Distribution of nitzschioid diatoms in Kütahya waters

Kütahya is located between Inner and Western Anatolia and has a rich river and stream network, which includes three different river catchments (Susurluk, Sakarya and Gediz). A total of 53 sites were surveyed in the rivers and streams of these catchments. Samples were collected from large and fast flowing rivers (Emet, Gediz, Kocasu, Simav Rivers etc.) and some from slow flowing streams (Felent, Kokar, Kırık, Murat, Porsuk, Safa Streams) and from two thermal discharge waters (Eynal & Naşa thermals). Some of them were collected from small streams, located near villages of the Kütahya Province (e.g. Tiraz, Altintaş, Domaniç, Eynal etc.; Fig. 1, Table 1). The Emet River, about 90 km long, is located in the village of Saruhan and some small springs join together to form a river called the Kocadere Stream. Then, it flows into Lake Uluabat (Ramsar area). The Gediz River, approximately 400 km long, is one of the largest and most important rivers in the Aegean region. It originates in the village of Akkaya and flows into the Aegean Sea in İzmir. The Kocasu River, approximately 45 km long, originates in the Naşa village and is one of the largest tributaries of the Emet River. The Simav River, 321 km long, has its sources in Simav and flows

Figure 1

Distribution of the surveyed localities

into the Sea of Marmara. The Kırık and Safa Streams are small tributaries of the Emet River. The Felent, Kokar and Murat Streams are also small streams and main tributaries of the Porsuk River (Akbulut et al. 2009).

Some physicochemical parameters – dissolved oxygen (DO, mg I^–1), temperature (TEMP, °C) and conductivity (COND, μS cm^–1) – were measured in the field using Lange Hach 40d (Table 2). The conductivity was classified according to Taylor et al. (2006): < 50 μS cm"¹ – very low electrolyte content; 50–100 μS cm^–1 – low electrolyte content; 100–500 μS cm^–1 – moderate electrolyte content; > 500 μS cm^–1 – high electrolyte content; > 1000 μS cm^–1 – very high electrolyte content. The general distribution and ecological features of the species are presented according to Krammer & Lange-Bertalot (1988), Van Dam et al. (1994) and Wojtal(2013).

Epilithic samples (38 samples in total) were collected by brushing submerged stones, while epipelic samples (15 samples in total) were obtained by using a pipette aspirator. Samples were boiled with H₂O₂ and HCl to remove the organic matter. After repeated washing with distilled water, the material was air-dried on cover glasses and mounted in Naphrax. Observations of the diatoms were performed both at the University of Szczecin, Poland, and Dumlupınar University. Light microscope (LM) observations were conducted using an OLYMPUS BX-51 and a NIKON Eclipse e800 light microscope. Micrographs were taken with a Nikon DS-Fi1 camera. Diatoms were identified according to Krammer & Lange-Bertalot (1991), Hofmann et al. (2011), Bąk et al. (2012), Bey & Ector (2013) and Wojtal (2013). The size (length & breadth) of the species was measured using the ImageJ software (Schneider et al. 2012). The distribution of the Turkish flora is presented according to Gönülol (2017). We have tried to use the latest classification system for freshwater diatoms (Fourtanier & Kociolek 2011). Species and infraspecific taxa are arranged alphabetically in the text and figures.

Figure 2

1,2– Cylindrotheca gracilis (Brébisson) Grunow in Van Heurck; 3, 4 – Denticula subtilis Grunow; 5, 6 – Hantzschia abundans Lange-Bertalot; 7, 8 – H. cf. abundans; 9, 10 – H. amphioxys (Ehrenberg) Grunow; 11 – H. calcifuga Reichardt &Lange-Bertalot; 12–15–Nitzschia abbreviata Hustedt; 16, 17– N.acicularis (Kützing) W.Smith; 18, 19– N.acidoclinata Lange-Bertalot; 20–22 – N. alpina Hustedt; 23–24 – N. amphibia Grunow. Scale bar: 10 μm

Basionym: Ceratoneis gracilis Brébisson

Ref. Hofmann et al. 2011 (p. 142, pl. 118:6).

Dimensions of the examined specimens. 65.3–128.7 μm long; 4.0–5.6 um wide.

Distribution and ecology in Kütahya waters. K19, K32, K33, K42, K48, K52. The species was found in samples characterized by moderate to very high electrolyte content (107–1449 μS cm^–1).

Distribution in Turkey. The taxon occurs in the Inner Anatolia and Aegean regions (Gönülol 2017).

General distribution and ecology. It is a ß-mesosaprobious, eutraphentic, aerophile and brackish water species (Van Dam et al. 1994). According to Wojtal (2009), the species is also rarely found in Polish waters.

Ref. Krammer & Lange-Bertalot 1991 (p. 140, pl. 96: 1–9), Hofmann et al. 2011 (p. 168, pl. 117:38–42).

Dimensions of the examined specimens. 12.0–13.3 μm long; 3.2–3.3 μm wide; 9 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K42. The species was found only in one sample, characterized by a very high electrolyte content (1449 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Hofmann et al. 2011 (p. 333, pl. 102:6–10).

Dimensions of the examined specimens. 40.8–67.5 um long; 8.3–10.2 μm wide; 4–7 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K7, K13, K15, K16, K40. The species was found in several samples characterized by moderate or high electrolyte content (314–689 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora. The species is likely confused with H. amphioxys in Turkish waters.

