Phuket Marine Biological Center Special Publication 21(3): 539-546 (2000) 539
BASIC RIJLES OF SCIEI{TIFIC NOMENCI,A TURE
Richard Kilburn
Natal Museum South Africa (TMMP) 540 Tlopical Marine Mollusc Programme
BASIC RULES OF SCIENTIFIC (1985) edition ofthe Code, but at the begin- NOMENCLATURE ning of year 2000, a new edition will apply, in which some of the rules have been Background: As you will agree, to estab- changed to take recent practical develop- Iish the correct name for most species of ments into account. Some of the more im- tropical Indo-Pacific Mollusca is often a com- portant changes are included in these notes. plex challenge, particularly when resources Both the Code and the Commission are com- are limited. Very few recent revisions or monly abbreviated to the "ICZN". monographs are available for the region, so that identification usually entails searching through a large number ofbooks and papers, THE INTERNATIONAL mostly dealing with the fauna of countries CODE OF other than one's own! For poorly studied ZOOLOGICAL NOMENCLATURE groups one must extend one's search to the literature of the previous century. All too The Code is published as a small book, with ofben one frnds the same species under dif- the same text repeated in English and ferent names, even in contemporary litera- French. It consists of two types of rules: ture! How does one establish which of these Articles and Recommendations . "Arti- names is the correct one? cles" are compulsory and must be strictly The first step is to estabiish whether the followed. "Recommendations" suggest the different names really do apply to the same best process to follow where a situation is species. For this, it is essential to consult not covered by an Article, and should be fol- the original description, and - wherever Iowed if at all possible. Articles and recom- possible - actual type specimens. But what mendations are numbered, and can be does one do if one establishes that several quoted as, for example, "ICZN Article 13 names have been given to the same species, (aXI)". or the same name to different species? Or, if The Commission alone has the power to one finds a name that has been overlooked overrule the Code; they can be asked to use or apparently ignored? these "plenary powers" in cases where strict Guidance will be found in the International application of the rules would cause confu- Code of Zoological Nomenclature, whose sion or instability by upsetting a widely used rules are folloryed by all modern zoologists. name. Studv of 19th centurv literature will re- veal thl benefits of s.rclia universal system. (Important: These notes include most of Early zoologists used personal choice in se- the more importantArticles and some of the Iecting which name to use. For example, Recommendations, but should be seen as an Lamarck often renamed a species if he introduction only.) thought its given name applied better to another! But of course there was often disa- greement as to which name was in fact the BRIEF HISTORY OF better, and opinions were often divided along NOMENCLATURE: national lines. In 1895 the 3rd International Congress of (1) The binomial (or binominal ) system Zoology established the International Com- (bl = two, norrlen = n&m€) was first intro- mission of Zoological Nomenclature, whose duced by Linnaeus (also called Linnb), and function was to develop a system of rules first used consistently for all animals in that would stabilize the use of scientific 1758, in the 10th edition of his Systema names. We are presently using the Srd Ncr.turae. Phuhet Marine Biological Center Special Publication 21(3): 539-546 (2000) 547
(2) Before Linnaeus, writers used names masculine genus (eg Conus), "(tlbe." after a either in their own language (termed popu- feminine one (eg. Cypraea),"&lbLtm" after a lar, vernacular or "'nrrlgar" names), or a Latin neuter one (eg Vexillum). One can usually name (really a short description) of several follow published examples to work out the to many words (called a polynomial ). Un- correct gender, otherwise one must use a til the present century, Latin was the com- Latin dictionary.If the genus was not Latin mon language of western scientists. or Greek in origin, one has to follow the ex- (3) Linnaeus simplified the system by us- ample set by its describer or any clues he ing two categories of names: a group name may have given as to the gender of his new (or genus), and a specific name. name. (4) Modern taxonomy recognizes other ranks such as the Family (and higher levels Personal names up to Phylum), Subgenus and Subspecies. if a species is named after a man, the spe- We discuss these later. cific name ends in "l" or "ii" lwhichever spell- (5) In the years after Linnaeus, zoologists ing was used originally must be retained, found it practical to add the author's name . but it is recommended that the single "1" be To this, taxonomists now add the date of used for new names], if after awomert"ctre", publication, as an aid to tracing the original if after several people "orLf,m", if after sev- description. These are essential in taxonomic eral women "arLtrm". work, but are not compulsory under the Code, as they do not actually form part of Geographic names the name of an animal. (They are thus often If a species is named after a place or a re- left out by ecologists, physiologists, etc.) gion, the name usually