Cantellius hoegi, Achituv, Yair, Tsang, Ling Ming & Chan, Benny Kwok Kan, 2009

Achituv, Yair, Tsang, Ling Ming & Chan, Benny Kwok Kan, 2009, A new species of Cantellius and a redescription of C. sextus (Hiro, 1938) (Cirripedia, Balanomorpha Pyrgomatidae) from the elephant skin coral, Pachyseris speciosa (Dana, 1846) (Scleractinia, Agariciidae) from Taiwan, Zootaxa 2022, pp. 15-28 : 17-19

Cantellius hoegi sp. nov.

( Figs 1–3 )

Materials examined. Holotype, ASIZCR 0 0 0 202, Dong-Qing-Wan, Lanyu Island, Taiwan (22°01’, 121°32’), 5–10 m, coll. B.K.K. Chan; paratype, ASIZCR 000203-205, data same as holotype.

Diagnosis. Wall with approximately 20 internal ribs; lengths of scutal basal and tergal margins subequal; tergum with broad spur, external spur furrow shallow, spur length approximately 1/2 length of scutal margin.

Description. Parietes slightly projecting above coral surface, covered by coral skeleton overlying external ribs, number of ribs indistinct ( Fig. 1 A, B). Rostro-carinal diameter to 4 mm; wall of 4 parietes, approximately 20 internal radial ribs radiating from central orifice, some secondary ribs reaching 1/2 way between wall circumference and orifice ( Fig. 1 C); tubes between sheath and parietes largely filled. Orifice oval; 1/5 of rostro-carinal diameter. Sheath pigmented, orange, with concentric growth ridges extending more than 1/2 way down internal surface of parietes ( Fig. 1 C). Carina wider than rostrum. Basis white, solid, thin, shallow cup-shape.

Opercular valves thin, orange-red. Scutum triangular, basal margins slightly longer than tergal margins; externally growth ridges coarse, crossed by fine striae, alternate ridges forming teeth on occuludent margins ( Fig 1 D, F). Tergal portion of scutum inflected. Apical angle approximately 60°, 11–14 rows of round pits at apical angle forming honeycomb-like surface ( Fig. 1 E). Basal margins sinusoidal. Internally adductor ridge not extending beyond basal margin. Pit of lateral depressor muscle small; rostral tooth absent.

Tergum ( Fig. 1 G, I) with blunt spur, spur width approximately 1/2 tergal width, external furrow shallow, open from apex to spur base, angle between spur and basal margin obtuse. Pits similar to those on Scutum, forming honeycomb-like surface at apex ( Fig. 1 H). Sinusoidal, fine growth ridges on tergum surface. Tergal wing height approximately 1/2 tergal length (including spur). Internally small pits for tergal depressor muscle present ( Fig. 1 I).

Trophi: Mandibles with quadridentoid cutting edge ( Fig. 2 A), 2nd and 4th teeth bidentate, first 3 teeth occupying more then 3/4 length of cutting edge ( Fig. 2 C). Lower mandibular margin smooth, without fine setae or spines ( Fig. 2 A). Lateral side of mandible bearing serrulate setae with fine setules ( Fig. 2 B). Labrum with deep, V-shaped notch, 2 large teeth on each side of notch ( Fig. 2 D). Maxillule straight, row of 9 strong spines of differing sizes ( Fig. 4 E), serrulate setae at base of large spines ( Fig. 2 F). Mandibular palp and maxilla bearing serrulate setae with short and dense setules ( Fig. 2 G, H, I, J).

Cirri: Cirrus I with rami unequal, exopodite of 13 articles, endopodite of 5 ( Fig. 3 A). Setae on rami serrulate ( Fig. 3 B) with dense setules. Protopodite bearing serrulate setae with sparsely distributed setules ( Fig. 3 C). Cirrus II with expopodite and endopodite similar length, 6–7 articles ( Fig. 3 D), rami bearing serrate setae with 3 rows of setules ( Fig. 3 E, F), setules distally curved, sharply pointed ( Fig. 3 F). Cirrus III with exopodite and endopodite thin ( Fig. 3 G), rami bearing serrate setae with 3 rows of setules ( Fig. 3 H). Protopod bearing plumose setae with long setules ( Fig. 3 C, I). Cirri IV–VI similar ( Fig. 3 J), articles of rami with 2–3 pairs of thin, serrulate setae, distal pair longest ( Fig. 3 K).

Etymology. The species is named in honor of Jens T. Høeg’s (University of Copenhagen, Denmark) in recognition of his contribution to the study of cirripede phylogeny.

Figures

FIGURE 1. Cantellius hoegi sp. nov. Hard parts. A) Stereomicrograph of barnacle specimen (fixed in 95 % ethanol) covered by coral sclerosept; B) outer view of barnacle with coral deposition removed; C) inner view of parietes; D) scutum, outer view; E) apical end of scutum showing honeycomb-like structure; F) scutum, inner view; G) tergum, outer view; H) apical end of scutum showing honeycomb-like structure; and I) tergum, inner view.

FIGURE 2. Cantellius hoegi sp. nov. Trophi. A) Mandible, general view; B) serrulate-type setae on mandible; C) lower margin of mandible; D) left side of labrum; arrows indicate marginal teeth; E) maxillule, general view; F) serrulate-type setae on maxillule; G) mandibulatory palp, general view; H) serrulate setae on mandibulatory palp; I) maxilla, general view; and J) serrulate-type setae on maxilla. Scale bar in μm.

FIGURE 3. Cantellius hoegi sp. nov. Cirri. A) Cirrus I, general view; B) serrulate setae on rami of cirrus I; C) serrulate setae on protopod of cirri I and III and rami of cirrus II, D) cirrus II, general view, E) serrate setae with three rows of setules, located on rami of cirrus II; F) tip of serrate setae in E; G) cirrus III, general view; H) serrate setae on rami of cirrus III; I) plumose setae with long setules on protopod of cirrus III; J) cirrus IV, general view; and K) serrulate setae on rami of cirrus IV. Cirri V and VI not shown as they are similar to cirrus IV. Scale bar in μm.

FIGURE 4. Cantellius sextus. Hard parts. A) Inner view of parietes under SEM; B) inner view of one of the paries; C) scutum, outer view; D) scutum, inner view; E) apical end of scutum showing honeycomb-like structure; F) tergum, outer view; and G) tergum, inner view.