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
Tenerodus fallax
(Lüttschwager, 1922)
,
n. comb.
Figs.
5g
–h
,
13b–c
,
15–16
Non
Alcyonium purpureum
Lamarck, 1836: 608
.
Alcyonium purpureum
(non Lamarck, 1836) Hickson, 1904: 215–217, pls. 7, 9; Thomson, 1910: 566–568, pls. 3–4; Lüttschwager, 1914: 25–26; Thomson, 1921: 156; Thomson, 1923: 47, 52, 68; Day et al. 1970: 15.
Alcyonium fallax
Lüttschwager, 1922
(nom. nov.): 520, 534; Lüttschwager, 1926: 288.
Alcyonium fauri
(non Thomson, 1910) Broch, 1939: 8–11; Williams, 1992a (part): 277–282, fig. 1B; 1992b: 381–385, 396, fig. 20G; Branch et al. 2010: 38, fig. 12.8.
Parerythropodium fallax
Day et al. 1970: 15
.
Parerythropodium purpureum
Day, 1974: 34
; Branch & Branch 1981: 152, pls. 34, 37.
?
Parerythropodium wilsoni
(non Thomson, 1921) Day 1974: 34; Branch & Branch, 1981: 152.
FIGURE 15.
Tenerodus fallax
n. comb.
RMNH Coel. 40214 (SAF072). a, club-like sclerites from polyps and colony surface; b, asymmetrical spinose clubs from polyps and colony surface; c, tentacle sclerites; d, radiates and tuberculate spheroids from colony surface.
FIGURE 16.
Tenerodus fallax
n. comb.
RMNH Coel. 40214 (SAF072). Radiates and tuberculate spheroids from interior of colony.
Material
examined
.
RMNH
Coel.
40218
(
SAF013),
CASIZ 222381
(SAF014), SAF015,
South Africa
,
Western
Cape
,
Mossel Bay
,
Phluffy Reef
,
34º10.988'S
,
22º09.745'E
, depth
12–15 m
, coll.
C.S. McFadden
, 0
8 March 2008
.
RMNH
Coel.
40216 (SAF059),
RMNH
Coel.
40215 (SAF067),
South Africa
,
Eastern
Cape
,
Port Elizabeth
, Algoa Bay, Bell Buoy 1,
33º58.927’S
,
25º41.473’E
, depth
20 m
, coll.
C.S. McFadden
,
10 March 2008
.
RMNH
Coel.
40214 (SAF072),
CASIZ 222384
(SAF073), SAF084,
South Africa
,
Eastern
Cape
,
Port Elizabeth
,
Algoa Bay
,
Philips Reef
,
33º15.933'S
,
25º41.768'E
, depth
10–12 m
, coll.
C.S. McFadden
,
10 March 2008
.
SAF098,
South Africa
,
Eastern
Cape
,
Port Elizabeth
,
Algoa Bay
,
Riy Banks
,
33º59.069'S
,
25º51.841'E
, depth
14–17 m
, coll.
C.S. McFadden
,
11 March 2008
.
RMNH
Coel.
40217 (SAF383), SAF384,
CASIZ 222395
(SAF386),
South Africa
,
Western
Cape
,
Cape
Peninsula, Vulcan Rock,
34º03.970'S
,
18º18.627'E
, depth
15–27 m
, coll.
C.S. McFadden
,
23 March 2008
.
Description
. As re-described by Williams (1992a),
Alcyonium fauri
Thomson
sensu lato
encompasses material with a wide range of colony growth forms (“membranous, globular to capitate, or lobate”), colors (“purple, pink, white, golden yellow, orange, or dark smoke-grey to dark brown”), and polyp armature (polyp sclerites ranging from dense to very sparse or absent). We consider it likely that multiple species have been lumped within this broad definition of this taxon. Here we re-describe newly collected material that matches the original description of
Alcyonium purpureum
Hickson
(=
Alcyonium fallax
Lüttschwager
) and Thomson’s (1910) later more detailed description of that species. Some of our material was collected from a site very close to the
type
locality in Mossel Bay.
