Sinanodonta woodiana occasions: in 1987 three species were noted (the Lea and Corbicula fluminea (O. F. Müll.). S. woodiana above two plus Anodonta anatina), and in 1972 five was first found in 1999 in the Sasyk canal of the (the three already mentioned, plus A. cygnea and A. Danube delta, in 2001 single individuals were noted complanata). A. complanata was sporadic in 1972 (0.2% in Anankinom oxbows, and small colonies appeared all unionids), but A. cygnea was more numerous than in Kuril shallows (3 indiv./m2). The maximum length U. pictorum. The absence of A. anatina in 2002 is sur- of the bivalves was 19 cm. In 2002 bivalve colonies of a prising – 30 years earlier it was a dominant species biomass exceeding 500–800 g/m2 were found in the (70% all unionids), though in 1987 it was twice less whole delta. The first two specimens of C. fluminea in abundant than U. tumidus. The depth range of occur- the Danube delta were found in 2000, their shell rence of unionids has decreased from 0.5–5.5 m in lenght being 0.8 and 1.9 cm. Single individuals were 1972 to 0.5 m in 2002; the number of sites has also noted in the lower branch of Limbowsko and dropped from ten in 1972 to four in 2002, and the age Starostambulsko. In 2001 the species was present in of the oldest individuals has decreased from 9–10 virtually all zones of the delta. It preferred open or years in 1972 to 6 years in 2002. poorly vegetated shallows of sandy, sandy-muddy and muddy bottom; the depth range observed was 0.2–11 m. Most specimens were 9–13 mm long, the mean DYNAMICS OF MOLLUSC COMMUNITIES density in 2002 was 20–25 indiv./m2. UNDER HUMAN IMPACT – SINK-HOLE PONDS IN CZU£ÓW NEAR KATOWICE INTENSIFICATION OF ROMAN SNAIL I. LEWIN (HELIX POMATIA) REPRODUCTION IN FARM Zak³ad Hydrobiologii, Katedra Ekologii, CONDITIONS IN 2003 Wydzia³ Biologii i Ochrony Œrodowiska, Uniwersytet Œl¹ski, Katowice M. LIGASZEWSKI, A. £YSAK, Z. MACH-PALUSZKIEWICZ Instytut Zootechniki wBalicach k. Krakowa,Balice The 1993–2002 survey included 7 sink-hole ponds resulting from coal bed exploitation by the Murcki The studies were conducted in a greenhouse of mine in Czu³ów. Physico-chemical properties of water 24.5 m2, and involved snails at least 3 years old (3+) in were determined, macrophytes were identified and 2002, and snails aged 2+ to 3+ in 2003. The total num- malacocenoses analysed. Twenty one mollusc species ber of snails was 1,550, mean body mass 19.80 g, mean were found. In 1997 there was a mass expansion of shell diameter 32.91 mm. In 2003, till July 16th, out of Potamopyrgus antipodarum (Gray); since 2000 Ferrissia 1,066 snails which laid eggs, 18.34% laid eggs for the wautieri (Mirolli) has established a permanent popula- second time, and 1.52% for the third time in the sea- tion; in 2001–2002 protected bivalve species appeared: son. Most productivity indices were significantly higher Musculium lacustre (O. F. Müll.) and Pisidium casertanum in the first batch compared to the second. During 48 (Poli). Physella acuta (Drap.) and Hippeutis complanatus days, 54.5 batches were laid with a total of 1,210 eggs (L.), rare in the Silesian Upland, and Stagnicola per 1m2 greenhouse. The number of batches and eggs palustris (O. F. Müll), atypical for such reservoirs, were produced daily from the beginning of the season till found in the sink-hole ponds. Gyraulus albus (O. F. July 16th was positively correlated with time, while the Müll.) was associated with fine-grained bottom sedi- mean batch mass, number of eggs per batch and mean ments, Bithynia tentaculata (L.) avoided macerated egg mass were negatively correlated with the time fac- Seminar report 109 tor. Using younger snails, aged 2+–3+, for reproduc- oocytes present from April till the beginning of July tion seems to yield good results in farm conditions. and from the end of August till October. Growing oocytes are visible in August and December. Newly-hatched snails appear from April till the begin- THE EFFECT OF INVASION OF LARVAE ning