ends in"ensis" or iLs neuter version "ense" (eg"chinensls"). How- ever, the endings "(trrLrm" l"orum'(eg HOW SCIENTIFIC NAMES ARE " p hilip p in ar um" ) ar.d " (re" (e g. " au s t r al iae") FORMED AND WRITTEN: also occur, or the name may be changed to an adjective (eg. "indicus" meaning "In- Fonts dian"). The name of a genus (and subgenus) and all higher ranks always begin with a capital Subgenera (upper-case) letter, specific (and subspecific) The subgeneric name (a smaller grouping names with a small (lower-case) letter, even of more closely-related - or similar - spe- if named after a person or place. It is stand- cies than a genus) is written after the genus ard to print these in italics (or underline but in brackets: eg Erronea (Adusta) onyx. them if hand-written) so that they stand out from the rest of the text. Examples Erronea Subspecies onytc or: Erronea onyx. In cases where subspecies (morphologically distinguishable and geographically-sepa- Gender rated populations or groups ofpopulations) Scientific names follow the rules of Latin are recognised, the name becomes a trino- (and Greek) in that they have genders ("mas- mial: a third or subspecific name is added culine", "feminine" or "neuter"). A genus after the specific name: eg. "Erronea orlyx name is always a noun in the singular, but adusta. The population inhabiting the type if the specific name is an adjective (descrip- locality is called the nominate ("name-bear- tive word) its ending must agree in gender ing" or "nominotypical") subspecies, and its with that of the genus. For example"ulbus" subspecific name is the same as that of the (Latin for "white") would be used after a species: eg. Erroruea onyx onyx. 542 Tlopical Marine Mollusc Programme (TMMP)
Author Otherwise, the original spelling must be The name of the person who first validly used unless proofcan be found in the origi- published a scientific name follows the name nal publication that the name was acciden- without any punctuation. Exception: when tally misspelled. a species is transferred to another genus, A name that has been intentionally the author's name is enclosed in brackets changed is called an emendation . An un- (parentheses). For example Voluta mitra necessary change is called an "unjustifred Linnaeus, L758, is now Mitra mitra emendation" and becomes a synonym of the (Linnaeus, 1758). Note that the date is al- original name, but can be used if a replace- ways separated from the author's name by ment name is needed at a later date.An un- a comma. intentional change to a name (in other In the rare case of a name published words, an incorrect spelling or "laps. cal." ) anonymously before 1951 (after this date has no status. such names are not available) and the au- thor's name is known from another source, it is placed in square brackets (example: VALID AND INVALID NAMES [Lightfoot, 1786]). Sometimes the person originally respon- Only names that are available under the sible for a name may not be an author of the ICZN rules may be used. Available names book or paper in which it appeared (the au- are notnecessaryvalid (thatis, the correct thor may have used a name taken from name), but are the only ones that may be someone else's manuscript or label), or may regarded as eligible for use: be only one of a group of authors. In such cases, authorship is shared: for example, much of the first draft of the text of the MAIN CONDITIONS FOR 'Conchologicct l lllustrations' was written by AVAII,ABILITY: Gray, who then withdrew from the project, ieaving it to be completed by the illustrator, When it was first proposed a name must G. B. Sowerby, who gave Gray credit for have been: some of the new names: eg. Palrnadusta (1) Binomial that is, published in a con- (Gray - contaminato in Sowerby, 1825). sistently binomial work. Names published is not strictly necessary to give It the au- by non-binomial authors such as Chemnitz, thor and date in the case ofhigher levels (eg Martini, Meuschen and Martyn are not families, classes), unless one has reason to available (unless the ICZN has specifically do so. ruled otherwise). (2) Properly published in a widely avail- Original spelling able publication, usually requiring mul- The original spelling must be used unless tiple copies printed in ink on paper. proof can be found publica- in the original (3) Written in Latin (that is "western") let- tion that the name is accidentally mispelled. ters. This does not mean that it has to be (2000) However, under the new rules, if a classical Latin (or even Greek) in origin name "in prevailing - use" is found to have names such as empressqe (English), Nquma been wrongly spelled, it should not be re- (Zulu) and Uzumakiella (Japanese) still placed by the correctly spelled name. In or- fulfrll the Rules. der grammar, to comply with Latin accents (4) Identifiable there must have been an or hyphens are ignored (except - for the Ger- indication of its identity, either a descrip- man umlaut "ti" which is changed to "ue" in tion containing at least one distinguishing case of names published the before 1985). character, or a reference to a published de- Phuhet Marine Biological Center Special Publication 21(3): 539-546 (2000) 543
