Non-native fishes in eight rivers of South China: species
composition, distribution patterns, and potential influencing factors
Abstract:
Non-native fish invasions
are
among the greatest threats to freshwater ecosystems worldwide. In South
China, the same climatic conditions that facilitate the culture of some
non-native fishes may also support their invasive potential. We
conducted systematic collections of fish in eight main rivers of South
China, from 2016 to 2018, to investigate and analysis species
composition and the distribution of non-native fishes. The data reveal
that non-native fishes are widespread in the sampled rivers: of the
98,887 fish collected, 11,832 individuals representing 20 species were
not native. Of the non-native fish species, 17 are used in aquaculture
and 19 are native to the tropics; 13 are omnivores while other seven are
predators. Based on dissimilarity of the non-native fish species
distributions across the eight rivers, the different rivers could be
divided into four assemblages.
Geographical
isolation and temperature were identified as affecting the distribution
patterns of non-native fishes, thereby influencing fish species
composition, species number, dominant species, and distribution
variations in the South China rivers. Species composition of the
non-native fishes in the rivers in this region are related to their
introduction vector, compatibility with their native habitat, and
trophic position. And their distribution pattern was mainly influenced
by the geographical location and temperature.
Key words: freshwater ecosystems, geographical isolation,
invasive species, spatial pattern, survival, temperature