Larval Fish Ecology
A Critical Management Concern
A 24-minute instructional videotape prepared in 1985 for the
United States Fish and Wildlife Service Office of Information Transfer

by Darrel E. Snyder
Larval Fish Laboratory
Colorado State University
Fort Collins, Colorado 80523

Produced in cooperation with the
Colorado Cooperative Fish and Wildlife Research Unit and
Office of Instructional Services, Colorado State University

Version with Spanish narrative by Helena Molina Urena prepared in 1989 

Abstract:

Relative to their adult counterparts, fish larvae are ecologically distinct organisms; they usually have different habitat requirements and play different roles in the aquatic community. These requirements and roles change as fish grow. As their initial habitat, the spawning ground, becomes inadequate, larvae either drift or actively migrate to more suitable nursery grounds. Effects of changes in habitat or community structure on fish larvae may also be quite different from effects on embryos, juveniles, and adults. Loss or alteration of larval-fish habitat by installation and operation of dams or major water diversions is the most typical environmental impact. Fish are often more sensitive to pollution as larvae than during other periods of development. Larvae, as well as pelagic eggs, are especially susceptible to entrainment in water withdrawal systems. Extremely high mortality during embryonic and larval periods is normal for most fish species and is accounted for in their reproductive strategies. Environmental changes that significantly affect survival of fish embryos or larvae can have a corresponding effect on the eventual size of an adult population. Fish larvae must be produced and survive in sufficient numbers if there are to be enough adult fish to manage. The ecology of fish larvae must be considered in management efforts and decision-making processes.

Description:

This 24-minute videotape is an introduction to larval fish, their ecology, and the impacts of human disturbance on their habitat. It was prepared as a training update for aquatic resource managers and biologists of the U.S Fish and Wildlife Service. The video includes segments on the early life stages of fish; reproduction, eggs, and larvae of some representative North American species; various aquatic habitats; and some of the adverse impacts that affect fish larvae. Also included are segments on fish culture, stocking, and collection and laboratory study of fish larvae. Although the video is based mostly on fish larvae in freshwater ecosystems, most of the concepts and concerns apply equally to marine species and habitats.

Availability:

For U.S. Fish and Wildlife Service, National Biological Service, and other U.S. federal natural resource offices or personnel (also, state natural resource agencies and public schools, colleges, or universities), copies can be borrowed for up to 10 work days from:

For others, or U.S. federal offices or personnel so wishing, copies of the videotape can be purchased from: