Gastropods of Two Important Streams of Gökova Bay (Muğla, Turkey) and Their Relationships with Water Quality

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1 International Journal of Science & Technology Volume 3, No 1, 27-36, 28 Gastropods of Two Important Streams of Gökova Bay (Muğla, Turkey) and Their Relationships with Water Quality Hasan Kalyoncu 1, Murat Barlas 2, M. Zeki Yıldırım 3 and Bülent Yorulmaz 2 1 Süleyman Demirel Üniversitesi Fen Edebiyat Fakültesi Biyoloji Bölümü, Isparta 2 Muğla Üniversitesi Fen Edebiyat Fakültesi Biyoloji Bölümü, Muğla 3 Mehmet Akif Ersoy Üniversitesi Eğitim Fakültesi Fen Bilgisi Öğretmenliği Bölümü, Burdur yorulmaz@mu.edu.tr (Received; ; Accepted: ) Abstract: This study was carried on two important streams of Gökova Bay between March and August 21. Within the study period 7 taxa were determined on. In Akçapınar stream, Theodoxus heldreichi fluvicola Schütt and Şeşen 1992, Pseudamnicola geldiayana Schütt, 197, Bithynia leachi troschelii (Paasch, 1842), Valvata piscinalis (O. F. Müller, 1774), Potamopyrgus jenkinsi (Smith, 1889), Planorbis planorbis (Linnaeus, 178) and Stagnicola palustris O. F.Müller, 1774 were found. In Akyaka Kadın Azmağı stream additionally to these 7 taxa, Radix labiata (Rossmässler,183) and Oxyloma elegans (Risso,1826) were also determined. Furthermore, frequency, dominance, and distributional patterns of taxa for each station were analyzed. The relationship between some water quality parameters and the distribution of aquatic gastropods were analyzed. According to the results, physiochemical changes in water affect the development and distribution of aquatic gastropods. Keywords: Gastropoda, Water Quality, Gokova Bay, Muğla Gökova Körfezi (Muğla, Türkiye) nin İki Önemli Akarsuyunun Gastropodları ve Su Kalitesi İle İlişkisi Özet: Bu çalışma, Gökova Körfezi ne dökülen iki önemli akarsu üzerinde Mart ve Ağustos 21 tarihleri arasında yapılmıştır. Akçapınar deresinde 7 takson tespit edilmiştir. Akçapınar deresinde Theodoxus heldreichi fluvicola Schütt ve Şeşen 1992, Pseudamnicola geldiayana Schütt, 197, Bithynia leachi troschelii (Paasch, 1842), Valvata piscinalis (O. F. Müller, 1774), Potamopyrgus jenkinsi (Smith, 1889), Planorbis planorbis (Linnaeus,178) ve Stagnicola palustris O. F.Müller, 1774 bulunmuştur. Akyaka Kadın Azmağı deresinde bu taksonlara ilaveten Radix labiata (Rossmässler,183) ve Oxyloma elegans (Risso,1826) da bulunmuştur. Ayrıca bu akarsular üzerindeki her bir istasyonda taksonların sıklık, baskınlık ve dağılımları analiz edilmiştir. Bazı su kalitesi parametreleri ve akuatik gastropodların dağılımı arasındaki ilişki incelenmiştir. Bu sonuçlara göre fiziko-kimyasal değişimler akuatik gastropodların gelişimini ve dağılımlarını etkilemektedir. Anahtar Kelimeler: Gastrapoda, Su Kalitesi, Gökova Körfezi, Muğla 1. Introduction Molluscs, in which also gastropods are placed, are distributed in many habitats with their highly adaptation abilities. Generally grouped among primary producers concerning the niches and feeding types, they are known to be consumed largely by a wide variety of organisms, mainly being fish, amphibians, and crustaceans. Therefore, ecologically they constitute an important part of life in terrestrial and aquatic ecosystems. As some are edible, many being agricultural pests, ectoparasites or hosts to parasitic organisms, they have also an economic

2 H. Kalyoncu, M. Barlas, M. Z. Yıldırım and B. Yorulmaz and parasitological importance [1-3]. Furthermore, they can be used as bioindicators of pollution or productivity in aquatic ecosystems [4]. Turkey, a unique part of Western Palaearctic sub region, has also a unique and rich malacofauna of great zoogeographical importance, though yet not fully covered []. Studies to determine distribution and taxonomy of gastropods in Turkey have mostly been carried out by foreign researchers in certain areas, especially geographically available points [6-12]. Recently, a great deal of advance in malacological studies in west part of Turkey has been observed [13-16]. Because of the summarized importance of the group above, determination of their distribution is essential. In this study, gastropod fauna were determined in the two streams located within Aegean region of Turkey, near Gökova Bay, which have qualitatively and quantitatively rich malacofauna. 