of July and from the end of August till the begin- OF FASCIOLA HEPATICA ON THE ACTIVITY ning of October. The spring generation may complete OF GLUCOSE-6-PHOSPHATASE IN THE their growth or winter over as 4–5-whorl snails, the au- ALBUMEN GLAND OF LYMNAEA TRUNCATULA tumn generation always winter over as juveniles. The life cycle is a three-year cycle, with not more than six A. £APETA batches produced per lifetime. The activity is the high- Instytut Biologii i Ochrony Œrodowiska, est in the spring and autumn, the winter torpor lasting Pomorska Akademia Pedagogiczna, S³upsk from the end of October till the beginning of April. The snails came from a laboratory culture, and were infected with invasive forms of F. hepatica also ob- GAMETE PRODUCTION DYNAMICS IN VERTIGO tained in the laboratory. G-6-P was detected with PUSILLA O. F. MÜLL. (GASTROPODA: ultracytochemical methods. In the initial period after : VERTIGINIDAE) infection (20th day) the G-6-P activity was higher than in control snails, while at the end of larval parasitic M. MAZURKIEWICZ1,B.M.POKRYSZKO2 phase (60th day) the activity was weaker. The increase 1Instytut Zoologiczny, Uniwersytet Wroc³awski, in the activity of the enzyme was probably caused by 2Muzeum Przyrodnicze, Uniwersytet Wroc³awski the toxic and energy-exhausting effect of developing larvae, while the decrease in its activity could result Gonads of individuals of various ages (young of dif- from exhaustion of reserves of the host’s nutritive ferent number of whorls, adult before and after re- substances. production) were examined with standard histological methods. No gonad primordia could be found in individuals of 2 whorls or less. The first germ LIFE CYCLE AND POPULATION DYNAMICS cells appeared at the stage of 3.3 whorls: few and OF HELICODONTA OBVOLUTA (O. F. MÜLL.) poorly developed gonad vesicles contained fine mitot- (GASTROPODA: PULMONATA: HELICIDAE) ically dividing cells and cells in meiotic prophase, with the first growing oocytes in the peripheral parts of the T. K. MALTZ vesicles. At 4-whorl stage the oocytes entered Muzeum Przyrodnicze, Uniwersytet Wroc³awski vitellogenesis and increased in volume. In subadult individuals the oocyte volume and the volume of the Courtship behaviour of H. obvoluta includes meet- whole gonad increased considerably, besides the ad- ing, recognition, courtship dance, copulation, rest and vanced vitellogenic oocytes newoocytes appeared, parting. Sperm transfer is reciprocal, no spermato- the number of spermatids increased and the first phores were found. Copulation takes place in a hori- spermatozoa were observed. The gonad of pre-repro- zontal position, late in the evening or in the night. ductive adults contained numerous late-vitellogenic Eggs are laid in spring and autumn, under bark or in oocytes, young growing oocytes and many spermato- rotting wood. The eggs are white, calcified, oval zoa. In post-reproductive individuals there were no (2.10–2.85 × 2.00–2.60 mm), 9–27 per batch. Incuba- mature oocytes, spermatozoa were few, but the pres- tion takes 14–31 days, hatching is asynchronous, last- ence of young oocytes and mitotically dividing cells ing 1–4 days. No egg cannibalism was observed. The indicated resumption of gamete production. mean time from hatching to maturity is 379 days, the growth being quicker in the initial phase and just be- fore lip formation. In the reproductive system the go- HYDROBIOLOGICAL REGIONALISATION nad is the first to develop; the development of male OF UPPER SILESIA, CRACOW-CZÊSTOCHOWA and female copulatory organs is synchronous. In the UPLAND initial stage of gonad development (3–4 whorls) mitoti- cally dividing cells prevail, and the first oocytes and A. MICHALIK-KUCHARZ spermatocytes appear. At 5-whorl stage the number of Zak³ad Hydrobiologii, Katedra Ekologii, cells in meiotic prophase increases, the first growing Wydzia³ Biologii i Ochrony Œrodowiska, oocytes appear, while there are no spermatids and Uniwersytet Œl¹ski, Katowice