Caulerpa peltata Lamouroux, 1809a: 332

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 : 2984-2986

* Caulerpa peltata Lamouroux, 1809a: 332

References: Tseng, 1984: 282, pl. 140, figure 3 ; Kraft, 2000: 599, figure 33E, F; Payri et al., 2000: 92, figures pp. 89, 93; Skelton and South, 2002: 163, figure 25B .

Type locality. Antilles, West Indies.

Vouchers. HEC 14633, 18 September 2001, western side of Cotton Bay (s.s. 13) ; HEC 14702 (zS), 20 September 2001, Rivière Banane (s.s. 12) .

Ecology. Epilithic in the subtidal fringe; on horizontal as well as on vertical substrate.

Distribution. Aldabra Islands, Andaman Islands, Australia, Bangladesh, Christmas Island, Comores, Diego Garcia Atoll, India, Indonesia, Kenya, Laccadives, Madagascar, Malaysia, Maldives, Mauritius ( Dickie, 1874: 197, Børgesen, 1940: 51; 1946: 39–40; 1952: 11; 1953: 9), Mozambique, Nicobar Islands, Oman, Pakistan, Réunion ( Jadin, 1935: 156), Rodrigues (this paper), Seychelles, Singapore, Somalia, South Africa, Sri Lanka, Tanzania, Thailand, Yemen.

Notes. (1) On Rodrigues Caulerpa peltata is abundant on the reef crest, at about spring low water level, at sites exposed to very strong surf and on wellilluminated horizontal substrate. Sole peltate branchlets are placed on the wellattached and intricate, thin stolons. No intermediates were found with C. racemosa var. laetevirens or var. turbinata . (2) Two other similar morphospecies of Caulerpa grow on Rodrigues. In the first one the thallus is fleshier (thick stolons and assimilators), and the rachis of the erect assimilators bears several side branches placed in three dimensions. In some specimens all branchlets are peltate. We consider this entity as C. racemosa var. peltata ( Coppejans and Beeckman, 1989: 388, figures 27–29 ). Sometimes the basal branchlets are cylindrical, becoming clavate or turbinate in the middle part of the rachis and peltate towards the rachis apices. We identify this entity as an intermediate between C. racemosa var. laetevirens and var. peltata . In C. racemosa var. laetevirens s.s. the basal branchlets are cylindrical, becoming clavate higher up and turbinate at the tips of the rachis (no peltate branchlets). We also collected C. nummularia , with thin stolons, peltate branchlets on the stolon (not on a rachis) bearing another peltate branchlet either on the margin of the disc-shaped part of the branchlet or from its middle part, resulting in superposed peltate structures. C. nummularia was found growing together with C. peltata and therefore might be a growth form of the latter. Molecular research will give more insight into the phylogenetic relationships of these species and varietal complexes.

* Caulerpa racemosa (Forsskål) J. Agardh, 1873: 35–36

References: Jaasund, 1976: 25, figure 50 (~ var. clavifera f. macrophysa); Magruder and Hunt, 1979: 19, figure 1 p . 18 ; Tseng, 1984: 282, pl. 140, figure 4 (~ var. clavifera (Turner) Weber-van Bosse); Coppejans and Meinesz, 1988: 191, figures 22, 23 (~ var. clavifera ); Coppejans and Beeckman, 1989: 384, figure 4 (~ var. clavifera f. macrophysa); Coppejans, 1992: 401, figure 4C, D (~ecad racemosa ); Coppejans and Prud’homme van Reine, 1992: 698, figure 18A, B (~ecad racemosa ); Allen and Steene, 1994: 19, 27; Coppejans et al., 1995a: 78, figure 7 (~ecad racemosa ); Cribb, 1996: 17, figure p. 16 (~ var. clavifera ); Kraft, 2000: 602, figure 34A–D; Littler and Littler, 2000: 370, figure p. 371; Payri et al., 2000: 94, figures pp. 89, 95; Littler and Littler, 2003: 226, middle figure p. 227.

Type locality. Suez, Egypt .

Vouchers. HEC 14660, 19 September 2001, Gravier (s.s. 16) ; HEC 14700, 20 September 2001, Rivière Banane (s.s. 12) .

Ecology. Epilithic on the fringing reef; at about spring low tide and exposed with good tides.

Distribution. Aldabra Islands, Andaman Islands, Australia, Bangladesh, Burma, Djibouti, India, Indonesia, Kenya, Laccadives, Madagascar, Malaysia, Maldives, Mauritius ( Børgesen, 1940: 51; 1946: 39; 1948: 32; 1949: 14; 1952: 11; 1953: 8), Mozambique, Nicobar Islands, Pakistan, Réunion ( Jadin, 1935: 156 ~ Caulerpa clavifera (Turner) C. Agardh ; Payri, 1985: 640 ~ Caulerpa racemosa (Forsskål) J. Agardh var. clavifera (Turner) Weber-van Bosse), Rodrigues (this paper), Seychelles, Singapore, Somalia, South Africa, Sri Lanka, Tanzania, Yemen.

Note. Recent molecular research clearly indicates that the C. racemosa - complex is polyphyletic. The distinction on varietal level here is solely based on the ‘traditional’ morphological characters, which are very variable (see Note 2 with C. peltata ).

Figures

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).

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 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).

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).