A revision of the genus Radicipes Stearns, 1883 (Anthozoa: Octocorallia: Chrysogorgiidae)
Author
Perez, Carlos D.
text
Zootaxa
2017
2017-11-11
4319
1
1
26
journal article
32144
10.11646/zootaxa.4319.1.1
7b43fe29-e505-4e3c-867c-086153fb3514
1175-5326
893037
Fc97523C-3Fe9-4Bd1-9A3B-174E0969E78A
Radicipes gracilis
(
Verrill, 1884
)
Figs. 2
E–F, 9, 10
Lepidogorgia gracilis
Verrill, 1884
: 220
; 1885: 512, 533, pl. 2, fig. 10, 10a.—VerSluyS, 1902: 16.—
ThomSon & HenderSon, 1906
: 27
(tabular key).
Strophogorgia fragilis
Wright & Studer, 1889
: 4
, pl. 2, fig. 2, pl. 5a. fig. 4.
Lepidogorgia fragilis
.—VerSluyS, 1902: 16-17.—
ThomSon & HenderSon, 1906
: 27
.
Radicipes gracilis
.—
Kükenthal, 1919
: 548
; 24: 412.—
Verrill, 1922
: 42
, fig 10, 10a.—
Deichmann, 1936
: 237
.—
MadSen, 1944
: 46
–49, text-figS. 37–41.—
Bayer, 1979
: 882
, fig. 2c.—
Bayer & Macintyre, 2001
: 342
(mineralogy).—
Watling & AuSter, 2005
: 28
(liSted).—
McFadden
et al.
, 2006
: 525
, figS. 1–3.—
Wareham & Edinger, 2007
: 295
, 298, 302, fig. 1J.—
CogSWell
et al.
, 2009
: fig. 10G.—
Buhl-MortenSen
et al.
, 2010
: 43
(mentioned). —
Pante &
France
, 2010
: 597
.—
Watling
et al.
, 2011
: 59
(liSted).—
Baker,
et al.
, 2012
: 239
, 240, 244.—
Pante &
France
, 2012
: figS. 2–3, Supplemental table 1 (liSted).—
Cordeiro
et al.
, 2015
: 94
, 95 (tabular key).—
Buhl-MortenSen
et al.
, 2015
: 39
–61, figS. 2f,
3i
, 4, 5.
?
Lepidogorgia challengeri
.
—
JungerSen, 1915
: 1184
.
Radicipes fragilis
.—
Kükenthal, 1924
: 143
. —
Tixier-Durivault & d’Hondt, 1975
: 1410
. —Braga-HenriqueS
et al.
, 2013: 4026 (liSted).—
Cordeiro
et al.
, 2015
: 95
(tabular key).
Lepidogorgia verrilli
.
—
ThomSon, 1927
: 20
–21, pl. 3, fig. 18, pl. 5, fig. 20.
Types
and
Type
Localities
.
Radicipes gracilis
:
USNM 9118
(
syntype
),
Alb-
2072,
41°53'N
,
65°35'W
(off
Massachusetts
),
1569 m
;
USNM 8877
,
USNM 9350
,
USNM 26030
,
USNM 30283
,
USNM 33570
,
YPM 8768
and
YPM
10045 (
syntypes
),
Alb-
2037,
38°53'N
,
69°23'30"W
,
3166 m
(off
Massachusetts
); part of the
syntype
series (from
Alb
-2036) is lost.
Strophogorgia fragilis
: BM 1889.5.27.4 (
holotype
, one specimen),
Chall-
70:
38°25’N
,
35°50’W
(west of
Azores
),
3063 m
.
Material Examined
.
Del-
23, 39°55'55"N, 67°11'W,
1155 m
(USNM 1111944, YPM 35442 and YPM 36838);
Alb-
2569, 39°26'N, 68°03'30"W, 3259 (USNM 11913 and YPM 10049);
Del-
29, 39°53'N, 67°23'W, 1395 (USNM 1110402);
Alb
-2209, 39°34'45"N, 71°31'30"W,
1975 m
(USNM 8193 and YPM 10051);
Alb
-2570, 39°54'05"N, 67°05'30"W,
3316 m
(USNM 11914);
Alb
-2575, 41°07'N, 65°26'30"W,
3128 m
(USNM 11908);
Alb
-2563, 39°18'30"N, 71°23'30"W,
2601 m
(USNM 11929 and YPM 10106);
Del
-14, 39°53'N, 67°26'24"W, depth unknown (USNM
100900
);
Del
-47-Bear, 39°52'58"N, 67°25'58"W,
1195-1402
(USNM 1010390);
Del-24
, 39°52'12"N, 67°20'18.6"W,
1428–1650 m
(YPM 36783);
Pisces
-16, 40°10'54"N, 67°26'40.2"W,
1961 m
(YPM 72083).
