On Recent species of Spiraserpula Regenhardt, 1961, a serpulid polychaete genus hitherto known only from Cretaceous and Tertiary fossils

66 Pages·1994·27.8 MB·

by  T Gottfried Pillai

Bull. not. Hist. Mus. Lond. (Zool.)60(1): 39-104 Issued23June 1994
On
Recent species of Spiraserpula
Regenhardt, 1961, a serpulid polychaete
genus hitherto known only from Cretaceous
and Tertiary fossils
T. GOTTFRIED PILLAI
Marine BiologicalServices Division, DepartmentofZoology, The NaturalHistory Museum, Cromwell
Road, London SW75BD
HARRY A. TEN HOVE
Universiteit van Amsterdam, Instituut voor Taxonomische Zoologie, Postbus 94766, 1090 GT
Amsterdam, Nederland
CONTENTS
Synopsis 39
Introduction 39
Methodsand materials 40
Terminology 40
Diagrammaticrepresentationsofinternal tube structures 41
DiagnosisofSpiraserpula Regenhardt, 1961 41
Keytothe Recent speciesofSpiraserpula Regenhardt, 1961 46
Descriptionofspecies 49
Discussion 99
Acknowledgements 103
References 103
Synopsis. A groupof Recent serpulid species related to the genusSerpula Linnaeus, 1758, but differing from it in
two important characters, is described in this paper. The first is a hitherto undescribed character, namely, the
possession of internal tube structures which consist of longitudinal ridges and other structures, the form and
arrangement of which, in combination with characters of the worms themselves, served to separate the various
species. Thesecond isthatthe thoracicmembranesofthe twosidesin thewormdonot unite ventrallyattheendof
the thorax to form a flap or apron as in Serpula. These characters are also common to 18 species, including three
previously described ones. On the basis of the tube structures, these Recent species can be referred to the genus
Spiraserpula Regenhardt, 1961, which was previously known only from fossils (Pillai, 1993). Scissiparity was
observed in at least threeofitsspecies. A key to the known Recent speciesofSpiraserpula and a discussionon the
systematicsofthegenusare included.
INTRODUCTION provided evidence oftheir having been forcefully broken off
from the rest of the abdomen. The cause of the difficulty in
extracting complete worms was revealed by opening their
In the course ofa study of the serpulids currently referred to tubes carefully from their anterior ends all the way to their
the genus Serpula Linnaeus, 1758, it was observed that the posterior ends. It was found that the posterior end of the
wormsoflargerspeciescouldfrequently be extractedundam- abdomen was retracted very tightly into the posterior coiled
aged from the anterior ends of their tubes with a pair offine part ofthe tube and, quite surprisingly, against a longitudinal
forceps, while they wereinvariably damaged in the process in rowofsharpserrationsprojectingfrom the inside ofthe tube.
certain small species as, for instance, in the well-known Examinationofmorematerial showedthat these wereconsis-
Mediterranean species Serpula massiliensis Zibrowius, 1968. tent for 5. massiliensis.
