Anatolichthys sureyanus (Neu, 1937)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 714-715

Anatolichthys sureyanus

Common name. Burdur killifish.

Diagnosis. Distinguished from other species of Anatolichthys by: ○ usually scales on back and belly absent / ○ usually 1–3 lines of large, usually not or only slightly overlapping

Anatolichthys sureyanus ; Lake Burdur, Türkiye; female, 38 mm SL. scales on midlateral flank / ○ lateral head profile triangular or rounded, lower jaw small, directing forward / ○ body depth 3.2–4.2 times in standard length / ○ caudal peduncle depth 11–14 % SL / ○ head depth at nape 61–69 % SL / ○ head width at nape 51–60 % SL / ○ nuptial male with grey dorsal base / ○ male with white anal and wide, black margin or completely black. Size up to 45 mm SL.

Distribution. Türkiye: Lake Burdur.

Habitat. Lacustrine along shores also found in mouths of inflowing streams and springs on lakeshores. Lake Burdur has very high sodium sulfate (Na 2 SO 4) concentrations and alkalinity (pH 8.9–9.5).

Biology. Live up to 4 years, mature in 100–120 days. Starts spawning at end of March. Incubation period 7–8 days at 22–24°C water temperature. Non-nuptial males and females form large schools. Arctodiaptomus burduricus and Brachionus plicatilis are major food items.

Anatolichthys sureyanus ; Lake Burdur, Türkiye; male, ~ 30 mm SL. © M. Sağdıç

Conservation status. EN; appears to be declining within its small range. The main threats are drying up of Lake Burdur and increasing salinity and pollution, which are continuing. Lake Burdur has lost about 30 % of its surface area since the 1980s due to water abstraction and retention. Reduced inflow has led to increased salinity and pollutant concentrations. Between 2016 and 2019, the species disappeared from the lake after massive fish kills. It was confined to springs and tributaries, suffering from competition and predation from non-native Gambusia holbrooki . In 2000, it was found in the lake again after much rain and fewer algal blooms. Lake Burdur is a Ramsar site, a “Protected Area of First-Degree Importance”, and a “Wildlife Development Zone” under national law.

Remarks. In the past, Anatolichthys from Lake Burdur showed a wide range of squamation patterns. Fish with a partially bare body and reduced, non-overlapping scales on the flank coexisted with fish with a body completely

Anatolichthys transgrediens ; AcıgÖl, Türkiye; female, 30 mm SL.

covered by overlapping scales. Early authors placed a high value on scale patterns and placed fish with fullscale coverage in genus Aphanius and those with reduced scales in genus Anatolichthys . Later, authors treated all fishes as one variable species, mostly based on inconclusive hybridisation experiments and intermediate fishes in the lake. Fish from Lake Burdur were described as A. sureyanus without giving details of scale patterns, A. burdurensis based on fish with reduced scales and a slender body, and A. burduricus based on fish with fullscale coverage and a deep body. Today, Anatolichthys show reduced scale patterns or no scales at all. Molecular studies (cytochrome b, cytochrome c oxidase 1) have yet to provide evidence to distinguish fish from Lake Burdur (without detail in scale patterns) from fish inhabiting springs and lakes in the wider Lake Burdur basin, identified here as A. fontinalis .

Further reading. Akşıray 1955 (description); Yoğurtçuoğlu 2018 (conservation status); Yoğurtçuoğlu & Freyhof 2018 (identification); Güçlü et al. 2007 (biology).