Larval Fish ID – Larval Fish & Egg Taxonomic Keys

Larval fish ID logoAccurately identifying early life stage (ELS) fishes is important for fisheries management, regulatory compliance, research, conservation, and rehabilitation efforts. LimnoTech and the Electric Power Research Institute (EPRI), with support from others, have developed web-based taxonomic keys for larval fish and eggs in and around the United States.

The keys are based on information from key publications and resources, beginning with the seminal Identification of Larval Fishes of the Great Lakes Basin With Emphasis on the Lake Michigan Drainage (Auer, 1982). The original freshwater key has been expanded to include freshwater egg, yolk-sac larvae, and larvae in the Great Lakes, Colorado River, Upper Mississippi River, Ohio River, and Tennessee River watersheds (more than 193 species from 31 families). Additional keys for fishes found along both the Atlantic (more than 1,072 species from 193 families) and Pacific (more than 1,060 species from 150 families) coasts of the United States have also been added.

These keys provide a resource of accepted, assembled data in order to facilitate improved identification of fish egg and larvae taxa with the following caveats:

  • Many early life stage descriptions of North America’s fishes remain inadequate for species-level identification, with data more complete at the family level.
  • More data is available for post yolk-sac larval stages than for egg and yolk-sac.
  • More data is available for some families and species than others and thus a targeted species might be eliminated from a search because of that gap.
  • There may be regional variations between fish of the same or similar species

LimnoTech, Electric Power Research Institute, Nancy Auer