Amphioplus, Rowe & Richmond, 2004

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 : 3290-3297

Amphioplus sp. nov.

Material. Three specimens, Passe Coco; 20 specimens from a shallow coral reef area (no further data).

Coloration. Red and white banded.

Comments. Clark and Rowe (1971) record only one amphiurid ( Amphiodia dividua ) from the Mascarene Islands. The occurrence of A. squamata (above) was to be expected, although the discovery of a species of Amphioplus suggests the family may be better represented among these islands than present records portend. Further analysis is required before a species name can be assigned to these specimens.

Distribution. Rodrigues.

Family OPHIOTRICHIDAE

Macrophiothrix longipeda (Lamarck, 1816)

See: Clark and Rowe, 1971: 82 (distribution), 114 (key); Hoggett, 1991: 1103.

Material. One specimen, Grand Pate´, 15 m, under rock.

Coloration. Disc pale with patterns of white, dark brown and black; arms sandy beige with darker brown banding.

Comments. Numerous other specimens were found under boulders and coral lumps at the reef crest of Rivière Banane.

Distribution. Originally described from Mauritius, this is a widespread species in the Indo-west Pacific, although not recorded from the Red Sea, south-east Arabia, Arabian Gulf or Hawaii.

Macrophiothrix robillardi (de Loriol, 1893) See : Clark and Rowe, 1971: 82 (distribution: Mauritius as M. robillardi ; northern

Australia as M. rugosa H. L. Clark, 1938 ), 114 (key); Hoggett, 1991: 1136,

figures.

Material. One specimen (d.d. ~ 8.5 mm, a.l. ~ ca 78 mm); Totor Reef, 1–2 m, corals; one specimen (d.d. ~ 16 mm, a.l. ~ 230 mm), Rivière Banane, under stones below reef crest.

Coloration. Dark, blackish disc with lighter radial shields; tapering arms greenish and cream with brown banding.

Comments. A distinctive character exhibited by each of the specimens above, and not described by Hoggett (1991) is a median, longitudinal cleft in the dorsal arm plates, which coincides with the longitudinal markings of the arms.

Distribution. Originally described from Mauritius. In referring M. rugosa to the synonymy of M. robillardi, Hoggett (1991) has shown the species to be more widespread, extending eastwards from Mauritius to include Rodrigues (new record herein), northern Australia, Philippines, southern China and islands of the south-western Pacific Ocean.

Family OPHIOCOMIDAE

Ophiarthrum elegans Peters, 1851

See: Clark and Rowe, 1971: 86 (distribution), 121 (key).

Material. One specimen (d.d. ~ 15.5 mm, a.l. ~ 73 mm), Coton Baie, reef crest.

Coloration. Disc uniformly velvet black; arms conspicuously banded red and white.

Comments. Only a single specimen found.

Distribution. Described from off Mozambique, East Africa, this is a new record for the Mascarene Islands for this otherwise widespread Indo-west Pacific species. The species has yet to be recorded from the north-western Indian Ocean and Maldive regions, or from Hawaii.

Ophiocoma brevipes Peters, 1851

See: Devaney, 1970: 12–13; Clark and Rowe, 1971: 86 (distribution), 119 (key).

Material. One specimen (d.d. ~ 8 mm), Grand Baie, reef crest; five specimens (d.d. ~ 9.2, 13.6, 13.9, 14.0, 15.7 mm), Coton Baie, low tide under rocks; one specimen (d.d. ~ 14 mm), Coton Baie; one specimen (d.d. ~ 18.3 mm), Graviers, under boulders; one specimen (d.d. ~ 16.4 mm) Coton Baie, reef crest.

Coloration. Some specimens with mottled disc of green/grey/black and white; arms cream-coloured with darker grey banding; others almost uniformly light brown with beige patterns and bands (see figure 6 ).