Description
. Colonies golden, stiff, tall, up to
90 cm
in height, coiled in clockwise or counterclockwise manner; aXis
2.2 mm
, maXimum diameter. Young colonies brittle and iridescent. Holdfast calcareous, profusely branched, usually thinner than aXis. Coenenchyme thin, fragile and easily detachable from aXis. At least one quarter of lower part of colony devoid of polyps. Distance between polyps about
1.5 mm
in proXimal portions to 10.0 mm distally. Polyps 2.5–5.0 mm long, cylindrical to slightly trumpet-shaped (
Fig. 2
E–F), disposed in a single longitudinal line (polypar side), spaced 4.0–10.0 mm apart in a frequency of three to five per centimeter (usually three). Eight longitudinal rows of rods in the body wall of completely developed polyps, with adaXials usually less developed,
0.18–0.7 mm
long and
0.02–0.06 mm
wide. Longest rods of body wall aligned with abaXial side, but no large supporting rods in abaXial side. AbaXial line from the lower portion of polyp to distal portion with four to siX juXtaposed pairs of rods in alternate lines, relatively homogeneous in size. Sclerite size decreases from abaXial to outer lateral rows. Inner lateral and adaXial rows composed of loosely placed rods, sometimes naked. Oral portion with rods similar in size to those from lower portion of polyp. Infrabasal and adaXial portions filled with flattened rods, slightly 8-shaped,
0.15–0.26 mm
long and
0.04–0.05 mm
wide (
Figs. 9
A, 10A). Infrabasal and abaXial rods with slightly flattened tips becoming more rounded and sparse in oral portion. AbaXial row of rods eXtending through coenenchyme between polyps, connecting them. Coenenchymal sclerites rare or completely absent, when present, similar to those of infrabasal and adaXial portions. Tentacular rods
0.07–0.18 mm
long and
0.01–0.04 mm
wide, becoming flatter in proXimal-distal wall (
Figs. 9
B, 10C). Pinnules filled with small scales,
0.1–0.13 mm
in length and
0.01–0.04 mm
in width (
Figs. 9
C, 10B).
Comparisons
. Colonies of
R. gracilis
differ from the Atlantic species
R. challengeri
and
R. kopelatos
by having larger polyps (Table 1) and by having their body wall densely filled with sclerites (
Fig. 2
). Although the longest polyps in
R. kopelatos
reach up to
3.3 mm
, most polyps in a colony are very short in comparison to those in
R. gracilis
, usually half their length. As well, the aXis diameter in
R. gracilis
is usually thicker. The Pacific species
Radicipes stonei
has a similar polyp shape, but differs in having one or two long supporting rods in the lower abaXial side, having irregular infrabasal flattened rods, and having body wall rods with at least one flat tip.
FIGURE 9.
ScleriteS of
Radicipes gracilis
(Verrill, 1884)
(USNM 8877, Syntype). A: rodS from polyp body Wall; B: flattened tentacular rodS; C: pinnular ScaleS. Scale barS: A, B: 0.1 mm; C: 0.05 mm.
FIGURE 10.
ScleriteS of
Radicipes gracilis
(Verrill, 1884)
(BMNH1889.5.27.4, holotype of
R. fragilis
(Wright & Studer, 1889))
. A: rodS from body Wall; B: pinnular ScaleS; C: tentacular rodS. Scale barS: A,C: 0.1 mm; B: 0.05 mm.
Remarks
.
Radicipes gracilis
is the most frequently recorded species in the genus, with at least 12 records presented herein and several others gleaned from the literature (
Fig. 3
, Supplementary file). Most studies have treated mid-Atlantic (
R. fragilis
) and western Atlantic (
R. gracilis
) populations as separate species. Nonetheless, no revisions including eXaminations of both
types
have been carried out until now. The
type
remains of
R. fragilis
consist of just a fragment of tissue (no aXis) with several polyps. But this is enough to determine that the
types
are indistinguishable (compare
Fig. 2
E,E’ with 2F and
Fig. 9
with
Fig. 10
). Several misconceptions about the morphological features of
R. gracilis
can be seen in the available literature.
Thomson & Henderson (1906)
, for eXample, implied that the species has more coenenchymal sclerites than
R. pleurocristatus
(see
Thomson & Henderson, 1906
: p. 27, comparative table of species of
Lepidogorgia
). According to
Madsen (1944)
and
Cordeiro
et al.
(2015)
, the main differences between the two species can be seen in the measurements of the polyps, twice as long in
R. gracilis
, and the longer body wall rods in
R. fragilis
(
Cordeiro
et al.
, 2015
)
. We understand that the ‘polyp distinction’ is due to the measurements given by
Madsen (1944)
, which included tentacles in the total polyp length determination, whereas no other author has included the tentacles to describe this character. Actually, both species have the same polypar length range, from 2.5 to 4.0 mm, not 5.0 to 10.0 mm as stated by Madsen. Rods from the body wall were slightly longer in the
R. fragilis
type
(up to
0. 75 mm
long, whereas usually just up to
0.5 mm
in western Atlantic specimens). Even though we only eXamined one mid-Atlantic colony, we consider it to be the same species, considering the sclerite size to be more related to age of the colony and seXual maturation.
It remains to be seen if the sequenced mid-Atlantic specimen ‘VER2041’ (
Pante
et al.
, 2012
) fits our
R. gracilis
definition, or
R. challengeri
,
or is a different species. Considering Pante’s phylogenies, in the first case, one could consider treating
R. gracilis
as a cryptic species compleX or one could suggest the reestablishment of
R. fragilis
as a valid name. Our eXaminations however do not allow us to keep both as valid.
Distribution
. In western Atlantic from
North Carolina
to
Canada
; Mid-Atlantic Ridge, Seamounts and
Portugal
(
Azores
), from
500–3259 m
.