scription or figure. For example early au- though Conus gilchristi Sowerby, 1903, was thors such as Rdding and Link published once synonymised with the earlier Conus names without descriptions - instead they natalis Sowerby, 1857, recent studies treat gave references to illustrations published by C. gilchristi as a valid species in its own earlier writers such as Chemnitz; the actual right). characters will be found in these sources. Synonyms published at the same time : For example, the name Thctis lnow Purpuraf when two names for the same species are panama Rriding, 1798, was proposed with- published on the same date, even in the out description or even locality, but a refer- same work, the senior synonym is which- ence was given to Chemnitz 1788: pl. 154, ever name is used as the valid name by the fig.1467-8, which enables the species to be first reviser . The first reviser is the frrst recognised. (Furthermore, as Chemnitz author to choose one of the names as the gave the locality Tranquebar for his speci- valid one. The same applies when a name is men, this automatically becomes the type spelled in different ways in the same work. locality (see below) for Thais panama.) Although page priority was once used as the A name published without any associated only criterion in selecting the senior sSmo- description or illustration is called a nomen nym, it is no longer considered important. nudum , and is not available. A name whose identity is uncertain because of an inad- Homonymy equate description or figure remains avail- A homonym is the same name proposed for able and is termed a nomen dubium . different species. The later name to be pub- (5) After 1999 there must be an indication Iished - the junior homonym - must be that the name is new ("sp. nov.", "new sp." replaced, either by finding a later available etc), a holotype (or slmtype series) must be name or by proposing a new name (see next designated, and the institute where they are section). Even a one-letter difference is suf- housed must be given. ficient to prevent homonymy, except for cer- tain letters that are interchangeable in Latin (such as i and ii, or c and fr). RULES OF VALIDITY At the specific (and subspecific) Ievel there are two kinds of homonyms: Synonymy Synonyms are names that are spelled dif- Primary homon5rms are names that were ferently, but which apply to the same taxon. identical when they were first published, If they share the same type (see below), even though based on different species: ex- whether they are species, genera or higher, ample, Cerithium morus Larnarck, 1822, they are called objective s5rnonyms . If the was based on a different species to the ear- synonymy is a matter of opinion the names lier Cerithium morus Bruguibre, L7 92), and are called subjective sJrnonJruns we must use a later name, Cerithium The most basic rule is Priority : the first bifasciatum Sowerby, 1855, for Lamarck's available name for a species should be used, species. We cite the first name as Cerithium unless the ICZN rules make it invalid. The nlorus Lamarck, l822,non Bruguidre, 1792. earliest (valid) name is called the senior (The word non (meaning "not") is also used synonym, ater names are called junior to indicate a misidentification. sJmonJ[ns, Even after a name has been rejected as a A secondary homon5rm is created if a spe- sJrnonym, it remains available - if another cific name is moved to a genus in which there author believes it to be valid he may restore is already another species with that name. it using a different interpretation (eg. al- As an example, Conus torquatus Martens, 544 Tlopical Marine Mollusc Programme (TMMP)
1901, is a junior secondary homonym of type genus designated by the describer. Cucullus torquatus Rriding, 1798, as both Subfamily names end in "-inae". now belong in Conus. A name that was re- Superfamily names end in "-oidea", al- placed because it was declared a junior sec- though until a few decades ago, molluscan ondary homonym before 1961 remains per- superfamilies were given an "-acea" ending. manently invalid. If such a replacement happened after 1960, the original name DATE OF PUBLICATION must be reinstated if an author transfers it to another genus. We must use the actual date given in the publication unless there is outside proofthat Unused nqmes it was incorrect. If different parts of a publi- As from year 2000, a name that has been cation appeared over a period of time, with- used as a valid name by at least 10 authors out a precise date being available for each in 25 publications over the past 50 years part, the final date known is to be adopted should not be rejected if it is found to be a for the entire publication. If only the year junior synonym of an earlier name that has of publication is known, then it is taken as not been recognised as valid since 1899. 31st December of that year, and if only the month is known, publication is considered to have been on the last day of the month. REPLACEMENT NAMES
If a name is invalid, the earliest of its junior THE TYPE CONCEPT - FIXING synonyms should be used to replace it. If no THE IDENTITY OF A NAME such alternative name exists, a taxonomist may propose a new name. When published, The basis for defining each taxon is its type. this must be clearly marked "new name" or The type serves as a fixed reference point, ("nomen "nom. nov.tt rlovrrm", sometimes although it need not be typical - to general- called a "nomen substitutum" or substitute ise, the characters of the taxon must include name). the most important characters of the type.
