PEARLFISH PRESSGlossary - Suggested Reading - Topical - Errata - Other Sites of Interest
Last updated:
August, 1999
FREQUENTLY ASKED QUESTIONS
This list of Frequently Asked
Questions will continue to grow, at no predetermined rate,
as I field questions in the course of disseminating and discussing
Pearlfish Press publications. For the sake of readability,
I have not boldfaced Glossary words that appear here in
FAQ, although the Glossary may be helpful.
Q: Why is there such
inconsistency with regard to the plural usage of "fish"
vs "fishes?"
Q: Why is there such inconsistency regarding
the use of parentheses around the author and date following a
scientific binomial
Q: Why do the scientific names of some fishes change?
Q:
Why is there such inconsistency with regard to the plural usage
of "fish" vs "fishes?" I've seen both forms
used not only within the same document, but even within the same
sentence. Is this just sloppiness?
A; While it could be sloppiness, if your source
is an authoritative one, and the writer's credentials would seem
to preclude such sloppiness, then the inconsistency is probably
intentional. The stylistic convention that gives rise to this
apparent inconsistency goes thusly: If reference is to a group
of individual specimens belonging to the same species, then the
plural form is the same as the singular, i.e., "fish."
The plural "fishes," on the other hand, is used in
reference to more than one species. So, while one might properly
refer to the number of "fish" in a brood of, say, Limia
nigrofasciata, the discussion of same would properly be included
in a larger work entitled The Fishes of Hispaniola. There
are exceptions to this rule that are dictated by nothing more
than the avoidance of conspicuously awkward usage. While the
study of "fish husbandry," or the publication of "fish
books," for example, implicitly refer to consideration of
more than a single species, the use of "fish" in these
cases is nevertheless accepted for its less awkward sound. One
of the people with whom I work closely in the production of my
calendars insistently refers to my "fishes calendars,"
which I found to be really annoying until I realized that he
was merely following (to the letter!) the above rule which I
had previously explained to him. So, use this rule unless common
sense strongly suggests otherwise.
Q:
Why is there such inconsistency with regard to the use of parentheses
around the author and date following a scientific binomial?
A: The seeming caprice with which parentheses
are used in citing authors and dates of original descriptions
is illusory. Parentheses are used or not used according to very
specific guidelines of the International Code of Zoological
Nomenclature, and their presence or absence conveys information
pertaining to changes in generic placement of the species so
cited. Very simply, if the species was originally described in
a genus other than the one indicated in the current usage, then
the name of the author (original describer) is placed within
parentheses to indicate this subsequent change in generic placement.
If the date of publication of the original description is also
used in the citation--and this is a matter of style; the Code
does not require use of the date along with the author and binomial--then
it too is placed within parentheses along with the name of the
author. For example, the fish on the cover of my 1999 Killifishes
calendar, Fundulus catenatus, was originally described
by Storer in 1846 as Poecilia catenata. The use of parentheses
around Storer's name and the date of description is required
following the (new) combination, Fudulus catenatus, and
in any subsequent usage where this species is used in combination
with a genus other than Poecilia. Although the chances
are virtually nil that some future taxonomic revision would ever
refer catenatus back to the (now exclusively livebearing!)
genus Poecilia (or that Fundulus would ever become
a junior synonym of Poecilia), purely for the sake of
argument one can imagine that if that ever did happen, then rules
of the Code would stipulate omitting the parentheses when
reverting back to the original combination, i.e., Poecilia
catenata Storer, 1846.
This is probably one of the most persistently misunderstood nomenclatural
conventions. The editors at one of the mainstream aquarium magazines
once went through a checklist of species that I had compiled
to accompany one of my articles, and purged same of all parentheses
surrounding authors and dates before printing it. They probably
thought that they were doing me a favor by making my list absolutely
consistent with regard to the absence of parentheses throughout,
when what they actually did was to render my list entirely useless
as a reliable and authoritative nomenclatural resource. And all
because they had no idea what function parentheses serve when
citing authorship of scientific names.
Q: Why do the scientific names
of some fishes change, often repeatedly, while the names of others
may remain consistent over their entire history (i.e., from the
date of their original description)?
