Platylepas hexastylos ( Fabricius, 1798 )

Chan, Benny K. K. & Hayashi, Ryota, 2012, Epibiotic barnacles (Crustacea: Cirripedia: Thoracica) collected by the Kumejima 2009 Expedition, with descriptions of two new species *, Zootaxa 3367, pp. 21-48 : 42

publication ID	https://doi.org/ 10.5281/zenodo.281652
DOI	https://doi.org/10.5281/zenodo.6174493
persistent identifier	https://treatment.plazi.org/id/03FC87D4-FFCA-8A0F-C7D7-21A75629F898
treatment provided by	Plazi
scientific name	Platylepas hexastylos ( Fabricius, 1798 )
status

Treatment

Platylepas hexastylos ( Fabricius, 1798)

( Figs. 2 View FIGURE 2 F, 14, 15)

Lepas hexastylos Fabricius, 1798: 35 , pl. 10, figs 1–2. (not seen)

Coronula bissexlobata De Blainville, 1824: 379 , tab 117, fig. 1.

Platylepas bissexlobata .— Darwin 1854: 428, pl. 17, figs. 1a–d. — Weltner 1897: 253. — Gruvel 1905: 276, fig. 300.

Platylepas hexastylos .— Pilsbry 1916: 285, pl. 67, figs. 1–1c. — Broch 1924: 18, fig. 6. — Hiro 1936: 319. — 1937b: 472, fig. 43. — Kolosvàry 1943: 101. — Henry 1954: 444. — Stubbings 1967: 300. — Utinomi 1959: 384. — 1970: 360. — Newman & Ross 1976: 44. — Ren 1980: 188, fig. 2 pl. 1. — Liu & Ren 2007: 312, fig. 138. — Ross & Frick, 2011: 62. — Hayashi 2012: 117: fig. 7.

Material examined. RUMF-ZC-1561, ten specimens (BD 3.08–5.38 mm); collected from a dead sea turtle, Chelonia mydas , in a gill net, Tomari Port, 19 Nov. 2009.

Diagnosis. Shell white; 6 tubiferous plates, externally with horizontal growth ridges, internally with median longitudinal sulcus.

Description. Shell white, conical, low, outer margin of plates serrated, surfaces with horizontal growth ridges ( Fig. 2 View FIGURE 2 F, 14A), plates tubiferous, with median longitudinal sulcus of inner surface visible from basal view ( Fig. 14 View FIGURE 14 A, B), line of median longitudinal sulcus obvious, dividing each plate into two main lobes ( Fig. 14 View FIGURE 14 A); radii narrow. Orifice narrow, oval shaped ( Fig. 2 View FIGURE 2 F). Scutum rectangular, wider than high. Tergum triangular, occludent margin and basal margin forming obtuse angle.

Maxilla sub-triangular, serrulate setae apically ( Fig. 14 View FIGURE 14 C). Maxillule without notch, cutting margin straight, 2 large setae at upper margin followed by 8 smaller, simple setae ( Fig. 14 View FIGURE 14 D). Mandible with 5 main teeth, second, third and fourth bifid, secondary tooth between second and third, and third and fourth; inferior angle pectinated, covered with fine pectinations ( Fig. 14 View FIGURE 14 E, F). Mandibular palp oval; lateral margin covered with long, fine setae; upper margin with short, fine setae ( Fig. 14 View FIGURE 14 G). Labrum notched, 3 large teeth on either side of cutting margin ( Fig 14 View FIGURE 14 H).

Cirrus I with rami unequal, anterior and posterior rami 7- and 10-segmented, respectively, both rami with serrulate setae ( Fig. 15 View FIGURE 15 A, B). Cirrus II with anterior and posterior rami 7-segmented ( Fig. 15 View FIGURE 15 C); both rami with serrulate setae. Cirrus III with anterior and posterior rami 9- and 12-segmented ( Fig. 15 View FIGURE 15 D). Cirri IV to VI long, slender ( Fig. 15 View FIGURE 15 E), intermediate segments of posterior ramus of cirrus IV ( Fig. 15 View FIGURE 15 F) and cirrus VI ( Fig. 15 View FIGURE 15 G) with 3 pairs of long serrulate setae with very fine setules and 1 pair of shorter, simple setae.

Penis long, length about 1.5 times length of cirrus VI; pedicel with small basi-dorsal point ( Fig. 15 View FIGURE 15 H).

Distribution. Cosmopolitan in temperate and tropical waters; attached to the carapace, plastron, head, flipper, legs and soft skin of sea turtles.

Remarks. In Japanese waters, P. h e x a s t y l o s has been recorded on the Loggerhead turtle Caretta caretta ( Linnaeus, 1758) in Niigata ( Utinomi 1970b), Iwate, Fukui, Okinawa, Kagoshima, Hachijojima Island and Chiba ( Hayashi 2012), on the Green turtles Chelonia mydas ( Linnaeus, 1758) in Okinawa, Ogasawara Island, Wakayama and Kanagawa ( Hayashi 2012), on the Black turtle Chelonia mydas agassizii (Bocourt, 1868) in Iwate ( Hayashi et al. 2011), on the Hawksbill turtles Eretmochelys imbricata (Linnaeus, 1766) in Chiba, Fukui and Okinawa ( Hayashi 2012) and on the Leatherhead turtle Dermochelys coriacea (Vandelli, 1761) in Niigata and Ishikawa ( Utinomi 1970b).

Kingdom	Animalia
Phylum	Arthropoda
Class	Maxillopoda
Order	Sessilia
Family	Platylepadidae
Genus	Platylepas