Doliolum denticulatum Quoy & Gaimard, 1834

Karunarathne, Krishan D. & Croos, M. D. S. T. De, 2021, Pelagic tunicates (Appendicularia and Thaliacea) of Sri Lanka: two first records with an annotated checklist, Zootaxa 5067 (3), pp. 352-376 : 357

Doliolum denticulatum Quoy & Gaimard, 1834

Doliolum denticulatum Quoy & Gaimard 1834: 599 , Pl. 89 Figs. 25–28. Herdman 1888: 44. Smith et al. 1901: 103, Fig. 23. Tokioka 1960: 353. Godeaux 1998: 283, Figs. 17.8b, 17.11d. Van Soest 1998: 236, Table 14.1. Gershwin et al. 2014: 9. Purushothaman et al. 2017. Adam & Ishak 2018: 150, Figs. 2.1, 2.2 .

Material examined. A gonozooid and a nurse ( MDAFWU 2020 /371–372), St.205, January 2020 .

Description. Gonozooid: Body 3 mm long, transparent and barrel-shaped with eight muscle bands. Dextral arched intestine, alimentary canal opens at the front side of M V, anus present at M VI. Branchial septum strongly arched from M II dorsally to M V, then curving and running to M III ventrally. Endostyle is short, from M II to M IV. Neural ganglion at M III 3/4. Testis long and swollen, situated horizontally in front of M III.

Nurse: Barrel-shaped, 2 mm long, with nine muscle bands, without visceral mass, except for a heart. Muscle-bands M II–VIII fused into a continuous sheet. Budding on the dorsoventral projection.

Global distribution. The Atlantic Ocean, Indian Ocean, western Pacific, Australian waters, the Mediterranean Sea and Red Sea ( Van Soest 1998). Type locality: Ile Vanikoro, Pacific.

Figures

FIGURE 2. Firstly reported pelagic tunicates to Sri Lanka in “Waya-jel-Survey” (A–F): a live colony of Pyrostremma spinosum near to the sea surface (A & B), and an illustration of its blastozooid (C); Thalia sibogae solitary zooid in preserved form (D), ventral view of medioventral projections (E), and an illustration of its posterior part (F). a—anus; ap—atrial palp; dmp— dorsal medioventral projection; e—endostyle; es—excurrent/buccal siphon; g—ganglion; is—incurrent/atrial siphon; lp—lateral projection; n—nucleus; o—ovary; pb—pharyngeal basket; pp—posterior projection; sl—stolon; sm—stomach; t—testis; vmp—ventral medioventral projection. Scales: E = 0.5 mm; C, D, F = 1 mm; A & B = 0.4 m. Images A & B by Franco Banfi from off Mirissa, Sri Lanka