spermatozoa. All the cells characteristic of a mature go- nad are present in lip-building snails. The gonad of The material was collected in 1998–2001 in fish mature snails contains oocytes and spermatozoa ponds, clay pits, dam reservoirs, oxbows and ditches. throughout the year, but the number and size of Aquatic habitats of the Cracow-Czêstochowa Upland oocytes change seasonally, with large vitellogenic are the poorest in Upper Silesia, with only 19 species 110 Seminar report of aquatic snails. Lymnaea palustris, L. truncatula, L. three-week acclimation at 5°C in short-day conditions peregra, Planorbis planorbis, Anisus spirorbis and Gyraulus (8L:16D) resulted in a significant increase in glycerol albus were common. The remaining 13 species were concentration in the haemolymph, while there were no rare. Three species occurred commonly in fish ponds: significant changes in the long-day (16L:8D) group at L. stagnalis, L. peregra and G. albus, and ten species in the same temperature. Glycerol concentration in the dam reservoirs: L. stagnalis, L. palustris, L. truncatula, haemolymph in the group acclimated at 5°C during L. auricularia, L. peregra, P. planorbis, A. spirorbis, G. three weeks in summer was nearly three times higher albus, G. crista and Planorbarius corneus. No constant than in autumn, but it did not differ significantly from aquatic snail community could be distinguished in that in specimens examined in the middle of winter. the region; all the species co-occurred sporadically. The concentration in groups acclimated at 5°C and Hydrologically the Cracow-Czêstochowa Upland is 8L:16D during three weeks in summer did not differ the closest to the Silesian Lowland, but the aquatic compared to the autumn group. Entering the torpor snail communities of the two regions are dissimilar. and its duration seem to depend on ambient tempera- ture, but resumption of activity is a controlled process, independent from temperature and light:dark cycle. A RECORD OF ANODONTA WOODIANA (LEA) FROM THE SIERAKOWSKI LANDSCAPE PARK REACTION OF AQUATIC MOLLUSCS TO T. MIZERA, M. URBAÑSKA OPENING OF AN OXBOW (OSOKOWY STAW) Katedra Zoologii, Akademia Rolnicza OF THE S£UPIA RIVER im. A. Cieszkowskiego, Poznañ K. OBOLEWSKI The first five specimens of Anodonta woodiana,of Zak³ad Ekologii i Ochrony Morza, shell length 17–25 cm in fish ponds in Samita, Wronki Pomorska Akademia Pedagogiczna, S³upsk district, Wielkopolskie voyvodeship, were caught in July 2002. In September of the same year hundreds of The areas adjacent to the S³upia River abound with large individuals were observed in the deepest part of drainage ditches and canals. The ditches connect the pond. In the shallowpart Anodonta anatina was fragments of numerous oxbows on both banks of the very abundant. Most probably, A. woodiana appeared river. They were dug in 1915–1919 and 1922, when 50 in the pond five years earlier, as a result of stocking oxbows were cut off. Osokowy Staw contains water with carp fry from Gos³awice near Konin. throughout the year and is 0.27 ha in surface area. In 2000 it was re-connected with the S³upia River. For comparison, another, unconnected, oxbowKoñski EFFECT OF TEMPERATURE ON WINTER staw, and a section of the river at the level of Osokowy TORPOR OF THE ROMAN SNAIL Staw, were studied. Molluscs were surveyed in 1999–2002. In the first year of studies there were no A. NOWAKOWSKA, M. CAPUTA, snails or bivalves on the bottom of the oxbow. The sit- J. ROGALSKA, K. WENTOWKA uation improved with introduction of river water: Zak³ad Fizjologii Zwierz¹t, Instytut Biologii Ogólnej members of the genus Pisidium dominated in the i Molekularnej, Uniwersytet Miko³aja Kopernika, Toruñ study period in the oxbowand the river. Snails – Lymnaea stagnalis L., Acroloxus lacustris L., Planorbarius In order to study the preferred temperatures dur- corneus L. – were fairly numerous on Stratiotes aloides L. ing natural onset of winter torpor, snails were placed in Because of an