General distribution and ecology. The species is cosmopolitan (Lange-Bertalot 1993). According to Van Dam et al. (1994), it is a neutrophilous, a-mesosaprobious, eurytraphentic and fresh-brackish water species.

Basionym. Eunotia amphioxys Ehrenberg

Ref. Krammer & Lange-Bertalot (1991 p. 128, pl. 88: 1–7), Hofmann et al. 2011 (p. 333, pl. 102:1–5).

Dimensions of the examined specimens. 30.0–46.7 μm long; 5.3–8.3 μm wide; 19–26 striae and 6–8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K13, K14, K15, K22, K27, K38, K39, K40. The species was found in samples characterized by moderate or high electrolyte content (292–765 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Solak & Wojtal 2012; Gönülol 2017).

General distribution and ecology. It is a neutrophilous, α-mesosaprobious, eurytraphentic and fresh-brackish water species (Van Dam et al. 1994). According to Wojtal (2009), the species is also rarely found in Polish waters.

Dimensions of the examined specimens. 36.7-61.7 μm long; 6.7–8.3 μm wide; 20–23 striae in 10 μm.

Distribution and ecology in Kütahya waters. K12, K22, K40. The species was found in a few samples characterized by low to high electrolyte content (88–534 μS cm^–1).

Remarks. The species is similar to H. abundans and H. amphioxys. However, striation and areolation are more visible and the dorsal outline is more rounded. The striae density in this species (21 in 10 μm) is similar to H. amphioxys (20–29 striae in 10 μm, according to Hofmann et al. 2011).

Ref. Hofmann et al. 2011 (p. 334, pl. 102: 11).

Dimensions of the examined specimens. Only one valve was found: 90.0 μm long; 8.3 μm wide; 14 striae and 5 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K39. The species was found in one sample characterized by high electrolyte content (599 μS cm^-1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Hofmann et al. 2011 (p.431, pl. 112: 21–27).

Dimensions of the examined specimens. 6.1–9.3 μm long; 2.1–2.6 μm wide; 28–30 striae and 10–14 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K2, K10, K11, K31, K46, K52. The species was found in several samples characterized by moderate to very high electrolyte content (130–1365 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Basionym. Synedra acicularis Kützing

Ref. Krammer & Lange-Bertalot 1991 (p. 123, pl. 85: 1–4), Hofmann et al. 2011 (p. 123, pl. 107: 20–24).

Dimensions of the examined specimens. 45.2–65.3 μm long; 3.7–4.8 μm wide; 17–21 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K14, K32, K33, K36, K37, K41, K44. The species was found in several samples characterized by moderate to high electrolyte content (370–814 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Solak & Wojtal 2012; Gönülol 2017). Most of the data on the distribution of N. acicularis come from Turkish lakes (Solak et al. 2002). This diatom was also found in rivers, in plankton and benthic samples. Its saprobity was estimated as eurysaprobic, and salinity as oligohalobous-indifferent (Özer et al. 2018).

General distribution and ecology. The species is also very common in Poland. According to Van Dam et al. (1994), it is an alkaliphilous, α-mesosaprobious, eutraphentic and fresh-brackish water species.

Ref. Hofmann et al. 2011 (p. 431, pl. 112: 50–54), Bey & Ector 2013 (p. 996).

Dimensions of the examined specimens. 19.2–20.0 μm long; 2.7–3.0 μm wide; 25 striae and 10–11 fibulaein 10 μm.

Distribution and ecology in Kütahya waters. K41, K52. The species was found in two samples characterized by moderate electrolyte content (107–370 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora. General distribution and ecology. The species is also common in Poland. It prefers oligotrophic waters with low conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, ß-mesosaprobous, mesotraphentic and freshwater. It was observed in waters with very low to high conductivity, but high dissolved oxygen concentrations in the Tatra springs (Wojtal 2013).

Ref. Hofmann et al. 2011 (p. 432, pl. 112: 41–45), Wojtal 2013 (p. 117, pl. 114: 1–12).

Dimensions of the examined specimens. 19.1–31.2 μm long; 3.2–3.7 wide; 25–26 striae and 10–13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K3, K7, K11, K13, K30, K42, K52. The species was found in samples characterized by moderate to very high electrolyte content (130–1449 μS cm^–1).

Distribution in Turkey. The species was found only in the Black Sea region by Tunca et al. (2014). General distribution and ecology. The species was found in waters characterized by low to moderate conductivity and high to very high dissolved oxygen concentrations (Wojtal 2013).

Ref. Hofmann et al. 2011 (p.433,- pl.117:9–15).

Dimensions of the examined specimens. 8.9–41.7 μm long; 4.1–5.3 μm wide; 16–20 striae and 6–9 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K8, K9, K10, K28. The species was found in samples characterized by moderate to high electrolyte content (118–758 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Solak & Wojtal 2012; Gönülol 2017). General distribution and ecology. The species is a cosmopolitan diatom, occurring in waters characterized by a wide range of conductivity (Krammer & Lange-Bertalot 1998). According to Van Dam et al. (1994), it is an alkaliphilous, α-mesosaprobous, eutraphentic and fresh-brackish water species. It was also found in waters with moderate specific conductivity and high dissolved oxygen concentrations (Wojtal 2013).

