Museums, Zoological Parks and Herbaria

Museums, Zoological Parks and Herbaria

Institutions that hold and organise specimens are essential infrastructure for taxonomy, because a classification can only be checked and revised by comparing new material against a permanent physical reference.

Zoological parks (zoos) keep living wild animals in captivity for public display, breeding and conservation. For classification, a zoo is valuable because it lets a taxonomist observe an organism's external morphology, coloration, locomotion and behaviour continuously and at close range over its whole lifetime — features that are hard to judge from a single preserved specimen. Zoos also serve as a live reference collection: when the identity of a species is in doubt, a captive, well-documented individual of known provenance is a check against which claims can be verified, and they support breeding programmes that maintain genetic diversity in endangered taxa used in comparative study.

Preservation of specimens — museums and research collections keep dead specimens permanently so that the original material used to describe a species (the type specimen) can be re-examined by later workers. Common preservation methods include:

• Fluid preservation — specimens are fixed and stored in a preservative liquid, most commonly formalin (dilute formaldehyde solution) or ethyl alcohol, which halt decomposition and keep soft tissues intact for dissection or microscopy.
• Dry preservation — hard or externally rigid material (shells, exoskeletons, bones, insect bodies) is simply air-dried and stored, often pinned or mounted, since these structures do not decompose the way soft tissue does.
• Taxidermy — the skin of a vertebrate is removed, treated and mounted over an artificial form so that it keeps the natural external appearance of the living animal; used chiefly for larger vertebrates displayed in museums. …