improvement in physico-chemical a chamber with linear thermal gradient and their pref- parameters of water, the connection with the river re- erences were registered during three weeks. Another sulted in a rapid increase in the biomass compared to experiment, in the middle of winter, involved snails in the unconnected Koñski Staw(mean gastropod bio - natural torpor, placed in various thermal conditions in mass twice higher); in 2002 a further increase in snail order to study the latency of activity resumption and biomass on Stratiotes was observed. preferences immediately after. An experiment carried out in March was aimed at ascertaining if the snails were able to get active in spring in spite of the constant AN UNUSUAL MODE OF SHELL GROWTH temperature of 5°C and darkness. In autumn the snails IN UNIONID ONTOGENY were not capable of active selection of increasingly lower temperatures. No individual formed an B. ORZECHOWSKI epiphragm and entered winter torpor. Activity resump- Zak³ad Ekologii i Ochrony Morza, tion in the middle of winter proved to be strictly de- Pomorska Akademia Pedagogiczna, S³upsk pendent on the ambient temperature: the snails got ac- tive when the temperature exceeded 10°C, and the la- The aim of the study was an estimate of weight of tency was in inverse proportion to temperature. A shell valves depending on their length in age-size Seminar report 111 classes. The material included a fewpopulations of chromosomes are macrochromosomes (above 1 µm). Unio tumidus Philipsson and Anodonta anatina L. In U. The first and second pairs are submetacentric, III–V tumidus initially the left shell valve showed a faster in- and VII–IX – metacentric, VI – acrocentric. crease in weight in four, and the right valve in one population. In one population the growth of both valves was equal. In A. anatina the growth of the right IS SPECIES PROTECTION OF MOLLUSCS valve was faster in three, and of the left valve in two NECESSARY? populations. In older age classes of both species the tendency became reversed, and as a result the valve A. PIECHOCKI which initially was slower to grow, reached the larger Katedra Zoologii Bezkrêgowców i Hydrobiologii, size. Uniwersytet £ódzki The list of molluscs under species protection in Po- SHELL POLYMORPHISM IN CEPAEA NEMORALIS land includes ca. 60 species which is nearly 25% FROM THE EASTERN DISTRIBUTION BORDER Polish fauna. The number is very high compared to other European countries: only three species of bi- M. O¯GO valves are protected in the Czech Republic Instytut Biologii i Ochrony Œrodowiska, (Margaritifera margaritifera, Anodonta cygnea and Unio Pomorska Akademia Pedagogiczna, S³upsk pictorum), and 22 snail and two bivalve species in Slovakia. The inclusion in the list is often un- The analysis of colour and banding polymorphism grounded. Problems implied by legislation are in included 8,000 shells from 51 sites in five towns of the many cases an obstacle in ecological, hydrobiological Subcarpathian region: Tarnów, Rzeszów, £añcut, and faunistic studies. Any field work which involves Jaros³awand Przemyœl. Yellowshells (71%) prevailed. collecting protected species requires a permission Pink shells constituted 29% and brown shells only from the voyvode or even ministry. This is especially 0.06% (found in £añcut only). Considering the colour important for benthos-studying hydrobiologists since and banding together, yellow, single-banded shells con- no larger sample of bottom fauna can be taken with- stituted a half of all shells. Pink shells with one band out sphaeriids all of which (21 species) are under pro- were also numerous (17%), as well as yellow tection in Poland. It seems reasonable that species five-banded shells (16%). The percentage of yellow protection should apply only to easily identifiable, shells increased eastward, and the tendency results attractive molluscs which are valuable to collectors probably from increasing continentalisation of cli- (e.g. some large unionids, helicids, clausiliids). Small mate. In sunny sites the percentage of yellowshells was molluscs which are difficult to find require protection significantly higher than in shady sites. In over half in nature reserves and national parks rather than sta- sunny sites the frequency of yellowshells exceeded tus of protected species. 