Figure 3

25–27 – Nitzschia angustata (W.Smith) Grunow; 28–30 – N. angustatula Lange–Bertalot; 31–33 – N. archibaldii Lange-Bertalot; 34–36 – N. bacilliformis Hustedt; 37–39 – N. bergii Cleve-Euler; 40, 41 – N. brunoi Lange-Bertalot; 42–44 – N. capitellata Hustedt; 45–47 – N. clausii Hantzsch; 48–50 – N. communis Rabenhorst; 51–53 – N. denticula Grunow; 54–56 – N. desertorum Hustedt. Scale bar: 10 μm

Basionym. Tryblionella angustata W. Smith

Ref. Krammer & Lange-Bertalot 1991 (p. 48, pl. 36: 1–5),

Dimensions of the examined specimens. 35.8–64.7 μm long; 5.1–7.5 μm wide; 16–18 striae in 10 μm.

Distribution in Kütahya waters. K5, K6, K14, K16, K23, K24, K25. The species was found in samples characterized by moderate electrolyte content (405–539 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Ref. Krammer & Lange-Bertalot 1991 (p. 48, pl. 36: 6–10), Hofmann et al. 2011 (p. 434, pl. 104: 8–12).

Dimensions of the examined specimens. 16.6–26.3 μm long; 3.8–4.9 μm wide; 17–18 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K5, K6, K14, K16. The species was found in a few samples characterized by moderate electrolyte content (405–515 μS cm^–1).

Distribution in Turkey. The taxon was found only in Western Anatolia (Kütahya lotic waters) by Solak et al. (2016) and Inner Anatolia (the Dicle River by Varol & Sen 2014).

Ref. Krammer & Lange-Bertalot 1991 (p. 115, pl. 81: 10–12), Hofmann et al. 2011 (p. 435, pl. 111: 30–34).

Dimensions of the examined specimens. 22.6–26.3 μm long; 2.3–2.6 μm wide; 14–18 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K23, K32, K34, K51, K52. The species was found in samples characterized by moderate to high electrolyte content (107–638 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

General distribution and ecology. The species is widespread in oligosaprobic to β-mesosaprobic waters with moderate conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, ß-mesosaprobous, eutraphentic and fresh-brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 102, pl. 74: 18–26).

Dimensions of the examined specimens. 11.6–16.3 μm long; 3.0–3.4 μm wide; 24–28 striae and 10–13fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K13, K28, K52. The species was found in a few samples characterized by moderate to high electrolyte content (107–689 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Krammer & Lange-Bertalot 1991 (p. 113, pl. 80: 10–15).

Dimensions of the examined specimens. 18.0–21.9 μm long; 3.4–4.0 μm wide; 14–19 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K12, K32, K33, K34, K36, K37, K40, K41, K44, K48, K52. The species was commonly found in waters characterized by low to high electrolyte content (88–814 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Hofmann et al. 2011 (p. 437, pl. 104: 1–2).

Dimensions of the examined specimens. 67.3–112.1 μm long; 9.5–11.9 μm wide; 12–13 striae in 10 μm.

Distribution and ecology in Kütahya waters. K3, K14, K15, K16, K50. The species was found in several samples characterized by moderate to high electrolyte content (362–665 μS cm^–1).

Distribution in Turkey. The taxon was found only in the Aegean region (Kütahya lotic waters) by Solak et al. (2016).

Ref. Krammer & Lange-Bertalot 1991 (p. 88, pl. 62: 1–12), Hofmann et al. 2011 (p. 438, pl. 113: 11–16).

Dimensions of the examined specimens. 18.5–49.7 μm long; 4.5–5.2 μm wide; 12–13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K1, K4, K28. The species was found in a few samples characterized by moderate to high electrolyte content (118–913 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. The species is cosmopolitan, reported frequently from waters with moderate conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, α-meso-polysaprobous,hypereutraphentic and brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 27, pl. 19: 1–6), Hofmannetal. 2011 (p. 438, pl. 116: 15–18).

Dimensions of the examined specimens. 31.6–35.6 μm long; 3.5 μm wide; 9 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K15. The species was found in one sample characterized by moderate electrolyte content (550 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. The species is cosmopolitan (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, α-mesosaprobous, eutraphentic and brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 110, pl. 79: 1–6), Hofmann et al. 2011 (p. 439, pl. 112: 1–5).

Dimensions of the examined specimens. 16.1–32.7 μm long; 3.9–5.1 μm wide; 9–12 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K3, K4, K5, K7, K16, K28, K35, K36, K37, K38, K40, K41, K44, K45, K50. The species was commonly found in samples characterized by moderate to very high electrolyte content (118–1502 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. The species is cosmopolitan, preferring waters with high conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, α-meso-polysaprobous, eutraphentic and fresh-brackish water species. It was found in waters with moderate to very high conductivity (Wojtal 2013).

Ref. Krammer & Lange-Bertalot 1991 (p. 143, pl. 99: 11–23), Hofmann et al. 2011 (p. 441, pl. 26–31).

Dimensions of the examined specimens. 18.7–38.7 μm long; 5.3–7.0 μm in wide; 5–7 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K15, K16, K24, K31, K47. The species was found in several samples characterized by moderate to very high electrolyte content (405–1365 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Ref. Krammer & Lange-Bertalot 1991 (p. 98, pl. 70: 10–13).

Dimensions of the examined specimens. 14.7–26.4 μm long; 4.4–4.7 μm wide; 21–22 striae and 9–13 fibulaein 10 um.

