Two new genera in the family Podospongiidae (Demospongiae: Poecilosclerida) with eight new Western Pacific species
Author
Sim-Smith, Carina
Author
Kelly, Michelle
text
Zootaxa
2011
2976
32
54
journal article
10.5281/zenodo.200731
beebae8a-07f2-46d4-97c6-176978b0d8ae
1175-5326
200731
Neopodospongia exilis
gen. nov.
sp. nov.
(
Fig. 1
D, 4N–R)
Material examined.
Holotype
―
NIWA
52579: RV
Kaharoa
Stn KAH0204/9, Cavalli Seamounts,
34.111° S
,
174.138° E
,
562–600 m
,
14 Apr 2002
.
Type
location.
Cavalli Seamounts, off N
New Zealand
.
Distribution.
Known only from
type
location.
Description.
Thinly encrusting sponge,
10 mm
long
x
10
mm wide
x
1
mm thick, attached to a piece of coral rubble (
Fig. 1
D). Surface is smooth, granular, easily detached from underlying choanosome, slightly wrinkled. Oscules are not visible but tiny pores, 25–100 μm in diameter, can be seen under magnification. Texture of ectosome is tough and translucent like cellophane. Choanosome is soft, fragile. Colour in ethanol opaque white, interior creamy yellow.
Skeleton.
Ectosome a thin collagenous layer of aciculospinorhabds that are densely packed in a vertical arrangement with the apical spine pointing away from the surface. Choanosomal skeleton composed of dense radiating brushes of megascleres that emerge from the base of the sponge radiating towards the ectosome. The orientation of the brushes in the
holotype
is messy and generally oblique to the surface as a result of desiccation. Aciculospinorhabd microscleres are also scattered throughout the choanosome.
Megascleres
(
Fig. 4
N, Table 2)―
Strongyloxeas
with central thickening and polytylote swellings, faintly subtylostylote, occasionally curved; 596 (483–680)
x 8
(7–9) μm.
Microscleres
(
Fig. 4
O–R, Table 2)―
Aciculospinorhabds I
(
Fig. 4
O & R); large, stout, compact. Basal whorl typically with four stout directly opposed spines extending obliquely away from the shaft towards the base of the spicule, the median whorl is located slightly off centre along the shaft and has eight stout spines arranged in diverging pairs. Apical whorl composed of up to eight spines in diverging pairs, each with bifurcate tips, one branch frequently being longer than the other, extending obliquely away from the shaft towards the apical spine. Apex expanded and extended into a spire of four directly opposed and merged blades with serrated edges; 70 (56–76)
x 40
(34–46) μm.
Aciculospinorhabds II
(
Fig. 4
P–Q, Table 2); small, slender, heavily spined. Basal and apical whorls are very similar in the possession of four long irregularly disposed spines that emerge obliquely from both base and apex. Median whorl is relatively regular with numerous spines arranged in diverging pairs. The apex may consist of a single long spine (
Fig. 4
P), or several long spines (
Fig. 4
Q); 45 (25–59)
x 21
(13–27) μm. The protoaciculospinorhabd is sigmoidal in shape (
Fig. 4
R).
Substrate, depth range, and ecology.
Attached to dead coral rubble between 562 and
600 m
depth.
Etymology.
Named for the morphology of the sponge, being small, thin, and meagre in proportions (
exilis
= Latin for meagre).
Remarks.
Neopodospongia exilis
gen. nov.
sp. nov.
differs primarily from the shallow water species
N
.
pagei
gen. nov.
sp. nov.
and
N
.
bergquistae
gen. nov.
sp. nov.
in having much larger megascleres and microscleres. While the aciculospinorhabds of the two latter species are more similar to each other in terms of structure and ornamentation, those of
N
.
exilis
gen. nov.
sp. nov.
are quite different, with strongly sculpted and spired forms compared to the other species (
Fig 4
).
Neopodospongia exilis
gen. nov.
sp. nov.
also has two quite discrete forms of aciculospinorhabds as in
N
.
pagei
gen. nov.
sp. nov.
Neopodospongia exilis
gen. nov.
sp. nov.
is rare; the
holotype
was the only specimen collected from
New Zealand
waters, despite numerous recent voyages. It is a deep-water species, having been collected between 500 and
600 m
whereas the other two
Neopodospongia
gen. nov.
species are from comparatively shallow waters.
Neopodospongia exilis
gen. nov.
is similar to an informally named shallow water Chilean species,
Sigmosceptrella tupecomareni
, illustrated in
Willenz
et al
. (2009)
. The key difference between this species and the
New Zealand
species is in the ornamentation of the larger aciculorhabd of
S
.
tupecomareni
, in which the apical whorl is merged with the apex forming a large bushy structure, unlike in
N
.
exilis
in which the apical whorl is quite separate (
Fig. 4
O). The smaller aciculospinorhabds of
S
.
tupecomareni
have much shorter spines that are themselves diversely spined, unlike those of
N
.
exilis
; which have long smooth spines.