Leptoclinides lissus Hastings, 1931

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 : 2422

Leptoclinides lissus Hastings, 1931

( Figures 1C , 18D ) Leptoclinides lissus Hastings 1931, p 93 and synonymy.

Distribution

Previously recorded (see Kott 2001): Queensland (Low Is). New records: Northern Territory (Bynoe Harbour, QM G308709 ) .

Description

The newly recorded colony is a firm, irregular sheet with grey patches in the surface where black pigment particles are mixed with the crowded white spicules in the thin surface layer of test. The surface of the colony is hard and a superficial spicule-free layer of bladder cells is not present. Spicules are present throughout, but are most crowded in the surface and on the base of the colony. They are stellate, to 0.56 mm diameter, with 9–11 conical or chisel-shaped ray tips. Primary common cloacal canals extend almost the whole length of the zooids and penetrate around the relatively large thoraces of individual zooids. The vas deferens coils seven times around the four or five testis follicles. Many embryos, including tailed larvae, are in the basal half of the colony. The larval trunk, 0.64 mm long, has three pairs of ectodermal ampullae, three antero-median adhesive organs and a short external horizontal ectodermal ampulla on the left side. The tail is wound three-quarters of the way around the trunk.

Remarks

Other than the holotype, the newly recorded specimen is the only one known and the larva is described for the first time. The species differs from most in the genus in its extensive thoracic common cloacal systems and its crowded spicules. The shape of the spicules and the number of rays is similar to L. aciculus Kott, 2001 , L. constellatus Kott, 2001 and L. placidus Kott, 2001 (which all have larger spicules), L. compactus Kott, 2001 (which has a particularly extensive three-dimensional cloacal system and spicules confined to thin layers in surface and base and around the common cloacal cavity), and L. rigidus Kott, 2001 (which has a superficial layer of bladder cells).

Figures

Figure 1. (A, B) Leptoclinides frustus sp. nov. (SAM E3255, holotype): (A) vertical section through a common cloacal canal (semi-diagrammatic); (B) zooid. (C) Leptoclinides lissus (QM G308709): larva. Scale bars: 0.5 mm (A); 0.1 mm (B, C).

Figure 18. In situ images of: (A) Leptoclinides decoratus (SAM E3257); (B) Leptoclinides frustus (SAM E3255, holotype); (C) Leptoclinides imperfectus (SAM E3243); (D) Leptoclinides lissus QM G308709); (E) Leptoclinides rigidus (QM G308708); (F) Leptoclinides seminudus (SAM E3264); (G) Polysyncraton cuculliferum (QM G308715); (H) Polysyncraton galaxum (SAM E3261).