Distribution and ecology in Kütahya waters. K7, K8, K9, K10, K25, K32, K33, K40, K42, K44. The species was commonly found in samples characterized by moderate to high electrolyte content (314–1449 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Figure 4

57–59 – Nitzschia dissipata (Kützing) Rabenhorst; 60–62 – N. dissipata var. media (Hantzsch) Grunow; 63–65 – N. draveillensis Coste & Ricard; 66 – N. dubia W.Smith; 67–69 – N. elegantula Grunow; 70 – N. flexa Schumann; 71–73 – N. fonticola (Grunow) Grunow; 74 – N. graciliformis Lange-Bertalot & Simonsen; 75, 76 – N. gracilis Hantzsch; 77–79 – N. hantzschiana Rabenhorst; 80 – N. heufleriana Grunow; 81 – N. homburgiensis Lange-Bertalot. Scale bar: 10 μm

Basionym: Synedra dissipata Kützing

Ref. Hofmann et al. 2011 (p. 441, pl. 109: 8–13), Hofmann et al. 2011 (p. 441: 8–13).

Dimensions of the examined specimens. 16.7–28.4 μm long; 4.8–5.2 μm wide; 9–12 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K2, K6, K7, K8, K9, K10. The species was found in samples characterized by moderate to high electrolyte content (478–806 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Solak & Wojtal 2012; Gönülol 2017).

General distribution and ecology. The species is cosmopolitan, one of the most frequently reported diatoms from waters with moderate and high conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, β-mesosaprobous, meso- to eutraphentic and fresh-brackish water species.

Basionym: Nitzschia media Hantzsch

Ref. Krammer & Lange-Bertalot 1991 (p. 19, pl. 11:8–14), Hofmannetal. 2011 (p. 441: 14–18).

Dimensions of the examined specimens. 32.4–73.4 μm long; 3.6–5.1 μm wide; 6–8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K2, K5, K6, K7, K9. The species was found in several samples characterized by moderate to high electrolyte content

(478–806 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. The species occurs in waters with a wide trophic spectrum (Lange-Bertalot 1993). According to Van Dam et al. (1994), it is an alkaliphilous and fresh-brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 123, pl. 85: 5, 6), Hofmann et al. 2011 (p. 463, pl. 106: 13).

Dimensions of the examined specimens. 32.9–38.3 μm long; 3.0–3.2 μm wide; 19–21 fibulae in 10 μm.

Distribution in Kütahya waters. K35, K41. The species was found in two samples characterized by moderate to high electrolyte content (370–609 μS cm^–1).

Distribution in Turkey. The taxon was found only in the Inner Anatolia (Çanıllı and Asartepe Reservoirs by Atıcı et al. 2008 and Atıcı & Obalı 2010) and Aegean regions (Kütahya lotic waters by Solak et al. 2016).

Ref. Krammer & Lange-Bertalot 1991 (p. 55, pl. 41: 1, 2), Hofmann et al. 2011 (p. 442, pl. 105:1, 2)

Dimensions of the examined specimens. 109.4–111.9 μm long; 14.0–16.5 μm wide; 23 striae and 8–10 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K7, K8, K25. The species was found in a few samples characterized by high electrolyte content (539–641 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. The species is cosmopolitan, especially in brackish waters (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, β-mesosaprobous, eutraphentic and brackish-freshwater species.

Ref. Krammer & Lange-Bertalot 1991 (p. 120, pl. 83: 20–24).

Dimensions of the examined specimens. 13.7–19.4 μm long; 2.8–3.8 μm wide; 26–28 striae and 12–14 fibulaein 10 um.

Distribution and ecology in Kütahya waters. K48. The species was found in one sample characterized by moderate electrolyte content (338 μS cm"¹).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Krammer & Lange-Bertalot 1991 (p. 16, pl. 4: 6, 9: 1–4).

Dimensions of the examined specimens. 77.1–116.8 μm long; 3.3–5.4 μm wide; 7–10 fibulae in 10 μm.

Distribution in Kütahya waters. K14, K16. The species was found in two samples characterized by moderate electrolyte content (405–514 μS cm^–1).

Distribution in Turkey. The taxon was found only in the regions of Western Anatolia (Tunca River by Öterler et al. 2014) and the Black Sea (Kızılırmak River by Baytut & Gönülol 2016).

Basionym: Nitzschia palea var. fonticola Grunow

Ref. Krammer & Lange-Bertalot 1991 (p. 103, pl. 75: 1–22), Hofmann et al. 2011 (p. 444, pl. 108:9–15).

Dimensions of the examined specimens. 20.4–40.7 μm long; 3.8–4.3 μm wide; 26–28 striae and 10–12 fibulaein 10 um.

Distribution and ecology in Kütahya waters. K5, K6, K7, K9, K11, K20, K23, K27, K35, K36, K41, K49, K50, K52, K53. The species was commonly found in samples characterized by moderate to high electrolyte content (107–765 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Solak & Wojtal 2012; Gönülol 2017).

General distribution and ecology. The species is probably cosmopolitan and common in European waters characterized by a broad range of conductivity and oligosaprobic to β-mesosaprobic conditions (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, β-mesosaprobous, meso- to eutraphentic and fresh-brackish water species. It was found in waters with moderate conductivity (Wojtal 2013).

Ref. Krammer & Lange-Bertalot (p. 115, pl. 81: 8, 9).

Dimensions of the examined specimens. Only one valve was found: 62.0 μm long; 2.6 μm wide; 18 fibulaein 10 μm.

