Four new species and a ribosomal phylogeny of Rhabdopleura (Hemichordata: Graptolithina) from New Zealand, with a review and key to all described extant taxa
Author
Gordon, Dennis P.
National Institute of Water & Atmospheric Research (NIWA), Private Bay 14901, Kilbirnie, Wellington 6241, New Zealand
Author
Randolph Quek, Z. B.
0000-0001-7998-7052
National Institute of Water & Atmospheric Research (NIWA), Private Bay 14901, Kilbirnie, Wellington 6241, New Zealand & Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore
randolphquek@u.nus.edu
Author
Huang, Danwei
National Institute of Water & Atmospheric Research (NIWA), Private Bay 14901, Kilbirnie, Wellington 6241, New Zealand & Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore & National Institute of Water & Atmospheric Research (NIWA), Private Bay 14901, Kilbirnie, Wellington 6241, New Zealand & Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore 117377, Singapore & National Institute of Water & Atmospheric Research (NIWA), Private Bay 14901, Kilbirnie, Wellington 6241, New Zealand & Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore 119227, Singapore & National Institute of Water & Atmospheric Research (NIWA), Private Bay 14901, Kilbirnie, Wellington 6241, New Zealand
text
Zootaxa
2024
2024-03-14
5424
3
323
357
http://dx.doi.org/10.11646/zootaxa.5424.3.3
journal article
10.11646/zootaxa.5424.3.3
1175-5326
10821361
524CF65D-F877-42E1-B983-EDC7D3ED1623
Rhabdopleura striata
Schepotieff, 1909
(
Fig. 4E, F
)
Type
locality.
Kankesanturai
, northern
Sri Lanka
,
2‒3 m
depth
on hardstone
.
Key features.
Inception of ringed erect tubes is indirect. The
type
colony was described as
7‒8 cm
long, with erect-tube height
11‒12 mm
and diameter
1 mm
; the zooid is 1.0‒
1.5 mm
long and yellowish with pigment spots. Creeping tubes are almost straight, with few blind-ending lateral branches, all (with few exceptions) along one side only; these are proximally adherent for
2‒3 mm
before rising perpendicularly. Unique to
R. striata
is a wedge or web of cuticle, with fusellar sutures, in the angles where lateral branches diverge from the creeping tube (
Fig. 4F
). Fusellar collars are weakly developed, “so that at low magnification the living tubes appear clearly longitudinally striped [
i.e.
having aligned vertical fusellar striae], but not transversely ringed” [“so dass bei schwacher Vergrösserung die Wohnröhren deutlich längsgestreift, nicht aber quergeringelt erscheinen” (
Schepotieff 1909
, p. 431)]. There are 8‒10 ‘panels’ in each fusellar ‘circle’ [between fusellar collars]. The number of ‘circles’ varies from 150 to 500 depending on tube length. Fusellar height is 100‒125 μm.
Comment.
Rhabdopleura striata
is exceptional for its large tubes and zooids, with aligned longitudinal striae in ‘panels’ within the fusellae. Furthermore, in contradistinction to
R. normani
and similar species with indirectly budded erect tubes, side branches issue almost exclusively from just one side of the creeping tube.