Darwiniella conjugatum (Darwin, 1854)

Chen, Yi-Yang, Lin, Hsiu-Chin & Chan, Benny K. K., 2012, Description of a new species of coral-inhabiting barnacle, Darwiniella angularis sp. n. (Cirripedia, Pyrgomatidae) from Taiwan, ZooKeys 214, pp. 43-74 : 47-50

Darwiniella conjugatum (Darwin, 1854) Figs 10-17

Pyrgoma conjugatum Darwin 1854: 364-365, pl. 12, fig. 7 a–c.; Weltner 1897: 255; Gruvel 1905: 306-309; Annandale 1906: 143; Hoek 1913: 264; Broch 1922: 344; Hiro 1931: 154; Sakakura 1934: tab. II (not seen); Hiro 1935: 47, 59-60, 66, 69, fig. 8 a–c; Hiro 1937: 468 (not seen); Nilsson-Cantell 1938: 13, 66, tab. III; Broch 1947: 7; Kolosváry 1947: 427; Utinomi 1949: 69 (not seen).

Pyrgoma (Nobia) conjugatum Baluk and Radwanski 1967: 487.

Nobia conjugatum Ross and Newman 1973: 155, fig. 12 d–e; Newman and Ross 1976: 58; Foster 1982: 209, tab. 5, pl. 1G, fig. 7F; Soong and Chang 1983: 244-245, fig. 3; Galkin 1986: 1292; Ren 1986: 146, pl. IV, 15-18; Ogawa and Matsuzaki 1990: tab. I (not seen); Anderson 1992: 306-309, figs 20-21, 37F; Ogawa et al. 1998: 3, fig. 2; Jones et al. 2000: 276; Jones 2003: tabs 6, 8; Poltarukha and Dautova 2004: 111, fig. 66.

Nobia conjugata Ogawa and Matsuzaki 1992: app. tab.

Darwiniella conjugatum Anderson 1992: 329, figs 38F, 39; Simon-Blecher et al. 2007: tabs I–II.

Darwiniella conjugata Asami and Yamaguchi 1997: 13-14, figs 1-2.

Materials examined.

CEL-RYU-28-1, Dafu Fishing Harbor, Siaoliouciou Island, Taiwan (22°20'N, 120°22'E), August 2010, coll. B.K.K. Chan, on coral host Cyphastrea serailia ( Forskål, 1775). CEL-RYU-28-2 data same as CEL-RYU-28-1. CEL-RYU-38-4, Shanfu Fishing Harbor, Siaoliouciou Island, Taiwan (22°21'N, 120°21'E), August 2010, coll. B.K.K. Chan, on coral host Cyphastrea serailia . CEL-RYU-47-4 data same as CEL-RYU-38-4. CEL-RYU-66-1, Lobster Cave, Siaoliouciou Island, Taiwan (22°20'N, 120°23'E), August 2010, coll. B.K.K. Chan, on host coral Cyphastrea sp.. CEL-RYU-170-1, Shanfu Fishing Harbor, Siaoliouciou Island, Taiwan (22°21'N, 120°21'E), August 2010, coll. B.K.K. Chan, on coral host Cyphastrea japonica .

Diagnosis.

Scutum subtriangular, rostral tooth and obvious adductor plate present. Adductor plate angle not obvious. Tergum subtriangular, lateral depressor muscle crests, medial furrow and spur present. Spur triangular, long, curved and sharp.

Description.

Shell (8 mm in maximum basal diameter, rostro-carinal diameter to 6 mm) plates fully fused, purple, oval, externally surface with about 25 strip-like projections differing in length and radiating from nearly subcentral orifice to plate margin (Fig. 10A). Bases of shell with about 27 internal ribs radiating from the rim of the inner operculum to the basal margin of the shells (Fig. 10B). Orifice oval, long and narrow, about 3/8 length of rostro-carinal diameter.

