Taxonomic Procedures: Collection, Preservation, and Keys

Comprehensive vocabulary flashcards covering Chapter 5: Taxonomic Procedures, including collection sampling, preservation solutions, curation practices, and taxonomic identification keys.

Specimen

An individual organism examined by a systematist for study, identification, or classification.

Systematic series

A group of two or more specimens assembled to represent samples of different demes of a species or different species of a larger taxon.

Statistical sample

The number of specimens examined from each series across geographic areas to statistically analyze morphological and sexual variation within a species.

Allopatric species sampling

The taxonomic practice of sampling populations specifically from the adjacent borders of geographic ranges (such as hybrid zones or peripheral edges) when two species are allopatric.

Long branch attraction

An anomalous result encountered in higher-level molecular phylogenetic studies caused by inadequate taxon sampling due to limited available tissues.

Voucher specimen

A physical specimen preserved and deposited in a museum to document species identification, permitting future researchers to verify molecular data or the collector's initial identification.

Systematics collection

A curated repository of documented series or lots of specimens housed in museums or universities that functions similarly to a research library to document regional flora and fauna.

Field notes

Primary documentation recorded at the time of collection that links specimen tags to specific locality data, coordinates, dates, collector names, and collection methods.

Museum loan period

The standard duration granted to qualified researchers for studying borrowed museum specimens, typically ranging from six months to one year.

Curation

The series of ongoing activities—from accessioning and sorting to cataloging and protection against pests, light, and humidity—that ensures specimens remain preserved and accessible.

Accessioning

The curatorial act of officially acknowledging and registering the intake of an entire newly arrived collection into museum holdings.

Primary type specimens

Specimens that anchor a species or infraspecific taxon's name (such as holotypes, lectotypes, and neotypes), which receive special curatorial care and are set aside from the main collection.

Secondary type specimens

Reference specimens associated with a species description (such as paratypes) that may be curated together with primary types or kept within the main general collection.

Universally unique identifier (UUID)

A unique digital identifier number assigned to a specimen or lot, often encoded in a barcode, allowing distributed computing systems to manage and track collection records.

Retrospective cataloging

The process undertaken by museums to convert historical specimen data from paper books and ledgers into searchable electronic databases.

Euthanizing

Putting an animal to death for specimen collection in a humane manner that leaves tissues undamaged, contortion-free, and fully relaxed.

Fixing

The step in specimen preservation where relaxed organisms are chemically treated and arranged in trays so they permanently harden in the proper anatomical position.

Nembutal

The commercial trade name for Pentobarbital Sodium, sold at $1\,\text{g/cc}$ strength and diluted with water at a 1:9 ratio for euthanizing reptiles via injection into or near the heart.

Chloretone

The commercial trade name for Chlorobutanol (Hydrous), prepared by dissolving one level teaspoon of powder per gallon of water to euthanize amphibians by immersion.

Formalin

A commercial solution of formaldehyde gas ($\text{CH}_2\text{O}$) in water at $38\%$ to $40\%$ strength, diluted to a $10\%$ working concentration (1 part formalin to 9 parts water) for tissue injection and fixation.

Alcoholometer

A measurement device used to evaluate the concentration of alcohol solutions used for storage, which lose strength over time via evaporation.

Kahle's solution

A specialized fluid preservative formulated from 15 parts ethanol, 5 parts concentrated formaldehyde, 1 part glacial acetic acid, and 30 parts distilled water, used to preserve soft-bodied adult or immature arthropods.

Taxidermy

The method of preserving and mounting an animal's skin over an artificial mannequin or form for scientific study or lifelike display.

Form (Taxidermy)

An artificial mannequin or cast produced from plaster, polyester resin, glass cloth, clay, or polyurethane that serves as the foundation over which an animal's skin is mounted.

Whirl-Pak Bags

Heavy-duty, leak-proof polyethylene bags utilized in field collections for temporary storage and transport of fluid-soaked specimens wrapped in cheesecloth.

Taxonomic keys

Analytical devices and decision frameworks designed to facilitate the rapid identification of biological specimens.

Structured keys (single-access keys)

Identification tools constructed as sequential decision trees that offer an abbreviated series of contrasting characters leading step-by-step to a taxon's identity.

Dichotomous keys

Single-access structured keys that present users with a choice between two mutually exclusive alternative character states at every step.

Couplet

A pair of mutually exclusive, contrasting statements presented together at an identification step in a dichotomous key.

Lead

An individual statement or branch within a couplet of a dichotomous key.

Natural key

A taxonomic identification key structured to follow evolutionary relationships and natural phylogenetic classification systems.

Artificial key

A taxonomic key constructed using practical, easily observable, and convenient morphological characters rather than phylogenetic relationships.

Indented keys

Dichotomous keys formatted with matching leads of a couplet indented at equal distances from the left margin, with subsequent couplets indented further beneath.

Bracketed keys

Dichotomous keys that arrange contrasting couplets side-by-side on consecutive lines with numerical or lettered labels, conserving page space.

Polyclave keys (multiaccess keys)

Computer-based identification systems operating on a taxon-character matrix, allowing users to enter multiple freely selected morphological traits to identify specimens via process of elimination.

BLAST (Basic Local Alignment Search Tool)

A molecular polyclave search algorithm that aligns submitted nucleotide or protein query sequences against database sequences to establish specimen identity.

GenBank

The primary public biological database and sequence repository utilized alongside BLAST to match, retrieve, and identify molecular genetic data.