Distribution and ecology in Kütahya waters. K6. The species was found in one sample characterized by moderate electrolyte content (478 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Krammer & Lange-Bertalot 1991 (p. 93, pl. 66: 1–11), Hofmannetal. 2011 (p. 447, pl. 107: 10–14).

Dimensions of the examined specimens. 65.2–68.2 μm long; 3.5–3.8 μm wide; 13–16 fibulae in 10 μm.

Distribution in Kütahya waters. K17. The species was found in one sample characterized by high electrolyte content (751 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017). Most of the data on the distribution of the species come from rivers (Solak et al. 2002).

General distribution and ecology. According to Van Dam et al. (1994), the species is a neutrophilous, β-mesosaprobous, mesotraphentic strictly aquatic and freshwater species.

Ref. Krammer & Lange-Bertalot 1991 (p. 101, pl. 73: 9–18), Hofmannetal. 2011 (p. 448, pl. 112:61–65).

Dimensions of the examined specimens. 15.2–45.3 long; 3.1–3.5 wide; 22–25 striae and 10–13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K7, K12, K13, K38, K41, K49, K50, K52. The species was found in samples characterized by low to high electrolyte content (88–689 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017). General distribution and ecology. The species is probably cosmopolitan (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, oligosaprobous, mesotraphentic, aerophilous and freshwater species.

Ref. Krammer & Lange-Bertalot 1991 (p. 22, pl. 13: 1–5), Hofmann et al. 2011 (p. 448, pl. 109: 19–23).

Dimensions of the examined specimens. 112.1–152.1 μm long; 5.8–7.1 μm wide; 24–25 striae and 9–11 fibulaein 10 μm.

Distribution and ecology in Kütahya waters. K25. The species was found in one sample characterized by moderate electrolyte content (539 μS cm"¹).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Ref. Hofmann et al. 2011 (p. 449, pl. 105: 9–13), Hofmann et al. 2011 (p. 449, pl. 105: 9–13).

Dimensions of the examined specimens. 32.2 μm long; 4.4 μm wide; 15 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K39. The species was found in one sample characterized by moderate to high electrolyte content (118–758 μS cm^–1).

Distribution in Turkey. The taxon occurs rarely in the Inner Anatolia and Aegean regions (Pamukkale travertines by Güner 1966 and some lakes in Anatolia – Isikli, Uluabat, İznik, Salda, Burdur – by Skuja 1937).

Figure 5

82–84 – Nitzschia inconspicua Grunow; 85–87 – N. leistikowii Lange-Bertalot; 88, 89 – N. linearis (C.Agardh) W.Smith; 90–92 – N. microcephala Grunow; 93 – N. palea (Kützing) W.Smith; 94, 95 – N. paleacea (Grunow) Grunow; 96–98 – N. pusilla Grunow; 99–101 – N. recta Hantzsch; 102, 103 – N. rosenstockii Lange-Bertalot; 104–106 – N. sigma (Kützing) W.Smith; 107, 108 – N. sigmoidea (Nitzsch) W.Smith; 109– 111 – N. sociabilis Hustedt; 112–114 – N. solgensis A.Cleve-Euler. Scale bar: 10 μm

Ref. Krammer & Lange-Bertalot 1991 (p. 95, pl. 69: 1–13), Hofmann et al. 2011 (p. 446, pl. 112: 35–40).

Dimensions of the examined specimens. 5.0–12.3 μm long; 2.9–3.2 μm wide; 10–11 fibulae in 10 μm.

Distribution in Kütahya waters. K2, K5, K6, K7, K9, K10, K11, K28, K31, K35, K45, K52. The species was commonly found in samples characterized by moderate to very high electrolyte content (118–1365 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. The species is cosmopolitan, common in waters with moderate and high conductivity, up to the α-β-mesosaprobic zone (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, α-mesosaprobous, eutraphentic and brackish-freshwater species.

Ref. Krammer & Lange-Bertalot 1991 (pl. 68: 20–24).

Dimensions of the examined specimens. 8.6–13.2 μm long; 2.5–3.1 μm wide; 26–28 striae and 12–13 fibulaein 10 um.

Distribution and ecology in Kütahya waters. K2, K7, K9, K28, K36. The species was found in several samples characterized by moderate to high electrolyte content (118–806 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Basionym: Frustulia linearis C.Agardh

Ref. Krammer & Lange-Bertalot 1991 (p.69, pl. 55: 1–4), Hofmann et al. 2011 (p. 452, pl. 106: 1–3).

Dimensions of the examined specimens. 58.8–105.4 μm long; 5.4–6.0 μm wide; 10–12 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K5, K7, K33, K36. The species was found in a few samples characterized by moderate to high electrolyte content (515–834 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Solak & Wojtal 2012; Gönülol 2017).

General distribution and ecology. The species is one of the most frequently reported diatoms, with a wide ecological spectrum, neutrophilous (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, β-mesosaprobous, mesoto eutraphentic and fresh-brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 120, pl. 83: 10–18), Hofmann et al. 2011 (p. 452, pl. 111:43–47).

Dimensions of the examined specimens. 9.0–13.8 μm long; 3.3–3.4 μm wide; 16 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K40, K45, K51. The species was found in a few samples characterized by moderate to very high electrolyte content (314–1502 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017). Most of the data on the distribution of the species come from Turkish lakes (Solak et al. 2002).

