INTERNATIONAL CODE OF ZOOLOGICAL NOMENCLATURE (ICZN)
- The International Code of Zoological Nomenclature (ICZN or ICZN Code) is a widely accepted convention in zoologythat rules the formal scientific naming of organisms treated as animals. The rules principally regulate:
- How names are correctly established in the frame of bionomial nomenclature
- Which name must be used in case of name conflicts
- How scientific literature must cite names
Zoological nomenclature is independent of other systems of nomenclature, for example botanical nomenclature This implies that animals can have the same generic names as plants. The rules and recommendations have one fundamental aim: to provide the maximum universality and continuity in the naming of all animals, except where taxonomic judgment dictates otherwise. The Code is meant to guide only the nomenclature of animals, while leaving zoologists freedom in classifying new taxa.
In other words, whether a species itself is or is not a recognized entity is a subjective decision, but what name should be applied to it is not. The Code applies only to the latter, not to the former. A new animal name published without adherence to the Code may be deemed simply “unavailable” if it fails to meet certain criteria, or fall entirely out of the province of science .
The rules in the Code determine what names are valid for any taxon in the family group, genus group, and species group. It has additional (but more limited) provisions on names in higher ranks. The Code recognizes no case law. Any dispute is decided first by applying the Code directly, and not by reference to precedent.
The Code is also retroactive or retrospective which means that previous editions of the Code, or previous other rules and conventions have no force any more today and the nomenclatural acts published ‘back in the old times’ must be evaluated only under the present edition of the Code. In cases of disputes concerning the interpretation, the usual procedure is to consult the French Code, lastly a case can be brought to the Commission who has the right to publish a final decision.
Historical Background :
The origin of an internationally accepted Code of Rules for Zoological Nomenclature is a consequence of the confusion of names that occured in the zoological literature of the early part of the 19th century.
Following the publication of the 10th edition of the Systema Naturae by Linnaeus in 1758, and his adoption in it of binominal names for species of animals, the next century saw the new system expanded and developed in different places, and in different ways for different animal groups. By the second quarter of the 19th century disparate usages were common and the need for an agreement to achieve universality in the scientific names of animals and a greater stability had become apparent everywhere.
Moreover, the great explosion in known species, caused by the growth of science and by active exploration in countries outside Europe, resulted in a multiplicity of names; many of these were synonyms resulting from the work of scientists researching independently. It became critical to devise universally accepted methods for choosing between them.
The most important of the early attempts to regulate zoological nomenclature was that by Hugh Strickland. The rules proposed by Strickland and his colleagues developed into what has since been called the British Association Code or the Stricklandian Code; its official title was Series of Propositions for Rendering the Nomenclature of Zoology Uniform and Permanent.
Following its presentation at the British Association for the Advancement of Science in 1842, by a Committee that included such distinguished Zoologists as Charles Darwin, Richard Owen and John Westwood, that Code was translated and circulated widely and had great influence.
It was published in France, Italy and the United States of America. It was received by the Scientific Congress at Padua in 1843, by the American Society of Geologists and Naturalists in 1845, and was adopted by the British Association for the Advancement of Science in 1846. It was revised in succeeding years, and provided the basis for the code formulated by Henri Douvillé (1881) which was adopted internationally by geologists, and for the American Ornithologists’ Union Code (1886).
Following discussion at International Congresses of Geology (Paris, 1878; Bologna, 1881) it became clear that there was need for a formal international agreement to be made for rules to cover all zoological names, irrespective of which bodies or disciplines required to use them and applicable to both fossil and extant animals.
At the 1st International Congress of Zoology (Paris, 1889), the Congress adopted, in part, rules drawn up by Maurice Chaper and Raphael Blanchard and referred the matter for discussion at the 2nd Congress (Moscow, 1892).
The 3rd Congress (Leiden, 1895) appointed a Commission of five zoologists (R. Blanchard, J.V. Carus, F.A. Jentink, P.L. Sclater and C.W. Stiles) to formulate a “codex” and to report to the 4th Congress (Cambridge, England, 1898). This was the birth of the present International Commission on Zoological Nomenclature.
Following the addition of ten more members and further consideration, a report was adopted by the 5th Congress (Berlin, 1901) and a Code of rules embodying the decision of that Congress was published in French, English and German in 1905.