90%. Significant differences between adjacent locali- ties of different insolation indicate a high rate of adap- tation to conditions found at the distribution border. A CONCEPT OF A GUIDE TO AQUATIC MOLLUSCS OF POLAND, WITH NOTES ON MODERN TAXONOMY OF SNAILS KARYOLOGICAL STUDIES ON LITHOGLYPHUS AND BIVALVES PYRAMIDATUS MÖLLENDORFF FORM THE GORYÑ RIVER (W UKRAINE) A. PIECHOCKI1, B. WAWRZYNIAK-WYDROWSKA2 1Katedra Zoologii Bezkrêgowców i Hydrobiologii, I. PERSZKO Uniwersytet £ódzki, 2Zak³ad Paleooceanologii, Katedra Zoologii, Uniwersytet Pedagogiczny Uniwersytet Szczeciñski w¯ytomierzu, Ukraina The authors are preparing a modern guide to all There is no literature information on chromo- freshwater and marine (Baltic) molluscs of Poland. somes in Lithoglyphidae. According to the currently The guide will include colour photos of shells. The accepted classification there are four taxa of photos will show essential features, such as shell shape Lithoglyphus in Eastern Europe: L. apertus (Küster), L. and sculpture, aperture shape, operculum etc. SEM pyramidatus Möllendorff and L. naticoides (C. Pfeiffer) photos will show hinge structure in bivalves. Besides, with two subspecies: L. n. naticoides and L. n. the book will contain a general part dealing with mor- berolinensis (Westerlund). L. pyramidatus was collected phology, anatomy, biology and ecology. Species de- in the Goryñ River (W Ukraine) in the summer of scriptions will include shell and soft parts, variation, 2002. Chromosome slides were made with standard bionomics and distribution. The systematic arrange- methods. The chromosome number is 2n = 18; all the ment will correspond to that proposed for the 112 Seminar report programme Fauna Europaea; there are considerable SHELL VARIATION IN DREISSENA BUGENSIS changes regarding prosobranch snails, as well as some ANDR. IN THE RESERVOIR OF THE CHERNOBYL pulmonates, e.g. lymnaeids and planorbids. NUCLEAR POWER PLANT

A. R. PROTASOV DISTRIBUTION AND ROLE OF MACOMA BALTHICA IN THE POLISH ZONE Instytut Hydrobiologii UAN, Kijów OF THE BALTIC The cooling reservoir of Ch. NPP is 21.7 km2 in sur- Z. PIESIK1, J. KEMPTER2,E.WNUK-G£OWEDEL3 face area and 149 mln. m3 in volume. Before the 1986 accident there was a significant increase in water tem- 1Zak³ad Ekologii i Ochrony Morza, perature (in the discharge channel from 17.2 up to Pomorska Akademia Pedagogiczna, S³upsk, 32.5°C, in the intake channel – from 8.2 up to 25.6°C 2Zak³ad Parazytologii, Akademia Rolnicza, Szczecin, within a year). In that period Dreissena polymorpha Pallas 3Drawieñski Park Narodowy, Drawno settled mainly in the coolest part, basically – in the in- Populations of Macoma balthica were studied in the take channel. In 1990 D. bugensis Andr. was noted Polish shore zone of the Baltic (to 3 miles), in the there. In December 2000 the NPP closed down. Based Gulf of Pomerania and in the open coast of Middle on the thermal history of the reservoir five zones could Pomerania. Density, wet biomass and frequency of be distinguished: old cold (OC), newcold (NC), new Macoma were determined for the regions of the warm (NW), old warm (OW) and old hot (OH). A mouths of rivers Odra, Wieprza, S³upia, £upawa and hundred specimens of D. bugensis were collected in £eba. The frequency of Macoma in the zone was each zone in October 2002. The shell length, height 77.4% while in the open sea it was 39.8%. The density and thickness were measured to the nearest 0.1 mm. in the shore zone ranged from 0 to 304 indiv./m2, the The form index Kv was calculated according to the for- wet mass from 0 to 99.2g/m2. M. balthica found better mula: Kv = ((L+h+d)/3)3/Lhd, where: L- length, h- conditions