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 In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

), to allow study, increase public knowledge of

zoology Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

. Zoological specimens are extremely diverse. Examples are bird and mammal study skins, mounted specimens, skeletal material, casts, pinned insects, dried material, animals preserved in liquid preservatives, and microscope slides.

Natural history museums A natural history museum or museum of natural history is a scientific institution with natural history scientific collection, collections that include current and historical records of animals, plants, Fungus, fungi, ecosystems, geology, paleon ...

are repositories of zoological specimens

Study skins

Bird and mammal specimens are conserved as dry study skins, a form of taxidermy. The skin is removed from the animal's carcass, treated with absorbents, and filled with cotton or polyester batting (In the past plant fibres or sawdust were used). Bird specimens have a long, thin, wooden dowel wrapped in batting at their center. The dowel is often intentionally longer than the bird's body and exits at the animal's vent. This exposed dowel provides a place to handle the bird without disturbing the feathers. Mammal study skins do not normally utilize wooden dowels, instead preparators use wire to support the legs and tail of mammals. Labels are attached to a leg of the specimen with thread or string. Heat and chemicals are sometimes used to aid the drying of study skins.

Skeletal Preparations (Osteology)

Osteological Osteology () is the scientific study of bones, practised by osteologists. A subdiscipline of anatomy, anthropology, and paleontology, osteology is the detailed study of the structure of bones, skeletal elements, teeth, microbone morphology, func ...

collections consist of cleaned, complete and partial skeletons, crania of

Vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...

, mainly birds and mammals. They are used in studies of

comparative anatomy Comparative anatomy is the study of similarities and differences in the anatomy of different species. It is closely related to evolutionary biology and phylogeny (the evolution of species). The science began in the classical era, continuing in t ...

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, more accurately known as Bynesian decay, is a peculiar and permanently damaging condition resulting from an ongoing chemical reaction which often attacks mollusk shells and other calcareous specimens that are in storage or on dis ...

which also affects birds eggs. The study of dry mollusc shells is called

conchology Conchology () is the study of mollusc shells. Conchology is one aspect of malacology, the study of molluscs; however, malacology is the study of molluscs as whole organisms, whereas conchology is confined to the study of their shells. It includ ...

as distinct from

malacology Malacology is the branch of invertebrate zoology that deals with the study of the Mollusca (mollusks or molluscs), the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, ...

(wet specimens).

Insects and similar invertebrates

Most hard-bodied insect specimens and some other hard-bodied invertebrates such as certain

Arachnid Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroon ...

a, are preserved as pinned specimens. Either while still fresh, or after rehydrating them if necessary because they had dried out, specimens are transfixed by special stainless steel entomological pins. As the insect dries the internal tissues solidify and, possibly aided to some extent by the integument, they grip the pin and secure the specimen in place on the pin. Very small, delicate specimens may instead be secured by fine steel points driven into slips of card, or glued to card points or similar attachments that in turn are pinned in the same way as entire mounted insects. The pins offer a means of handling the specimens without damage, and they also bear labels for descriptive and reference data. Once dried, the specimens may be kept in conveniently sized open trays. The bottoms of the trays are lined with a material suited to receiving and holding entomological pins securely and conveniently. Cork and foam plastics are convenient examples. However, open trays are very vulnerable to attack by museum beetle and similar pests, so such open trays are stored in turn inside glass-topped, insect-proof drawers, commonly protected by suitable

pesticide Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...

s or repellents or barriers. Alternatively, some museums store the pinned specimens directly in larger trays or drawers that are glass-topped and stored in cabinets. In contrast to such dried specimens, soft-bodied specimens most commonly are kept in "wet collections", meaning that they are stored in alcohol or similar preservative or fixative liquids, according to the intended function. Small specimens, whether hard or soft bodied, and whether entire,

dissected Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause ...

, or

sectioned Involuntary commitment, civil commitment, or involuntary hospitalization/hospitalisation is a legal process through which an individual who is deemed by a qualified agent to have symptoms of severe mental disorder is detained in a psychiatric hos ...

, may be stored as

microscope slide A microscope slide is a thin flat piece of glass, typically 75 by 26 mm (3 by 1 inches) and about 1 mm thick, used to hold objects for examination under a microscope. Typically the object is mounted (secured) on the slide, and then b ...

preparations.

