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Upper Midwest Environmental Sciences Center

Farm ponds as critical habitats for native amphibians
A Field Guide to Amphibian Larvae and Eggs of Minnesota, Wisconsin, and Iowa
Field guide contents

Preserving amphibian eggs and larvae

Samples of amphibian eggs and larvae can easily be preserved to make a voucher or reference collection or to send to a specialist for positive identification. Most states require collection permits issued by the state Department of Natural Resources or other similar agency. Remember to observe all wildlife laws and only collect where it is legal and where the collection of a few individuals will not affect the population.

Larvae should be anesthetized according to the procedure recommended by Green (2001). There is no perfect preservative and techniques for preserving specimens are still debated (McDiarmid and Altig 1999). We recommend preserving amphibian eggs and larvae by placing them in a small vial filled with a 10% formalin solution. Alcohol is more pleasant to work with and safer than formaldehyde, but tends to dehydrate specimens. Whatever preservative you use, read the relevant Material Safety Data Sheets (MSDS) to learn how to safely handle and store that chemical. Larvae can be placed individually, or as a lot of 5-20 individuals, in screw top vials. Do not place too many individuals in one container. Immediate labeling is a must; use pencil or indelible ink on all submerged tags. Field tags should be linked to corresponding field notes; labels with detailed information must be kept with the specimens. Do not rely on memory as a record of locality, date, and habitat information. The minimum information includes date, locality (kilometers from a crossroad or other landmark, or GPS coordinates), habitat description, and name of the collector. We recommend maintaining a numbered log that links to tags on the vials. Other important information includes notes on live coloration (specimens quickly lose color in preservative). Specimens should be deposited in a museum or university collection where they can be appropriately cataloged, maintained, and available for researchers worldwide.

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Page Last Modified: December 29, 2010