Worms are never wrong!
50 years of polychaete studies
Kristian Fauchald
Department of Invertebrate Zoology
National Museum of Natural History
Smithsonian Institution
Biogeographic pitfall
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Primary record:
– G.O. Sars: “I found this specimen among material left over from my
father, presumably from western Norway”
•
First citation:
– Canon Norman: “This species has been reported from western Norway”
•
Secondary citation:
– No names to protect various sensitive National egos: Bergen
• Blame to go around:
• Papa Sars for not labelling his material; Baby Sars for describing a
species from an unknown location.
• Norman and the “unknown citer” for being inaccurate in their
citations.
What did we know? (I)
• Genetics - fruit-flies and peas
• Benthic ecology - Parallel bottom
communities (fide Gunnar Thorson)
• Invertebrate zoology
– Libbie Hyman’s first 3 volumes were out,
echinoderms in 1955; aschelminths in 1959
– Beklemishev in Moscow and Remane in Germany
• Biogeography – Sven Ekman ruled the seas
(1935 in German, 1953 in English)
What did we know? (II)
• Systematics –
– We read Mayr and Simpson -- and believed most of
what we read!
– Hennig first issued in 1950, in German, to English in
1966. We knew no cladistics, no phenetics, no
molecular systematics and got no background in
theory.
• Physiology
– Krebs cycle known; the role of haemoglobin in
electron transport mostly understood; role of
haemoglobin in polychaetes “poorly understood”;
photosynthesis not yet fully elucidated.
Instrumentation etc.
• We had compound and stereo microscopes. Drawing
apparatuses were cumbersome; photography too
expensive to waste on students.
• Transmission EM just developing beyond
experimentation.
• Scanning Electron Microscopes or Confocal
Microscopes did not exist
• Computers – In Bergen the two-room UNIVAC could,
provided that the radio-tubes had not popped, do
minimal math (tic-tac was the most exciting computer
game other than chess).
1950’s polychaete systematists
(a not-so-random selection)
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Pierre Fauvel (active 1895-1958) - France
Enrique Rioja (active 1916 – 1962) – originally Spain, Mexico
Pavel Uschakov (active 1923 – 1984) – Soviet Union
John Day (active 1932 – 1984) – South Africa
Elise Wesenberg-Lund (active 1934 -1962) - Denmark
Olga Hartman (active 1936-1973) - USA
Carl Støp-Bowitz (active 1945 – 1992) - Norway
Marian Pettibone (active 1953 –1997) - USA
When critizing earlier scientists, please
remember….
• If only two taxa are known, one character with two states
is all that is needed to keep them apart
• As more taxa are found, descriptions become complex.
Complexity also linked to the quality of the microscopes.
• We probably have too many taxa to distinguish in
relation to our capability to distinguish them.
• Deflating a feature as a character is usually a personal
bias and should not be accepted without documentation
• Most scientists retain the science style they develop
early in life. We will always have both old and young
scientists working on any group and thus lots of variation
in styles.
Morphology linked to systematic structure?
• Many morphological differences in a taxon (e.g.,
polynoids, ampharetids) yields many genera with
(relatively) few species in each; trend especially seen
over the last 100 years.
• Limited morphological differentiation (e.g., lumbrinerids,
cirratulids) often yields many new species in few
genera.
• Capitellids are unique: Genera are largely defined on
combinations of numbers of thoracic segments and
number of segments with capillary chaetae. Very nearly
each new species described gets its own new genus.
• IS THIS GOOD TAXONOMY? PROBABLY NOT
How Many Polychaetes?
• Hartman (1959) handled roughly 10,000 names,
considered 5341 as currently acceptable.
• Fauchald (ca. 2000) found 14,400 original
names and more than 20,000 combinations of
genus and species names; estimated number of
currently acceptable species ~ 7,000.
• Considering what I know about unidentified
material in collections, I estimate that there must
be another 4,000 to be described, so we still
have a ways to go.
Traditions in s/m studies
• Primary faunistic studies such as Grube’s Philippine
study (1878); Claparède’s Gulf of Naples studies
(1860’s), most of Hartmann-Schröder’s papers and
Hartman’s studies.
• Reviews of local faunas: Faune de France, Tierwelt
Deutschlands, Fauna of India, Day’s Polychaeta of
southern Africa; Hartman’s Atlas’s.
• Morphological/systematic reviews of single taxa, I.a.,
Eisig’s 1887 of capitellids, Darboux’s 1900 on scale
worms, Gustafson’s 1930 on amphinomids and
euphrosinids.
• Morphological studies of organ-systems: Racovitza
on prostomia; Hanström on anterior nervous systems;
Goodrich 1890’s and 1946 on nephridia.
Recent studies
• World-wide reviews focused on systematics (Blake,
Fauchald, Fitzhugh, Glasby, Hutchings, Pettibone,
Pleijel, Salazar-Vallejo)
• Regional systematic studies with overviews of the rest
of the world (Hutchings, Imajima, Orensanz)
• Continued morphological studies e.g., anterior
nervous system (Orrhage), nephridia etc (Bartholomaeus
• Unusual environments (Desbruyères, Blake, Miura,
Pettibone), especially from deep water
• Development of interactive keys (Glasby, Fauchald,
Hutchings, Wilson)
• Comprehensive or focused cladistic studies
(Fitzhugh, Pleijel, Rouse and in part Fauchald)
Some philosophical issues
• Do scientists ever change their minds? Kuhn (1962)
and paradigm shifts in a polychaete setting.
