*3.1. Limiting Factors for P. reticulata Distribution*

MaxEnt GIS modeling revealed the following limiting and important factors (percent contribution) for the distribution of guppies: bio4 (Temperature seasonality)—21.9%, bio3 (Isothermality)—10.6%. In this "ecological envelope" 68.1% of guppies are found in the temperature range of +10–+28 ◦C, mean—22 ◦C (bio1, Figure 2, [28]). The temperature of +10 ◦C may have appeared as a result of extrapolation to northern areas, where warm drains are located (in large cities, etc.). According to our observations of "wild" populations of guppies in warm water bodies of the Bortnychi aeration station in Kyiv (2011–2020; 50.3837◦ N, 30.6642◦ E, Ukraine), these fish are quite unpretentious in terms of water quality and are generally demanding to the water temperature. The total body length in males is 1.85–3.24 cm, and in females—2.00–5.50 cm. Guppies breed all year round and even in winter in warm sewage waters; in December 2020 (water temperature +16 ◦C) mainly juvenile individuals were registered (Figure 1A). And owing to the high water temperature, they reproduce all year round. Therefore, these fish are more synanthropic, and are more likely to get along in warm urban drains in Eastern Europe. Consequently, annual mean temperature (bio1) within the native range has optimum—+14–+28 ◦C, mean—24 ◦C (Figure 2, [28]), and this species is rather unpretentious to water quality (Figure 1).