In almost every collection ofthe latter, the worms which had Study of similar material from various other geographical
been previously extracted from their tubes were incomplete localitiesrevealed theexistenceofspecieswithotherformsof
posteriorly, and the ends of their longitudinal musculature internaltube structures. Evidently, these serve foranchorage
)TheNaturalHistoryMuseum, 1994
40 T.G. PILLAI AND HA. TEN HOVE
of the worm when withdrawn into the tube, and thereby, METHODS AND MATERIALS
have an additional protective function. The form and
arrangement of the internal tube structures, in combination
with characters of the worms themselves, served to separate The tubes and their internal structures, as well as whole
the various species. They are absent in Serpula Linnaeus, worms and parts were examined and drawn under a stereo
1758, and have not been described in any ofthe other known microscope fitted with a drawing attachment. Measurements
generaofSerpulidae. Theydifferfrom the transverse tabulae were taken with a pair offine dividers against a scale having
of certain serpulids, an account of which is given by Lom- an accuracy of 0.5 mm, of total length of the tube when
merzheim (1979). Another important character common to possible, external diameter of the tube, total length of the
the group is that, unlike in Serpula, the thoracic membranes worm, width of the thorax just posterior to the pair of collar
ofthetwosidesare not unitedposterior to the thorax toform fascicles, length and diameter of operculum, length of the
aventral flap or apron. opercular peduncle, and length of the longest radiole and its
In the search for a name for this group, the genera pinnule-free tip when present. Radioles and thoracic seg-
Pseudoserpula Straughan, 1967 and Protoserpula Uchida, ments were counted on both sides, while the abdominal
1978, were considered, among others. The former was found uncinal tori of one side were counted to determine the
to be invalid, and an account of the study which led to this number of abdominal segments. The chaetae were mounted
conclusion is provided under Spiraserpula minuta, in polyvinyl lactophenol or aquamount and figured underthe
(Straughan, 1967), in this paper. It was not possible to oil immersion lens of a high power microscope fitted with a
examine the type specimen of Protoserpula to establish drawing attachment. Measurements of chaetae were made
whether it has ITS or not. It is not in the National Science with an eyepiece micrometer standardised with a stage
Museum, Tokyo, and other efforts to locate it were unsuc- micrometer. Scanning electron micrographs of chaetae of
cessful. some ofthe species are also provided (Plates 1-5).
H. Zibrowius of Station Marine d'Endoume, Marseille, The sources of material have been detailed under the
who went through the manuscript of this paper, and the respective descriptions aswell asthe acknowledgements. Full
secondauthordiscussedthegroupwith M. JagerofRohrbach details of E. Atlantic stations surveyed by the 'Tydeman'
Zement, Dotternhausen, Germany,whore-examined the fos- Canary and Cape Verde Islands Expeditions of 1980, 1982
sil serpulids studied by him (Jager, 1983), and other material, and 1986 (CANCAP-IV, VI and VII), (e.g. CANCAP
and found that some of them too possessed internal tube 4.D14, 6.134) can be found in van der Land (1987); of E.
structures, although they had not been reported earlier. The Indonesian stations sampled during the Indonesian-Dutch
collaboration which followed (pers. comm.) led to a study of Snellius II Expedition (e.g. Snellius II4.051) in van derLand
likely Cretaceous and Tertiary serpulid genera and species & Sukarno (1986). The following abbreviations have been
(Pillai, 1993), which revealed that the group belongs to the used in the text: AM: Australian Museum, Sydney; AMNH:
genus Spiraserpula Regenhardt, 1961, previously known only American Museum ofNatural History, NewYork; BM(NH):
fromfossil species. Spiraserpula Regenhardt, 1961, has prior- British Museum (Natural History), London, presently. The
ity over Protoserpula Uchida, 1978, even ifthe latterwere to Natural History Museum, London; FSBC I: Florida Depart-
possessinternal tube structures, henceforth referred to in the ment of Natural Resources, Invertebrate collection, St.
