Pharyngodictyon sp.

Monniot, Francoise, 2021, New records of deep-sea ascidians (Tunicata, Ascidiacea) from the New Caledonia region, Zootaxa 4996 (3), pp. 443-468 : 446-447

Pharyngodictyon sp.

Figure 3

Stations: Kanadeep CP 5062; CP 5095. Seven specimens. In spite of seven specimens collected it is not possible to ascertain a species name. Each colony is comprised of a triangular anterior part thinning progressively to a narrow cylindrical peduncle ( Fig. 3 ). The “head” is damaged in all specimens, soft with encrusted sand, 5 to 17 mm wide. The peduncle is hardened with sediment, cylindrical, 2 mm in diameter, often broken and up to 15 cm long. The zooids are in poor condition the thorax for most of them is absent. No siphonal apertures could be seen. In one zooid 4 transverse branchial bars can be seen. The abdomens lie vertically into the “head” prolonged by a very long post-abdomen inside the peduncle; their structure cannot be detailed. Some embryos are present in the tunic.

The specimens described above can be related but not assigned to P. elongatum Millar, 1992 from New Zealand. Millar’ species is similar in shape to the Kanadeep specimens and has four branchial bars.

Three Pharyngodictyon species were described from the New Caledonian area ( Monniot & Monniot 1991). Pharyngodictyon cauliflos Monniot C. & Monniot F., 1991 differs by large colonies divided into several branches. Pharyngodictyon bisinus Monniot C. & Monniot F., 1991 has a single head on a long peduncle, the thorax short with only two branchial transverse bars. Pharyngodictyon magnifili Monniot C. & Monniot F., 1991 , also with a colony in a single head, has numerous branchial bars and gonads placed far back in the postabdomen.

Pharyngodictyon reductum Sluiter, 1906 colonies are not pedunculate and the branchial bars carry papillae; this species likely belongs to a different genus.

The geographic distribution of the genus Pharyngodictyon is restricted to the South Western Pacific Ocean.

Figures

FIGURE 3. Pharyngodictyon sp., scale bar = 1cm.