Hiroa stubbingsi Ross and Newman, 1973

Achituv, Yair & Newman, William A., 2002, The barnacles of Astreopora (Cirripedia, Pyrgomatini / Scleractinia, Acroporidae): organization plans, host speci ® city, species-richness and geographic range, Journal of Natural History 36 (4), pp. 391-406 : 394-398

Hiroa stubbingsi Ross and Newman, 1973

Material examined. RED SEA: no exact locality, MNHN Ci 2934 from Astreopora pulvinaria Lamarck, 1816 (= A. myriophthalm a), (Botta collection); KENYA: RMNH C2277 from A. myriophthalma (Coel 17057), Watamu; TANZANIA: USNM from A. myriophthalm a Cat. no. (259858), oV Pemba Island; MOZAMBIQUE: RMNH from A. listeri (Coel. 12065), Inhaca Island; REUNION: MNHN Ci 2935 from A. myriophthalma ( REU 662), La Saline Reef; SEYCHELLES: RMNH C 2272, from A. myriophthalma (Coel. 19221), Aride Island; RMNH C2271 from A. myriophthalma (Coel. 19025), North of Poivre Island; INDONESIA: RMNH C2274 from A. expansa Bruggemann, 1877 (Coel. 14862), Southwest Sulawesi; RMNH C 2276 (wet and dry samples), from A. myriophthalma, Sabah , Southwest Sulawesi; WAM C 24509 from Astreopora sp. (137-92), Southwest end, Pulau Manukan; PHILIPPINES: MTQ W- 13660 from A. listeri ( AIMS 99:3); AUSTRALIA: MTQ W- 13646 from A. cucullata (G-31404) Chester®eld Atoll Bennett Island, GBR; MTQ W- 13642 from A. gracilis (G-31304), Flinder Reef, GBR; MTQ W- 13643 from A. listeri (G-31280), Swain Reefs, GBR; MTQ W- 13644, from A. listeri (G-31292), Britomart Reef, GBR; MTQ W- 13645 from A. listeri (G-3183 3), Big Mary Reef, GBR; MTQ W- 13646 from A. listeri (G-3128 1), Maer Island (Murray Island), GBR; MTQ W- 13647 from A. ocellata (G-31905) Elizabeth Reef, GBR; MTQ W- 13648 from A. moretonensis (G-48583), Murray Island, GBR; MTQ W- 13649 from A. moretonensis (G-31917), Wistari Reef, GBR; MTQ W- 13650 from A. myriophthalm a (G-31396), Raine Island, GBR; MTQ W- 13651 from A. myriophthalma (G-31378), Houghton Island, GBR; MTQ W- 13653 from A. myriophthalm a (G-3136 7), Lihou Reef, Turtle Island, GBR, MTQ W- 13654 from A. myriophthalma (G 31393), Big Mary Reef, MTQ W- 13655 from A. myriophthalma (G-3185 6), Lihou Reef, Turtle Island, GBR; MTQ W- 13656 from A. myriophthalm a (G-31863), Magdelaine Cay, GBR; MTQ W- 13657 from A. myriophthalma (G-3136 6), GBR; MTQ W- 13658 from A. myriophthalma (G-31376), Raine Island, GBR; MTQ W- 13659 from A. sp. (G-31352),Chester®eld Atoll, Bennett Island, GBR; NEW CALEDONIA: MNHN Ci 2936 from Astreopora sp. (Z3 220e), no exact locality; MNHN Ci 2937 from A. myriophthalma : (BP 26 W, Coll. no. 20001) north-east coast of Art Island, Belep Islands (North of New Caledonia); MARSHALL ISLANDS: SIO sample C8003, from A. myriophthalma, Enewetok Atoll ; RMNH from A. myriophthalma (Coel. 14343); USNM from Astreopora sp. (cf. A. incrustans ) (Cat. no. 89493); CAROLINE ISLANDS: SIO C-5923 (paratypes), from Astreopora sp. , Ollan Island, Truk Islands; GILBERT ISLANDS: USNM from A. myriophthalm a (Cat no. 259857), Onotoa Atoll, south-east of Rakai Ati reef; USNM from A. myriophthalm a (Cat. no. 259855), Rawa ni Karoro lagoon, Tongatapu Island; TONGA ISLANDS: BMNH NHM 2000.898 2 from A. listeri (1895.7.22 .7).

Other than for Truk Islands, the type locality for Hiroa ( Ross and Newman, 1973) , and the records from Taiwan ( Soong and Chang, 1983) and Japan ( Ogawa and Matsuzaki, 1990; Asami and Yamaguchi, 1997), the foregoing locality records are new. Of historical interest, the type specimen of A. myriophthalma Lamarck, 1816 , from an unknown locality, housed in the historical coral collection of the MuseÂum National d’ Histoire Naturelle, Paris has several specimens of Hiroa on it.