Comments. This species differs in colour from O. dentata (see below) and can be otherwise distinguished by its generally smaller size and occurrence of five arm spines on the proximal arm plates. Ophiocoma brevispinosa Smith, 1876b , described from Rodrigues, is a synonym of brevipes (see Devaney, 1970).

Distribution. Throughout the Indo-west Pacific region, except the Red Sea and north-western parts of the Indian Ocean.

Ophiocoma dentata Müller and Troschel, 1842

See Devaney, 1970: 12; Clark and Rowe, 1971: 86 (distribution), 119 (key).

Material. One specimen (d.d. ~ 11.6 mm), Ile aux Chats, inner reef crest; three specimens (d.d. ~ 22–29 mm), no other data one specimen (d.d. ~ 18 mm), Coton Baie.

Coloration. The smallest specimen has a dark disc with a pale centre and banded arms. The paler plates have a pale brown, square pattern, while the spines have a longitudinal reddish, mid-line stripe. The four larger specimens have a uniformly dark disc and banded arms, though two of the specimens bear some whitish granules over the radial shields (see figure 7 ).

Comments. This species differs from O. brevipes principally in its coloration and in having only four arm spines proximally (though occasionally an isolated proximal arm plate may bear five spines). This latter character appears to be more consistently recognizable for the species than the measurement of length of the longest arm spine versus width of dorsal arm plate, used by Devaney (1970) to separate the species from O. brevipes . Ophiocoma variegata Smith, 1876b , described from Rodrigues, is a synonym of dentata (see Devaney, 1970).

Distribution. Throughout the Indo-west Pacific with the apparent exception of the Red Sea and north-western Indian Ocean.

Ophiocoma erinaceus Müller and Troschel, 1842

See Devaney, 1970: 32–38; Clark and Rowe, 1971: 86 (distribution), 119 (key).

Material. One specimen, Grand Pate´, in coral, 20 m.

Coloration. The typical uniformly black disc and arms describes all specimens found.

Comments. Common at various lower intertidal sites under boulders. The present record confirms the occurrence of this common Indo-west Pacific species at Rodrigues, reported by Smith (1876b).

Distribution. Widespread in the Indo-west Pacific region, with the exception of the Arabian Gulf and coasts of Pakistan and western India.

Ophiocomella sexradia (Duncan, 1887)

See: Clark and Rowe, 1971: 86 (distribution), 118 (key); Cherbonnier and Guille, 1978: 178.

Material. Three specimens, no data; three specimens, Ile aux Fous, among coral lumps.

Coloration. Arms banded green and purple.

Comments. The six specimens accord well with the specimens reported from Pula We´, Sumatra by Price and Rowe (1996). These authors commented on the relationship between O. sexradia and Ophiomastix sexradiata A. H. Clark, 1952 , the latter species being considered conspecific with O. sexradia by Clark and Rowe (1971) and Cherbonnier and Guille (1978).

Distribution. New record for the Mascarene Islands, but otherwise distributed across the Indo-west Pacific region except for the north-western parts of the Indian Ocean.

Ophiomastix venosa Peters, 1851

See: Clark and Rowe, 1971: 88 (distribution), 120 (key); Devaney, 1978: 350; Clark, 1984: 100.

Material. Several specimens collected, photographed and deposited at the Shoals Rodrigues office.

Coloration. The usual appearance of gold with fine black patterns; arms pale orange with single, central, dark brown stripe.

Comments. This species has been recorded from Rodrigues by Smith (1876b); the identification of the specimen having been verified by Clark (in Clark and Rowe, 1971: 91 footnote). Clark (1984) comments of venosa that it is ‘the largest ophiuran in the western Indian Ocean, with specimens sometimes exceeding 400 mm’.

Distribution. According to Devaney (1978) O. venosa is distributed along the east African coast from Inhaca Island to Zanzibar, Madagascar, Aldabra and Rodrigues. Records from east of this area need verification because the specimens have been misidentified, according to Devaney.

Family OPHIONEREIDAE

Ophionereis porrecta Lyman, 1860

See: Clark and Rowe, 1971: 88 (distribution), 122 (key); Cherbonnier and Guille, 1978: 207.