This Code, entitled Règles internationales de la Nomenclature zoologique, with a series of amendments resulting from subsequent Congresses (Boston, 1907; Monaco, 1913; Budapest, 1927; Padua, 1930) remained in force until 1961 when it was replaced in its entirety by the first edition of the International Code of Zoological Nomenclature. This resulted from studies at Congresses following the 1939-45 War (Paris, 1948; Copenhagen, 1953; and London, 1958); a very detailed account of the work that culminated in the 1961 edition is given by Norman R. Stoll, Chairman of the Editorial Committee, in his Introduction to that edition. A second edition was published in 1964 incorporating amendments adopted at Washington (1963).
To most zoologists at the time, the 17th International Congress of Zoology (Monaco, 1972) appeared likely to be the last general Congress of Zoology. Decisions were taken there to amend the second (1964) edition, and in addition, to ensure mechanisms for continuity and future up-dating, a decision was taken to transfer responsibility for future Codes (and the Commission) from the International Zoological Congresses to the International Union of Biological Sciences (IUBS).
Responsibility for the Code and the Commission was accepted by IUBS at the XVIII IUBS General Assembly (Ustaoset, Norway, 1973). In response to proposals for major and substantive changes to the Code, made by the community of zoologists at that time, and to eliminate ambiguities, a third edition of the Code was prepared and was approved by the Commission, with the authority of IUBS, late in 1983 and published in 1985.
A more detailed account of the development of zoological nomenclature and the events leading to the modern Code are given by Richard Melville, former Secretary of the Commission, in the centenary history of the Commission which was published in 1995 entitled Towards stability in the names of animals.
The decades of the 1970s and 1980s witnessed further marked changes in professional orientation and education of zoologists, changes in the methodology of taxonomy mostly resulting from new genetic information and the application of computers, a burgeoning literature, and accelerating changes in information technology including electronic publishing.
It became clear that the Commission should work towards a fourth edition to accommodate the consequences of these and other factors, including a greater ecumenism in biological science leading to pressure within IUBS for greater consistency between the various codes of nomenclature.
An Editorial Committee was appointed by the Commission in Canberra in October 1988, and proposals were canvassed and discussed at meetings of the Commission and of the IUBS Section of Zoological Nomenclature in Maryland (1990) and Amsterdam (1991), and at meetings of the Committee in Leiden (1991) and Hamburg (1993).
Following these, a Discussion Draft was publicly issued in May 1995. Within a year this resulted in almost 800 pages of comments from some 500 sources, many of which consisted of groups of zoologists; a number of these comments were published in the Bulletin of Zoological Nomenclature.
All the comments (mostly transmitted by electronic mail) and the text were considered by the Editorial Committee in Vicenza in June 1996, and in August of that year a report was presented to the Commission and the Section of Zoological Nomenclature in Budapest.
The comments showed that some of the tentative proposals in the Discussion Draft (such as a proposal for mandatory “registration” of new names and the abolition of gender agreement within combinations of generic and specific names) were not sufficiently acceptable to zoologists to be adopted. A revised draft was accepted by the Commission by postal vote (1997) with minor amendment. The Commission, in voting, made a number of suggestions for clarification which have been incorporated in this edition
Preamble of International Code of Zoological Nomenclature (ICZN)
The International Code of Zoological Nomenclature is the system of rules and recommendations originally adopted by the International Congresses of Zoology and, since 1973, by the International Union of Biological Sciences (IUBS). The objects of the Code are to promote stability and universality in the scientific names of animals and to ensure that the name of each taxon is unique and distinct. All its provisions and recommendations are subservient to those ends and none restricts the freedom of taxonomic thought or actions.
Priority of publication is a basic principle of zoological nomenclature; however, under conditions prescribed in the Code its application may be modified to conserve a long-accepted name in its accustomed meaning. When stability of nomenclature is threatened in an individual case, the strict application of the Code may under specified conditions be suspended by the International Commission on Zoological Nomenclature. Precision and consistency in the use of terms are essential to a code of nomenclature. The meanings given to terms used in this Code are those shown in the Glossary. Both this Preamble and the Glossary are integral parts of the Code’s provisions.
The International Commission on Zoological Nomenclature is the author of the Code.