Supplementary description

This supplementary description is based on material collected at Sulawesi, Indonesia ( RMNH C 2276), by Dr B. W. Hoeksema. The hard parts, especially the scuta and terga, are generally similar to the description of the type from Truk, Caroline Islands ( Ross and Newman, 1973). However, the strongly produced, overlapping scutal growth ridges of each side, that together span the entire width of the ori®ce of the wall as well as interdigitate with each other across the aperture of the operculum when closed (®gure 2A, E), are unprecedented in the Sessilia other than for a few other pyrgomatines (see Foster, 1982, Plate 2A). While the growth ridges are fairly strong and certainly interdigitate along the aperture when closed in H. stubbingsi s.s., it does not look like they overlap each other much, if at all. This, and small diVerences in the proportions of opercular plates, raises the question as to whether or not H. stubbingsi is really a wide-ranging species or a complex of two or more species. Unfortunately the material on hand is not suYcient to establish the range of variability for these shell characters within a population, and even if it were, until complete, preserved specimens of the Truk population become available, so that a full description of its appendages as well as the hard parts can be made, the designation of a new species-group taxon within the genus would be tenuous at best.

The wall of the type specimens could not be fully studied because they had been completely overgrown and entombed by the coral. The exterior of the wall of the Sulawesi population is oval, ¯at in pro®le and ribbed, but neither projecting above the coral nor normally with pronounced overgrowths of coral skeleton (®gures 2A, 5A), up to 7 mm in rostro-carinal and 4.5 mm in lateral diameter, divided into four plates with radii which are usually externally obscure. Primary and secondary external ribs of the wall, radiating from the centrally placed ori®ce, consist of a series of closely spaced columns or tubercles commonly contiguous at their bases (®gures 2B, 5A). The internal, marginal portion of each rib ends with a row of teeth (®gure 2D) which ®t into the groove between the internal ribs of the basis (®gures 2B, 5A). The sheath, formed by the inner lamina of the wall, is separated from the outer lamina by tubes formed between the radial (longitudinal) septa (®gure 5A). The tubes, largely ®lled proximally, are subdivided by three or four transverse septa between the radial septa. Ori®ce central, oval, approximatel y one-third rostro-carina l diameter.

Scutum [®gures 2F (articulated), Ga and Gb (disarticulated)] elongated, occludent margin strongly toothed, teeth interdigitating deeply with those of the opposite scutum when closed (®gure 2A, E), adductor ridge projecting below basal margin. While growth lines on the general exteriorare ®ne, there are none on the broad teeth formed along the occludent margin; e.g. these teeth are formed at intervals during otherwise gradual growth of the plate, just as they are in most balanomorphs in general. A diVerence here is that the interruption, rather than extending clear across the plate, is con®ned to the occludent margin. It can also be observed that the nine teeth exposed on each plate (®gure 2B) are spaced about 0.1 mm apart and there are at least eight growth lines on the sheath (®gure 2C) with a similar spacing.

Tergum (®gures 2F, Gc, Gd) narrow, with low growth ridges and a deep, elongated spur and furrow, no crests for tergal depressor muscles. The length of the spur, the nature of its furrow, and relative proportions of the region for attachment of the tergal depressor muscles, diVer to varying degrees in animals from diVerent localities. Some of these may be speci®c diVerences, but the small number of specimens available from any one locality makes it diYcult to reach any clear conclusion in this regard.

Basis solid, internally ribbed, starting as a`point’ and reaching a height of some 40 mm.

Trophi. Labrum (®gure 3A), ¯anked by the palps, relatively high and narrow, with a pair of small teeth on either side of a deep notch. Cutting edge of mandible (®gure 3C) quadridentoid, ®rst three teeth occupying more then three-quarters the length of cutting edge; a wide gap between the ®rst and the second tooth, and between the second and the third tooth, third tooth bicuspid, fourth close to but not conūent with inferior angle; inferior angle molariform, not spinous. First maxilla (®gure 3D) with a straight cutting edge with a row of strong spines of diVerent lengths. Second maxilla (®gure 3E) bilobed.

Cirri. Rami of cirrus I (®gure 4A) with posterior ramus less than half length of anterior ramus; the posterior bears setose setae (®gure 4B) on its inner side. Cirrus II (®gure 4C) shorter than I and III, rami subequal, anterior ramus longest, anterior margin of posterior ramus with pinnate setae (®gure 4B). Cirrus III with the anterior slightly longer than the posterior ramus (®gure 4D). Rami of cirri IV± VI (®gure 4E) essentially equal in length, but number of segments diVers between rami and between sides ( table 1). There are two to three pairs of simple spines on each intermediate segment, more proximal segments usually having three pairs (®gure 4F), more distal ones two.

Penis. Penis with but a few setae and pigment spots along its length (®gure 4G).