Galkinius maculosus, Chan, Benny Kwok Kan & Liu, Jennie Chien Wen, 2017

Chan, Benny Kwok Kan & Liu, Jennie Chien Wen, 2017, Galkinius Perreault, 2014 or Darwiniella (Anderson, 1992)? A new coral-associated barnacle sharing characteristics of these two genera in Pacific waters (Crustacea, Cirripedia, Thoracica, Pyrgomatidae), ZooKeys 719, pp. 1-22 : 4-6

Galkinius maculosus sp. n.

Material examined.

HOLOTYPE. ASIZCR000343, SE of Dongsha outer atoll, Taiwan (20°36.937'N, 116°53.143'E), June 2015, coll. Pei-Chen Tsai,Yao-Fong Tsao, and Yen-Wei Chang, on coral host Lobophyllia de Blainville, 1830 sp. PARATYPES. ASIZCR000344, NW of Dongsha Atoll, Taiwan (20°36.173'N, 116°52.110'E), May 2015, coll. Pei-Chen Tsai,Yao-Fong Tsao, and Yen-Wei Chang, on coral host Lobophyllia sp. ASIZCR000345, NE of Dongsha Atoll, Taiwan (20°46.616'N, 116°47.203'E), May 2015, coll. Pei-Chen Tsai,Yao-Fong Tsao, and Yen-Wei Chang, on coral host Lobophyllia sp., ASIZCR000346, Dongsha wreck (20°42.282'N, 116°42.097'E), May 2014, coll. Chen Hsi-Nien, and Pei-Chen Tsai, on coral host Lobophyllia agaricia (Milne Edwards & Haime, 1849). MNHN-IU-2016-8720, PKK2, Madang, Papua New Guinea, November 2012, coll. B.K.K. Chan, on coral host Lobophyllia radians (Milne Edwards & Haime, 1849) Edwards & Haime, 1849. ADDITIONAL SPECIMENS. CEL-LAN-075-09, Rock Yunuyen, Orchid Island, Taiwan (22°08.111'N, 121°52.000'E), October 2007, coll. B.K.K. Chan, coral host unknown. CEL-DSA-012-1-9, Dongsha wreck, Taiwan (20°42.282'N, 116°42.097'E), May 2014, coll. Pei-Chen Tsai, on coral host Lobophyllia agaricia . CEL-DSA-075, Dongsha wreck, Taiwan (20°46.767'N, 116°48.402'E), August 2015, coll. Pei-Chen Tsai, Yao-Fong Tsao, and Yen-Wei Chang, on coral host Lobophyllia sp., CEL-DSA-084-1, 2, 4, 5, data same as paratype ASIZCR000344. CEL-DSA-097-1, 2, data same as paratype ASIZCR000345. CEL-DSA-117-1-5, data same as holotype. CEL-DSA-131-3, Dongsha wreck, Taiwan (20°42.380'N, 116°42.088'E), May 2015, coll. Pei-Chen Tsai, on coral host Lobophyllia sp., CEL-DSA-201, SE of Dongsha outer atoll, Taiwan (20°36.825'N, 116°53.012'E), May 2016, coll. Pei-Chen Tsai, Yao-Fong Tsao, and Yen-Wei Chang, on coral host Lobophyllia sp., PNG-020-01, 02, data same as paratype MNHN-IU-2016-8720.

Diagnosis.

Galkinius with fused shell wall, spotted aperture frill; cirri, maxilla, and penis with dark spots, scutum with relatively narrow adductor plate, tergum with wide spur.

Description.

(Description based on holotype: basal diameter 12 mm, rostro-carinal orifice diameter 9 mm). From in-situ observation, shell of barnacles covered by thick coral tissue, aperture frill black with white spots (Fig. 2), colouration did not changing after preservation in 95% EtOH. Shell oval, plates fully fused, pink externally after bleach treatment, external surface smooth (Fig. 3A, B). Base of shell with 30-40 internal rids radiating from rim of inner operculum (Fig. 3C). Orifice oval, long, narrow, about 1/3 length of rostro-carinal diameter.

