Taxonomic review of Hadromerida (Porifera, Demospongiae) from British Columbia, Canada, and adjacent waters, with the description of nine new species
Author
Austin, William C.
Author
Ott, Bruce S.
Author
Reiswig, Henry M.
Author
Romagosa, Paula
Author
G, Neil
text
Zootaxa
2014
3823
1
1
84
journal article
36829
10.11646/zootaxa.3823.1.1
cdc3964e-ebf3-491e-b10c-9ad6592cb0f0
1175-5326
286373
0D42FA17-3B11-4DBB-9E48-D7D505F9CE29
Polymastia piscesae
n. sp.
Fig. 10
A–I
Etymology.
The species was named after
PISCES
IV
, the submersible used to collect this species and many others in BC deep waters.
Material examined.
Holotype
:
RBCM
009-00054-001, KML sta. 186/83, Observatory Inlet,
BC
, (
55° 16.9′N
,
129° 48.4′W
),
213 m
depth, coll. W.C. Austin,
1 specimen
.
Description.
Macroscopic features.
Fig. 10
A. Sponge cushion-shaped; sampled fragment about
6 cm
in greatest diameter by
1.2 cm
thick, smooth in some regions, microhispid in others (spicules protrude
0.3–0.5 mm
). Fistulae
1–1.8 cm
high by
2.5–4 mm
wide at base. Fistulae densely distributed across sponge surface (2 per mm2), conical or flattened with pointed apices. Three fistulae in the sample contain an osculum; the others are thinner and pointed with no indication of an apical opening. A cross section
1 mm
back of the apex revealed 10 equal-sized 100 µm diameter canals. Colour in alcohol grey; fistulae cream colour.
Microscopic features,
Fig. 10
B. Ectosome of main body cortical,
0.8 to 1 mm
thick, with palisade of small tylostyles, apices outward, piercing surface. Underlain by intermediate tylostyles, mostly tangential to surface. Small tylostyles abundant.
Fistulae canals lined by tangential layer of intermediate tylostyles. Intermediate-size tylostyles at surface, forming discontinuous superficial palisade and extending up to 100 µm beyond the surface. Principal multispicular tracts radiating from choanosome into base of fistulae, but not penetrating fistular surface.
Choanosome composed of radiating multi-spicule tracts up to
5 mm
thick, composed of principle styles or occasional subtylotes. Intermediate and small tylostyles scattered throughout choanosome. Principal spicules extending into ectosome, may or may not penetrate outer surface.
Spicules.
Principal styles to subtylostyles straight to slightly curved (I). Intermediate tylostyles to subtylostyles (II), slightly curved, rarely fusiform; small tylostyles.
Holotype
RBCM 009-00054-001
Remarks.
P. piscesae
n. sp.
is compared with other
Polymastia
species known from the N. Pacific in Table 3,
Table 4
and
Fig. 6
.
Polymastia kurilensis
has only two
types
of tylostyles with the smaller forming an ectosomal palisade in contrast to three
types
of tylostyles and the lack of spines in
P. piscesae
n. sp.
Polymastia pachymastia
has stouter fistulae than
P. piscesae
n. sp.
, a different spicule compliment, and occurs in intertidal to shallow depths.
Polymastia pacifica
has cylindrical fistulae which are much smaller than the cone-shaped fistulae in
P. piscesae
n. sp.
Polymastia granulosa
Brøndsted, 1924
has principal subtylostyles which are approximately 40% of the length of those in
P. piscesae
n. sp.
Polymastia laganoides
lacks a palisade of small tylostyles, and has fistulae which are low warty protuberances; its megascleres are exclusively tylostyles rather than styles to subtylostyles.
Polymastia affinis
Thiele, 1898
has very large (to
6 mm
) echinating styles, and fistulae are small and papillose, which is again different from
P. piscesae
n. sp.
Both
Polymastia affinis
Thiele, 1898
and
Polymastia fluegeli
Lehnert, Stone & Heimler, 2005
have shorter and fatter fistulae than those in
P. piscesae
n. sp.
Spicule Type |
Fig. |
Length |
Width |
Styles to subtylostyles I |
10D, E |
860–(1268)–1600 |
15–(20)–25 |
Subtylostyles to tylostyles II |
10F–G |
230–(384)–580 |
9–(10)–13 |
Subtylostyles to tylostyles III |
10H, I |
88–(164)–220 |
3–(7)–10 |
Differences in size and form between two
types
of fistulae in
P. piscesae
suggest they have separate inhalant and exhalent functions. This is confirmed by the presence of 10 equal-sized canals with no larger central canal in the thinner pointed fistulae indicating that they are solely inhalant.
FIGURE 10.
Polymastia piscesae
n. sp.
A, large living specimen, scale bar approx. 1 cm; B, cross section showing fibre tracts extending to ectosome, scale bar 3 mm; C, palisade of small tylostyles in ectosome, scale bar 300 Μm; D, style I, scale bar 500 Μm; E, head of style I, scale bar 50 µm; F, subtylostyle II, scale bar 100 µm; G, tylostyle II, scale bar 50 µm; H, fusiform tylostyle III, scale bar 200 Μm; I, head of tylostyle III, scale bar 10 µm.
In terms of the abundance, shape (elongate pointed inflated or flattened cones) and size (
0.8 cm
diam,
1.7 cm
) of the fistulae, our specimen externally bears a strong resemblance to the smaller (
5 cm
x
6
cm) specimen of “
Polymastia robusta toporoki
”
figured in
Koltun (1966;
Fig. 7
)
.
Koltun (1966)
included
Polymastia euplectella
Resvoj 1927
as a synonym of
Polymastia robusta
.
However,
Plotkin (2004)
considered
Polymastia euplectella
to be a valid species and he reported several differences from
Polymastia robusta
as characterized by
Boury-Esnault (1987)
. These characters include: fistula length—
P. euplectella
(
2–5 cm
),
P. ro bu s t a
(
0.2–0.8 cm
),
P. piscesae
n. sp.
(
1–1.7 cm
); exhalent and inhalant fistula—
P. euplectella
(present),
P. ro bu s t a
(absent),
P. piscesae
n. sp.
(present); number of spicule types—
P. euplectella
(3),
P. robusta
(2),
P. piscesae
n. sp.
(3).
The fistulae of
P. euplectella
are considerably larger than in our species.
Polymastia euplectella
has also not been recorded from the Pacific.
Polymastia robusta
has only 2 spicule
types
, lacking an intermediate tylostyle size class. It also does not have separate exhalent and inhalant fistulae as in
P. piscesae
.
Conclusions.
We conclude that our specimen represents a new species based on differences in form and differential function of the fistulae from all North Pacific species.
Polymastia euplectella
has larger fistulae and occurs only in the Atlantic.
Bathymetric range.
213 m
depth.
Geographic distribution.
Known from the
type
locality only, Observatory Inlet, BC.