Invasive mosquitofish, Gambusia holbrooki, in the Ripoll. © Matt Ford

Check out our video of native cyprinids Barbus meridionalis Risso 1827 and Squalius laietanus Doadrio, Kottelat & de Sostoa 2007. Both species are endemic to a few river basins in northeaster Spain and southern France, in this case the Ripoll River, a tributary within the larger Bésos drainage close to Barcelona. This is a typical Mediterranean river which flows more strongly during winter and spring and contains less water during the dry summer period.

Drought conditions can also extend between years, and a dry winter in 2013/2014 has caused the native fishes to become concentrated in permanent pools. Also present in these refuge habitats are the invasive mosquitofish Gambusia holbrooki Girard 1859, pumpkinseed sunfish Lepomis gibbosus (Linnaeus 1758), and red swamp crayfish Procambarus clarkii (Girard 1852), all of which were introduced from the United States in the twentieth century and now represent a serious ecological issue throughout Spain.

This is our first attempt at editing a video with captions, music, etc., so please bear with it!

The study uses the zebra danio, Danio rerio, in its case example. © Mike Norén

New study reveals how environmental DNA could be used to identify potentially invasive species in the ornamental fish trade… Continue reading »

The gonopodium of the new species features 4 distinct ‘hooks’. © N. Carolina State University

A new species of Gambusia has several interesting – “and perhaps cringe-inducing” – characteristics, including a series of four hooks on the male genitalia, said North Carolina State University this week. Continue reading »