Revisionary systematics of the endemic soft coral fauna (Octocorallia: Alcyonacea: Alcyoniina) of the Agulhas Bioregion, South Africa
Author
Mcfadden, Catherine S.
Author
Van Ofwegen, Leen P.
text
Zootaxa
2017
2017-12-13
4363
4
451
488
journal article
31177
10.11646/zootaxa.4363.4.1
a141fa76-cc88-4901-944a-306171e41413
1175-5326
1114473
86DE1B94-63AE-4ABF-B28A-0ECEA22D2F10
Lampophyton spinatum
n. sp.
Fig. 3a–e
,
4
,
5a
Alcyonium planiceps
Williams 1986a: 56
(part)
Material
examined
.
Holotype
.
RMNH
Coel. 40198
(
SAF164),
South Africa
,
Eastern
Cape
,
Algoa Bay
,
White Sands
15;
33º59.900'S
,
25º42.522'E
,
14–16 m
, coll.
C.S. McFadden
,
12 March 2008
.
Paratypes
.
RMNH
Coel. 40199 (SAF195),
South Africa
,
Algoa Bay
,
White Sands
6;
34º00.368'S
,
25º43.166'E
, depth
21–25 m
, coll. B.
FIGURE 3.
a, b:
Lampophyton spinatum
n. sp.
, holotype, RMNH Coel. 40198 (SAF164); b, close-up of polyparium surface and margin of stalk; c-e:
Lampophyton spinatum
n. sp.
, SAF125; d, lateral view of polyparium surface; e, top view of polyparium; f, g:
Lampophyton planiceps
RMNH Coel. 40200 (SAF237), lateral view of polyparium and margin of stalk; g, top view of partially retracted polyparium. s = sclerites protruding through colony surface.
FIGURE 4.
Lampophyton spinatum
n. sp.
, holotype, RMNH Coel. 40198 (SAF164). a, sclerites from upper region of stalk and polyparium; b, tuberculate spindles and needles from base of stalk; c, smooth spindles from base of stalk; d, details of tubercular ornamentation: top and middle, spindles of upper surface of stalk; bottom, spindles of base of stalk.
Picton
,
12 March 2008
.
CASIZ 222392
, same as
RMNH
Coel.
40199.
Other
material.
SAF125,
South Africa
,
Eastern
Cape
,
Algoa Bay
,
Riy Banks
;
33º59.069'S
,
25º51.841'E
, depth
14–17 m
, coll.
C.S. McFadden
,
11 March 2008
.
Lampophyton planiceps
:
CASIZ 222386
(SAF136), SAF137,
South Africa
,
Eastern
Cape
,
Algoa Bay
,
White Sands
6;
34º00.368'S
,
25º43.166'E
, depth
21–25 m
, coll.
B. Picton
,
12 March 2008
.
RMNH
Coel.
40200
,
RMNH
Coel.
40201
,
CASIZ 222393
,
South Africa
,
Eastern
Cape
,
Algoa Bay
,
Evans Peak
,
33º50.578'S
,
25º48.988'E
, depth
22–28 m
, coll.
C.S. McFadden
,
14 March 2008
.
The
holotype
is an unbranched colony
2.8 cm
tall, with a distinct stalk and retractile polyps (
Fig. 3a
).
Approximately one-half of the upper region of the stalk and a portion of the polyparium have been removed for
DNA
analysis. The stalk is
0.6 cm
in diameter near its base, but flares to
0.9 cm
at the distal end. The stalk surface is rough with numerous longitudinal furrows and transverse wrinkles. Large sclerites can be seen on the stalk surface and protruding from the base. Numerous large spindles also protrude from the margin of the stalk, surrounding the polyparium (
Fig. 3b
). The polyparium is withdrawn within the stalk, with only the dome-shaped surface, with 8–10 large polyps in various stages of retraction, visible. Additional large spindles protrude from the surface of the polyparium, extending from the coenenchymal space between the polyps (
Fig. 3b
). The polyps themselves are devoid of sclerites.
The sclerites of the polyparium are large, fat spindles, 1.0–
1.4 mm
long and up to
0.25 mm
wide, with complex tubercles (
Fig. 4a, d
). The lower region of the stalk includes similar spindles up to
2.3 mm
long, as well as needlelike forms,
1.1–1.75 mm
long (
Fig. 4b
), and rather smooth rods to
0.45 mm
long (
Fig. 4c
).
Paratypes
and other material: SAF125 is a
1.8 cm
tall colony, with a stalk that is
0.4 cm
in diameter at its base and flares to 1.0 cm at the distal end (
Fig. 3c
). The dome-shaped polyparium has about 25 polyps, most of which are fully retracted. Large sclerites protrude at various angles from the upper part of the stalk and vertically from the surface of the polyparium between the polyps (
Fig. 3d, e
).
RMNH
Coel. 40199 (SAF195) and
CASIZ
222392 are similar in appearance but
2.6 cm
tall. In other respects the
paratypes
resemble the
holotype
.
Color
. In life, polyparium yellow with purple polyps (
Fig. 5a
). Brown in ethanol.
Etymology
. From the Latin
spinatus
, crowned with thorns, denoting the large spindles that protrude through the surface of the polyparium.
Remarks
.
L. spinatum
n. sp.
is distinguished from
L. planiceps
by the presence of large spindles in the polyparium. These sclerites are arranged longitudinally around the polyps, and the ends of some protrude from the polyparium surface and around the margins of the stalk (
Fig. 3a–e
). In contrast,
L. planiceps
lacks sclerites in the polyparium, and no or very few sclerites protrude from the surface of the stalk (
Fig. 3f, g
). The form of the spindles in the stalk is the same in the two species, but those of
L. planiceps
are on average longer and narrower (to
0.2 mm
wide) (
Fig. 6
). Williams (1986a) states that the polyparium of
L. planiceps
lacks sclerites “except in two specimens collected from
eastern Cape
” (SAM H-3713). It is likely, therefore, that the material he examined included individuals of both species, but his specimens were not available to us for examination. Whereas the polyparium of
L. planiceps
can be retracted completely, with the distal end of the stalk folding over to enclose the polyparium within,
L. spinatum
n. sp.
appears to be incapable of such retraction. All of the preserved specimens retain a vaseshaped form, and, although the polyps are fully or partially retracted, the surface of the polyparium remains visible and the distal margins of the stalk are not folded over it, as they are in the majority of
L. planiceps
specimens (
Fig. 3f, g
). The morphological distinctions among these two very similar species are supported by molecular phylogenetic data. Individuals that have large sclerites protruding from the polyparium (
L. spinatum
n. sp.
) differ from those that lack sclerites in the polyparium (
L. planiceps
) at each of the loci we sequenced. Pairwise genetic distances (K2p) between the two species were 2.3% at
mtMutS
, 1.0% at
COI
and 1.6% at
28S rDNA
, all values greater than those typical of intraspecific differences in octocorals (McFadden
et al
. 2011, 2014).