The conservation of data deficient species is often hampered by inaccurate species delimitation. The galaxiid fishes Aplochiton zebra and Aplochiton taeniatus are endemic to Patagonia (and for A. zebra the Falkland Islands), where they are threatened by invasive salmonids. Conservation of Aplochiton is complicated because species identification is hampered by the presence of resident as well as...

Abstract High reproductive performance is the key attribute of male fitness, especially due to high skew among males most animal species. Males long-lived iteroparous species have opportunities improve upon their previous attempts with increasing age. We collected individual-specific behaviour and age data on a cyprinid fish, asp ( Leuciscus aspius ), from 2015 2019. tested whether changed over...

In this work we aimed to characterise the diet of Astyanax taeniatus (Jenyns 1842) (Characiformes, Characidae) along the Mato Grosso stream and we hypothesised that the diet of this species would vary according to spatial, seasonal and ontogenetic differences. Specimens were collected every second month at three sites with different physical attributes. The feeding habits of 651 specimens were ...

Aplochiton is a small genus of galaxiid fishes endemic to Patagonia and the Falkland Islands whose taxonomy is insufficiently resolved. Recent genetic analyses confirmed the existence of only two closely related species, Aplochiton taeniatus and Aplochiton zebra, while a third controversial species, Aplochiton marinus, remained lost to synonymy with A. taeniatus. Using an integrative taxonomy f...

Group living is widespread in animals. In nature, groups usually not only differ in phenotypic characteristics but also in the social relationships among group members. Theory predicts that individuals adjusting their shoaling decisions—to join certain groups or not—based on social criteria, such as familiarity or genetic relatedness, can increase their fitness. Although numerous studies report...

Many endangered fish species in the wild are artificially bred, and their populations strengthened by stocking of aquaculture-raised juveniles. Because from aquaculture generally not well prepared for challenging life wild, we tested whether training selected challenges could improve survival after stocking. We chose conditioning on predation pressure (by learning predator image northern pike E...

Abstract The northern section of the Caspian Sea and lower reaches Zhaiyk (Ural) River is an important fishery for Kazakhstan. In present study, a total 1597 individuals ten fish species were analysed. caught over three years, from 2018 to 2020. For each studied – Abramis brama , Alosa saposchnikowii Atherina boyeri caspia Carassius gibelio Chelon auratus Cyprinus carpio Leuciscus aspius Rutilu...