T. fallax
n. comb.
forms encrusting to lobate colonies in which the polyps arise from a membranous base and are fused together along their lengths to form a more-or-less homogeneous mass (
Fig. 13b, c
). The polyps are prominent, and remain oriented vertically with their oral surfaces facing upwards, even when retracted. There is little colony coenenchyme between neighboring polyps, with the result that in those polyps that are located on the periphery of the colony the entire length of the polyp body remains visible and distinguishable from its neighbors. When fully retracted the polyps remain visible as coenenchymal mounds. Colonies range from encrusting, a few mm thick, to erect forms>
3 cm
tall with multiple lobes. They often grow attached to other organisms such as worm tubes or bivalve shells.
The polyp sclerites are robust spindles and slightly clubbed forms,
0.16–0.25 mm
long, with complex tubercles (
Fig. 15a
), and torch-like clubs,
0.13–0.22 mm
long, with asymmetrical heads of smooth, spinose processes (
Fig. 15b
). They are arranged in eight longitudinal tracts in the base of the polyp and extend distally to form points at the bases of the tentacles. A collaret of transverse sclerites is lacking. The tentacles have smooth, flat, antler-like rods,
0.12–0.18 mm
long (
Fig. 15c
). In the surface of the polyparium and base of the colony there are radiates,
0.06–0.11 mm
long, and tuberculate spheroids,
0.08–0.13 mm
long (
Fig. 15d
), in addition to the same
types
of spindles and clubs found in the polyps. As one moves from the base of a polyp to the base of the colony the proportion of sclerite
types
shifts gradually from predominantly spindles and clubs to predominantly radiates and spheroids, but there is no sharp demarcation in sclerite form between different anatomical regions. The colony interior contains mostly spheres and radiates of the same sizes and shapes as those found in the surface of the base (
Fig. 16
).
Color
. In life, vivid purple, yellow, pink, or white with purple or yellow highlights (
Fig.
5g
, h
). All colors turn brown to cream in EtOH. Sclerites colorless.
Remarks
. Hickson (1904) first described
Alcyonium purpureum
non Lamarck, a bright purple colony collected from the jetty at Mossel Bay. Thomson (1910) subsequently identified this same species in his material. Thomson’s description and illustration of
A. purpureum
Hickson
best matches the specimens described here: colonies consisting of a number of lobes arising from an encrusting membrane; sclerite forms are mostly clubs, spindles, tuberculate spheres and "double spheres", similar in all parts of the colony; spindles arranged in eight parallel bands and irregularly
en chevron
in the polyps; some radiates (“double clubs”) in the colony base; color in life due to a soluble purple pigment. From this description we conclude that our material corresponds to Thomson’s
A. purpureum
Hickson. Lüttschwager (1922)
recognized that the name
A. purpureum
used by Hickson was preoccupied by a species from
Australia
(
A. purpureum
Linnaeus
), and re-named the South African species
Alcyonium fallax
nom. nov.
In the same paper in which he identified purple, lobate colonies as
A. purpureum
Hickson, Thomson (1910)
described
Alcyonium fauri
, a brown, encrusting colony that lacks sclerites in the polyps and colony interior, and has only “double wheels” in the colony surface. From his illustrations these sclerites appear to be compact radiates or spheroids with sparse ornamentation and a median waist. Based on examination of material collected by Carlgren (and apparently not the material of Thomson), Broch (1939) concluded that there was wide variation in the degree of polyp armature and presence of interior sclerites among specimens, and consequently synonymized
A. fauri
with
A. fallax
, the former name taking precedence. Williams (1992a) accepted Broch’s conclusion that
A. fauri
and
A. purpureum
Hickson
(=
A. fallax
Lüttschwager
) are synonyms, but he also does not appear to have examined the material of Thomson. Thomson's original material was also unavailable to us for examination, but based on his illustrations and detailed descriptions, we disagree that these two forms are synonymous, and retain the species name
fallax
for material that fits the description given above. Thomson’s (1910) description of
A. fauri
does not closely match any species recorded subsequently from
South Africa
with the possible exception of
Porphyrophyton distinctum
n. comb.
(see remarks above for that species).
Although Williams (1992a) illustrated the range of variation in polyp armature and sclerite form he observed among three colonies he examined, he did not indicate which specimens were illustrated or which sclerite variants came from which colony. The absence of such information makes it impossible to determine if any of the specimens he included within
A. fauri
sensu lato
match those we recognize here as different species. The colony forms he illustrates in
Figs. 1B
,
13B, and 13E
, and the polyp armature depicted in
Fig. 14A
most closely match
T. fallax
n. comb.