Family types INFRA-SUBSPECIFIC Each family takes its name from its type NAMES genus (example the Trochidae from the ge- nus Tlochus). Even if the name of the type Since 1961, "varietal" or "forma" names have genus falls into slmonymy, we still retain the had no validity, and should not be used. original family name, unless it threatens (Howeveq if a name originally proposed as stability (eg. we still use the name a"var." before this date has previously been Psammobiidae, even though Psammobia is recognised as available (before 1985), we now regarded as (at most) a subgenus of must treat it as having subspecies rank for Gari) the purposes ofthe Code Generic types Each genus has a t5rye species , which may NAMES ABOVE THE have been lixed in various ways: GENUS-LEVEL (a) formally designated by the original au- thor ("by original designation ", abbrevi- A family name is formed by writing the end- ated to "od"). This is now required under ing "idae" after the stem of the name of the ICZN rules for future generic names to be Phuket Marine Biological Center Special Publication 21(3): 539-546 (2000) 545
available. precedence over the neotype. If a type ex- (b) designated in a later publication ("by ists but lacks diagnostic characters (for ex- subsequent designation "). The species ample it is too badly damaged for certainty must have been included in the genus when about its identity), the Commission may be the genus was proposed; usually cited along asked to set the status ofthe existing type the lines of "sd Gray, 1847". aside and designate a neotype. although this (c) it was the only species included when will only be done in exceptional cases. the genus was proposed ("by morrotypy ", Only holotypes, syntypes, Iectotypes and abbreviated to "m"). neotypes have a name-bearing function, and (d) a species originally included in a ge- are termed "ptimary" types. In other words nus and sharing the same name ("by abso- they are the only specimens used to fix the lute tautonymy ").,8g. the type species of usage of names. "Secondary" types - Haustelluirr Schumacher, 1817, is Murex paratypes and paralectotypes - are useful in hct ustellum Linnaeus, 1 758. providing information on the author's con- cept of the amount of variation in his spe- Species-leuel types cies, but have NO name-bearing functions. (type specimens) Until the 20th century, very few malaco- The type series includes all the specimens logists designated types and seldom even that were studied by the author when a new indicated which specimens they had exam- species (or subspecies) is described. ined. As types may be the only way in which There are several categories oftypes: we can conclusively determine the identity (a) the holotype: a single specimen (ide- of a species, much modern taxonomic re- ally the most typical) selected to represent search has to be devoted to tracking down a species, and specified as such in the origi- actual (or possible) types. nal description.. During the late 18th and early 19th centu- (b) paratypes : the other specimens from ries, few taxonomists published figures of the type series from which the holotype was their species, but instead gave references to chosen. previously published illustrations in non- (c) syntypes : a series of type specimens binomial works. Study of these figures is ofequal rank (once called "cotlrpes"), in other crucial when actual type specimens are no words, where a holotype was not desig- longer traceable (for example Lightfoot, nated.. Link, Gmelin, Rdding). The specimens from (d) the lectotype : if it is necessary to which such illustrations were drawn have clarify the use of a name, a subsequent the status of syntypes (or the holotype, if worker may choose a specimen (preferabiy only one specimen was involved). the figured example) from among the Other type categories are seldom used, syntypes to be the name-bearing type. The other than topotype (any specimen from remaining syntypes are called paralecto- the type locality). Figured specimens, al- types. though not forming part of the type series, (e) the neotype: a specimen designated may have important status, as they have as such when all genuine types have been ofben been important in influencing inter- Iost or destroyed. This should only be done pretation of a species. as part of a taxonomic revision, in order to solve a dispute by permanently frxing the Type locality identity of the disputed name. The neotype This is the locality from which the holotype, should be from as close as possible to the lectotype, neotype or syntypes came. Ifsev- type locality. However, if actual types are eral localities were given, or a very general- subsequently rediscovered, they will take ised one (eg. "China Seas"), a later writer 546 Tfopical Marine Mollusc Programme (TMM?)
may restrict it to a more precise locality. If Offrcial journal of the ICZN: The Bulletin of no (or type locality the wrong one) was origi- Zoological Nonrenclq,ture, published 4 times given, nally one should designate a new one a year by the International Trust for Zoo- or emend the old, after carefully studying logical Nomenclature. Address: The Execu- the historical sources of specimens available tive Secretary, ICZN, c/o Natural History to the original describer. Museum, Cromwell Road, London SWZ It is essential to take into account the sBD, U. K. vague geographic concepts ofearly European writers! For example, "l'Oc6an indien" of However, it is possible to subscribe annu- Lamarck did not mean the modern Indian ally and get separates of all Applications, Ocean, but was anywhere from south-east- Comments and Opinions relating to Mol- ern India to Indonesia. The "China Seas,, of Iusca nomenclature. Adams & Reeve and Hinds often meant modern Indonesia and Malaysia. However, Internet site :
BROWN, R. W. 1954. Composition of Scien- IMPORTANT LITERATURE tific Words. Washington: Smithsonian Insti- tution Press. TISBN 0-87 47 4. 186-21 Iruternational Code of Zoological Nomencla- ture. 4th Edition. 1g99. University of Cali- STEARN, W. T. 1983. Botanicul Latin.Lon- fornia Press: London. don: David & Charles. TISBN 0-Z1bB-8548-81