Conspectus cobitidum - Raffles Museum of Biodiversity Research

priate but, in order to simplify texts, is not usually used. The
type specimen is the type of a name, not of a species. It is
therefore erroneous to understand the type as a 'model' representation
of a species or a specimen to which all specimens
must be identical in order to be called the same species.
The type concept is exclusively a nomenclatural standard
and totally independent of any taxonomic judgements
or philosophical theory. The type is only used to objectively
relate to which species the name must be applied. After its
original description, if a species X is redescribed, re-defined
or re-diagnosed and it is found that the type specimen of
name Y belongs to that species, then this fixes Y as the name
to be applied to species X. If type specimens of more than
one name are found to belong to that same species X, this
makes these names synonyms.
Only primary types (name bearing types) are listed here.
Primary types belong to the categories holotype, lectotype,
neotype and syntypes. Other type categories recognised by
the Code are paratypes and paralectotypes but have no nomenclatural
status. Other 'type' categories (e.g. allotypes,
topotypes, paratopotypes, paraneotypes) are not recognised
by the Code, should not be used and are ignored here. Among
them, the word allotype is sometime used to designate one
of the paratypes of a sex different from that of the holotype;
the word topotype is used as a shortened way to say "specimens
collected at the locality where the primary type was
collected".
The holotype is the specimen that has been explicitly designated
so (or by a similar wording) in the original description,
or if there is clear evidence that the author based the
nominal species on a single specimen. There is only one
holotype per nominal species. In all cases where there is clear
evidence that the author based the species name on more
than one specimen (including literature records) but did not
designate a holotype, then all these specimens are syntypes.
If it is not possible to determine from the original description
if a name is based on one or several specimens, I am
usually listing 'syntypes' or 'holotype ?').
If the nominal species is based on a specimen explicitly
designated as holotype and a number of additional specimens
are also explicitly designated as types, these are
paratypes; allotypes are thus paratypes. The sum of the holotype
and paratypes or the sum of the syntypes is called
type series.
In cases where there is no holotype but only a series of syntypes,
one of the syntypes may be selected as lectotype; it
then has the same value as the holotype. The remaining syntypes
then become paralectotypes and lose their status as
primary types. Lectotypes are designated when it is demonstrated
or suspected that the type series includes more than
one species; it allows the name to be definitively fixed to the
nominal species to which the lectotype belongs. Incidentally,
the designation of a lectotype also restricts the type locality
to the locality of the lectotype, no longer the sum of the
localities of the syntypes. Paratypes and paralectotypes are
not listed hereunder as they are not name-bearing types.
THE RAFFLES BULLETIN OF ZOOLOGY 2012
7
If none of the specimens of the original type series remains,
or if the holotype or lectotype no longer exist (they have not
been preserved, are lost, or destroyed) and if the name cannot
be unambiguously linked to a valid species, then (and
only then) a specimen can be designated as neotype that will
have the same function as the holotype. All designations of
neotypes that do not fully satisfy these conditions are invalid
and must be ignored. Incidentally, the designation of a
neotype also fixes the type locality to the locality of the neotype.
A number of neotype designations are invalid because the
need for a neotype is not stated or demonstrated. This requirement
did not exist in the 1985 Code (art. 75(b)) and an
implicit justification was enough. The requirement became
explicit in the 1999 Code, with an added clause (art. 75.3.1)
requiring "a statement that [the neotype] is designated with
the express purpose of clarifying the taxonomic status or the
type locality of a nominal taxon".
After the original description, it may be necessary for later
authors to re-examine the primary type of a nominal species
in order to decide to which taxonomic species it applies, for
example in cases when several similar species are later discovered
and the original description does not mention the
characters now decisive to determine to which of these species
the name must be applied. It is, however, not a necessity
to examine a primary type if the original description provides
all the information needed for identification. In fact,
types may be fragile specimens, and they should not be handled
if not justified, and persons without experience should
not be permitted to handle them. Primary types must be deposited
in museums or other responsible institutions and with
staff able to conserve them and make them accessible to later
researchers. Even if there is political pressure in some
countries to consider that types are a national property, types
do not belong to a country but to science and must be accessible
to competent scientists irrespective of their nationality.
Neotypes must be deposited in a museum (Code art. 75.3.7).
A number of species described by earlier authors do not have
known types or they have been lost since the original description.
This does not affect the availability of a name. For
example, a specimen described in the field and later eaten
by a hungry author remains the type specimen. Or a specimen
used as model for a figure remains the type specimen,
even if it has not been preserved.
When known, institutions in which primary types are deposited
are listed, together with register numbers and, when
known, the number of specimens in square brackets (example:
"AAA 1234 [2], AAA 1233 [1]"). When the primary
types were deposited in a collection but cannot presently be
located, the institution is listed as they may still be present
(misidentified, misplaced, uncatalogued), or as a starting
point for further search. The source for the catalogue number
is given when it is not the original description; besides,
many catalogue numbers listed in the original descriptions
have also been checked in published catalogues or in the
institutions themselves. When there is a series of syntypes, I