in the Gulf of Pomerania compared to height, d – thickness of the shell. The size structure dif- Middle Pomerania (density 4.5 times higher, wet mass fered slightly between the zones (in NW zone domi- 2.5 times higher). M. balthica provides food resources nance peak displaced towards smaller sizes). The ex- for birds and fishes and contributes to water purifica- ternal volume of the shell of small specimens (6–10 tion (biofiltration, biosedimentation). mm) decreased from zone OC to zone OH, while large specimens (16–20 mm) showed no essential differ- ences. The colour pattern and sculpture of the shells POPULATION DYNAMICS OF VERTIGO varied between the zones. In zone NW there was no MOULINSIANA (DUPUY) (GASTROPODA: phene E (diagonal division of colour pattern), the fre- PULMONATA: VERTIGINIDAE) FROM BAGNOR quency of phenes G (arched components of the pat- IN S ENGLAND tern) and L (spots) was the lowest, the frequency of phenes J (wavy components of the pattern) and K (ra- 1 2 B. M. POKRYSZKO ,I.J.KILLEEN dial components) was the highest; the shell growth was 1Muzeum Przyrodnicze, Uniwersytet Wroc³awski, not reflected in its sculpture. Similarity estimate with r 2Malacological Services, Felixstowe, UK criterion showed that zones OC and NC were similar in their colour pattern, zone OW was close to them, while Translocation of a fragment of habitat with a part of zone NW was dissimilar (r parameter significantly dif- a snail population is one of the recently introduced ferent from 1). Likewise, zone OH was different from means of active protection of molluscs. In 1996 a part the remaining zones. In zones OC and NC the propor- of a threatened population of Vertigo moulinsiana in tion of asymmetrical specimens was 9%, while in the Bagnor in S England was translocated to a new and safe other zones it ranged from 0 to 3%. site. It was monitored during the next three years, re- sulting in a good basis for an analysis of its abundance dynamics and age structure. The results indicate three SHELLS OF HELIX AS INDICATORS reproductive periods: spring (April), early autumn OF ACCUMULATION IN BIOMONITORING (September) and winter (December). Growth to matu- OF SOME TRACE ELEMENTS rity probably takes at most 4 months and the life span seems not to exceed half a year. Out of 15 European M. RAÆ,Z.MACHOY species of Vertigo, growth rate, number of generations Katedra i Zak³ad Biochemii i Chemii, per year and reproductive period are known only for V. Pomorska Akademia Medyczna, Szczecin pusilla, V. angustior and V. geyeri. All the studied species of Vertigo have short life cycles (not exceeding one The objective of the study was to determine the de- year), quick growth and maturity (several months) and gree of accumulation of fluorides and selected metals reproduce basically once in a lifetime. (Cu, Zn, Pb) in shells of Helix from natural habitats Seminar report 113

(vicinity of Szczecin and the Poprad National Park in in the coolest canal (1.0–3.0 mm) and in the canal Slovakia) and laboratory culture (snails fed with stan- connecting Lakes Licheñskie and P¹tnowskie dard mixture with addition of sodium fluoride, cop- (0.5–2.0 mm). The size structure in this part of the per, zinc and lead nitrates). Fluoride content in shells population was diverse (Shannon index 3.146 and was determiend with ion-selective fluoride electrode, 3.436, respectively). An equally significant diversity metal content – with atomic absorption spectrometry. was characteristic of D. polymorpha attached to live Differences in fluoride content in shells of Helix from Anodonta woodiana in the cooler part of the initial natural habitats versus laboratory indicate a possibil- cooling reservoir, Lake Licheñskie and the canal con- ity of using the shells for fluoride pollution necting lakes Licheñskie and P¹tnowskie. biomonitoring, but the shells seem to be useless for metal biomonitoring. ENDANGERED SNAILS AND BIVALVES IN UKRAINIAN WATERS A FEW WORDS ABOUT THE CLECOM PROJECT