A revision of Trimuricea Gordon, 1926 (Cnidaria: Octocorallia: Plexauridae) with the description of six new species
Author
Samimi-Namin, Kaveh
Author
Van Ofwegen, Leen P.
text
Zootaxa
2016
4105
1
1
44
journal article
10.11646/zootaxa.4105.1.1
cf0a97f6-504a-4de4-a51c-a11c5c80bca3
1175-5326
271230
621E2759-DDBF-4ADC-A1EC-3CA8F581C336
Trimuricea caledonica
Grasshoff, 1999
(
Figs. 4
c, 7–8)
Trimuricea caledonica
Grasshoff, 1999
: 48
, figs. 81–83;
Grasshoff & Bargibant 2001
: 183
; Fabricius & Alderslade 2001: 196.
Material:
SMF
6752, part of
holotype
,
New Caledonia
, W lagon, Off Nouméa, Ilot Canard, Stn 136, 23 m;
SMF
6753, part of
paratype
,
New Caledonia
, W GRext, Passe de Koumac,
35 m
;
SMF
6754,
paratype
, South Pacific Ocean,
New Caledonia
Description (modified after
Grasshoff 1999
).
The complete
holotype
was a large fan
50 cm
high, with many anastomoses; only a portion is shown in
Fig. 4
c. The polyps are situated all around the branches, densely crowded, leaving little free coenenchyme in between. Calyces are dome shaped and up to
0.30 mm
high and
1 mm
wide.
The points have 2–4 triradiates (
Fig. 7
a) and 1–2 curved, hockeystick or boot-shaped sclerites, or spindles (
Fig. 7
b),
0.10–0.20 mm
long. The upper ray of the triradiates and the upper part of the spindles is smooth for up to
0.15 mm
, rather wide and blunt ended. The collaret spindles are
0.20–0.30 mm
long (
Fig. 7
c); the middle part is less tuberculate than both ends. These polyp sclerites have very few tubercles. A few tentacle scales are present, up to
0.09 mm
long (
Fig. 7
d).
The calyces have thornscales,
0.20–0.30 mm
long, with a short, smooth, blunt thorn up to
0.12 mm
long (
Fig. 8
a).
The coenenchyme has spindles and crosses,
0.15–0.40 mm
long, with simple tubercles (
Fig. 8
b). Some of these spindles have a side branch which maybe thorn-like. Furthermore, small, irregular shaped sclerites are present,
0.10–0.16 mm
long (
Fig. 8
c).
Colour.
The live colony was red (for live colony photo see
Grasshoff & Bargibant 2001
). When dry it is dark brown, but it is yellowish-grey when preserved in fluid. No information about the colour of polyps is available.
Remarks.
This species differs from all other
Trimuricea
species by having small, irregular shaped sclerites in the coenenchyme (
Fig. 8
c), which were not reported by Grasshoff. Noteworthy, we noticed irregular radiates, and derivatives of radiates, similar to those in
Fig. 8
c, that occur in the basal parts of colonies, and in branches with relatively solid axis, in other
Trimuricea
species. Therefore, we do not exclude the possibility that the piece of the colony we received from SMF might have been cut from the basal parts or older side branches of the colony, not from the top of the colony. This might also explains why Grasshoff did not mention these
types
of sclerites in the original description of
T. caledonica
. On the other hand it is possible that these small sclerites were missed by Grasshoff’s technician making the drawings.
If we assume that the irregular radiates (
Fig. 8
c) are not from the top of the colony, then
T
.
caledonica
mostly resembles
T. inermis
, and
T. omanensis
n. sp.
, however, it differs in having many thornscales and triradiates in the polyp with very smooth, blunt, thorn and upper ray. In addition, these thornscales are slightly larger and have wider and more tuberculate base than those in
T. omanensis
n. sp.
and
T. inermis
.
The specimens described by Grasshoff were later broken in parts and stored in both MNHN and SMF. There is an additional fragment of
paratype
stored in SMF (SMF 6754), which is not mentioned by
Grasshoff (1999: 48)
, and it could be a fragment of SMF 6753. Grasshoff did not mention the number of spindles in the collaret.