Memoirs of Museum Victoria 59(2): 277–296 (2002) NEW GENUS AND SPECIES OF SOUTHERN AUSTRALIAN AND PACIFIC ASTERINIDAE (ECHINODERMATA, ASTEROIDEA) P. MARK O’LOUGHLIN Honorary Associate, Marine Biology Section, Museum Victoria, GPO Box 666E, Melbourne, Vic. 3001, Australia (e-mail: [email protected]) Abstract O’Loughlin, P.M., 2002. New genus and species of southern Australian and Pacific Asterinidae (Echinodermata, Asteroidea). Memoirs of Museum Victoria 59(2): 277–296. The diagnostic characters of the Asterinidae species Asterina atyphoida H.L. Clark from southern Australia and Asterina gibbosa (Pennant) from the Atlantic, type species of Asterina Nardo, are reviewed. Asterina atyphoida is referred to Meridiastra gen. nov., with four other species: Meridiastra fissura sp. nov. and Meridiastra nigranota sp. nov. from southern Australia, Meridiastra rapa sp. nov. from the central south Pacific, and Meridiastra modesta (Verrill) from the Pacific coast of Panama and Mexico. Asterina agustincasoi Caso is synonymised with Meridiastra modesta (Verrill). Asterinides Verrill is recognised as a valid genus. Meridiastra fissura is fissiparous. Meridiastra is distributed from southern Australia to the Pacific coast of Mexico and Panama. A key is provided for the species of Meridiastra. Introduction ambulacral internal plates, the internal alignment of abactinal and actinal plates towards the body Rowe (in Rowe and Gates, 1995 and in a note in margin, and the arrangement of cleared actinal Campbell and Rowe, 1997) considered that plates were helpful in distinguishing the genera. species of the Asterinidae from Australian waters These diagnostic features are included in the which were assigned to the genus Asterina descriptions below, without judgement as to their Nardo, 1834 were not congeneric with the type significance. Clark and Downey (1992) used the species Asterina gibbosa (Pennant, 1777), and first two of these characters in their diagnosis of required reassignment to an existing or new Asterina, referring to an absence of super- genus. Rowe and Berents (in an unpublished draft ambulacral plates and to the reinforcement of the manuscript, cited in this work as pers. com.) ventrolateral angle by an internal overlapping of anticipated assigning one of these species, Aster- the adjacent abactinal and actinal plates often ina atyphoida H.L. Clark, 1916, to a new genus with additional plates, but did not describe the together with a new fissiparous southern Aus- arrangement of actinal plates. In this study the tralian species. This anticipated genus is estab- arrangement of cleared actinal interradial plates lished here, and a second new species from was found to be inconsistent for a specimen and a southern Australia is included. The remain- species, and the apparent arrangement on ing Australian species assigned to Asterina are uncleared specimens was sometimes different to not reallocated to this new genus, and their that revealed on cleared specimens of the same reassignment is not treated in this work. species. For Asterina gibbosa the actinal series on Marsh (1974) reported an Asterina sp. from one uncleared specimen appeared to curve at an Rapa I. in the South Pacific, and this species is acute angle distally from furrow to margin (Fig. described below and assigned to the new genus. 1e), while on a cleared specimen the series curved The eastern Pacific species Asterina agustincasoi obliquely (obtusely) from furrow to margin Caso, 1977 and Asterina modesta Verrill, 1870 (Fig. 1f). are synonymised, and A. modesta is reassigned to Verrill (1913) reassigned Asterina modesta to the new genus. his new genus Asterinides Verrill, 1913. Fisher Rowe and Berents (pers. com.), in their antici- (1919) synonymised Asterinides with Asterina. pated review of the genera of the Asterinidae, A.M. Clark (1983) and Clark and Downey (1992) considered that the presence or absence of super- 277 278 P. M. O’LOUGHLIN considered that Asterinides (type species Aster- which were assigned to Asterina: A. alba H.L. iscus folium Lütken, 1860, from the West Indies) Clark, 1938 from the Tasman Sea; A. anomala could be revived from its synonymy with Asterina H.L. Clark, 1921 from Torres Strait; A. atyphoida and recognised at least as a valid subgenus. Rowe H.L. Clark, 1916 from southern Australia; A. (in Rowe and Gates, 1995 and in a note in Camp- cepheus (Müller and Troschel, 1842) from north- bell and Rowe, 1997) supported the recognition ern Australia; A. coronata von Martens, 1866 of Asterinides as a valid genus. Rowe and Berents from northern Australia; A. heteractis H.L. Clark, (pers. com.) considered that their anticipated new 1938 from the Tasman Sea; A. inopinata Living- genus, described below, was close to Asterinides, stone, 1933 from