New Australian Hexactinellida (Porifera) with a revision of Euplectella aspergillum *
Author
Tabachnick, Konstantin R.
Author
Menschenina, Dorte Janussen And Larisa L.
text
Zootaxa
2008
2008-09-03
1866
1
7
68
https://biotaxa.org/Zootaxa/article/view/zootaxa.1866.1.3
journal article
10.11646/zootaxa.1866.1.3
11755334
5133305
Farrea occa ouwensi
Ijima, 1927
(
Fig. 15
,
16
;
Tab. 14
)
Material
.
Types
:
ZMA
POR; POR 5101
–
RV
Siboga
, sta 119.
ZMA
POR (
two specimens
)
–
RV
Siboga
, sta 122.
ZMA
POR; POR 3427 –
RV
Siboga
, sta 124.
ZMA
POR–
RV
Siboga
, sta 226.
ZMA
POR 5098
–
RV
Siboga
, sta 252.
FIGURE 15.
Farrea occa ouwensi
Ijima, 1927
, spicules. A, dermal or atrial pentactin. B, anchorate clavule. C; FJ, pileate clavule. D, discohexaster. E, oxyhexaster. KO, outer ends of microsclers: K, onychoidal; LN, discoidal; O, oxyoidal. AC, MNHN (fr875). FO, types: FL, ZMA POR?, sta. 124; MO, ZMA POR?, sta. 119.
New specimens
:
MNHN
(fr875) (
two specimens
)—
Cidaris I
,
RV
Franklin
, sta. 15
3, 17
o
45.49’
S 148
o
37.52’
E, depth
945 m
.
Description.
Body: Both new specimens are small and tubular (probably juveniles). The bigger one is a
26 mm
long tube,
3.5 mm
in diameter in the lower part and
5 mm
in diameter in the upper part, with basidictyonal remnants about
5 mm
in diameter. The small specimen is
15 mm
long,
2.5 mm
in diameter in the lower part and
5 mm
in diameter in the upper part.
Framework: Dictyonal skeleton; typical farreoid skeleton, which consists 2–3 dictional layers. Skeletal beams are smooth or rarely rough
0.04–0.1 mm
in diameter, distances between the spicules’ centers are
0.2– 0.5 mm
, the free meshes are rectangular or rarely triangular,
0.1–0.4 mm
. The free rays, which protrude inside and outside the body wall, are short, 0.08–0.1/
0.02 mm
, usually rough with rounded outer ends. Some small hexactins are fixed to the dictyonal skeleton by one of their rays; these hexactins have rays of 0.01–0.03/
0.002
–0.003
mm
. In one of the
type
specimens,
ZMA
POR 5098
, the beams are spined
.
Loose spicules: The variability of the loose spicules may be observed in
Tab 14
. It is worth noting that pentactins with spines outwardly directed seems to predominate among dermal pentactins, while the pentactins with rough rays are usually atrial spicules. The form of the heads of pileate clavules varies in the speciemens of the
type
series.
Microscleres: The microscleres are discohexasters, oxyhexasters and rarely onychohexasters and their hemihexasterouse forms.
Ijima (1927)
described two the latter
types
as tylohexasters. Oxyhexasters were not found in
one type
species from sta. 122.
Remarks.
The subspecies looks to be very polymorphic even in the
type
series. The original description of
Ijima (1927)
is not satisfactory and we supplement it here by new data given above, the spicule measures are defined more precisely in
Tab. 14
. The new material perfectly goes within the
type
series variation.