Reproductive parameters of invasive topmouth gudgeon Pseudorasbora parva (Temminck and Schlegel, 1846) from Slovakia.

Females of an invasive population of topmouth gudgeon Pseudorasbora parva (Temmick and Schlegel, 1846) from the Šúr pond (Bratislava, Slovakia) were examined to analyze their fecundity and other life history traits. Samples were collected during both pre-spawning (n = 137) and post-spawning (n = 89) periods. Standard length of the females from the pre-spawning period ranged from 23.42 to 59.71 mm (mean 32.80 mm), body weight from 0.260 to 5.442 g (mean 0.965 g), and eviscerated body weight from 0.207 to 4.882 g (mean 0.748 g). Absolute fecundity varied between 121 and 7124 oocytes (mean 1106 oocytes). In 75.22% of the females, two or three size groups of oocytes were clearly distinguished. Overall, the life history traits observed in invasive topmouth gudgeon from the Šúr pond demonstrated a high flexibility in their reproductive strategy. This, together with previously described great morphological variability, is likely to make this species such a successful invader. [ABSTRACT FROM AUTHOR]