Dictyosphaeria Decaisne ex Endlicher

Coppejans, Eric, Leliaert, Frederik, Verbruggen, Heroen, de Clerck, Olivier, Schils, Tom, de Vriese, Thomas & Marie, Daniel, 2004, The marine green and brown algae of Rodrigues (Mauritius, Indian Ocean), Journal of Natural History 38 (23), pp. 2959-3020 : 2973-2975

Dictyosphaeria Decaisne ex Endlicher

Key to the species from Rodrigues

1 Undisrupted thalli hollow, older specimens cup-shaped..... D. cavernosa

– Thalli solid, extremely tough............. D. versluysii Dictyosphaeria cavernosa (Forsskål) Børgesen, 1932

References: Børgesen, 1932: 2; Egerod, 1952: 350–351, figures 1b–f , 2f, g ; Jaasund, 1976: 15, figure 32; Magruder and Hunt, 1979: 27, figure 1 p . 26 ; Tseng, 1984: 268, pl. 133, figure 5 ; Moorjani and Simpson, 1988: 15, pl. 24; Sartoni, 1992: 319, figure 13A ; Cribb, 1996: 29, figure p. 28 ; Leliaert et al., 1998: 188, figures 30 –33; Huisman, 2000: 240, unnumbered figure; Kraft, 2000: 578, figure 27A, B ; Littler and Littler, 2000: 332, figure p. 333; Payri et al., 2000: 76, figure p. 77; Littler and Littler, 2003: 202, bottom figure p. 203.

Syntype localities. ‘ Gomphodae’ (Al-Qunfudhah), Saudi Arabia ; Mokha, Yemen.

Vouchers. HEC 14636, 18 September 2001, western part of Cotton Bay (s.s. 13) ; HEC 14788, 25 September 2001, Passe Grand Bassin (s.s. 2) .

Ecology. Epilithic in the lower part of the intertidal zone.

Distribution. Aldabra Islands, Amirante Islands, Andaman Islands, Australia, Bahrain, Bangladesh, Cargados Carajos, Chagos Archipelago, Cosmoledo Atoll, Diego Garcia Atoll, India, Indonesia, Kenya, Kuwait, Laccadives, Malaysia, Maldives, Mauritius ( Børgesen, 1940: 12; 1946: 13–14), Mozambique, Nicobar Islands, Qatar, Réunion ( Jadin, 1935: 157 and Montagne and Millardet, 1862: 4 ~ Dictyosphaeria favulosa (C. Agardh) Decaisne ex Endlicher, Payri, 1985: 640 ), Rodrigues ( Dickie, 1877a: 7), Saudi Arabia, Saya de Malha Bank, Seychelles, Singapore, Somalia, South Africa, Sri Lanka, Tanzania, Thailand.

* Dictyosphaeria versluysii Weber-van Bosse, 1905: 144

References: Egerod, 1952: 351, 354–355, figures 1a , 2h–k ; Jaasund, 1976: 15, figure 33; Magruder and Hunt, 1979: 27, figure 2 p . 26 ; Tseng, 1984: 270, pl. 134, figure 2 ; Moorjani and Simpson, 1988: 15, pl. 24; Sartoni, 1992: 319–321, figures 13B , 14A, B ; Allen and Steene, 1994: 20; Cribb, 1996: 29, figure p. 28 ; Leliaert et al., 1998: 188, 190, figures 37–39; Littler and Littler, 2000: 334, figure p. 335; Payri et al., 2000: 76, figure p. 77; Skelton and South, 2002: 162, figure 23C, D ; Littler and Littler, 2003: 200, bottom figure p. 201.

Syntype localities. ‘Plusieurs récifs dans l’Archipel Malaisien’. Voucher. HEC 14624, 18 September 2001, western part of Cotton Bay (s.s. 13). Ecology. Frequent on horizontal rock substrate in middle to low intertidal. Distribution. Aldabra Islands, Chagos Archipelago, Indonesia, Kenya ,

Madagascar, Maldives, Mauritius ( Børgesen, 1940: 12–15, figures 1 , 2a, 3 ),

Mozambique, Réunion ( Payri, 1985: 640 ~ Dictyosphaeria setchellii Børgesen ),

Rodrigues (this paper), Seychelles, Somalia, South Africa, Tanzania, Thailand.

Phyllodictyon Gray

* Phyllodictyon anastomosans (Harvey) Kraft and Wynne, 1996: 139 References: Børgesen, 1952: 7–8, figure 3 (~ Struvea anastomosans (Harvey) Piccone and Grunow ex Piccone ), Egerod, 1952: 359–361, figure 4 , pl. 31; 1971: 123–125, figures 10–16 (both~ Struvea anastomosans ); Tseng, 1984: 276, pl. 137, figure 2 (~ Struvea anastomosans ); Sartoni, 1992: 317–319, figure 12B, C (~ Struvea anastomosans ); Coppejans et al., 1995a: 96, figure 38 (~ Struvea anastomosans ); Kraft and Wynne, 1996: 131, figures 16–20 ; Leliaert et al., 1998: 186–187, figures 23–24 ; Littler and Littler, 2000: 328, figure p. 329; Payri et al., 2000: 74, figure p. 75. Type locality. Fremantle, Western Australia.

Voucher. HEC 14827 (zF), 27 September 2001, Baie de l’Hermitage (s.s. 19) .

Ecology. Very abundant as loose-lying balls on the silty-sandy bottom of the lagoon, subtidal, 22 to 24 m. Co-occurring with balls of Boodlea composita .