2. Material and Method This study was carried out from March to August 21 in six selected stations (Figure 1) on two streams; the first stations of both streams were spring areas and the third stations were mouth parts of the streams having estuarine character, whereas the second stations were located between these. The literatures; Zhadin [1], Malek and Cheng [2], Glöer et al., [3] are used for collection method and for identification of the gastropods samples. Figure 1. Map of study area and stations. 28

3 Gastropods of Two Important Streams of Gökova Bay (Muğla, Turkey) and Their Relationships with Water Quality Water samples and gastropods were collected at the same time. Temperature, dissolved oxygen, ph, electrical conductivity parameters were measured in the field, while other parameters were measured in laboratory. Water hardness and quality levels were determined according to Klee [17]. Dominancy and frequency determinations were calculated according to Kocataş [18], similarity with Sorensen index and diversity analyses to Margalef [19]. 3. Results 3.1. Water quality parameters measured in stations Mean values of some water quality parameters of selected stations are given in table (Table 1). In Akyaka Kadın Azmağı Stream, range of mean values of water temperature; o C, ph; , E.C.; -6 µs/cm, dissolved oxygen;.4-.8 mg/l, chloride ion; mg/l, total hardness; o dh, carbonate hardness; o dh, BOD values;.4-.7 mg/l, sulphate ion; mg/l, ammonia; mg/l, nitrite values were found trace on all three stations, nitrate; mg/l, orthophosphate;.2-.3 mg/l, acid binding ability; mg/l, calcium ion; , magnesium ion; mg/l were determined. In, range of mean values of water temperature; o C, ph; , E.C.; µs/cm, dissolved oxygen; mg/l, chloride ion;.1-9 mg/l, sulphate; mg/l, total hardness; o dh and carbonate hardness; o dh, acid binding ability; mg/l, calcium ion; mg/l, magnesium ion; mg/l were determined. Ammonia (1 mg/l), nitrite (. mg/l) and nitrate (1 mg/l) were found only on the third station and orthophosphate was not found on all stations in Akçapınar stream Determined gastropod species Within the study period, 67 individuals were collected from belonging to 7 genera and 7 taxa. Theodoxus heldreichi fluvicola, Pseudamnicola geldiayana, Bithyina leachi troschelii, Valvata piscinalis, Potamopyrgus jenkinsi belong to Prosobranchia; while Planorbis planorbis and Stagnicola palustris belong to Pulmonata. In stations I and II, the most dominant taxon except in June-July period stations I and II was B. leachi troschelii (Figure 2 and 3). In station III, the dominant taxa were P. jenkinsi and P. planorbis. Table I. Mean values of water quality parameters in stations of Akyaka Kadın Azmağı and s Akyaka K.A. Stream PARAMETERS Station I Station II Station III Station I Station II Station III Temperature ( o C) ph E. Conductivity (µs/cm) D. oxygen (mg/l) Chloride ion (mg/l) Sulphate ion (mg/l) Ammonia (mg/l) Nitrite (mg/l) Trace Trace Trace - -. Nitrate (mg/l) Orthophosphate(mg/L) Total hardness o dh Carbonate hardness o dh Acid-binding ability Calcium ion (mg/l) Magnesium ion (mg/l) BOD (mg/l)

4 H. Kalyoncu, M. Barlas, M. Z. Yıldırım and B. Yorulmaz 14 March 3 June B. l. troschelii P. planorbis P. jenkinsi T. h. fluvicola a 2 1 B. l. troschelii P. planorbis P. jenkinsi d 3 April 3 July B. l. troschelii P. planorbis T.h. fluvicola V. piscinalis P. geldiayana P. jenkinsi S. palustris b 1 B. l. troschelii P. planorbis T.h. fluvicola P. jenkinsi S. palustris e 3 May 3 August B. l. troschelii V. piscinalis P. geldiayana P. planorbis T.h. fluvicola c 1 B. l. troschelii P. planorbis T.h. fluviocola P. jenkinsi f Figure 2 (a-f). Monthly distribution of gastropod taxa in 3