Basionym: Synedra palea Kützing

Ref. Krammer & Lange-Bertalot 1991 (p. 85, pl. 59: 1–10), Hofmann et al. 2011 (p. 454, pl. 111: 1–9).

Dimensions of the examined specimens. 34.7–46.3 μm long; 3.5–4.1 μm wide; 8–13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K48. The species was found in one sample characterized by moderate electrolyte content (338 μS cm^–1).

Distribution in Turkey. The taxon is widespread inTurkey (Solak & Wojtal 2012; Gönülol 2017).

General distribution and ecology. The species is cosmopolitan and common, especially in α-mesosaprobic and polysaprobic waters (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, polysaprobous, hypereutraphentic and fresh-brackish water species.

Basionym. Nitzschia subtilis var. paleacea Grunow

Ref. Krammer & Lange-Bertalot 1991 (p. 114, pl. 81: 1–7), Hofmann et al. 2011 (p. 455, pl. 111: 21–29).

Dimensions of the examined specimens. 23.1–25.7 μm long; 2.9–3.0 μm wide; 13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K5, K44. The species was found in two samples characterized by high electrolyte content (515–745 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora. General distribution and ecology. The species is cosmopolitan and very common in eutrophic waters with moderate or high conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, α-mesosaprobous, eutraphentic and fresh-brackish water species.

Ref. Hofmann et al. 2011 (p. 457, pl. 112: 10–15).

Dimensions of the examined specimens. 18.3–21.7 μm long; 3.3–3.7 μm wide; 15–19 fibulae in 10 μm.

Distribution in Kütahya waters. K32, K33, K34, K37, K40, K41, K51. The species was found in samples characterized by moderate to high electrolyte content (307–834 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. The species is cosmopolitan and common, characterized by a wide ecological tolerance, up to α-mesosaprobic (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, β-mesosaprobous, eurytraphentic and fresh-brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 20, pl. 12: 1–11).

Dimensions of the examined specimens. 38.2–71.6μm long; 4.4–5.0 μm wide; 6–7 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K6, K7, K9, K10, K14, K15, K49. The species was found in samples characterized by moderate to high electrolyte content (263–758 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017). General distribution and ecology. According to Van Dam et al. (1994), it is an alkaliphilous, β-mesosaprobous, eurytraphentic, strictly aquatic and fresh-brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 116, pl. 81: 17–20).

Dimensions of the examined specimens. Valves 9.5–11.2 μm long; 3.4–3.8 μm wide; 13–15 fibulae in 10 μm.

Distribution in Kütahya waters. K11, K35, K41, K42, K49. The species was found in several samples characterized by moderate to high electrolyte content (130–609 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Basionym: Synedra sigma Kützing

Ref. Krammer & Lange-Bertalot 1991 (p. 32, pl. 23: 1–9).

Dimensions of the examined specimens. 48.7–56.7 μm long; 5.5–5.9 μm wide; 10–13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K14, K19, K42. The species was found in a few samples characterized by high to very high electrolyte content (514–1449 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. According to Van Dam et al. (1994), it is an alkaliphilous, α-mesosaprobous, eutraphentic and brackish water species.

Basionym: Bacillaria sigmoidea Nitzsch

Ref. Krammer & Lange-Bertalot (1991 p. 12, pl. 5: 1–5).

Dimensions of the examined specimens. 125.3 μm long; 8.5 μm wide; 7 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K14, K15, K16. The species was found in a few samples characterized by high electrolyte content (405–514 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017). General distribution and ecology. It is a cosmopolitan diatom, common in mesotrophic and eutrophic waters with moderate and high conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, β-mesosaprobous, eutraphentic and fresh-brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 83, pl. 83: 1–9).

Dimensions of the examined specimens. 20.6–36.8 μm long; 3.5–4.1 μm wide; 8–10 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K2, K6, K7, K8, K9, K10, K15, K21, K26, K28, K36, K49, K50. The species was commonly found in samples characterized by moderate to very high electrolyte content (118–1125 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

General distribution and ecology. It is probably a cosmopolitan diatom species, particularly common in waters with moderate to very high conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, β-mesosaprobous, eutraphentic and fresh-brackish water species.

Ref. Hofmann et al. 2011 (p. 461, pl. 117: 21–25).

Dimensions of the examined specimens. 7.3–18.3 um long; 2.4–3.6 um wide; 23–25 striae and 4–5 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K13, K27, K37, K53. The species was found in several samples characterized by moderate to high electrolyte content (327–765 μS cm^–1).

Distribution in Turkey. The taxon was found only in the eastern Black Sea region (Kızılırmak River by Baytut & Gönülol 2016).

General distribution and ecology. The species is cosmopolitan, particularly common in waters with moderate to very high conductivity, β- and α-mesosaprobic (Krammer & Lange-Bertalot 1988). In Germany, classified as in regression (Lange-Bertalot 1996). According to Van Dam et al. (1994), it is an alkaliphilous, β-mesosaprobous, aerophilous, meso- to eutraphentic and fresh-brackish water species.