Distribution. Aldabra Islands, Australia, Diego Garcia Atoll, India, Indonesia (Java), Kenya, Laccadives, Malaysia, Maldives, Mauritius ( Børgesen, 1952: 7–8, figure 3 ; 1953: 5), Mozambique, Pakistan, Rodrigues (this paper), Seychelles, Somalia, South Africa, Sri Lanka, Tanzania ( Coppejans et al., 2000: 65), Thailand, Yemen.

Note. The distinction between Boodlea composita and Phyllodictyon anastomosans is unclear. Traditionally the former is distinguished from the latter by the formation of three-dimensional net-like thalli lacking a stipe, while P. anastomosans is characterized by stipitate, reticulate, monostromatic blades. Mature thalli of P. anastomosans , however, form three-dimensional blades that anastomose with other blades resulting in three-dimensional net-like thalli with obscure stipes. Comparison of partial LSU rRNA of these two species (Leliaert et al., 2003) reveals nearly identical gene sequences.

Ventricaria Olsen and West * Ventricaria ventricosa (J. Agardh) Olsen and West, 1988: 104 References: Jaasund, 1976: 13, figure 27 (~ Valonia ventricosa J. Agardh ); Magruder and Hunt, 1979: 35, figure 1 p . 34; Tseng, 1984: 272, pl. 135, figure 1 (~ Valonia ); Sartoni, 1992: 323, figure 14E ; Allen and Steene, 1994: 21; Cribb, 1996: 37, figure p. 36; Huisman, 2000: 243, unnumbered figure; Littler and Littler, 2000: 336, figure p. 337; Payri et al., 2000: 80, figure p. 81; Littler and Littler, 2003:

204, bottom figure p. 205.

Lectotype locality. Guadeloupe, West Indies.

Vouchers. HEC 14686 (zF), 20 September 2001, Rivière Banane (s.s. 12) ; HEC 14821, 27 September 2001, Ile Hermitage (s.s. 18) .

Ecology. Infralittoral fringe, mostly between branches of dead acroporoid corals; a single collection of specimens almost completely sunken in the sediment between Halophila stipulacea in the lagoon, 0.5 m deep.

Distribution. Aldabra Islands, Diego Garcia Atoll, India, Indonesia (Sumba), Kenya, Maldives, Mauritius ( Børgesen, 1940: 11; 1948: 20), Réunion ( Payri, 1985: 640), Rodrigues (this paper), Seychelles, Somalia, Tanzania, Thailand.

Figures

FIG. 1. Sampling stations. See table 1 for a list of the stations and their GPS coordinates. Map redrawn from Wells (1988). The outer grey line represents the fringing reef.

FIGS 2–6. Chlorophyta. (2) Microdictyon tenuius, detail of branching and anastomosing patterns (HEC 14849). (3) Bryopsis pennata var. pennata, branchlets of last order contiguous and in a single plane (HEC 14796 p.p.). (4) Bryopsis pennata var. leprieurii, branchlets of last order interrupted and in a single plane (HEC 14757).(5) Bryopsis pennata var. secunda, branchlets of last order curved in one direction (HEC 14796 p.p.). (6) Chamaedoris delphinii (HEC 14617). Scale bars: 250 mm (2); 5 mm (3–5); 1 cm (6).

FIGS 25–30. Phaeophyta. (25, 26) Cladosiphon mauritianus (HEC 14789b): (25) general morphology; (26) apical branches. (27, 28) Chnoospora implexa (HEC 14674b): (27) compact form; (28) thin, slender form. (29) Hydroclathrus tenuis (HEC 14756d). (30) Asteronema breviarticulatum, rope-like appearance of intertwined filaments (HEC 14884). Scale bars: 2 cm (25); 1 cm (26–30).

FIGS 7–13. Caulerpa brachypus, variation in the general morphology and margin structure of the assimilators. (7) Large growth form collected in grooves between bumps of coral rubble, frequently branching and with secondary stolons (HEC 14867). (8) Intermediately large growth form with wide assimilators (HEC 14769). (9) Intermediately large growth form with relatively narrow assimilators (HEC 14656a). (10) Typical specimen with simple or scarcely branched assimilators (HEC 14612). (11) Assimilator with smooth margin (HEC 14612). (12) Assimilator with coarsely dentate margin (HEC 14656a). (13) Assimilator with densely dentate margin (HEC 14718). Scale bars: 2 cm (7–10); 1 mm (11–13).

FIGS 14–18. Caulerpa. (14) Caulerpa cupressoides var. lycopodium f. elegans, small, elegant specimen (HEC 14691). (15) Caulerpa cupressoides var. lycopodium f. elegans, coarse specimen with richly branched assimilators (HEC 14820). (16) Caulerpa sertularioides f. sertularioides, last order branchlets in a single plane (HEC 14739). (17) Caulerpa sertularioides f. farlowii, last order branchlets in several planes (HEC 14690). (18) Caulerpa webbiana (HEC 14699). Scale bars: 1 cm.

FIGS 19–24. Chlorophyta. (19) Caulerpa nummularia, proliferating from primary, peltate assimilator (HEC 14609 p.p.). (20) Rhipidosiphon javensis (HEC 14763). (21) Udotea sp. (HEC 14759). (22–24) Udotea palmetta (HEC 14817): (22) general morphology of large, fertile specimen; (23) gametangia growing from the blade surface; (24) gametangia growing from the blade margin. Scale bars: 2 mm (19, 20); 1 cm (21, 22); 1 mm (23); 500 mm (24).