Material. One specimen (d.d. ~ 14.2 mm, a.l. ~ ca 100 z mm), Totor Reef,

2–5 m, coral; one specimen (d.d. ~ 11 mm, a.l. ~ ca 80 mm), Graviers. Coloration. Disc mottled red/yellow/cream; arms similar.

Comments. The specimens from Rodrigues accord well with specimens described and figured by Cherbonnier and Guille (1978), particularly regarding the two colour forms they illustrate. The specimen from Graviers has the darker markings described by Cherbonnier and Guille (1978), though the oral shield is not as spearhead-shaped as those authors illustrate, being simple and more elongate to oval in shape.

Distribution. Widespread Indo-west Pacific, though not recorded from the north-western parts of the Indian Ocean.

Family OPHIODERMATIDAE

Ophiarachnella gorgonia (Müller and Troschel, 1842)

See: Clark and Rowe, 1971: 88 (distribution), 125 (key).

Material. Photographic record only of specimens from Coton Baie, found under boulders. Present also at Grande Paté reef crest. Specimens deposited at the Shoals Rodrigues office.

Coloration. Variable, with predominant colour of disc and arms being pale green or pale brown, with arm banding comprising a combination of two darker colours (black–red–black or red–brown–red).

Comments. Found under boulders on limestone reef crest. Present also at Grand Paté reef crest.

Distribution. Widespread in the Indo-west Pacific region, but not recorded from the Red Sea and north-western parts of the Indian Ocean, as far east and including the Maldives.

Family OPHIURIDAE

Ophioplocus imbricatus (Müller and Troschel, 1842)

See: Clark and Rowe, 1971: 90 (distribution), 128 (key); Rowe and Gates, 1995: 435.

Material. One specimen (d.d. ~ 12.4 mm, a.l. ~ ca 55 mm), Coton Baie, reef crest.

Coloration. Dark grey and medium brown banding and patterned disc.

Comments. This species was described from syntypic specimens collected from Mauritius (Ile de France) and Timor (see Rowe and Gates, 1995), though Clark and Rowe (1971) record Mauritius as the type locality.

Distribution. The species occurs widespread in the Indo-west Pacific region, but has yet to be recorded from the Red Sea, south-east Arabia, Arabian Gulf or Maldives.

Class ECHINOIDEA Family CIDARIDAE Phyllacanthus imperialis (Lamarck, 1816) See : Clark and Rowe, 1971: 140 (distribution), 150 (key).

Material. Loose spines and broken test found among coral at Chaland Reef; intact specimen found at Totor Reef. Present also at Ile aux Fous. Specimens deposited at the Shoals Rodrigues office.

Coloration. The usual pale-banded thick spines with finely grooved tips. Distribution. Widespread in the Indo-west Pacific region , though not recorded from the north-western part of the Indian Ocean or Hawaii .

Family DIADEMATIDAE

Diadema savignyi Michelin, 1845

See: Clark and Rowe, 1971: 140 (distribution), 153 (key).

Material. Found at several locations, usually at the seaward edges of the lower intertidal and among coral in the shallow subtidal to 20 m, including Totor Reef at 6 m and Grand Paté among coral, at 12 m depth. Specimens deposited at the Shoal Rodrigues office .

Coloration. Generally greyish black. Some specimens with pale pink and white-banded spines. Typically with blue, iridescent lines radiating from the apical region and into each of the interradial areas and five interradial white dots.

Comments. Further work is needed to establish whether the equally widely distributed sister species, D. setosum (Leske, 1778) (which lacks the iridescent blue lines, but has a conspicuous reddish orange ring around the anal opening), is present on Rodrigues, though it is also known from Mauritius.

Distribution. Described from Mauritius, D. savignyi occurs widespread in the Indo-west Pacific region, but is apparently absent from the Red Sea and parts of the north-western Indian Ocean.

