Species Diversity 20: 183–189 25 November 2015 DOI: 10.12782/sd.20.2.183 New Records of the Tetraclitid Barnacle Tesseropora alba (Cirripedia: Thoracica: Tetraclitoidea) in the Pacific Waters of Taiwan and Okinawa Ryota Hayashi1,3 and Benny K. K. Chan2 1 Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba 277-8564, Japan E-mail: [email protected] 2 Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan 3 Corresponding author (Received 8 December 2014; Accepted 6 August 2015) The four-plated barnacle Tesseropora alba Ren and Liu, 1979 is recorded for the first time away from its type locality in the Xisha Islands, South China Sea. The new localities are northwestern Taiwan and Okinawa. The species is redescribed in detail, with a discussion of its likely geographical range in the Pacific. Key Words: Tetraclitidae, distribution, redescription, western Pacific. In Southeast Asia, a small-sized white barnacle, Tessero- Introduction pora alba Ren and Liu, 1979 was described in Xisha Islands, South China Sea, Hainan Province of China. There have Tesseropora is a genus of barnacle of the superfam- been no subsequent records of this species, but we have re- ily Tetraclitoidea, and its species are among the most ple- cently collected T. alba from the Pacific coast of Taiwan and siomorphic members of the superfamily. The first species also from a buoy stranded in Okinawa, Japan, after a rough of Tesseropora was described by Krauss (1848), as Tetraclita weather (Fig. 1). These represent new records of this spe- rosea Kraus, 1848. Tesseropora was later proposed as a sub- cies in the Pacific Ocean. The morphological features of the genus of Tetraclita, distinguished by having four plates and species including hard and soft parts, are redescribed herein single row of pores in the parietal walls (Pilsbry 1916). Ross and compared with the description of the type specimen in (1969) raised Tesseropora from subgenus to genus level. In Ren and Liu (1979). Specimens were preserved in 99% etha- Tesseropora, 11 species (including five fossil species) and nol and deposited in the collections of the Coastal Ecology one subspecies have been described from all over the world Laboratory, Academia Sinica, Taiwan (CEL) and the Mu- (Table 1). The oldest known fossils of Tesseropora were col- seum of the University of Ryukyus, Fujukan (RUMF-ZC), lected from Oligocene deposits (de Alessandri 1895; Table Okinawa. 2). Table 1. Distributional records of extent species of genus Tesseropora. Species Localities References Tesseropora rosea (Krauss, 1848) Australia, the Kermadec Islands, South Africa Krauss (1848); Zullo (1968); Newman and Ross (1977); Otway and Anderson (1985); Costa and Jones (2000) Tesseropora pacifica (Pilsbry, 1928) Wake Island, Marshall Islands, Fiji, Guam Pilsbry (1927); Zullo (1968); Foster (1974); Pauley and Ross (2003) Tesseropora atlantica Newman and Bermuda, Azores, Saint Paul’s Rock (equatorial Newman and Ross (1977); Edwards and Lubbock Ross, 1977 Atlantic) (1983a, b); Southward (1998); Costa and Jones (2000) Tesseropora wireni (Nilsson-Cantell, Sumatra and Palau Islands Nilsson-Cantell (1921); Hiro (1935); Zullo (1968) 1921) Tesseropora wireni africana (Nilsson- Dar-es-Salaam, Diego-Garcia Nilsson-Cantell (1932); Newman and Ross (1976) Cantell, 1932) Tesseropora arnoldi Young, 1998* Azores. Young (1998) Tesseropora alba Ren and Liu, 1979 Xisha Islands, Taiwan, Okinawa Ren and Liu (1979); present study * Costa and Jones (2000) suggested the necessity for taxonomic work to confirm the status of T. atlantica and T. arnoldi. © 2015 The Japanese Society of Systematic Zoology 184 R. Hayashi and B. K. K. Chan Table 2. Records of fossil species of Tesseropora and the closely related Tesseroplax. Species Age Locality Reference Tesseropora isseli Oligocene Italy de Alessandri (1894) Tesseropora dumortieri Miocene Western Tethys; eastern Atlantic Fischer (1866); Carriol (2008) coast Tesseropora sp.* Middle Miocene France (Atlantic coast) Carriol (2005) Tesseropora chilensis Pliocene Chile Carriol and Schneider (2013) Tesseropora sulcata Plio-Pleistocene France (Channel coast) Carriol (1993) Tesseropora canariana Lower Pliocene Canary Islands Hornung (2014) Tesseroplax unisemita** Middle-Upper Pliocene Guardra Is., Gulf of California Zullo (1968) * Tesseropora sp. is a T. dumortieri according to Carriol (2008); ** Zullo (1968) described the new fossil species as Tesseropora unisemita, but Ross (1969) divided this species from Tesseropora and proposed the new genus Tesseroplax for it. Fig. 1. Type locality and sampling localities reported herein for Tesseropora alba. Order Sessilia Lamarck, 1818 Tesseropora alba Ren and Liu, 1979: 344.