• Paraphyletic vs. monophyletic taxa, does it make a
difference (except esthetically and emotionally)?
• Does the traditional systematic (Linnean) system
work? If not, what can take its place?
• Scoring problems: Can we represent complex visual
observations with a single number for all characters
or only for some kinds of characters?
A few rules
• Include author and publication year as part of the
name at least once in a paper (quadrinomials).
• List literature used for identification.
• If you propose a synonym, you must have seen
types or material from the type area.
• Include only citations for which you know that
voucher material is available; including
databases or papers from the grey literature.
• Don’t worry about ranks: The sooner we forget
them, the better off we will be.
• Illustrate, photographs are lovely but linedrawings often convey more information.
Homotypic and heterotypic
synonyms
• Homotypic synonyms come about when a name
is nomenclaturally incorrect or sometimes when
a species is moved from one genus to another.
Homotypic synonyms have a single (set of) type(s).
One name is valid; other name(s) are invalid with
reference to that type lot. Homotypic synonyms
concerns names or combinations
• Heterotypic synonyms reflect a scientific opinion
about distinctness of (terminal) taxa. Heterotypic
synonyms always have different sets of types. One
of the taxa is the currently accepted taxon..
Heterotypic synonyms concerns most often taxa
at the terminal or subterminal levels
More about synonyms
• Synonymy-lists contain three different elements,
homotypic synonyms, heterotypic synonyms and
mis-identifications.
• A synonym involves the whole taxon; a misidentification is an error by a scientist in applying
a name to one or more specimens.
• If previously mis-identified specimens belong to an
undescribed species, the taxonomic act is description
of a new species, NOT a new name.
• The term “new name” is appropriate when only the
name is being changed, while the taxon remains
unchanged
IS POLYCHAETA MONOPHYLETIC?
NO!
Probably not
ANNELIDA
• Includes Scolecida, Palpata, and Echiura
• Scolecida, in addition to some “polychaetes” includes the
clitellates
• Palpata includes all other “polychaetes” and can be
separated into two: Aciculata and Canalipalpata.
• Pogonophora/Vestimentifera is a clade in Sabellida
• Lumping and splitting various groups, especially of
canalipalpates will continue for some time.
•
• Beware of analyses in which the starting point is a
theoretical construct!
Comfort for conservatives:
• Birds, reptiles and amphibians were shown to be
paraphyletic a long time ago. Scientists still
consider themselves as ornithologists and
herpetologists.
• Shared literature, shared collections and shared
sampling methods and locations keep these
groups together.
• So, some concepts, even when unsupported
scientifically, remain in use for historical and
practical reasons.
Systematics as Comparative Biology
• Two flavors: Conceptually innovative and
Aggregation of data points. Most studies
include a bit of both, but tend to be focused
on one flavor.
• New thoughts without data are just as bad as
piling up data points
• Think of your study objects as living
organisms.
• Without knowledge of the rest of science,
and philosophy, we are unlikely to contribute
much beyond data points for others to
analyze or forgotten throughts.
Recent problems
• Food uptake is less linked to anterior
appendages than previously assumed
• Sperm transfer organs are far more
common than assumed
• Sperm storage organs are present in a
variety of polychaetes
• Planktotrophic larvae are less common
than assumed; direct development more
common
Furthermore….
• Some taxa appear to be rare no matter
where we look.
• Bacteria participate in food processing in
far more species than we had previously
anticipated.
• Some geographical areas appear to be
depauperate, others unreasonably rich in
species. Each unusual pattern may be the
consequence of historical accidents
New systematization in Rouse and Fauchald 1997
Echiura
Euarthropoda
On ychophora
Clitellata
Siboglinidae
Sabellariidae
Sabellidae
Serpulidae
Oweniidae
S ABELLIDA
Acrocirridae
Flabelligeridae
Cirratulidae
Alvinellidae
Amp haretidae
Pectinariidae
Terebellidae
Trichobranchidae
TEREBELLIDA
Apistobranchidae
Sp ionidae
Trochochaetidae
S PIO NIDA
Longosomatidae
M agelonidae
Poecilochaetidae
Chaetop teridae
Acoetidae
Aphroditidae
Eulepethidae
Polynoidae
Sigalionidae
Pholoidae
Chry sopetalidae
Glyceridae
Goniadidae
Paralacy doniidae
Pisionidae
Lacydoniidae
Phyllodocidae
Nep htyidae
Nereididae
Hesionidae
Pilargidae
Sp haerodoridae
Sy llidae
Amp hinomidae
Euphrosinidae
Dorvilleidae
Lumbrineridae
Eunicidae
Onuphidae
Arenicolidae
M aldanidae
Capitellidae
Opheliidae
Scalibregmatidae
Orbiniidae
Paraonidae
Questidae
Cossuridae
S ipu ncula
73
PHYLLO DOCIDA
C
A
N
A
L
I
P
A
L
P
A
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A
P
A
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P
A
T
A
A
C
I
C
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L
A
T
A
EUNCIDA
S
C
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C
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D
A
P
O
L
Y
C
H
A
E
T
A
A
N
N
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I
D
A
A
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C
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L
A
T
A
And, that’s all, folks!