Shallow-water Demospongiae (Porifera) from Sodwana Bay, iSimangaliso Wetland Park, South Africa
Author
Samaai, Toufiek
Author
Pillay, Ruwen
Author
Janson, Liesl
text
Zootaxa
2019
2019-04-23
4587
1
1
85
journal article
26978
10.11646/zootaxa.4587.1.1
30b2e4dc-5996-46b6-8be8-7bccdd041563
1175-5326
2651448
CC6CDA5A-E283-49AD-9F31-CE95C123A379
Dragmacidon sanguineum
(
Burton, 1933
)
(
Fig. 18
A–G)
Synonomy
Axinella sanguinea
Burton, 1933
, p 27
,
Fig. 4
Material examined.
SAMC–A24764
(cross-reference TS 841 & Saf 03-Sod 64),
Two Mile
reef,
Sodwana Bay
(
27.5167°S
,
32.6834°E
),
South Africa
, 0
5 November 2003
, collected by
T. Samaai
, depth
20 m
.
SAMC–A24765
(cross-reference TS 890 & Saf 03-Sod 14),
Ramsay
reef,
Sodwana Bay
(
27.4466°S
,
32.7152°E
),
South Africa
, 0
3 November 2003
, collected by
T. Samaai
, depth
18 m
.
Description.
Massive, flabellate sponge, with irregular thick, flattened planar lamellae, with irregular margins, 120 × 90 ×
40 mm
diameter, growing from a common base (
Fig. 18A, B
). Sponge attached to substrate directly, up to
100 mm
diameter or by small basal stalk,
30 mm
long. Surface finely hispid, fleshy and conulose, with fine ridges running vertically down blades. Conules are irregular,
1 cm
high, and linked to form meandering surface ridges. Oscules inside of ridges along axis of blade,
2 mm
in diameter. Texture soft and spongy, very compressible. Colour in life dark brick-red; in preservative, beige.
Skeleton
(
Fig. 18C, D
). Choanosomal skeleton differentiated into axial and extra-axial region. Well-developed spongin enclosed primary fibres; fibres reticulated in the axial region and cored by primary choanosomal styles or oxeas (rare). Primary fibres connected by secondary unenclosed spongin and formed by styles,
30–65 µm
in diameter, containing 3–7 spicules at any point. The mesohyl is augmented with long auxiliary oxeas. The extraaxial skeleton consists of several multispicular tracts (usually 2–3 megascleres) of ectosomal styles cemented by spongin, but not enclosed in sponging, running longitudinally diverging into a plumoreticulation towards the ectosome. The ectosomal skeleton has distinct brushes of ectosomal styles.
Spicules. Megascleres
(
Fig. 18
E–G). Styles, in two size classes: I) sharply pointed, fusiform with evenly rounded base, usually curved centrally, 244 (229–262) × 8 (8) µm, n = 10, II) long, slender and fusiform, 421 (395– 438) × 6 (6) µm, n = 10. Oxeas, in two size classes I) shorter, fairly thick, with one end fusiform and the other end hastate, 242 (222–263) × 8 (8) µm, n = 10, II) long and very slender, fusiform, 262 (254– 273) × 2 (2) µm, n = 10.
Microscleres
. Absent
Substratum, depth range and ecology.
Found on rocky ledges at a depth of
20 m
.
Geographic distribution.
Sodwana Bay, east coast of
South Africa
.
Remarks.
Our specimens agree well with the original published description of
Dragmacidon sanguineum
(
Burton, 1933
)
from Umkomaas,
KwaZulu-Natal
,
South Africa
. Differences concern mainly variations in spicule size. The spicule dimensions recorded for the specimens described here are larger than recorded for the
holotype
(styles
140 µm
; oxea
211 µm
).
Key diagnostic characters.
• Sponge massive and flabellate.
• Long slender styles.
• Blood-red colour.
• No microscleres present.