eastern Australia; A. sarasini but distinguished the two genera. Asterinides is (de Loriol, 1897) from northern Australia; and A. recognised below as a valid genus, but not the scobinata Livingstone, 1933 from south-eastern appropriate genus for Asterina modesta. Australia. Rowe (in Rowe and Gates, 1995) con- Molecular phylogeny studies of Asterinidae sidered that these species assigned to Asterina species, such as by Byrne et al. (1999), are pro- were not congeneric with the type species Aster- viding further evidence on which to review the ina gibbosa (Pennant, 1777) and required reas- assignment of species to the many existing Aster- signment to an existing or new genus. Of the inidae genera. In the current absence of adequate above nine species only Asterina atyphoida H.L. molecular evidence a review of the assignment of Clark is assigned here to a new genus. None of the species to Asterina and Asterinides is not under- remaining eight species is congeneric with A. aty- taken here. phoida (pers. obs. of AM specimens of all Terminology here follows that defined in the species). Possible reassignment of these eight glossary and illustrated in Figs 2 and 3 of Clark species is not undertaken in this work. Rowe (in and Downey (1992), except that “papular space” Rowe and Gates, 1995) considered that the genus is used for “papular area” (“restricted area with Asterina might be restricted to Atlantic waters. papular pores”) and “papulate areas” is used to With the description of a new genus below and refer to the parts of the abactinal surface where inclusion of two species previously assigned to papulae occur. “Ad-disc” refers to a location adja- Asterina, and the raising below of Asterinides out cent and distal to the plates bordering the disc. of synonymy with Asterina, the diagnosis of Aste- Abbreviations of institutions are as follows: rina requires emendment. But a re-examination of AM, Australian Museum, Sydney, Australia; the many species currently assigned to Asterina BPBM, Bishop Museum, Honolulu, USA; ICML- should be appropriately undertaken when the UNAM, Instituto de Ciencias del Mar y Limnolo- emerging molecular evidence is adequate, and an gia, Universidad Nacional Autonoma de Mexico, emended diagnosis is not given here. Mexico; MCZ, Museum of Comparative Zool- ogy, Harvard University, Massachusetts, USA; Asterina gibbosa (Pennant, 1777) NMV, Museum Victoria, Melbourne, Australia; NTM, Northern Territory Museum, Darwin, Aus- Figures 1a–f, 7f tralia; SAM, South Australian Museum, Ade- Synonymy. See Clark and Downey (1992: 184). laide, Australia; TM, Tasmanian Museum, Hobart, Australia; USNM, Museum of Natural Material examined. Atlantic Ocean, European seas (no History, Smithsonian Institution, Washington, other data), AM J1250 (1); Ireland, Co. Down, Granagh Bay, 5 Aug 1959, NMV F87241 (3); Wales, Gwynedd, USA; WAM, Western Australian Museum, Perth, Anglesey, Rhosneigr, under rocks, 28 Sep 1971, NMV Australia; YPM, Peabody Museum of Natural F87242 (5). Mediterranean Sea, France, Marseilles, Jun History, Yale University, Connecticut, USA; 1978, AM J 12408 (3); Italy, Bay of Naples, AM ZMUC, Zoological Museum, University of G11524 (2); donation from Naples Aquarium, 1890, Copenhagen, Denmark. NMV F45108 (3); Mediterranean (no other data), AM G7575 (2). Asterinidae Gray, 1840 Diagnosis. See Clark and Downey (1992: Asterina Nardo, 1834 184–185). Synonymy. See Clark and Downey (1992: 177). Remarks. Asterina gibbosa material examined in Type species. Asterina gibbosa (Pennant, 1777) this study differed in minor ways from the diag- nosis by Clark and Downey (1992), and these dif- Diagnosis. See Clark and Downey (1992: 177). ferences and additional observations are noted. Remarks. Rowe (in Rowe and Gates, 1995) listed The first five radials involved in forming a pen- nine Asterinidae species from Australian waters tagon bordering the disc were separated by single NEW SOUTHERN AUSTRALIAN AND PACIFIC ASTERINIDAE (ECHINODERMATA) 279 Figure 1. Asterina gibbosa (Pennant) (Mediterranean specimens, lot NMV F45108). a, cleared abactinal ray (R = 19 mm); b, cleared disc and madreporite (lower right), with one non-papular proximal interradius (arrow); c, abactinal spinelets (0.3 mm long); d, abactinal pedicellariae (one at arrow, 0.25 mm long); e, actinal interradius with gonopores (arrows); f, cleared actinal interradius, with plates in series curving obliquely from furrow towards margin, and with gonopores (arrows). 280 P. M. O’LOUGHLIN interradial plates. Papulate areas were more aborally; pedicellariae absent; triangular extensive than non-papulate areas. The madreporite. madreporite was oval to lobed, not triangular. A Abactinal plates closely imbricating, in regular carinal series of plates in the mid-third of each