Guide to Cyprinid Fish Larvae and Early Juveniles of the Upper Colorado River Basin with Computer Interactive Key

Authors: Darrel E. Snyder, Sean C. Seal, Jennifer A. Charles, C. Lynn Bjork

Year: 2016 (xlviii)

Abstract

Use of collections of fish larvae and young-of-the-year juveniles to help document fish spawning sites and seasons or assess larval production, transport, distribution, nursery habitat, survival, and other aspects of early life history, requires diagnostic criteria to accurately distinguish target species from similar appearing taxa in the waters sampled. To facilitate identification of the larvae and early juveniles of fifteen carps and minnows (most of the Cyprinidae) in the Upper Colorado River Basin (UCRB), including the five native species (three endangered), developmental series of reared and collected specimens were studied for differences in size relative to developmental state, morphology, meristics, and pigmentation. The results, including detailed descriptive species accounts, comparative summary tables, and instructions for downloading and using the associated computer-interactive key, were documented as a manuscript in a final report to the Upper Colorado River Endangered Fish Recovery Program and published as Colorado Parks and Wildlife (CPW, formerly CDOW) Technical Publication 47 (Snyder et al. 2016). Electronic (PDF) copies of the guide are available on the CPW and Larval Fish Laboratory (LFL) websites, the latter at http://warnercnr.colostate.edu/lfl- downloadable-keys-guides-and-bibliography; printed copies are available upon request to CPW. The associated key (as well as a family-level computer-interactive key) is available at the same LFL website and on a compact disk accompanying printed versions of the publication. This guide complements a previously published guide to the larvae and early juveniles of UCRB catostomids (Snyder and Muth 2004, CDOW Technical Publication 42). Together, these guides complete a long series of descriptive investigations begun over 35 years ago with publication of Contributions to a Guide to the Cypriniform Fish Larvae of the Upper Colorado River System in Colorado (Snyder 1981, Bureau of Land Management Biological Sciences Series No. 3, Denver).