5 Gastropods of Two Important Streams of Gökova Bay (Muğla, Turkey) and Their Relationships with Water Quality B. l. troschelii T.h. fluvicola P. jenkensi R. labiata O. elegans P. planorbis V. piscinalis P. geldiayana S. palustris B. leachi troschelii March April May June July August a b Figure 3 (a-b). (a) Distributions of all gastropoda species and (b) monthly distribution of B. leachi troschelii in Within the study period, 1 individuals were collected from Akyaka Kadın Azmağı Stream. Species composition in Akyaka Kadın Azmağı Stream was similar to ; additionally, R. labiata and O. elegans were found in this stream. The highest individual number is recorded in March. T. heldreichi fluvicola was the most dominant taxon except in March and July on station III as shown in the figure (Figure 4) March April P. geldiayana P. planorbis P. jenkinsi S. palustris V. piscinalis T.h. fluviocola a B. l. troschelii P. planorbis T.h. fluviocola V. piscinalis Radix labiata P. jenkinsi S. palustris b 31

6 H. Kalyoncu, M. Barlas, M. Z. Yıldırım and B. Yorulmaz 4 May 7 June B. l. troschelii V. piscinalis P. jenkensi T.h. fluviocola c B. l. troschelii P. planorbis P. jenkinsi T.h. fluviocola R. labiata O. elegans P. geldiayana d 6 July 3 August B. l. troschelii P. geldiayana P. planorbis T.h. fluviocola P. jenkinsi S. palustris e f Figure 4 (a-f). Monthly distribution of gastropod taxa in Akyaka Kadın Azmağı Stream 1 S. palustris P. planorbis P. geldiayana P. jenkinsi T. h fluviocola O. elegans V. piscinalis In stations I and II of Akyaka Kadın Azmağı Stream, dominant species was T. heldreichi fluvicola, followed by P. jenkinsi. But, 9. % dominance of T. heldreichi fluvicola in station II, highest value obtained ever in both streams, are quite interesting. In station III P. jenkinsi was replaced with V. piscinalis and B. leachi troschelii. In stations I and II of. B. leachi troschelii was the dominant species, followed by T. heldreichi fluvicola and P. planorbis in station I, while in station II followed by P. planorbis and S. palustris. In station III P. jenkinsi was dominant, followed by B. leachi troschelii, P. planorbis (Table 2-3). Continuous species of stations I and II in Akyaka Kadın Azmağı were determined as T. heldreichi fluvicola and P. jenkinsi. But in the station III, T. heldreichi fluvicola was the continuous species. In stations I and II of, continuous taxon was B. leachi troschelii, while T. heldreichi fluvicola was continuous organism only in station I and P. planorbis in the station II (Table 4). According to diversity values, highest diversity is seen in station III of Akyaka Kadın Azmağı Stream (Table ). 32

7 Gastropods of Two Important Streams of Gökova Bay (Muğla, Turkey) and Their Relationships with Water Quality Table 2: Dominance in different stations in Akyaka Kadın Azmağı Stream and Determined taxa Akyaka Kadın Azmağı Stream I. st. II. st. III. st. I. st. II. st. III. st. B. leachi troschelii 3,79 % - 12,12 % 6,6 % 48,93 %,88 % T. heldreichi fluvicola 9,1 % 9, % 7,14 % 24,79 % 6,8 % 2,3 % P. jenkinsi 28,8 % 11,2 6,6 % - 3,82 % 32,94 % R.. ovata - -,86 % O. elegans,37 % P. planorbis 3,79 %,46 % 4,76 % 12,66 % 33,19 % 23,2 % V. piscinalis 2,27 % - 14,71 % 2,27 % - 8,2 % P. geldiayana,9 % - 3,46 % 2, % -,88 % S. palustris 1,32 % 1,61 %,86 % - 11,6 % - Table 3: Frequencies of taxa in Akyaka Kadın Azmağı ve s Determined Taxa Akyaka Kadın Azmağı Stream I. st. II. st. III. st. I. st. II. st. III. st. B. leachi troschelii 66,66 % - 66,66% 1% 1% % T. heldreichi fluvicola 1% 1% 1% 1% % 16,66% P. jenkinsi 1% 83,33% 33,33% - 16,66% 66,66% R.. ovata ,33% O. elegans 33,33% P. planorbis 66,66% 16,66% 66,66% 66,66% 83,33% 66,66% V. piscinalis 33,33% - 66,66% 16,66% - 16,66% P. geldiayana 16,66% - % 16,66% - 16,66% S. palustris 16,66% % 16,66% - 33,33% - Table 4: Akyaka Kadın Azmağı ve diversity values Stations Akyaka Kadın Azmağı Stream Station I 2,7 1,6 Station II 1,14 1,68 Station III 2,9 2,6 Table : Similarity between the stations of Akyaka Kadın Azmağı and s Akyaka Kadın Azmağı Stream Stations I. st. II. st. III. st. Stations I. st. II. st. III. st. Station I 1,66,87 Station I 1,6,83 Station II - 1,66 Station II - 1,72 Station III Station III Order of similarity of stations, as seen in the Table, were observed in Akyaka Kadın Azmağı Stream as stations I-III, II-III and I-II, while in as stations I-III, II-III and II-I. 4. Discussion and Results According to some measured parameters; seasonal spring water temperatures in Akyaka Kadın Azmağı were inversely proportional. During winter, temperature values were recorded relatively high and ph values almost neutral, slightly alkaline. Salty sources added to the stream increases E.C. values. Chloride ion values indicate polisaprob character, indeed, level of chloride ion is caused by geological mechanism, not by pollution. High concentrations of chloride and sulphate are the mixing of the marine water, which 33

8 H. Kalyoncu, M. Barlas, M. Z. Yıldırım and B. Yorulmaz also affects total and permanently hardness resulting in high levels. According to ammonium, nitrate, nitrite and orthophosphate values, this stream should be placed in quality class I, while to total nitrogen values in only station I fits in quality level II standards, because of wastes damped by the fish restaurants nearby. BOD values indicate a water quality level I. This stream shows brackish water character. In temperature and ph aspects, Akçapınar Stream is mostly similar to Akyaka Kadın Azmağı Stream. But conductivity values were measured at markedly low levels (between 7-8 µs/cm) in respect to Akyaka Kadın Azmağı Stream. Chloride ion, total hardness, carbonate hardness and calcium values of were determined to be quite low, while dissolved oxygen values were relatively high. Concerning these features, has freshwater character. During the study period, T. heldreichi fluvicola, P. geldiayana, B. leachi troschelii, V. piscinalis, P. jenkinsi, P. planorbis, and S. palustris were determined in. In all stations B. leachi troschelii, known from various lentic and lotic systems in West and Southwest Anatolia were found to be dominant []. This euryoecious species is widespread from Europe to northern Africa and eastern Siberia. In the localities, T. heldreichi fluvicola comes as second in abundance, a subspecies common in Southwest Anatolia. This taxon, as with many other congeners, prefers undisturbed, spring or slow-flowing lotic waters, which explains its abundance in the first station. Additionally, other areas in which it is found less abundant can also be said relatively clean. Among stations, station I shows an undisturbed spring pattern without any outer effects. Station II is also somewhat similar in this aspect. Station III hosts species adapted to the physical parameters and more tolerant in ecological needs, e.g. the most dominant species P. jenkinsi and P. planorbis are more common and euryoecious species[1,3]. Represented with lower frequencies, P. geldiayana, V. piscinalis, and S. palustris are commonly found in south-western Anatolian waters [2]. 34 It has been determined 9 mollusc taxa from Akyaka Kadın Azmağı Stream and is quite similar to in respect to its malacofaunistic features. According to studies from March 21 to August 21, two streams differed in the abundance of T. heldreichi fluviocola in the former presumably due to the higher availability of feeding and breeding grounds. Another difference is also the presence of Radix labiata (station III; April and June) and O. elegans (station I; June and August) in Akyaka Kadın Azmağı Stream rarely, two rather euryoecious pulmonates, the latter regarded often as being a terrestrial form [1,3]. They are recognized with single shells for each record. In, total of 7 species were determined. According to water quality parameters, all stations in Akyaka Kadın Azmağı Stream were determined to be quality classes I-II. So these stations are less polluted freshwater sections. For station I and II, water quality levels couldn t be evaluated precisely due to in availability of some measurements. But station III was determined to be in water quality level II-III. In both streams, chloride content was very high. However, especially in, lack of pollutant sources and evenness of water quality including the mouth part suggest the geological factors may be the main reason. According to hardness values, Akyaka Kadın Azmağı Stream stations are classified as very hard whereas as hard. In Akyaka Kadın Azmağı Stream, the most dominant taxon was T. heldreichi fluvicola, followed by P. jenkinsi. Highest frequencies were determined from stations I and II. But in station III a great deal of decrease in specimen abundance were noted. The highest number of collected specimens was recorded in station I in March 21. These taxa were also determined from, but always in fewer numbers. The highest specimen abundance was obtained also in March 21. But in station III only 2 individuals of T. heldreichi fluvicola in July 21 were collected. This station was the most polluted section in both two streams, and absence of molluscs here should be explained with their

