Cladophora ordinata Hoek 1979

6. Cladophora ordinata (Bfrgesen) Hoek (1979). Map 1; Fig. 4A

Willeella ordinata BΦrgesen (1930:155).

Tufts erect, slightly stiff, grass-green in color. Specimens measuring (4–) 5 (–6) cm high (sometimes 8 cm high), attached to the substrate by branched rhizoids that sprouted from the proximal end of basal cells. Ramification abundant in one plane with opposite branches more or less equally developed. Conical apical cells with tapered tips measuring (46 –) 55 (– 65) µm wide and (115 –) 162 (– 233) µm long., with L/W ratio of (2 –) 3 (– 4). Ultimate branch cells measuring (86 –) 97 (– 110) µm wide and (178 –) 282 (– 394) µm long, with L/W ratio of (2 –) 3 (– 4). Main axes cells measuring (115 –) 140 (– 164) µm wide and (592 –) 771 (– 1006) µm long, with L/W ratio of (5 –) 6 (– 9).

Representative specimens examined: BRAZIL: Ceará: Caucaia, Praia do Pacheco, 17 Sept. 2001, Xavier (PEUFR 42759); 18 Sept. 2001, Xavier (PEUFR 42760); Icapuí, Praia de Redonda, 15 Apr. 1995, Fontenele (HPB 4523); Bahia: Ilhéus, Praia do Gravatá, 25 Aug. 2000, Nunes et al. (ALCB 53340); Espírito Santo: Aracruz, Praia dos Padres, 18 Aug. 1986, Guimarães et al. (PEUFR 42762); Praia de Aracruz, 22 Jan. 2001, Nassar (PEUFR 42763); Praia de Portocel, 20 Jun. 2001, Nassar (PEUFR 42764); Serra, Praia de Carapebus, 03 Jun. 2003, Nassar (PEUFR 42765).

Comments: Epilithic thalli were found attached to the substrate and were collected from tide pools exposed to wave action or on sand, partially submersed or from the frontal area of sandstone reefs (CE, BA, ES). The species grows close to C. montagneana, C. prolifera, C. vagabunda, Centroceras sp., Jania adhaerens and Chondracanthus acicularis. The thalli of C. ordinata have the following epiphytes: Pneophyllum fragile Kützing (1843b: 385), Ceramium vagans Silva et al (1987: 56), benthic diatoms and cyanobacteria.

Along the Brazilian coast, C. ordinata occurs from Ceará to the south of Espírito Santo, confirming the tropical distribution of this species. Cell dimensions were very similar in specimens from Ceará, Bahia and Espírito Santo.

Cladophora ordinata is the most characteristic species of the genus due to its ramification pattern. Therefore, there are no difficulties in identifying this species. Previously, Willeella was considered a separate genus from Cladophora, but Hoek (1982) argued that the characteristics that distinguished it from its closely related species (C. jongiorum, C. sericea and C. albida) were insufficient to consider it a separate genus. The specimens studied match descriptions of C. ordinata from the American North Atlantic (Hoek 1982) and Japan (Hoek & Chirara 2000). According to Hoek & Chihara (2000), C. ordinata is a sub-tidal species from the open sea and is only collected from deep water. However, in Venezuela C. ordinata was found growing attached to stones in areas of moderate wave action and approximately 1 – 2 m in depth (Hoek 1982). In Japan, C. ordinata occurs on sandy bottoms, pebbles, stones and on crustose coralline algae in water that is 25 – 30 m deep. Off the west coast of Africa, specimens (as W. ordinata) were collected from water 8 – 14 m deep (Lawson & John 1982). Recently, Yoneshigue-Valentin et al. (2006) recorded the occurrence of C. ordinata (as W. ordinata) in deep water (58 m) off the south coast of Bahia (16°47’14’’S and 038°41’33’’W). Cladophora ordinata belongs to the tropical amphiatlantic group and has been collected in the Caribbean, the tropical Indian Ocean (Silva et al. 1996), and Japan, its northern limit (Hoek & Chihara 2000). In Brazil, the boundary of its distribution is the south of Espírito Santo. This study presents the first record of this species from Ceará.