P. S TADNYCHENKO, G. E. KIRICHUK, A. RIEDEL R. K. MELNICHENKO,L.N.JANOVICH Muzeum i Instytut Zoloogii PAN, Warszawa Uniwersytet Pedagogiczny w ¯ytomierzu, Ukraina The classification system adopted by the authors of The decrease in abundance and species richness the CLECOM Project (Check-List of the European of aquatic molluscs of Ukraine is associated with Continental ) raises numerous objections, changes in physico-chemical properties of the habi- and introducing it as obligatory does not seem advis- tats, though the reasons for threat have not been stud- able. It does not ensure stability and univocality of ied in detail. The impoverishment includes mollusc nomenclature. Some of the taxonomic acts dissappearance of some species. During the last 25 from the first edition of the Check-List are in dis- years of the 19th c. snails of the genus Fagotia were still agreement with the basic assumptions of the Interna- present in the Dnester, but they have not been found tional Code for Zoological Nomenclature (e.g. uncrit- in the river or its tributaries for 50 years. Lymnaea ical resurrection of obliterated names is a misuse of glabra was reported by earlier authors from NW the priority principle), other find no support in taxo- Ukraine: the San and western Bug basins. It was last nomic and phylogenetic studies (e.g. elevating names found in Ukraine at the beginning of the sixties. of forms or subspecies to specific rank, resurrecting Abundance of some species decreases rapidly. Myxas species names – synonyms proposed by representa- glutinosa, never common in Ukraine, was nonetheless tives of the French Nouvelle Ecole, splitting or lump- found every year in various parts of the country. Only ing families or genera without presenting any argu- two specimens were found during the last 15 years. ments or citing relevant literature). The same pertains to unionids – Unio crassus, sensitive to the presence of ammonia in bottom sediments, seems especially threatened. The vertical range of SIZE STRUCTURE OF YOUNG DREISSENA unionids in lakes and other water bodies is another as- POLYMORPHA PALL. IN HETEROGENEOUS pect of the phenomenon; progressive eutrophication HABITAT CONDITIONS results in oxygen deficit in bottom sediments and the

presence of toxic H2S and ammonia. As a result the O. O. SINICYNA1,B.ZDANOWSKI2 bivalves move to shallowlittoral (from the depth of 1Instytut Hydrobiologii UAN, Kijów, 1–2 m to 0.2–1 m). 2Instytut Rybactwa Œródl¹dowego, Olsztyn Preliminary studies in the heated Konin lakes indi- THE EFFECT OF SELECTED EDAPHIC FACTORS cate that in summer young D. polymorpha (0.25–5.5 ON TERRESTRIAL GASTROPODS IN THE mm) can occur in various habitats in the lake system, MILITARY SHOOTING AREA BIEDRUSKO as dominants or subdominants. Their size structure NEAR POZNAÑ was studied in 2001 and 2002 (July-August), in ten sites. The water temperature ranged from 23.8 to M. URBAÑSKA 3 32.5°C, the flowfrom 6 to 25 m /sec. The size diversity Katedra Zoologii, Akademia Rolnicza was estimated with Shannon index. Dominance of im A. Cieszkowskiego, Poznañ particular size classes varied from 17 to 92%. Postlarval stage (0.25–0.7 mm) dominated in the ini- Though the soil acidity affected the number and tial cooling reservoir; in Lake Licheñskie individuals abundance of species in the studied area, it was not al- of 2.1–4.0 mm prevailed. Six size groups could be dis- ways the most important factor. In some cases the ef- tinguished in the canals; the size range was the widest fect of e.g. humidity or insolation was more pro- 114 Seminar report nounced. LowpH did not alwaysimply the lownum - ated. At an intense infection bradycardia was ob- ber of gastropods. For those species for which litera- served. Exposure of uninfected and infected L. ture data on edaphic requirements existed, it was pos- stagnalis to a solution containing 1 mg/dm3 of copper sible to make comparisons with the obtained results. sulphate resulted in a decrease in heart-beat by