9 Gastropods of Two Important Streams of Gökova Bay (Muğla, Turkey) and Their Relationships with Water Quality susceptibility to pollution. So the shells may have transported to the station via currents. According to Yıldırım [14], this taxon is known from several springs and their extensions in Burdur. Yıldırım and Karaşahin [21] evaluated the physiochemical features of localities where T. heldreichi fluvicola occurred around Eğirdir and stated that it was a stenoecious subspecies distributed generally in clean and undisturbed springs with high oxygen concentration. But in Akyaka Kadın Azmağı Stream, dissolved oxygen is approximately at mg O 2 /L, which means that T. heldreichi fluvicola is more tolerant to different oxygen levels. It was observed to live in the littoral of slow flowing streams rich in epilytic algae, together with clean springs. Genus Theodoxus, represented with T. heldreichi fluvicola in our study area, is broadly distributed in fresh and brackish waters of Palaearctic [22]. The Theodoxus species are generally dioeciously and euryhaline, but for many parameters like dissolved oxygen concentration or temperature, their tolerance is very limited. Furthermore, as passive transport is unlikely, only explanation for dispersal remains ancient hydro geographical connections. The dominance in Akyaka Kadın Azmağı can be explained by brackish character and low pollution levels. Dominant taxon in was generally B. leachi troschelii, although in station III sampling was possible only in March and July with still lower specimen abundances. During May, no shells were found in station III, which also produced the least material throughout the study period. Frequencies in station III were also relatively similar. Except for B. tentaculata, all Bithynia species are generally distributed in averagely polluted freshwater sections, and spring waters [23]. In B. leachi troschelii showed best development in station I, while nonexistent in station I of Akyaka Kadın Azmağı Stream throughout the study period and very scarce (single shells per month) in other stations. S. palustris was observed in Akçapınar Stream only in April and July. Yıldırım and Karaşahin [21], having located it only in a site, reported the ph spectrum being quite narrow, although Zhadin [1], Glöer et al., [3] and Meyer [23] describe it as a rather tolerant and widespread 3 species. S. palustris was generally collected from macrophytes as stated in the literature. It is found in almost all regions of Turkey [21]. General distribution includes Europe [3]. In station III of, 7 individuals to V. piscinalis were collected only in March, represented with 12 individuals in station I in May. But species couldn t be found in stations II during the study period. The highest specimen abundance has been obtained from station III. V. piscinalis is relatively tolerant organism. It lives generally in slow or steady waters, as with averagely polluted freshwater sections and it is placed in the water quality class II [23]. V. piscinalis showed best development in station III of Akyaka Kadın Azmağı Stream. P. jenkinsi showed a good development in stations I and II of Akyaka Kadın Azmağı Stream, as the most dominant taxon after T.heldreichi fluvicola. However, in station III dominance value decreased significantly. This drop was in correlation with the flowing direction of the stream. It wasn t seen in station I of and occurred in station II only with a low dominance value, but in station III it was the most dominant taxon. Despite its well distribution in spring sections, P. jenkinsi is also very tolerant to polluted parts. This idea is supported by its dominance in station III of. Thus, its tolerance to