A: The scientific name (i.e., the binomial
or trinomial) of a fish (or other organism, for that matter)
can change for a number of reasons. In some cases the change
may reflect some simple after-the-fact discovery or determination
regarding the priority (earliest date of publication) of several
available names. (It's the earliest published name that accompanies
a valid description that must be used.) Most often, however,
a nomenclatural change occurs when a taxon is revised, and new
ideas are proposed regarding the phylogenetic relationships among
the genera, species, and/or subspecies of which that taxon is
comprised. It should be noted that since the organism's name
reflects its placement in a taxon at or below the level of genus,
revisions effecting changes in higher order taxonomy don't result
in corresponding changes in nomenclature. For example when Costa
proposed removing the fish previously known as Rivulus robustus
from the genus Rivulus, he erected a new, monotypic genus,
Millerichthys, to contain it. Thus, the name of that organism
changed from Rivulus robustus to Millerichthys robustus
(at least for workers who agreed with Costa's taxonomic determination;
as discussed below, no one is bound to follow any proposed revision
simply because it's published in a scientific paper, or as in
Costa's case, a book). Had Costa thought that the species still
belonged in the genus Rivulus, but that it was not really
separable from some other species of Rivulus, then he
might have proposed their synonymy. And if the name of the species
with which he proposed synonymy (let's say, Rivulus tenuis)
had priority (i.e., an earlier date of description), then robustus
would have become a junior synonym of tenuis, and the
fish previously known as Rivulus robustus would now be
known as Rivulus tenuis, with robustus relegated
to the synonymy of tenuis (at least until another worker
came along and proposed otherwise). But had Costa acknowledged
the validity both of the species robustus and its placement
within Rivulus, while proposing, say, a change in the
placement of the genus Rivulus within some higher order
taxon, then there would have been no change in the name
(binomial) of the species. Even though the taxonomic changes
associated with the last example would have been, in a sense,
greater in magnitude, because they involved changes above the
level of genus, they would have been irrelevant to usage of the
binomial.
In a similar vein, when Lynne Parenti published her major revision
of the cyprinodontiform fishes in 1981, among many other things
she divided the genera of oviparous cyprinodontiforms (killifishes),
previously contained in the single family Cyprinodontidae, into
many different families. As extensive as her proposed taxonomic
changes were, because they involved mostly higher order taxonomy,
there were disproportionately few name changes at the species
level. Yet her revision of the single South American genus Orestias
three years later probably resulted in a greater number of nomenclatural
changes (including the descriptions of new species and the deletion
by synonymy of others).
Whether or not the name of a particular fish would change, often
or at all, or be placed in synonymy over the course of its history
would therefore depend upon many, potentially unrelated factors:
How much scientific activity there has been within the taxon
and related taxa; the inclinations of the people making authoritative
determinations pertaining thereto (e.g., whether they tend to
lump or split taxa); the insight of the original describer in
placing the species in one genus or another; the period of time
since the fish's description (all other factors being equal,
it's much more likely that a fish that has been known to science
for two hundred years will have had a more eventful nomenclatural
history than a fish that was described three years ago); and,
perhaps most importantly, the variability of a species and the
extent of its range. The widely ranging and extremely variable
killifish species Fundulus heteroclitus has been
described as so many different species since its original description
in 1766 that a partial synonymy in the Killifish
Master Index comprises several pages!
All of this is difficult enough for hobbyists to make sense of.
But even more vexing is the fact that however convoluted or otherwise
difficult all of this may seem in any absolute sense, it is made
potentially worse by the fact that no one is bound to accept
or reject any taxonomic proposal--and in its broadest sense,
even the naming of a new taxon is just that: a proposal;
the putting forth of a theory pertaining to the phylogeny of
that taxon--regardless of its provenance. Different groups (Americans,
as opposed to Europeans; cladists, as opposed to non-cladists;
etc.) interpreting from the same empirical body of data
will often reach diametrically opposing views of the relationships
within and among taxa, which may in turn result in the persistent
application of different names to the same organism. Such diversity
of opinion may be attributable to differences in personal philosophy,
to the prevailing sensibility at the sponsoring institution,
or even to personal relationships among workers where something
as trivial as the conservation of patronyms is concerned (sounds
petty, but some people don't like the idea of "dishonoring"
a popular colleague by invalidating a taxon that was named in
his or her honor!). What this means, among other things, is that
unless you're very familiar with the author of the book or paper
that you're using as a source of information, you don't know
whether any deviation from what you perceive to be the existing
orthodoxy is the intentional result of a critical determination
on the part of that author, or just an oversight, sloppiness,
or lack of familiarity with the subject at hand. Despite the
fact that most of Parenti's taxonomic proposals have achieved
a consensus of agreement in the twenty years since their publication,
there are still some authors who use the terms "killifish"
and "cyprinodontid" interchangeably. Out of context,
it's impossible to tell whether such a conflation is the result
of unfamiliarity with the recent literature, or if it is intended
to reflect a contrary opinion of the part of the author.
So, those who complain that fish taxonomy is a mess (read: a
dynamic, volatile, and ever-changing discipline) have pretty
much gotten it right. It is, by its very nature, always going
to be that way. But the good news is that it's an interesting
mess. And, moreover, the inexorable taxonomic shifts and corresponding
nomenclatural changes are now well addressed by the advent of
on-line databases which may be updated on an ongoing basis, in
contradistinction to their bound, hard-copy counterparts which
run the risk of obsolescence (if not in whole, then certainly
in part) at any time subsequent to publication.
Glossary - Suggested Reading - Topical - Errata - Other Sites of Interest
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