Trevathana isfae Achituv

Achituv, Yair & Langzam, Yaakov, 2009, Two new species of Trevathana (Crustacea, Cirripedia, Balanomorpha, Pyrgomatidae) from the Western Indian Ocean and French Polynesia, Zootaxa 2116, pp. 46-52 : 49-50

Trevathana isfae Achituv sp. nov.

Figure 3

Host coral Favia stelligera

Material examined: Barnacle removed from a colony of Favia stelligera , MNHN-scle20405, collected in 1906 by L. G. Seurat, locality marked on label Ile Gambier and Tuamotus, coral identified by Gilbert Ranson in 1957. Holotype and paratypes deposited in the Muséum national d' Histoire Naturelle, Paris.

Holotype: MNHN-Ci3029 Ile Gambier and Tuamotus.

Paratypes: MNHN-Ci3030 Ile Gambier and Tuamotus.

Diagnosis. Trevathana with pale pink, nearly rounded shell; about 25 radial ribs with up to five rough projections per rib. Width of scutum more than half its length, tergal tooth about half of scutal margin width, adductor ridge prominent, projecting over basal margin. Tergum nearly quadrangular, spur short and broad, long axis of internal tooth of tergum parallel to long axis of spur, broadening at basal margin.

Description. Shell pale pink, fused, slightly conic, nearly round, maximum rostro-carinal diameter 4 mm, ratio of rostro-carinal diameter to lateral diameter ratio nearly 1:1 ( Fig. 3 A). Surface with radiating ribs carrying rows of rough projections, maximum number of primary and secondary ribs 25. Shell tubiferous, number of radiating tubes equal to number of ribs. Inner side of shell highly concave, sheath pale pink, covering more than half of inner side of shell, concentric growth ridges on sheath ( Fig. 3 B).

Orifice elliptical, located in middle of shell, rostro-carinal diameter about 1/3 of rostro-carinal diameter ( Fig. 3 A), length-to-width ratio 2:1. Basis white, tapering.

Scutum and tergum white, separated.

Scutum ( Fig. 3 C, D) transversely elongated, convex, occludent margin almost twice as long as tergal margin. Outer surface with growth ridges, median closed furrow parallel to occludent margin. Tergal margin at about 45o to occludent margin. Angle between tergal and basal margin obtuse. Tooth projecting at tergal margin interlocking with tergum ( Fig. 3 E, F), pointing inward, located closer to occludent margin than basal margin. Width of tergal tooth about one third length of tergal margin. Adductor pits deep, lateral depressor shallow, hardly distinct, adductor ridge very prominent, projecting beyond basal margin.

Tergum ( Fig. 3 E) quadrangular, growth ridges on outer surface, spur distinct, shallow furrow on surface of spur. Longitudinal shallow furrow extending from middle of scutal margin to carino-basal angle. Depression accommodating tergal tooth on inner side on scutal margin, growth lines inside depression, small notch in middle of depression. Elongated, inwardly projecting tooth located on spur, long axis of tooth parallel to long axis of spur, widening toward end of spur.

Etymology: The specific name designates the Israel Scientific Foundation (ISF), in recognition of the support of this project.

Figures

FIGURE 3. SEM micrographs of Trevathana isfae attached to Favia stelligera from Ile Gambier and Tuamotus. (A) Shell outer view; (B) shell inner view; (C) scutum outer view (D) scutum inner view; (E) tergum inner and outer view; (F) scutum and tergum interlocked, inner view, showing position of internal tooth.