New and little-known species of Didemnidae (Ascidiacea, Tunicata) from Australia (Part 3)
Author
Kott, Patricia
text
Journal of Natural History
2005
2005-06-30
39
26
2409
2479
http://dx.doi.org/10.1080/00222930500087077
journal article
10.1080/00222930500087077
1464-5262
5215680
Leptoclinides decoratus
Kott, 2004b
(
Figures 14A
,
18A
)
Leptoclinides decoratus
Kott 2004b
, p 2469
and synonymy.
Distribution
Previously recorded (see
Kott 2004b
):
South Australia
(
Kangaroo I.
). New records:
South Australia
(
Kangaroo I.
,
SAM
E3257
)
.
Description
The newly recorded colony is a tough, gelatinous slab. Spicules crowded into white spots, and aggregations of black pigment particles crowded into similar-sized black spots are evenly spaced in the surface test. A sparse layer of spicules lines the common cloacal cavity but both spicules and pigment are not in the lower half of the colony, which is separated from the upper zooid-bearing half by vast posterior abdominal common cloacal cavities. Large common cloacal apertures with white spicule-filled rims are terminal on elevated lobes, including short vertical cylinders, produced from the upper surface of the colony. Each of these common cloacal apertures opens from a spacious cavity that connects with the posterior abdominal spaces. Spicules are stellate, to
0.06 mm
diameter with seven to nine short rays in optical transverse section, the rays with sharp chisel-shaped or pointed tips.
Remarks
Although the lobes on the surface of the colony often are cylindrical as in some species of the genus
Atriolum
, the present species does not have the long atrial siphon opening directly into a central cavity as in the latter genus. The species appears to be a southern Australian one, at present known only from Kangaroo I., characterized by its relatively small spicules with few rays which have chisel-shaped and conical tips. The spicules are gathered into small clumps in the surface layer of test where they are mixed with equal-sized clumps of black pigment. Spicules are also in a sparse layer lining the large common cloacal spaces. In life, the colonies look the same as they do in preservative and the
in situ
photographs, and the newly recorded colony and
type
material are similar. The appearance of these colonies is distinctive.
Leptoclinides compactus
has bulky colonies with rounded lobes with terminal common cloacal apertures, similar spicules (but with more rays) and although the spicules have a similar distribution as in the present species, they form a continuous layer beneath the superficial bladder cell layer rather than being gathered into small clumps.