ASTERINIDAE, Gray, 1840

Rowe, Frank & Richmond, Matthew, 2004, A preliminary account of the shallow-water echinoderms of Rodrigues, Mauritius, western Indian Ocean, Journal of Natural History 38 (23), pp. 3273-3314 : 3286-3287

Family ASTERINIDAE

The western Indian Ocean (including the Maldive Islands) appears pauperate of asterinid asteroids. With the exceptions of a record from the coast of Mozambique (East Africa) for Patiriella exigua (Lamarck, 1816) , and from the coasts of Pakistan and western India for Asterina lorioli Koehler, 1910 , Clark and Rowe (1971) record only Asterina burtoni (Gray, 1840) as occurring throughout the western Indian Ocean (and indeed, the Indo-west Pacific) region. The extent of the distribution of A. burtoni given by Clark and Rowe (1971) is, however, misleading. Included within it are locality records for three species of doubtful status. These are the pentaradiate, non-fissiparous A. cepheus (Müller and Troschel, 1842) (described from Indonesian waters, and long held to be conspecific with burtoni , e.g. see Smith, 1927), the pluriradiate, fissiparous species A. wega (Perrier, 1869) (described, as is burtoni , from the Red Sea, and also long held to be conspecific with burtoni , see Smith, 1927) and the pluriradiate, fissiparous species A. anomala H. L. Clark, 1921 (described from tropical Australian waters) which A. M. Clark (in Clark and Rowe, 1971) considered to be conspecific with burtoni , as well as any records for burtoni s. s., itself. More recently, Jangoux (1973) and Jangoux and Aziz (1984) have recorded A. burtoni as widespread both throughout the Indo-west Pacific region ( Jangoux, 1973) and within the western Indian Ocean ( Jangoux and Aziz, 1984). In light of the fact that both cepheus and anomala , at least, have subsequently been recognized as valid species (see Liao and Clark, 1995; Rowe, and Gates, 1995), it is clear that the extent of the distributions of these individual species remains to be resolved and all records for A. burtoni need rigorous re-examination and taxonomic re-assessment.

Further records of asterinids recorded from the western Indian Ocean also require investigation and taxonomic resolution. A. M. Clark (in Clark and Rowe, 1971) has identified two specimens from Zanzibar (East Africa) which she considers possibly referable to the genus Paranepanthia Fisher, 1917 (a genus otherwise known from Philippine, Indonesian and Australian waters). Interestingly, H. L. Clark (1938) comments on a specimen he examined, originating also from Zanzibar, and which he identified as Asterina coronata fascicularis Fisher, 1918 , though he thought it might prove to be a distinct species. [H. L. Clark’s (1938) record of this species was clearly missed by Clark and Rowe (1971) in their tables of asteroid distributions!]. More recently, Jangoux (1973) recorded three specimens he identified as Asterina coronata von Martens, 1866 , from Inhaca Island, Mozambique (East Africa), though Clark and Courtman-Stock (1976) and Walenkamp (1990) have identified other, similar, large, non-fissiparous specimens from south-eastern Africa as A. burtoni , refering Jangoux’s (1973) identification of A. coronata from Mozambique to burtonii. Records of Asterina sp. , reported by Rowe and Richmond (1997, 2002) are also based on specimens collected in the Zanzibar area by one of us (M.D.R.). We are inclined to believe all these records refer to a single, eastern African species that is likely to prove, as H. L. Clark (1938) suspected, as yet undescribed. However, resolution of this latter problem is outside the scope of this present account, though this shows that our knowledge of this family of Asteroidea within the region of the south-west Indian Ocean is far from accurate or complete.

It is with particular interest, therefore, that we can identify two species of ‘ Asterina ’ from Rodrigues (see figures 4, 5 ). Both species are represented by small specimens, one species being fissiparous and both pentaradiate and pluriradiate, the other simply pentaradiate and non-fissiparous. Due to the taxonomic confusion surrounding the identification of asterinids from the region, and in particular the identification of ‘ A. ’ burtoni , we refrain from naming the taxa beyond referral, in inverted commas, to the genus ‘ Asterina ’. In taking this latter action we concur with the views expressed previously by one of us (F.W.E.R.) that non-Atlantic Ocean species referred to the genus Asterina (type species A. gibbosa Pennant, 1777 ) should be re-assigned to other, or new genera within the family Asterinidae (see Rowe and Gates, 1995; Campbell and Rowe, 1997). It is our opinion that both the species reported herein are congeneric with ‘ A. ’ burtoni Gray, 1840 , and a number of other species referred to the genus ‘ Asterina ’ in Clark and Rowe (1971), but resolution of their generic and species status requires further research and will be dealt with by us elsewhere (O’Loughlin, Rowe and Richmond, in preparation).

Figures

FIGS 2–16. (2) Stephanometra indica (# RGS/Jeremy Neech). (3) Gomophia watsoni (# RGS/Jeremy Neech). (4) ‘Asterina’ sp. 1. (M. Richmond). (5) ‘Asterina’ sp. 2. (M. Richmond). (6) Ophiocoma brevipes (# RGS/Jeremy Neech). (7) Ophiocoma dentata (# RGS/Jeremy Neech). (8). Microcyphus maculatus (M. Richmond). (9) Bohadschia sp. 1 (M. Richmond). (10). Bohadschia sp. 2 (# RGS/Jeremy Neech). (11)?Bohadschia sp. 3 (# RGS/Jeremy Neech). (12) Holothuria impatiens s. s. (# RGS/Jeremy Neech). (13) Holothuria impatiens bicolor. (# RGS/Jeremy Neech). (14) Holothuria impatiens concolor. (# RGS/Jeremy Neech). (15) Psolidium ornatum (# RGS/Jeremy Neech). (16) Plesiocolochirus dispar (# RGS/Jeremy Neech).