text as ITS {vide Jager 1993)). Zibrowius (1972) described a Petersburg, Florida; HUJ: The Hebrew University, Jerusa-
RecentspirorbidspeciesbelongingtothegenusNeomicrorbis lem; MCZ: Museum of Comparative Zoology, Harvard;
Rovereto, 1904, which was previously known only from NNM: Nationaal Natuurhistorisch Museum, Leiden (for-
Cretaceous andTertiary fossils. merly Rijksmuseum van Natuurlijke Historie); NSMT:
In three of the Recent species of the genus Spiraserpula National Science Museum, Tokyo; QM: Queensland
definite proofofasexual reproduction was found, in the form Museum, Brisbane; RMNH: Collection numbers of NNM;
ofbranching tubes, corroborated by the presence ofa parent SME: Station Marine d'Endoume, Marseille (most material
with a schizont in one tube of Spiraserpula snellii sp. nov. will be deposited later in the Musee Nationale d'Histoire
Asexual reproduction had previously been reported for the Naturelle,Paris); USNM: United States National Museum of
genera Filograna Berkeley, 1835, Filogranula Langerhans, Natural History, Washington DC; V.Pol: Polychaete collec-
1884, Josephella Caullery & Mesnil, 1896, Salmacina Cla- tion numbers of ZMA; ZLU: Zoological Laboratory,
parede, 1870 and Rhodopsis Bush, 1905 (ten Hove, 1979; Utrecht; ZMA: Zoologisch Museum, Instituut voor Taxo-
Ben-Eliahu & ten Hove,1989). Pillai (1993) reports the nomische Zoologie, Amsterdam; ZMH; Zoologisches Insti-
occurrenceoftubebranchinginthefossilspeciesSpiraserpula tut und Zoologisches Museum, Hamburg; ZMK: Zoologisk
versipellis Regenhardt, 1961. It would not be surprising if it Museum, Kobenhavn.
turns out that scissiparity takes place in most, if not all,
species ofthe genus Spiraserpula, in view oftheir aggregated
occurrence.
Nineteen species of Spiraserpula, including the three
TERMINOLOGY
known ones referred to above and an unnamed one, are
described. They come from the Mediterranean, Madeira,
Canary and Cape Verde Islands, Gulfof Mexico, the Carib- The terminology used in this paper is explained in Figs 1 and
bean and Panama, the northern Red Sea, Mozambique, the
2.
eastern islands of Indonesia, Eastern Australia, Japan and
New Caledonia.
ON RECENTSPECIES OFSPIRASERPULA REGENHARDT, 1961 41
Hi
Plate 1 Scanningelectron micrographsoffracturedendsoftubesshowing internalstructures. A, C& D,Spiraserpulalineatuba (Straughan,
1967). B, S. ypsilon sp. nov.
DIAGRAMMATIC REPRESENTATIONS OF DIAGNOSIS OF SPIRASERPULA Regenhardt,
TUBES 1961
The various arrangements ofITS in the speciesdescribed are The original generic diagnosis ofSpiraserpula was based only
diagrammatically represented in Fig. 3. on the tube of its fossil type species, S. Spiraserpula Regen-
hardt, 1961. Pillai (1993) provides an emended definition for
fossil species based on characters of the tube. However, the
recent species described here are distinguishable not only by
characters of their tubes but also of the worms themselves,
42 T.G. PILLAI AND HA. TEN HOVE
Plate2 Scanningelectron micrographsofchaetae. A-D, Spiraserpulamassiliensis(Zibrowius, 1968): A, bayonetchaetae. B, thoracicuncini.
C, anteriorabdominal uncini. D, flattrumpet-shapedabdominalchaetae. E&F, 5. singularissp. nov.: E, bayonetchaetae. F, abdominal
uncini.
and they have been taken into consideration in the following wallofthetube, and/orventral, alongtheoppositeside. They
diagnosis: may be laminar, serrated orunserrated, or have otherforms,
Tube with internal structures, usually towards its earlier and accessory lateral ridges or other structures may also be
formed, coiled, posterior portions. They consist of internal present. An umbilicus and peristomes may be present. There
longitudinal ridges which vary in form and complexity in the is usually an external granular overlay which bonds together
different species; they may be dorsal, along the convex inner coils of individual tubes, or those of other tubes to form
ON RECENTSPECIES OFSPIRASERPULA REGENHARDT, 1961 43
Plate3 Scanningelectron micrographsofchaetae. A-D, Spirserpulanudicristasp. nov.: A, bayonetchaeta. B, thoracicuncini. C,
abdominal uncini. D, flattrumpet-shapedabdominalchaetae. E-G, S. lineatuba (Straughan, 1967): E, bayonetchaetae. F, abdominal
uncini. G, flat trumpet-shapedabdominalchaetae.