ca. Columella aspera was found on acid soils (pH 4.9 and 50%. Nevertheless, when exposed to a 0.2 mg/dm3 so- 5.92) of lowhumus content, lowbase saturation and lution, both the weakly infected and individu- lowcontent of exchangeable cations. Carychium als with intense infection reacted by increasing their tridentatum preferred soil of pH 6.51–6.06 and high general metabolism level. Their heart-beat increased Ca and Mg content. Cochlicopa lubrica was the most fre- by up to 11% compared to the normal frequency. quent in samples of high pH and content of ex- changeable cations, but was also present at low pH, Ca and Mg content. Punctum pygmaeum was found on var- HELICELLA OBVIA MENKE FROM THE REGION ious soils, but mostly with a high content of assimila- OF OSOWIEC (NE POLAND) ble nutrients. Finding Vertigo pygmaea in sites with the lowest and the highest pH suggests that acidity is not W. WOJTAŒ the limiting factor for this species. Discus rotundatus Zak³ad Zoologii, Instytut Biologii, was found on soils of rather high pH and rich in as- Akademia Pedagogiczna, Kraków similable potassium and magnesium. Width of protoconch, size of increment since hatching, shell height and diameter and aperture THE EFFECT OF TREMATODE INVASION height were measured in shells from two sites. Site I ON THE DAILY FOOD CONSUMPTION was an open, sunny, fallow land on the edge of a pine BY LYMNAEA OVATA forest, with xerophilous plants (Sedum acre L., Erigeron canadiensis L., Agrostis tenuis Sibth.). Site II was a strip O. VASYLENKO of herbaceous vegetation between a pine forest and a Katedra Zoologii, Uniwersytet Pedagogiczny road, with Agrostis tenuis Sibth., Taraxacum officinale w¯ytomierzu, Ukraina Web. ex Wiggers and Melilotus albus L., shaded by the forest during a part of the day. The snails from site II Uninfected snails consumed all the food pro- were larger in terms of shell height and diameter and posed. The highest percentage was formed of Populus protoconch width, which may suggest a direct habitat leaves; the mean daily ratio was 4.68±0.31%, includ- effect. ing 1.9 Alisma leaf, 12.4 Carex blade and 3.1 Salix leaf. Infected snails showed a rapid increase in consump- tion of all kinds of food, the increase being the most THE EFFECT OF DIGENETIC TREMATODE significant for Alisma leaves (2.4×) and Carex blades INFECTION ON CA CONTENT IN SHELLS (1.8×). The snail reaction to the presence of parasites OF LYMNAEA STAGNALIS (L.) seems to be non-specific, and consists in a generally increased metabolic rate manifest as increased food E. ¯BIKOWSKA consumption. Zak³ad Zoologii Bezkrêgowców, Instytut Biologii Ogólnej i Molekularnej, Uniwersytet Miko³aja Kopernika, Toruñ HEART-BEAT IN LYMNAEA STAGNALIS UNDER THE EFFECT OF HEAVY METALS AND PARASITE Calcium content in water and snail shells was mea- INFECTION sured with EDTA method. Half of 1,680 specimens from 6 lakes were trematode-infected, the other half D. A. VYSKUSHENKO were control specimens (not infected). Only in the Uniwersytet Pedagogiczny w ¯ytomierzu, Ukraina lake with the lowest calcium content the Ca content in shells of infected snails was higher compared to unin- The aim of the study was to test the possibility of fected snails. This does not provide evidence for using Lymnaea stagnalis (L.) and its heart-beat as an in- hypercalcification under the effect of trematodes. dicator of water toxicity. The normal heart-beat fre- The Ca content in the haemolymph of infected and quency in L. stagnalis is 17.5±0.4 and in infected snails uninfected snails from the same lake was similar. The – 17±0.4 per minute. A weak parasite infection did not data may suggest that the shell is a storage place for change the frequency. At a medium-intensity infec- any excess calcium, while its concentration in the tion, as a result of increase in the general metabolic haemolymph is maintained at a constant level, neces- rate (reaction to parasite), the heart-beat was acceler- sary for normal functioning of the organism.