critically polluted waters (quality levels II. to III.), in comparison to other organisms. P. planorbis was found in all stations as with T. heldreichi fluviocola. The highest dominance value is seen in Akçapınar stream station II. P. geldiayana couldn t be collected from stations II of both streams. Dominance values are quite low, the highest value was observed in (station III). Considering the material collected from both streams, the lowest number of material was obtained from the most polluted site, station III of, with 8 individuals to 6 taxa. The highest number of material was obtained from station I of Akyaka Kadın Azmağı Stream with 27 specimens, while 434 and 231 specimens were collected from stations II and III respectively. This stream was found richer in specimen abundance and number of the taxa. This shows that

10 H. Kalyoncu, M. Barlas, M. Z. Yıldırım and B. Yorulmaz physiochemical changes in water affect development and distribution of aquatic gastropods. Aquatic gastropods, their distribution and development with the physical and chemical features of water can be used for determination of water quality in streams. References 1. Zhadin, V. I. (192). Mollusks of fresh and brackish waters of the USSR. Academy of Sciences of the USSR, Israeli Program for Scientific Translations, Jerusalem, 368p 2. Malek, E. A. and Cheng, T. C. (1974). Medical and Economic Malacology. Academic Press Inc., London and New York 398p. 3. Glöer, P., Meier-Brook. C., Osterman, O., (1978). Süsswassermollusken; ein Bestimmungsschlüssel für die Bundesrepublik Deutschland. Deutscher Jugendbund für Naturbeobachtung (D.J.N), Hamburg, 46 p. 4. Hart, C. W. and Samuel L. H. F. (1974). Pollution Ecology of Freshwater Invertebrates. Academic Press Inc., New York. 389p.. Demirsoy, A., Genel ve Türkiye Zoocoğrafyası-Hayvan Coğrafyası. Meteksan A.Ş., Ankara, 63 p. 6. Schütt, H, (1964). Die Mollusken Fauna eines Reliktar an Quellsees der Südlichen Türkei. Arch. Moll. 93, Schütt, H. (196). Zur Systematik und Ökologie Türkischer Süsswasserprosobranchier. Zoologische Mededelingen, 41 (3), Radoman, P. (1973a). New Classification of fresh and brackish water Prosobranchia from the Balkans and Asia Minor. Prir. muz., Pos. izd. 32, Radoman, P. (1973b). On the relations some Freshwater Mollusca of the Balkan Peninsula and Asia Minor. Basteria 37, Radoman, P. (1976). Speciation within the family Bythinellidae of the Balkans and Asia Minor. Zeitschrift für Zoologische Systematik und Evolutionsforschung.14 (2), Schütt, H. (1991). Fossile Mollusken dreier Anatolischer Ovas. Arch. Moll. 12 (4/6), Schütt, H. (1992). Die Altpleistozane Molluskenfundort Kurnabei Burdur in der Türkei. Mitt. dtsch. malakozool. 49, Schütt, H. and Bilgin, F. H. (1974). Recent Melanopsines of the Aegean. Arch. Moll. 14 (1/3), Yıldırım, M. Z. (1999). Living and Fossil Molluscs of the Burdur Lake Basin. Club Conchylia Informationen. 31 (1/2), Schütt, H. and Yıldırım, M. Z. (1999). A new freshwater snail from the Beyşehir Lake in South- West Anatolica (Gastropoda.,Prosobranchia Hydrobioiden). Malak. Abh. Mus. Tierkde. Dresden. 19 (22), Yıldırım, M. Z. (24). The Gastropods of Lake Eğirdir. Turk. J. Zool., 28, Klee, O. (1991). Angewandte Hydrobiologie. G. Theieme Verlag, 2. neubearbeitete und erweiterte Auflage, Stuttgart-New York, 272 p. 18. Kocataş, A. (1994). Ekoloji ve Çevre biyolojisi. Ege Üniversitesi Fen Fakültesi Ders Kitapları Serisi No:142 (İkinci Baskı), Bornova/ İzmir, 64p. 19. Margalef, R. (198). Perspectives in ecological theory. University of Chicago Press, 111 p. 2. Bilgin, F. H. (1973). Yurdumuzda İlk Defa Tespit Edilen ve Tıbbi Önemi Olan Bir Tatlısu Gastropodu Melanoides tuberculatus (Müller, 1774) Hakkında. Ege Üniv. Fen. Fak. İlmi Rap. Ser., 167, Yıldırım, M. Z. and Karaşahin, B. (2). Antalya İli ve Civarındaki Tatlı Sularda Yayılış Gösteren Gastropoda Türleri. SDÜ. Fen Bilimleri Enstitüsü Dergisi 4 (1), Schütt, H. and Şeşen, R. (1989). Theodoxus in SE- Anatolia, Turkey (Gastropoda Prosobranchia, Neritidae). Basteria, 3, Meyer, D. (987). Makroskopisch- Biologische Feldmethoden zur Wassergütebeurteilung von Flieβgewässern, 3. Auflage, A.L.G., 6, 3, Hannover, 14 p. 36