One of my absolute favorite native fish species is the longnose dace (Rhinichthys cataractae). A weird minnow specialized for life in the most fast-flowing torrents of rocky rivers and streams, they use their funny snout to grub in the gravel for small invertebrates, algae and any edible detritus. They have perhaps the largest native distribution of any North American freshwater fish, found coast to coast across much of the northern US and most of Canada.
If you’ve ever been bitten by blackflies (Simuliidae), I hope you’ll be pleased to know that longnose dace are one of their main predators! Blackfly larvae cling to rocks in swift waters where few fish can brave the current but longnose dace feel right at home. Blackfly larvae make up a large proportion of their diet, so without the dace there would be a lot more blackflies around.
Young longnose dace, like in the video above, display fairly typical minnow behavior. They forage in schools and are active during the day, and like many minnows have a dark lateral line. As adults they lose the stripe, develop mottled brown or gold coloration, and become nocturnal, skulking under rocks during the day. However, during spawning they become active during the day and males develop orange highlights.