44 T.G. PILLAI AND H.A. TENHOVE
Plate4 Scanningelectron micrographsofchaetae. A-D, Spiraserpulazibrowiisp. nov.: A, bayonetchaetae. B, thoracicuncini. C,
abdominaluncini. D, flat trumpet-shaped abdominalchaetae. E&F, S. caribensis, sp. nov.: bayonetchaetae.
ON RECENTSPECIES OF SPIRASERPULA REGENHARDT, 1961 45
09KU 2.31KX 4.33H 8035
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Plate5 Scanningelectronmicrographsofchaetae. A-C, Spiraserpulacaribensissp. nov.: A, abdominal uncini. B, flattrumpet-shaped
abdominalchaetae. C-E, collarchaetae fromGrenadamaterial. F-H, 5. snelliisp. nov.: F, bayonetchaetae. G, abdominaluncini. H,flat
trumpet-shapedabdominalchaetae.
46 T.G. PILLAI AND HA. TEN HOVE
d.cx.w.
dr.
Fig. 1 Terminology. A,Tube: d.cx.w., dorsalconvexwall;d.r., dorsal ridge; v.cv.w., ventral concavewall; v.r.,ventral ridge. B, Radioles
ofbothsidesandoperculum: o.p., opercularpeduncle; p., pinnules; pf.t., pinnule-free tip; r., radius; rl., radiole; r.l.s., radiolesofleft
side; r.o., rudimentaryoperculum; r.r.s.,radiolesofrightside; t.r.l. triangularradial lobe; z.o.,zygomorphoperculum. C-G, Opercula:
en.,constriction betweenoperculum andpeduncle;i.r.g., inter-radial groove; ut.c, unthickenedcuticle, bs.o., bell-shapedoperculum;
r.r.l., roundedradial lobe; t.t.c., thickenedtransparentcuticle.
mutuallybondedaggregationsofafew to numerous individu- membranes end anterior to the last thoracic chaetigers, also
als. more frequently asymmetrically than symmetrically. Unlike
An operculum similar to that in Serpula, which is a in most species of Serpula sensu stricto, therefore, a post-
modification of the second most dorsal radiole, is often thoracic ventral flap (apron) is absent.
present on one side with, correspondingly, a rudimentary Collar fascicles bear chaetae of two kinds: bayonet
operculum on the other. There may only be a rudimentary chaetae and limbate chaetae, the blades of both of which
operculum on each side in certain species, while they may be are usuallyfinely serrated. In the former, there are afew to
presentinjuveniles andcompletely lostin olderspecimens in several comparatively large teeth, located at the distal end
others. Theshape ofthe fullydevelopedoperculum ischarac- of the shaft, separated from the bayonet-like blade by an
teristic for a particular species; it may be funnel-shaped, unserrated area (unserrated notch). The range in the
bell-shaped, zygomorphic or spherical. Its distal end may be number of such teeth and the length of the unserrated
concave or convex and usually bears radii which end as notch varies in the different species. Limbate chaetae bear
triangular or rounded lobes at the rim; but radii may also be simple, more or less curved, blades. Thoracic and anterior
lacking in some species. Its cuticle may be unthickened or abdominal uncini may bear teeth in a single row (saw-
thickened and transparent. shaped), or are partly (saw- to rasp-shaped) or completely
The numberofbranchial radiolesisusuallysmall, rarelyup rasp-shaped. Abdominal chaetae bear distally flat trumpet-
A
to 14pairs. Palpsabsent. pairofprostomial ocellarclusters shaped ends, and are replaced by capillaries in the poste-
is usually present. The number of thoracic chaetal tufts may rior segments. The distal ends ofthe abdominal chaetae of
exceed the seven pairs commonly occurring in many genera Serpula have been described as 'trumpet-shaped' in ser-
of Serpulidae, including Serpula, and those of the two sides pulid literature. We have discussed the inappropriateness
aremore frequentlyasymmetricalthansymmetrical. Upto 14 of the comparison, as demonstrated by the scanning elec-
have been counted on each side. Histological work is needed tron micrographs and drawings of these chaetae presented
to ascertainthe realextentofthesegments, andtheirrelation in this paper, and our attention has also been drawn to this
to numbers of chaetal tufts and uncinal rows, etc. The term by Zibrowius (pers. comm.). In order not to create confu-
'chaetiger' is, therefore, used here in the literal meaning of sion, it was decided to retain 'flat trumpet-shaped', for the
'hair bearer' and not as a synonym of segment. The thoracic present.