—Liu and Ren Suborder Balanomorpha Pilsbry, 1916 2007: 345, fig. 155. Superfamily Tetraclitoidea Gruvel, 1903 Tesseropora sp.: Shuto and Hayashi 2013: fig. 3b. Family Tetraclitidae Gruvel, 1903 Subfamily Tetraclitinae Gruvel, 1903 Materials examined. CEL-Te-sp-001, Suao, Taiwan, Genus Tesseropora Pilsbry, 1916 September, 2010, one specimen attached to shell of barna- Tesseropora alba Ren and Liu, 1979 cle Megabalanus tintinnabulum (Linnaeus, 1758). RUMF- ZC-02049, Kanna River Estuary, Ginoza village, Okinawa Fig. 2. Tesseropora alba Ren and Liu, 1979. A, an individual from Suao, Taiwan, attached to Megabalanus tintinnabulum ; B, shell wall of an individual from Kanna River Estuary, Ginoza, Okinawa, upper, basal, upper oblique, and lateral views; C, lateral compartment (external, internal and basal views); D, details of opercular plates (outer and inner), surfaces of tergum (upper) and scutum (lower); E, nauplius larva collected from within mantle cavity, with poorly developed swimming limbs and body with rich lipid reserves. Tesseropora alba from Okinawa and Taiwan 185 186 R. Hayashi and B. K. K. Chan Fig. 3. Trophi and cirri of Tesseropora alba Ren and Liu, 1979 (Kanna River Estuary, Ginoza, Okinawa). A, palp; B, labrum; C, mandible; D, maxilla I; E, maxilla II; F, cirrus I; G, cirrus II; H, cirrus III; I, cirrus IV; J, cirrus V; K, cirrus VI. December, 2006, several specimens collected from a strand- occludent margin with fine teeth, dorsal surface with promi- ed buoy. nent horizontal growth ridges; on ventral surface, adductor Diagnosis. Shell white, small, conical, external surface ridge prominent, rounded, extending about halfway up total smooth but with longitudinal ridges on basal region of wall height of scutum; articular ridge inconspicuous. Tergum plates. Radii narrow, summit oblique. Scutum white, basal narrow, apex pointed; spur apex blunt. margin convex, slightly longer than occludent margin. Ter- Mandibular palp rectangular, with serrulate setae on su- gum narrow, without medial furrow on dorsal surface, spur perior margin. Labrum bilobed with shallow notch, bearing long, apex of spur blunt. a few small teeth on each lobe. Mandibles with 5 sharp teeth Description. Shell small, conical, white; shell wall com- excluding inferior angle; second and third teeth bidentate, posed of 4 plates and singly tubiferous; tubes filled with liv- fourth tooth with serrate cutting edge, fifth tooth smallest, ing tissue; external surface of wall plates smooth, except for located close to lower margin; lower margin with 13 pecti- longitudinal ridges close to their basal region; radii narrow, nations, inferior angle ending in 2 large pectinations. Maxil- non-tubiferous; basis calcareous. Scutum triangular, basal lule notched, with 2 large setae above notch, 3 small setae margin rounded and slightly longer than occludent margin, at notch, and 10 setae below notch, cutting margin straight. Fig. 4. Details of trophi of Tesseropora alba Ren and Liu, 1979 (Suao, Taiwan). A, mandibulatory palp; B, serrulate setae on superior margin of mandibulatory palp; C, labrum; D, notch of labrum; E, mandibles; F, maxillule G, maxilla; H, serrulate setae at margins of maxilla. Scale bars in µm. Tesseropora alba from Okinawa and Taiwan 187 188 R. Hayashi and B. K. K. Chan Table 3. Number of segments in each cirrus (anterior ramus, posterior ramus) of Tesseropora alba. Cirrus I Cirrus II Cirrus III Cirrus IV Cirrus V Cirrus VI 6, 10 7, 8 11, 13 14, 16 16, 17 17, 18 Maxilla oval, with serrulate setae at the superior margin and cause the specimens were dry and poorly preserved. Howev- distally. Cirri I–III as maxillipeds, and cirri IV–VI as cteno- er, our re-examination of the shell walls and opercular plates pods. Segment number of each cirrus listed in Table 3. of these specimens allows us to confirm that these barnacles Remarks. The morphology of our specimens fits the de- were indeed T. alba. This represents a further record of this scription of T. alba in Ren and Liu (1979). In Taiwan, this species in Japan. species was collected low on an exposed rocky shore, on the surface of the barnacle Megabalanus tintinnabulum. In Oki- nawa, T. alba was collected on the surface of Megabalanus Acknowledgments sp. found attached to a stranded buoy on the beach near the Kanna Estuary, Ginoza village, after a rough weather. The We are much indebted to Prof. William A. Newman for type specimens of T. alba were collected from the surface providing his knowledge and references concerning bar- of the barnacle Megabalanus xishaensis (Ren and Liu 1978) nacles, and RH’s friend, Tomoaki Nakamura (Okinawa Zoo found low on the shore on basalt rocks in the Xisha Islands and Museum), for finding the encrusted buoy while beach (Ren and Liu 1979). combing. We also thank R.-P. Carriol (Muséum national d’Histoire naturelle, Paris,