RESOURCE

Field key to the Freshwater Fishes of British Columbia

A comprehensive key to identification of BC freshwater fishes, including introduced species.

EXCERPT: This set of keys is an attempt to provide rapid and dependable field identifications of BC freshwater fish. Traditional keys are not veryuseful in the field, since they are designed for use on preserved specimens – a definite drawback when working with rare or threatened species. Because field identifications are essential in inventory work, we’ve tried to design keys that work in the field. To this end we have included information that is rarely incorporated in traditional keys. For example, information on where a fish was caught (both the geographic locality and site-specific habitat) and what it looks like when alive, can make the identification of even complex species groups easy. For instance, sculpins (“bullheads” of the genus Cottus) are notoriously difficult to identify. In most keys you have to examine chin pores, make judgements about tubular nostrils and the degree of separation of the dorsal fins, as well as count dorsal, anal and pectoral fin rays, and determine if there are palatine teeth, before you can make an identification. In many cases this detail is unnecessary. First, there is no place in BC where all seven of our Cottus species coexist. Since there are only two or three species in
most drainage systems, as long as you know where you are there is no need to work through a key that includes all seven species. Also, many sculpin species have distinctive life-colours and usually occur in specific habitats. Consequently, geographic locality, together with habitat and colour pattern, often are enough for a reliable field identification.