Date: August 18th 7:00am
Today's fish of the day is the leopard dace!
The leopard dace, also known by the scientific name Rhinichthys falcatus, is a common fish in the Pacific Northwest. Their range extends from British Columbia down to Southern Oregon, from the Pacific ocean, as far east as central Idaho. Found in and around the Fraser and Columbia river, as well as Columbia river tributaries. Particularly the Willamette, Umatilla, and Snake rivers. Despite these rivers spreading further South, these fish are extremely limited by temperature limits, as these fish must be in cool, temperate waters below 23 degrees Celsius. As opposed to other dace fish in the same regions, the leopard dace can be found in areas of slow, and deep moving water. Living in and around gravel runs of rivers and streams. When in lakes or ponds, these fish will cluster around the rocky margins of the shore.
Daces are known for their insectivore diet, and the leopard dace is no different. Their diet is made up primarily of flies, and water bugs, although leopard dace fry and young consume primarily zooplankton and larvae until their first birthday. This diet allows them to get to a maximum size of 12cm (around 5 inches), although most will only achieve a length of 6cm before dying. As opposed to the many other dace in the region, you can differentiate the leopard dace by their irregular blotching patterns along the back and sides. This, as well as small barbels at the corner of the jaw help differentiate from closely related species, such as the longnose dace.
Spawning takes place in the early summer, particularly in early July to August. Eggs will be dispersed in calm, cold streams with areas of fine gravel. These eggs have an adhesive along their membrane, and will settle to the bottom of the stream, preventing predation, as well as significant displacement down the river. Fry will hatch, and then emerge from the gravel weeks later, feeding exclusively on zooplankton. Once these fish reach their first September, they may begin feeding on adult insects, with all fish eating adults by their second birthday. These fish can live as long as 5 years, although there are records of some living to 9 years in captivity. Other than these details, little is known about the reproductive strategies, and life cycle of the humble leopard dace.
That's the leopard dace, everybody! Have a wonderful day!
Sources:
“Leopard Dace.” Oregon Sea Grant, 14 Sept. 2024, seagrant.oregonstate.edu/WRF/native-fishes/carp/leopard-dace.
“Rhinichthys Falcatus Summary Page.” FishBase,fishbase.se/summary/2946.
Hammerson, G. “Species Summary: Rhinichthys Falcatus Leopard Dace.” Species Summary, BC Conservation Data Centre, 28 Sept. 1993, a100.gov.bc.ca/pub/eswp/speciesSummary.do;jsessionid=7JyYVbbX2nNylFJBZjt22Q0LvdWW39wgY73LvkNsnG7FT0bfxWpJ!217898076?id=19993.