ON RECENT SPECIES OFSPIRASERPULA REGENHARDT, 1961 47
Fig.2 Terminology. A& B, Bodyofworm: a.t., abdominal tori;cap., capillarychaetae;col., collar;col.s., collarchaetae;d.l.g., dorsal
longitudinalgroove; t.s., thoracicchaetae; t.t., thoracictori; v.l.g., ventral longitudinalgroove. C-G, Bayonet-shapedcollarchaetae (after
tenHove&Jacobs, 1984; allsame magnification): act., accessoryteeth; b.b., basal boss; f.t., fewteeth; l.s.b.Jongserratedblade;
m.l.s.h., moderately longserrated blade; s.s.b., shortserratedblade; s.t., several teeth; u.n., unserratednotch; v.s.dl.b., veryshort
dagger-like blade; v.s.t.b., veryshort tapered blade. H, Uncini, showingorientation in relation tothe bodyofthe worm: a., anterior; p.,
posterior.
KEY TO THE KNOWN RECENT SPECIES OF Tube with ventral longitudinal ridge only, exceptionally with
fewisolatedteeth (Fig. 3, F) 6
SPIRASERPULA REGENHARDT, 1961
Dorsal ridge unserrated, shapedlike aninvertedV(Fig. 3, B)
S. singularissp. nov. p.62
(See Figure 3 for terminologyofITS)
1. Tube with either dorsal or ventral internal longitudinal ridge Dorsalridgeserrated (Fig. 3,C-E) 4
only 2
Serrationsofdorsal ridge deltoid (Fig. 3, C)
Tubewithdorsalandventralinternallongitudinalridges .... 7 S. deltoidessp. nov. p.80
2. Tube withdorsal longitudinalridgeonly(Fig. 3, B-E) 3 Serrationsofdorsalridge notdeltoid (Fig. 3, D& E) 5
48 T.G. PILLAI AND HA. TEN HOVE
d.s.
Fig.3 DiagrammaticrepresentationsofITSinthe variousspecies. A, Generalizeddrawingwith all themainITS. The orientationofthe
tubeandterminologyusedarethesame forallthediagrams. Ant., anteriordirection, d, dorsalside, d.cx.w., dorsalconvexwall.d.l.r.,
dorso-lateralridge, d.r., dorsalridge, v,ventralside.v.cv.w., ventralconcavewall, v.r.,ventralridge. B, S. singularissp.nov. C, 5.
deltoidessp. nov.;d.s.,deltoidserrations. D,S. massiliensis (Zibrowius, 1968). E, S. capeverdensissp. nov.;k.c.d., knob-likecalcareous
deposits. F, 5. nudicristasp. nov. &5. snelliisp.nov.;v.v.r.,variant formofventral ridge. G, S. ypsilonsp. nov. & S.paraypsilonsp. nov.
H,S. sumbensissp. nov. I,S. iugoconvexasp. nov. J,S. vasseurisp. nov. K, S. plaiaesp. nov. L, S. caribensissp. nov. & 5. lineatuba
(Straughan, 1967). M, S. disciferasp.nov.;t.d., transparentdiscs. N, S. karpatensissp. nov. &S. minuta (Straughan, 1967). O, S. zibrowii
sp. nov.