Figure 6

115–116– Nitzschia solita Hustedt; 117–119– N.soratensis Morales & Vis; 120 – N.subacicularis Hustedt; 121 –N.subtilis (Grunow) Hustedt; 122–124 – N. supralitorea Lange-Bertalot; 125, 126 – N. tabellaria (Grunow) Grunow; 127–129 – N. thermaloides Hustedt; 130–132 – N. umbonata (Ehrenberg) Lange-Bertalot; 133 – N. vermicularis (Kützing) Hantzsch; 134, 135 – N. vitrea Norman; 136, 137 – N. vitrea var. salinarum Grunow; 138 – N. wuellerstorffii Grunow; 139, 140 – Simonsenia delognei (Grunow) Lange-Bertalot; 141–143 – Tryblionella apiculata W.Gregory. Scale bar: 10 μm

Ref. Krammer & Lange-Bertalot 1991 (p. 99, pl. 71: 1–12).

Dimensions of the examined specimens. 20.1–24.7 μm long; 4.7–5.1 μm wide; 27 striae and 12–13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K5, K6, K8, K9. The species was found in several samples characterized by moderate to high electrolyte content (478–634 μS cm^–1).

Distribution in Turkey. The taxon was found only in Inner Anatolia (Hafik & Tödürge Lakes by Sıvacı et al. 2007) and the Mediterranean region (Andık Stream by Kalyoncu et al. 2014).

Ref. Trobajo et al. 2013 (p. 47, figs 28–35).

Dimensions of the examined specimens. 5.5–7.5 μm long; 2.6–3.1 μm wide; 12–14 striae and 5–7 fibulae in 10 μm.

Distribution in Kütahya waters. K9, K35. The species was found in two samples characterized by high electrolyte content (609–634 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Hofmann et al. 2011 (p. 462, pl. 107: 20–24).

Dimensions of the examined Turkish specimens. 39.9 um long; 2.9 um wide; 29 striae and 13 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K5. The species was found in one sample characterized by high electrolyte content (515 μS cm^–1).

Distribution in Turkey. The taxon was found only in the western Black Sea region (Acarlar floodplain by Tunca et al. 2014).

Basionym. Synedra subtilis Grunow

Ref. Krammer & Lange-Bertalot 1991 (p. 70, pl. 55: 7–10).

Dimensions of the examined specimens. 44.4–56.9 μm long; 2.5–3.5 μm wide; 15–16 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K17.

The species was found in one sample characterized by high electrolyte content (751 μS cm^–1).

Distribution in Turkey. This is the first record of the species for the Turkish freshwater diatom flora.

Ref. Krammer & Lange-Bertalot 1991 (p. 97, pl. 70: 14–21), Hofmann et al. 2011 (p. 464, pl. 112: 66–71).

Dimensions of the examined specimens. 12.4–20.2 μm long; 2.7–3.9 μm wide; 24–27 striae and 13–16 fibulae in 10 um.

Distribution and ecology in Kütahya waters. K7, K17, K29, K42, K45. The species was found in several samples characterized by high to very high electrolyte content (541–1502 μS cm^–1).

Distribution in Turkey. The taxon was found in the Inner Anatolia region (Karagöl by Açıkgöz et al. 2005).

General distribution and ecology. The species is cosmopolitan, particularly common in eutrophic waters with moderate and high conductivity (Krammer & Lange-Bertalot 1988), According to Van Dam et al. (1994), it is a neutrophilous, α-mesosaprobous, eutraphentic, aerophilous and fresh-brackish water species.

Basionym. Denticula tabellaria Grunow

Ref. Krammer & Lange-Bertalot 1991 (p. 53, pl. 39: 10–13), Hofmann et al. 2011 (p. 464, pl. 117: 1–5), Bąk et al. 2012 (p. 260, pl. 76).

Dimensions of the examined specimens. 19.1–20.0 μm long; 7.2–7.8 μm wide; 21–23 striae and 6 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K16. The species was found in one sample characterized by moderate electrolyte content (405 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017). General distribution and ecology. The species is cosmopolitan (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is a neutrophilous, β-mesosaprobous, mesotraphentic and freshwater species.

Ref. Krammer & Lange-Bertalot 1991 (p. 59, pl. 44: 1–7).

Dimensions of the examined specimens. 15.3–48.9 μm long; 3.4–5.8 μm wide; 16–20 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K29, K42, K44, K45, K48. The species was found in several samples characterized by moderate to very high electrolyte content (338–1502 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Basionym: Navicula umbonata Ehrenberg

Ref. Krammer & Lange-Bertalot 1991 (p. 65, pl. 51: 1–6A), Hofmann et al. 2011 (p. 467, pl. 105: 4–8).

Dimensions of the examined specimens. 58.1–71.5 μm long; 8.0–8.2 μm wide; 6–8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K3, K4, K25, K26, K30, K31, K32, K33, K44. The species was commonly found in samples characterized by high to very high electrolyte content (539–1365 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Basionym: Frustulia vermicularis Kützing

Ref. Krammer & Lange-Bertalot 1991 (p. 14, pl. 4: 4, 5), Hofmann et al. 2011 (p. 468, pl. 115: 1–3).

Dimensions of the examined specimens. 132.2 μm long; 5.2 μm wide; 8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K9, K25. The species was found in two samples characterized by high electrolyte content (539–634 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017). Most of the data on the distribution of the species come from Turkish lakes (Solak et al. 2002).

General distribution and ecology. The species is cosmopolitan, occurring in oligotrophic and slightly eutrophic waters with moderate or high conductivity (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), it is an alkaliphilous, β-mesosaprobous, eurytraphentic and fresh-brackish water species.

Ref. Krammer & Lange-Bertalot 1991 (p. 72, pl. 56: 1, 2).