Echinothrix diadema (Linnaeus, 1758)

See: Clark and Rowe, 1971: 140 (distribution), 153 (key).

Material. Specimens were collected from Rivière Banane, test diameter 30 mm, from under boulders (common); Ile aux Fous, test diameter 80 mm; Grand Paté reef, among coral 12 m depth. All are deposited at the Shoals Rodrigues office.

Coloration. Typically black with an overall bluish green hue and with faint lighter banding on spines.

Comments. Analysis of all material revealed E. diadema to be the only species present. No spines were found to bear the characteristic transverse banding of fine thorns of E. calamaris (Pallas, 1774) , despite the coloration patterns suggesting otherwise. Similarly, no specimens were observed with the typical pale grey and fine black-spotted anal sac of E. calamaris . Further work is therefore required to ascertain the presence of the equally widespread species, E. calamaris , on Rodrigues, though it is known from Mauritius.

Distribution. E. diadema is widely distributed throughout the Indo-west Pacific region.

Family STOMOPNEUSTIDAE

Stomopneustes variolaris (Lamarck, 1816)

See: Clark and Rowe, 1971: 140 (distribution), 153 (key); Clark, 1984: 98.

Material. Two specimens collected and deposited at the Shoals Rodrigues office. Found in lagoons and pools along the northern shores between Baladirou and Grand Baie.

Coloration. Characteristically uniformly black. Distribution. Widely distributed in the Indo-west Pacific, but not recorded from the Red Sea, parts of the north-western Indian Ocean, Philippines or Hawaii.

Family TEMNOPLEURIDAE Microcyphus maculatus L. Agassiz, 1846 See : Clark and Rowe, 1971: 140 (distribution), 155 (key).

Material. One specimen (h.d. ~ 31.6 mm, v.d. ~ 21.3 mm, spine length to 5.2 mm), Ile Hermitage, under rocks, 10 m; one specimen (h.d. ~ 30.5 mm, v.d. ~ 20.2 mm, spine length to 4.8 mm), Ile Hermitage, among stones on sandy mud, 10 m.

Coloration. The inter-radial bare areas on the smaller specimen (h.d. ~ 30.5 mm) are a light dusky pink, whereas for the larger specimen (h.d. ~ 31.6 mm) they are a dusky olive with a pink hue. The spines of both are either almost entirely green with a narrow reddish brown base and white at the very tip of the spine, or coloured in proportions of 1:2:1, brown–green–white (see figure 8 ).

Distribution. The distribution of this endemic Mascarene species, known previously only from Mauritius, is extended eastward to Rodrigues (see Discussion).

Family TOXOPNEUSTIDAE

Toxopneustes pileolus (Lamarck, 1816)

See: Clark and Rowe, 1971: 142 (distribution), 156 (key).

Material. A single specimen collected from Coton Baie, in shallow lagoon, deposited at the Shoals Rodrigues office.

Coloration. Predominantly pink with fine white bands on spines and yellowish tinge to tube feet.

Distribution. Described from Mauritius, this species is generally widespread in the Indo-west Pacific region, though not recorded from parts of the northwestern Indian Ocean or Hawaii.

Tripneustes gratilla (Linnaeus, 1758)

See: Clark and Rowe, 1971: 142 (distribution), 156 (key).

Material. Specimens were common and collected from shores around Totor Reef, off Anse aux Anglais, deposited at the Shoals Rodrigues office.

Coloration. Typical variation in colour of the bare ambulacral areas, including black or blue, and with the usual white spines.

Distribution. This widespread Indo-west Pacific species appears to be unrecorded only from the Arabian Gulf and coasts of Pakistan and western India.

Family ECHINOMETRIDAE

Colobocentrotus atratus (Linnaeus, 1758)

See: Clark and Rowe, 1971: 142 (distribution), 158 (key).

Material. A single specimen was found under boulders on the exposed coast of Pointe Coton, and deposited at the Shoals Rodrigues office.

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).