Scutum and tergum white, fused without any junctions (Fig. 10C, D). Scutum subtriangular, width 1.5 times length of height, occludent margin slightly curved, with a rostral tooth on bottom (Fig. 10F) and continuous teeth along the ventral surface of occludent margin, tooth size increasing gradually from apex to base. Ventral view with an apparent oval-shaped adductor muscle scar (Fig. 10D). Dorsal view with obvious adductor plate, extending below basal margin, plate more than 1/2 height of scutum. Basal margin of adductor plate without obvious adductor plate angle (Fig. 10C). Dorsal surface of scutum with horizontal striations, striations with row of small pores (Fig. 10E).

Tergum subtriangular, lateral depressor muscle crests present. Spur triangular, long, curved and sharp, height reaching more than 1/2 height of tergum, basal margin not obvious due to the curved spur. Dorsal surface with medial furrow, curving from basal margin towards the carinal margin of tergum, width of furrow increased gradually from apex to base (Fig. 10C). Dorsal surface with horizontal striations, striations with row of small pores.

Maxilla oval (Fig. 11A), serrulate setae distally (Fig. 11B) and along inferior margin (Fig. 11C). Maxillule cutting edge straight, without notch, bearing row of 13 large, similar sized setae (consistent through 2 specimens, Fig. 11D, F, and inco nsistent through 2 specimens with 11 and 9 large setae, Fig. 11G, H, respectively). Region close to cutting edge with dense fine simple type setae (Fig. 11E), anterior and posterior margin with long simple type setae. Mandible with five teeth (excluding inferior angle) (teeth number consistent in five specimens but differed in morphologies, Fig. 12A, E, F, G, H). Second, third, fourth and fifth teeth bidentated (Fig. 12B, C), the first 4 teeth occupying most of length of cutting edge. Lateral surface, lower margin and cutting edge of mandible bearing simple type setae. Lower margin short, about 1/20 length of total length of mandible, inferior angle ending in a blunt angle with dense, fine setae (Fig. 12D). Mandibular palp rectangular, elongated (Fig. 13A), bearing serrulate setae distally (Fig. 13B) and on inferior margin (Fig. 13C). Labrum bilobed, with V-shaped notch between 2 lobes, 2 sharp teeth on each side of notch (inconsistent in three specimens, Fig. 13D, G, H).

Cirrus I with rami unequal, anterior ramus long and slender, with 17-segmented, posterior ramus 7-segmented (Figs 14A, 15A), bearing serrulate setae (Fig. 15B, C, D), dark spots exist on each segment of the ramus (Fig. 15A). Cirrus II with rami almost equal, anterior ramus 8-segmented and posterior ramus 6-segmented (Figs 14B, 15E), bearing serrulate setae (Fig. 15F, G, H), dark spots exist on each segment of the ramus (Fig. 15E). Cirrus III rami equal, anterior ramus 10-segmented, posterior ramus 8-segmented (Figs 14C, 16A), bearing serrulate setae (Fig. 16B, C, D), dark spots exist on each segment of the ramus (Fig. 16A). Cirrus IV–VI long, slender, with equal rami size. Number of segments on Cirrus IV (anterior 16, posterior 16), Cirrus V (21, 20), Cirrus VI (21, 18) (Figs 14D, E, F, 16E, 17A, C). Intermediate segments of Cirrus IV–VI with four pairs of serrulate setae (Figs 16G, 17D, E), distal pair longest, proximal pair shortest. Dark spots exist on each segment of the ramus (Figs 16E, 17A, C).

Penis long (1.2 times length of Cirrus VI), annulated, some dark spots present, scattered short simple type setae (Fig. 17G). Pedicel with basidorsal point (Fig. 17G, I), apex bearing short simple type setae (Fig. 17H).

Distribution.

South China Sea: Singapore, Mainland China (Hong Kong), Vietnam (Nhatrang Bay).Pacific Ocean: Taiwan (Green Island, Turtle Island, Siaoliouciou Island, Kenting, Suao), Japan, Australia (Western Australia & Great Barrier Reef),Philippine.Indian Ocean: Mauritius (Albion), Bay of Bengal, Thailand (Gulf of Siam), Sri Lanka,Red Sea.

Remarks.

Darwiniella conjugatum is widely reported in the Indo-Pacific Ocean. Note Ogawa and Matsuzaki (1992) and Asami and Yamaguchi (1997) misspelled the species name Darwiniella conjugatum as ‘conjugata’.