Polysyncraton purou

Kott, Patricia, 2005, New and little-known species of Didemnidae (Ascidiacea, Tunicata) from Australia (Part 3), Journal of Natural History 39 (26), pp. 2409-2479 : 2436

Polysyncraton purou C. and F. Monniot, 1987

( Figure 19D ) Polysyncraton purou C. and F. Monniot 1987, p 49; Kott 2002a, p 33 and synonymy; 2004c, p 40.

Distribution

Previously recorded (see Kott 2001, 2002a, 2004c): Northern Territory (Darwin and Bynoe Harbours); Queensland (Great Barrier Reef); Philippines; French Polynesia. New records: Northern Territory (Bynoe Harbour, QM G308707 G308726.)

Description

Both newly recorded colonies are thick, firm jelly-like and aspiculate. The relatively small zooids with large bifid anterior atrial lips line the deep, circular common cloacal canals that surround the zooid-free stands of solid test. In living specimens some brown pigment is in the surface test over these canals and around the common cloacal apertures at their junctions. In preservative, these canals are made conspicuous by the faecal pellets in them, although small brown pigment particles can be detected in the surface test.

Remarks

Many other species in this and other genera have similar cloacal systems with the zooids lining the circular canals that surround each zooid-free stand of solid test. However, most of these species have spicules throughout the test, or at least in a layer at the surface. The present species sometimes has a layer of spicules at the surface but usually it is patchy and the spicules are smaller than those in P. arvum Kott, 2004c and larger than those of P. dromide Kott, 2001 , the two other tropical species of this genus with zooids along each side of circular common cloacal canals (see Remarks, P. arvum Kott, 2004c ).

Figures

Figure 19. In situ images of: (A) Polysyncraton glaucum (QM G308736); (B) Polysyncraton papyrus (SAM E3253); (C) Polysyncraton pedunculatum (SAM E3272); (D) Polysyncraton purou (QM G308707); (E) Polysyncraton rica (SAM E3245); (F) Didemnum cilicium (SAM E3251, holotype); (G) Didemnum corium (SAM E3249, holotype); (H) Didemnum cygnuus (QM G308716).