Scutum and tergum white, plates fused without junctions (Fig. 3 D–G). Width of scutum similar to width of tergum. Scutum triangular, transversely elongated, width two times longer than height. Occludent margin straight, with 6-8 rostral teeth basally along ventral surface of occludent margin, teeth gradually increasing in size from apex to base (Fig. 3 D–G). Ventral view with oval-shaped adductor muscle scar. Dorsal view with horizontal striations, each bearing rows of small pores (Fig. 3H). Adductor plate convex, extending below basal margin half height of scutum (Fig. 3D, F). Tergum trapezoid, three times higher than scutum. Tergum apex pronounced, lateral depressor muscle crests not apparent. Spur wide, reaching one third width of basal margin of tergum, base convex, height of scutal side of spur three times longer than carinal side, height of spur about one third height of tergum. Dorsal surface with middle spur furrow, curving slightly from the basal margin towards carinal margin (Fig. 3D). Dorsal surface with horizontal striations, each bearing rows of small pores (Fig. 3I).

Maxilla oval, with dark spots (Fig. 4A), serrulate setae distally (Fig. 4B, C) and along inferior margin (Fig. 4D). Maxillule cutting edge straight without notch, bearing row of 9-12 large setae (inconsistent, withtwo specimens with 12 and 9 large setae, Fig. 4E, F, respectively). Region close to cutting edge with fine simple setae (Fig. 4H). Mandible with four teeth (Fig. 5A). First teeth largest and sharp (Fig. 5C). Second, third, and fourth teeth bidentate (Fig. 5C, E). First and second teeth well separated than remainder, third to fifth teeth smaller than first and second teeth. First three teeth occupying 3/4 length of cutting edge. Lower margin short, about 1/16 length of total length of mandible. Lateral side and lower margin of mandible bearing simple setae (Fig. 5 D–H). Mandibular palp rectangular, elongated (Fig. 6A), bearing serrated setae distally (Fig. 6B) and along interior margin (Fig. 6C). Labrum bilobed, V-shaped notch between two lobes, one sharp tooth on each side of notch (Fig. 6 D–G) (consistent in two specimens, Fig. 6D, H).

Cirrus I with rami unequal. Dark spots and stripes on each segment of anterior and posterior rami (Fig. 7A). Posterior ramus short (nine segments), bearing serrate setae (Fig. 7B), the anterior edges of the rami carry simple and serrulate setae (Fig. 7C). Anterior ramus long (17 segments), slender, anterior edges of the segments bearing simple and bi dentate serrulate setae (Fig. 7D). Cirrus II rami sub-equal. Dark spots and stripes on each segment of anterior and posterior rami (Fig. 7E) Anterior ramus (nine segments) and posterior ramus (seven segments), bearing serrulate setae. Anterior edges of both anterior and posterior rami with both simple and bidentate serrulate setae (Fig. 7F). Fan-shaped denticles present at the margins of middle segments (Fig. 7G) and conical spines present at the margin of distal two to three segments (Fig. 7H). Cirrus III rami subequal (Fig. 8A), dark spots and stripes exist on each segment of anterior and posterior rami. Anterior ramus (12 segments) and posterior ramus (10 segments), with simple and serrulate setae. Fan-shaped denticles (Fig. 8B) present at the surface of basal segments of posterior ramus Conical spines present at the margin of the distal three up to eight segments at both anterior and posterior rami (Fig. 8C). Anterior sides of both anterior and posterior rami with bidentate serrulate setae (Fig. 8D). Cirrus IV-VI long, slender, with equal rami length. Number of segments on Cirrus IV (22, 20) (Fig. 8E), Cirrus V (24, 24) (Fig. 9A), Cirrus VI (23, 23) (Fig. 9D). Stripes exist on each segment of the ramus (Figs 8E, 9A, 9D). Intermediate segments of Cirrus IV-VI has four pairs of serrulate setae (Figs 8F, 9B, C, E, F), distal pair longest, proximal pair shortest. Penis long (about one and a half times length of Cirrus VI), annulated, with scattered irregular dark spots (Fig. 9G). Pedicel with basidorsal point (Fig. 9G, H), apex of penis with short, simple setae (Fig. 9I).

Etymology.

The name maculosus means dappled or mottled, and therefore denotes the spots scattered around the aperture frill, maxilla, palp, Cirrus I-VI, and penis of this species.

Distribution.

Taiwan waters (Dongsha Atoll in the South China Sea, Orchid Island in the Pacific Ocean), Madang, Papua New Guinea.