Dimensions of the examined specimens. 51.7–52.8 μm long; 6.9–8.9 μm wide; 23–24 striae and 5–6 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K7, K48. The species was found in two samples characterized by moderate to high electrolyte content (338–541 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Ref. Krammer & Lange-Bertalot 1991 (p. 73, pl. 56: 3–5).

Dimensions of the examined specimens. 37.5–38.9 μm long; 5.8–6.7 μm wide; 24–26 striae and 7–8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K48. The species was found in samples characterized by moderate electrolyte content (338 μS cm^–1).

Distribution in Turkey. The taxon was found only in the Aegean region (Kütahya lotic waters by Solak et al. 2016).

Ref. Krammer & Lange-Bertalot 1991 (p. 13, pl. 6: 1–6), Hofmann et al. 2011 (p. 468, pl. 114: 1–4).

Dimensions of the examined specimens. 6.7–7.7 μm wide; 5.5–6.0 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K5, K24. The species was found in two samples characterized by moderate to high electrolyte content (435–515 μS cm^–1).

Distribution in Turkey. The taxon was found only in the western Black Sea region (Abant Lake by Çelekli & Külköylüoğlu 2006).

Basionym: Nitzschia delognei Grunow in Van Heurck

Ref. Krammer & Lange-Bertalot 1991 (p. 135, pl. 84: 13–19), Hofmann et al. 2011 (p. 540, pl. 47–50).

Dimensions of the examined specimens. 8.5–17.2 μm long; 1.2–2.5 μm wide; 17–21 striae in 10 μm.

Distribution and ecology in Kütahya waters. K7, K17, K18, K50. The species was found in several samples characterized by moderate to high electrolyte content (362–751 μS cm^–1).

Distribution in Turkey. The taxon was found only in

the Black Sea (Sarıkum Lagoon by Sıvacı et al. 2008), Marmara and Aegean regions (Türkmen Mountain springs and Yalova lotic waters by Witkowski et al. 2016).

General distribution and ecology. According to Van Dam et al. (1994), it is an α-mesosaprobous, eutraphentic and brackish-freshwater species.

Ref. Krammer & Lange-Bertalot 1991 (p. 43, pl. 35: 1–6).

Dimensions of the examined specimens. 27.3–46.6 μm long; 5.3–6.5 μm wide; 15–16 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K2, K5, K7, K9, K10, K15, K16, K19, K28, K31, K32, K33, K36, K43, K45, K51 The species was commonly found in samples characterized by moderate to very high electrolyte content (118–1502 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Figure 7

144, 145 – Tryblionella calida (Grunow) D.G.Mann; 146, 147 – T. debilis Arnott ex O'Meara; 148–150 – T. hungarica (Grunow) Frenguelli; 151, 152– Tryblionella sp. Scale bar: 10 μm

Basionym: Nitzschia calida Grunow

Ref. Krammer & Lange-Bertalot 1991 (p. 40, pl. 30: 1–5), Hofmann et al. 2011 (p. 437, pl. 103: 5–8).

Dimensions of the examined specimens. 37.3–47.9 μm long; 7.8–8.2 μm wide; 6–8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K8, K9, K10, K14, K15, K33. The species was found in samples characterized by moderate to high electrolyte content (405–834 μS cm^–1).

Distribution in Turkey. The taxon was found only in the western Black Sea region (Karagöl-Aksaz marsh by Sıvacı 2013).

Ref. Krammer & Lange-Bertalot 1991 (p. 39, pl. 27: 9–11), Hofmann et al. 2011 (p. 440, pl. 102: 12–17).

Dimensions of the examined specimens. 15.8–20.9 μm long; 6.8–8.0 μm wide; 8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K7, K12, K20, K51. The species was found in several samples characterized by low to high electrolyte content (88–758 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Gönülol 2017).

Basionym: Nitzschia hungarica Grunow

Ref. Krammer & Lange-Bertalot 1991 (p. 37, pl. 34: 1–3), Hofmann et al. 2011 (p. 449, pl. 104: 3–7).

Dimensions of the examined specimens. 32.3–62.0 μm long; 7.7–8.5 μm wide; 10–12 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K7, K9, K10, K17, K28, K30, K32, K33, K35, K36, K42. The species was commonly found in samples characterized by low to very high electrolyte content (118–1449 μS cm^–1).

Distribution in Turkey. The taxon is widespread in Turkey (Solak & Wojtal 2012; Gönülol 2017). Most of the data on the distribution of the species come from Turkish lakes (Solak et al. 2002).

General distribution and ecology. The species is cosmopolitan, common in brackish water, up to α-mesosaprobic (Krammer & Lange-Bertalot 1988). According to Van Dam et al. (1994), an alkaliphilous, α-mesosaprobous, eutraphentic, strictly aquatic and brackish-freshwater species.

Dimensions of the examined Turkish specimens. 72.3–115.0 μm long; 18.9–21.7 μm wide; 7–8 fibulae in 10 μm.

Distribution and ecology in Kütahya waters. K42. The species was found in samples characterized by a very high electrolyte content (1449 μS cm^–1).

Remarks. The species is morphologically similar to N. tryblionella. The central area in N. tryblionella is straight, but appears as a visible "knob-like" shape in the central part of a hitherto unknown species. Nitzschia tryblionella has more visible ridges on the valve face. The taxon is also morphologically similar to Nitzschia littoralis Grunow. However, our unidentified taxon is larger in size and has visible ridges on the valve face.