Wet specimens

"Wet" specimen collections are stored in different solutions. A very old method is to store the specimen in 70%

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...

with various additives after fixing with

formalin Formaldehyde ( , ) ( systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section F ...

or in these days sometimes with a salt-solution. Some methods are very useful, because the color can be preserved. (Salt-)Solutions like this are Jores, Kaiserling and Romhányi. Modern specimens are stored in

borosilicate glass Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (≈3 × 10−6 K−1 at 20 °C), ma ...

due to its chemical and thermal resistance and good optical clarity.

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). Depending on the animal group, 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 vertebrate with an alcohol-preserved skin and viscera, a cleared and stained head, the post-cranial dried skeleton,

histological Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures vis ...

, 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 () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

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 The species problem is the set of questions that arises when biologists attempt to define what a species is. Such a definition is called a species concept; there are at least 26 recognized species concepts. A species concept that works well for se ...

which mislead results. Type specimens are a special type of voucher specimen used in

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

Historic specimens

Museum zoological specimens may have historic significance. For example, the specimens collected by

Johann Baptist von Spix Johann Baptist Ritter von Spix (9 February 1781 – 13 March 1826) was a German natural history, biologist. From his expedition to Brazil, he brought to Germany a large variety of specimens of plants, insects, mammals, birds, amphibians and fish. ...

and

Carl Friedrich Philipp von Martius Carl Friedrich Philipp (Karl Friedrich Philipp) von Martius (17 April 1794 – 13 December 1868) was a German botanist and explorer. Life Martius was born at Erlangen, the son of Prof Ernst Wilhelm Martius, court apothecary. He graduated PhD f ...

during their Brazil Expedition (1817–1820) are housed in the Munich Zoology Museum.

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

invertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

Leopold and Rudolf Blaschka Leopold Blaschka (27 May 1822 – 3 July 1895) and his son Rudolf Blaschka (17 June 1857 – 1 May 1939) were glass artists from Dresden, Germany, native to the Bohemian (Czech)–German borderland, and known for the production of biological m ...

Examples

File:Eléphant d'Afrique naturalisé.JPG, Mount of African elephant and other animals in Paris Museum File:Chitra indica, skeleton.jpg, ''

Chitra indica The Indian narrow-headed softshell turtle (''Chitra indica''), also known as the small-headed softshell turtle or the Indo-Gangetic softshell turtle, is an endangered species of softshell turtle native to waterways and rivers of the Indian subc ...

'' (narrow-headed soft-shelled turtle) skeleton File:Dynastinae.jpg, Pinned insects (

Dynastinae Dynastinae or rhinoceros beetles are a subfamily of the scarab beetle family (Scarabaeidae). Other common names – some for particular groups of rhinoceros beetles – include Hercules beetles, unicorn beetles or horn beetles. Over 1 ...

) File:Caixa de preparacións microscópicas (vista frontal).jpg, Microscope slides File:Pseudocrypturus.jpg, Cast of a bird fossil File:Doris Mable Cochran (1898-1968), measuring a turtle shell.jpg, Zoologist measuring a turtle shell File:Acanthopterygii-senkenberg hg.jpg, Acanthopterygii (fish) at

Naturmuseum Senckenberg The Naturmuseum Senckenberg is a museum of natural history, located in Frankfurt am Main. It is the second-largest of its type in Germany. The museum contains a large and diverse collection of birds with 90,000 bird skins, 5,050 egg sets, 17,0 ...

File:Zoological Exhibition - NM Prague 17.JPG, Model of '' Arenicola marina'' in a zoological exhibition at

National Museum (Prague) The National Museum (NM) (Czech: ''Národní muzeum'') is a Czech museum institution intended to systematically establish, prepare, and publicly exhibit natural scientific and historical collections. It was founded in 1818 by Kašpar Maria Štern ...

File:Technique of diaphanization applied in a fish.jpg, Specimen of fish clarified for visualization of anatomical structures on display at the MAV/USP.

References

External links

Naturkundemuseum StuttgartZoological Collection Database SZN
Impressive. Images of wet specimens,labels,catalogues etc.

The role of voucher specimens in validating faunistic and ecological research
Museum handbook
Bird skin preparation
Texas Tech University
Halter, A.S. Standards for management of the recent mammal and bird collections Texas Tech University
Natural history collections of the University of EdinburghWet Specimen collection of the National Museum of Australia