The Paraonidae (Annelida: Sedentaria) from Norway and adjacent seas, with two new species, four new records, and a redescription of Paraonides nordica Strelzov, 1968 based on type material
Author
Sikorski, Andrey
text
Zootaxa
2017
2017-09-14
4320
1
41
67
journal article
32103
10.11646/zootaxa.4320.1.3
97eb2462-e968-4f36-81ab-fc2a832928ae
1175-5326
891538
878A01B5-C37C-4E46-8631-16927888D8D4
Cirrophorus brevicirratus
Strelzov, 1973
(
Fig. 3
)
Cirrophorus brevicirratus
Strelzov, 1973
: 124
, fig. 53A–J.
Material examined.
4020 Askøy 2007 KL1–4;
10.07.2007
; 60.4068°N–5.2286°E;
14 m
; one specimen. 6244 Veslefrikk VFR 03; 60.7760°N–2.9100°E;
170 m
;
27.05.2013
; five specimens.
Additional material.
BENTART–AP21, Antarctic Peninsula; 64.9000°S–63.0185°W;
107 m
;
23.02.2003
; three specimens.
Description.
All specimens incomplete, largest one
10 mm
long,
0.1 mm
wide for 80 chaetigers. Body slender, dorsoventrally flattened in pre- and branchial regions, cylindrical in postbranchial region. Prostomium triangular, slightly wider than long (
Fig. 3A
); minute median antenna in largest specimens only (
Strelzov 1973
), lacking in the examined specimens from
Norway
; apical sensory organ absent; pair of nuchal organs as slightly oblique nuchal slits (
Fig. 3A
). Notopodial postchaetal lobes of chaetiger 1 as short, rounded tubercles (
Fig. 3A
); slightly longer and piriform on remaining prebranchial chaetigers and in branchial region; short and digitiform in postbranchial region (
Fig. 3C
). Branchiae from chaetiger 4, 9 pairs, bearing ciliation on their inner edge, digitiform and distally rounded, up to four times as long as wide (
Fig. 3A, B
). Noto- and neurochaetae as geniculate bilimbated capillaries in prebranchial and branchial regions (
Fig. 3A, B
); in postbranchial region as thin, straight capillaries, clearly less numerous (
Fig. 3C
); from chaetiger 4–8 bearing 1–2 forked notopodial chaetae with tines similar in thickness but differing in length, with inner edges bearing short spinulation (
Fig. 3D
); modified neurochaetae absent.
FIGURE 3.
Cirrophorus brevicirratus
Strelzov, 1973
. A. Anterior end, dorsal view; B. Right parapodium of chaetiger 7, anterior view; C. Left parapodium of chaetiger 59, anterior view; D. Forked notochaetae of chaetiger 63. Scale bar: A: 0.19 mm; B, C: 95 µm; D: 30 µm.
Remarks.
Our specimens can be accurately referred to
C. brevicirratus
by having forked modified notochaetae, up to 15 pairs of branchiae and very short notopodial postchaetal lobes in the branchial region. Although typical of genus
Cirrophorus
, in this species the median antenna is very small and only appreciable in largest individuals, which are
0.4 mm
wide and possess more than 90 chaetigers (
Strelzov 1973
); this size is much larger than that of the examined specimens from
Norway
. The other two species within the genus that bear forked modified notochaetae, namely
C. americanus
Strelzov, 1973
and
C. furcatus
(
Hartman, 1957
)
, have more branchiae (up to 33 pairs in
C. furcatus
and
46 in
C. americanus
) and bear digitiform notopodial postchaetal lobes in the branchial region. In addition, the antenna of
C. brevicirratus
is much smaller when present than those of the other two species (
Strelzov 1973
). This species was described based on material from Southern Ocean, where it has been recorded several times (
Hartmann-Schröder & Rosenfeldt 1988
;
Sicinski 2004
;
Parapar
et al
. 2011
).
Strelzov (1973)
also included some material from western North Atlantic in the description, but the species was never again recorded outside of
Antarctica
or its vicinity. Thus, this record and its comparison with material collected from
Antarctica
confirms the Arctic-Antarctic distribution of the taxon.
Distribution.
New
England
(
Strelzov 1973
). South
Orkney
(
Strelzov 1973
) and South
Shetland
Islands
(
Sicinski 2004
); Antarctic (
Hartmann-Schröder & Rosenfeldt 1988
;
Parapar
et al
. 2011
). First record for
Norway
and adjacent waters.