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Records of the Australian Museum (2009) Vol. 61 
The above material appears to belong to a new species. 
However, further work on additional material would 
be needed in order to confirm whether the differences 
observed between the specimen from Tizard Bank and 
S. richardsmithi come within the scope of intraspecific 
variations of the latter or not. 
Spirobranchus tenhovi n.sp. 
Fig. 61B-H 
Spirobranchus latiscapus .—Monro (1939: 152); non 
Marenzeller, 1885. 
Material examined. BMNH 1941.3.3.1476, Tasmania, 41 o 03'S 148°42’E, 
128 m, coll. B.A.N.Z.A.R. Expedition, 24 Mar. 1931. Consists of a mixed 
collection of orange-yellow tubes labelled Spirobranchus latiscapus 
(Marenzeller); easily mistaken to be a single species, but actually consists 
of two genera, as follows: 8 empty tubes belonging to a Serpula crenata- 
like species (Fig. 61 A), and two specimens belonging to the genus 
Spirobranchus. One of the latter had the worm intact within its tube; in 
the other, the worm had been extracted previously from its tube, and was 
found lying loosely among the specimens. They were separated as holotype 
and paratype for the new species described below; and their respective 
registration numbers: NHM ANEA 2009.20., 2009.21. 
Description 
Measurements. Holotype: total length of tube, 48.0 mm; 
maximum width, 2.0 mm; maximum height, including 
fin-shaped extensions, 5.3 mm. Total length of worm, 
including its 2 stacked opercular plates, 34.5 mm; width 
of thorax, 3.0 mm; length of operculum and peduncle, 10. 
2 mm; length of operculum, including its two discs, 1.0 
mm; length of abdomen, 19.5 mm; number of abdominal 
segments, about 75. 
T\ibe. Colour, yellowish-orange to orange and white; a 
light caramel to yellowish-brown longitudinal band present 
along base of MLR. Its shape is quite unlike that of any of 
the other known species of Spirobranchus (Fig. 61B); is 
2Vi times as high as it is wide at its anterior end, where the 
MLR is highest; latter sinuous, comparatively very high 
and consists of long conspicuous, fin-shaped forwardly 
directed processes of varying lengths (Fig. 6IB). Two 
very low, thin lateral longitudinal ridges present on each 
side, one very close to base of MLR, and the other along 
its flank. Latter, well formed towards anterior part of tube, 
gradually becomes less so from its middle posteriorly (Fig. 
6IB). Along base of MLR, on either side of it, is a row of 
oblique, oval to elongated, forwardly directed foramina. 
Likewise, along either side of each LLR, at its base, is a 
row of similar foramina (Fig. 6IB). 
Worm. Operculum on left, no rudimentary operculum on 
right; conspicuously elongated (Fig. 61C-E), compared to 
that of the other “5. latiscapus-like” species dealt with in this 
account. Consists of well-formed stacked opercular plates, 
holotype with 2 (Fig. 61C,D); paratype with 4 (Fig. 6IE); 
each opercular plate has a thin rim along its edge. Peduncular 
wings unfringed (Fig. 61D,E). Number of radioles in 
holotype, 33 on each side in holotype, arranged in a circle; 
inter-radiolar membranes short, about Va as long as the 
radioles, unfringed (Fig. 61F); pinnule-free tips of radioles 
slightly thicker than pinnules. Thoracic chaetigers number 
7. Uncinal tori progressively increase in length posteriorly, 
leaving a clear inverted triangular area on ventral side of 
thorax; at ventral end of each uncinal torus there is dark 
pigment spot (Fig. 61G); apron present (Fig. 61G). Anterior 
abdominal tori short, located ventrolaterally. Long-shafted 
abdominal chaetae present throughout the abdomen, starting 
from about 2 segments from anterior end. 
Chaetae. Bayonet collar chaetae (Fig. 61H) lack a squarish 
or pronounced boss; position normally occupied by boss 
hardly recognizable; gradually merges with blade. Distal 
part of chaetal shaft preceding boss: serrated (Fig. 61H), 
its length together with that of boss, about equal to that of 
blade. Uncini: saw-shaped; thoracic uncini with about 13 
teeth, and anterior and posterior abdominal uncini about 11 
and 13 teeth, respectively, in addition to the anterior gouge. 
Remarks. Spirobranchus tenhovi n.sp. differs from S. 
latiscapus (Marenzeller, 1885) with regard to several 
characters, although the former was identified by Monro 
(1939: 152) as S. latiscapus (Marenzeller, 1885). Firstly, 
tube colour is yellowish-orange in S. tenhovi, and its shape 
is quite characteristic; its MFR consists of high wavy, fin- 
shaped sections, the most anterior one projecting forward 
conspicuously over the aperture. A row of oblique basal 
foramina is present on each side at the base of the MLR 
as well as at the base on either side of the two LLRs on 
each side. On the other hand, according to the original 
description of S. latiscapus by Marenzeller (1885), its tube 
colour is pinkish-red; it has longitudinal ridges bearing 
pointed processes or pointed lamellae, the MLR being 
the most prominent; sometimes only faint ridges present, 
frequently fine small spines or small pointed lamellae; 
sometimes only a single lateral ridge on each side. The 
special collar chaetae of S. tenhovi do not possess a 
prominent squarish boss, being hardly recognizable and 
merging smoothly between the shaft and the blade, unlike 
in S. latiscapus, where they possess a squarish boss. 
According to the literature, it had previously been thought 
that there is a single species of Spirobranchus having stacked 
opercular plates, namely, S. latiscapus (Marenzeller, 1885). 
However, the present study shows that there is a group of 
species having stacked opercula belonging to the genus. They 
include S. murrayi and S. tenhovi described in this paper, as 
well as two more species, namely, S. zelandicus n.sp., and 
S. zibrowii n.sp., as seen below. 
Etymology. Dedicated to Dr Harry A. ten Hove of the 
Institute of Systematics and Population Biology, Zoology 
Museum, University of Amsterdam, the Netherlands. We owe 
much of our current knowledge on the systematics, phylo- 
geny and biology of serpulids to his many contributions, 
both individually and in collaboration with many colleagues, 
including the present author, working on the group, as well 
as to sharing his unpublished data with his colleagues in the 
search.for answers to problems concerning the taxonomy and 
relationships of serpulimorph polychaetes. 
