Zoological specimen
Encyclopedia
A zoological specimen is an animal or part of an animal preserved for scientific use.
Various uses are : to verify the identity of a (species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

), to allow study, increase public knowledge of zoology
Zoology
Zoology |zoölogy]]), is the branch of biology that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct...

.
Zoological specimens are extremely diverse. Examples are bird and mammal study skins, mounted specimens
Taxidermy
Taxidermy is the act of mounting or reproducing dead animals for display or for other sources of study. Taxidermy can be done on all vertebrate species of animals, including mammals, birds, fish, reptiles, and amphibians...

, skeletal material, casts, pinned insects, dried material, animals preserved in spirit and microscope slides.
natural history museums are repositories of zoological specimens

Study skins

Birds and mammal specimens are conserved as dry study skins.
The skin is removed from the specimen, treated with absorbents and filled with cotton or polyester batting (in the past plant fibres or sawdust). Projecting thin wooden supports inside the bird specimens allow handling.Preparators use owire to support the legs and tail of mammals.Labels are attached to a leg of the specimen with thread. Study skins may be dried with heat or chemicals.

Skeletal Preparations (Osteology)

Osteological collections consist of cleaned, complete and partial skeletons, crania
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

 of Vertebrates , mainly birds and mammals. They are used in studies of comparative
Comparative anatomy
Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...

 anatomy and to identify bones from archaeological sites. Human bones are used in medical and forensic studies.

Molluscs

In museum collections it is common for the dry material to greatly exceed the amount of material that is preserved in alcohol.The shells minus their soft parts are kept in card trays within drawers or in glass tubes, often as lots (a lot is a collection of a single species taken from a single locality on a single occasion). Shell collections sometimes suffer from Byne's disease
Byne's disease
Byne's disease, more accurately known as Bynesian decay, is a peculiar and permanently damaging condition which often attacks mollusk shells that are in storage or on display for long periods of time....

 which also affects birds eggs.The study of dry mollusc shells is called conchology
Conchology
Conchology is the scientific or amateur study of mollusc shells. Conchology is one aspect of malacology, the study of molluscs, however malacology studies molluscs as whole organisms, not just their shells. Conchology pre-dated malacology as a field of study. It includes the study of land and...

 as distinct from malacology
Malacology
Malacology is the branch of invertebrate zoology which deals with the study of the Mollusca , the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, octopus and squid, and numerous other kinds, many of which have shells...

 (wet specimens).

Insects

Main articles: Insect collecting
Insect collecting
Insect collecting is the collection of insects for hobby, scientific study or profit. Historically insect collecting has been widespread and a very popular educational hobby. Insect collecting has left traces in European cultural history, literature and songs Insect collecting is the collection of...


Most insect specimens are pinned.The specimen is transfixed by a specially manufactured stainless steel pins called an entomological pin while it is hydrated.As the insect dries the integument grips the pin holding the specimen.The pins enable handling and also bear the data and determination labels. Once dried the specimens are kept in Unit trays.These are open-top boxes with a have a plastazote (foam) bottom. They fit inside glass-topped drawers. European museums use larger card boxes which are glass-topped and stored in metal cabinets. Soft-bodied insects are kept in alcohol (wet collections) or as microscope slide preparations.

Wet specimens

"Wet" specimen collections are stored in 70% ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

 (EtOH) with various additives after fixing with 10% formalin. Modern specimens are stored in screw-top glass jars with polypropylene lids if they are small or stored in stainless steel tanks if they are large. Specimens are also stored in 10% formalin.

Data

Minimum data associated with zoological specimens is the place and date of collection, attached to the specimen by a label. Additional information is the name of the collector and the habitat. Tissue from specimens may be saved for genetic studies (molecular data, DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

). Depending on the animal group
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

 other data may be included, for instance in bird collections the bird’s, breeding condition, weight, colours of its eyes, bills and legs and nature of the stomach contents.

Composite specimens

A single specimen may be a composite of preparations sharing a unique number. An example would be a verebrate with an alcohol-preserved skin and viscera, a cleared and stained head, the post-cranial dried skeleton, histological
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...

, glass slides of various organs, and frozen tissue samples. This specimen could also be a voucher for a publication, or photographs and audiotape.

Voucher specimens

A voucher is a representative specimen of the animal used in a study, such as a specimen collected as part of an ecological
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

 survey or a specimen which was the source of DNA for a molecular study.Voucher specimens confirm the identity of the species referred to in the study. They are a backup against misidentification, changing species concepts
Species problem
The species problem or species concept is a mixture of difficult, related questions that often come up when biologists identify species and when they define the word "species"....

 which mislead results. Type
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

 specimens are a special type of voucher specimen used in taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

.

Historic specimens

Museum zoological specimens may have historic significance
Timeline of zoology
A timeline of the history of zoology.- Ancient world :*28000 BC. Cave painting in Europe, especially Spain, depict animals in a stylized fashion...

 for instance the specimens collected by Johann Baptist von Spix
Johann Baptist von Spix
Dr. Johann Baptist Ritter von Spix was a German naturalist.Spix was born in Höchstadt, Middle Franconia, as the seventh of eleven children. His boyhood home is the site of the Spix Museum , opened to the public in 2004...

 and Carl Friedrich Philipp von Martius
Carl Friedrich Philipp von Martius
Carl Friedrich Philipp von Martius was a German botanist and explorer.Martius was born at Erlangen, where he graduated M.D. in 1814, publishing as his thesis a critical catalogue of plants in the botanic garden of the university...

 during their Brazil Expedition (1817-1820) are in Munich Zoology Museum
Zoologische Staatssammlung München
Zoologische Staatssammlung München or ZSM or The Bavarian State Collection of Zoology is a major German research institution for zoological systematics. With over 20 million zoological specimens it is one of the largest natural history collections in the world. The sections are Entomology,...

.

Models

Museums make extensive use of models.When these are accurate they are considered to be specimens in their own right. Examples are the glass coelenterates of Leopold and Rudolf Blaschka
Leopold and Rudolf Blaschka
Leopold Blaschka and his son Rudolf Blaschka were German glass artists, known for the production of biological models such as the Glass Flowers.-Early life of Leopold:...


External links

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