Leptoclinides multilobatus Kott, 1954

Kott, Patricia, 2008, Ascidiacea (Tunicata) from deep waters of the continental shelf of Western Australia, Journal of Natural History 42 (15 - 16), pp. 1103-1217 : 1170

Leptoclinides multilobatus Kott, 1954

( Figure 12E )

Leptoclinides multilobatus Kott, 1954, p. 166 ; 2001, p. 74 and synonymy

Distribution

Previously recorded (see Kott 2001): South Australia (Pearson I., Gulf St. Vincent, Flinders I.); Tasmania (Maria I.). New record: Western Australia CSIRO SS10/05 (Bald I., Stn 35, 157 m, 24.11.05, QM G328128).

The new record extends the known range of this species across the southern coast of the continent.

Description

The specimen is a smooth surfaced, rather elongate gelatinous mass divided into two rounded lobes with terminal common cloacal apertures. Internally the test is transparent and soft and the zooids are in a thin layer at the surface. The minute calcareous spicules are confined to a single layer in the superficial layer of test. Spicules are not more than 0.02 mm diameter. They have up to 17 pointed fusiform, rod-like or conical rays in optical transverse section. A shallow, horizontal posterior abdominal common cloacal cavity separates the surface zooid-bearing test from the internal core of the colony where the test is a clear, soft jelly-like consistency. The branchial siphon is conspicuous with a conspicuous sphincter muscle. The atrial siphon is also conspicuous and posteriorly orientated, opening into the posterior abdominal common cloacal cavity. Up to 16 stigmata are in a half-row in the branchial sac. The gut forms a double loop. Gonads lie against the dorsal side of the gut loop (posterior to the zooid) and the vas deferens makes an S-bend over the surface of a cluster of numerous, more or less spherical, male follicles before turning anteriorly toward the atrial cavity. A large yellow egg protrudes from the posterior end of the zooid.

Remarks

The soft colonies, spicules, their distribution, zooids and gonads are characteristic of this widely ranging species. The velum which forms a false siphon at the base of the branchial siphon was not detected in this specimen. The diversity of the particularly small spicules is characteristic, as is their distribution, the shape and consistency of the colony and the central test core in the centre of each lobe.

The most closely related species in this species group, the tropical L. dubius ( Sluiter, 1909) , is not known from the southern coast of the continent. It is distinguished from the present species by its larger spicules and zooids.

Figures

Figure 12. Atriolum tubiporum (QM G328004): A, colony. Leptoclinides fungiformis: B1,2 (QM G328106, QM G328105), colonies; C (QM G328105), zooid; D (QM G328105); larva Leptoclinides multilobatus (QM G328128): E, abdomen showing gut loop and gonads. Scales: A, 1.0 cm; B, 2.0 cm; C, 0.1 mm; D, E, 0.2 mm.