Bryopsis hypnoides

Thicketweed is a delicate-looking seaweed, just like its family member hen pen. However, the fronds look more like tufts than feathers. It consists of a single cell with many cell nuclei, without partitions. In the Netherlands, thicketweed is only found in the delta region, particularly in the Grevelingen, and in brackish water canals. It grows well near freshwater nutrient-rich inlets.

Bryopsis hypnoides J. V. Lamouroux

Bryopsis hypnoides J. V. Lamouroux, 1809d:333; Lamouroux, 1809b:135, pl. 1; fig. 2a,b; Setchell and Gardner, 1920b:159; Smith, 1944:73, pl. 9: fig. 2; Taylor, 1945:60 [with doubt]; Dawson, 1949:244; Dawson, 1961b:381; Abbott and Hollenberg, 1976:113, fig. 71; Huerta-Müzquiz, 1978:339; Pedroche and González-González, 1981:64; L. Aguilar-Rosas and Bertsch, 1983:116, 121; Huerta-Muzquiz and Mendoza-González, 1985:44; L. Aguilar-Rosas and Pacheco-Ruíz, 1986:77; Mendoza-González and Mateo-Cid, 1986:420; Sánchez-Rodríguez et al., 1989:39; Dreckmann et al., 1990:24, pl. 2: fig. 2; Mateo-Cid and Mendoza-González, 1991:27; Rocha-Ramírez and Siqueiros-Beltrones, 1991:31; Mendoza-González and Mateo-Cid, 1992:24; Mateo-Cid and Mendoza-González, 1992:25; Mateo-Cid et al., 1993:52; González-González, 1993:443; Servière-Zaragoza et al., 1993:481; R. Aguilar-Rosas and M. Aguilar-Rosas, 1994:517; Mateo-Cid and Mendoza-González, 1994a:52; Mateo-Cid and Mendoza-González, 1994b:45; Mendoza-González et al., 1994:103, 112; González-González et al., 1996:275, 365; Mendoza-González and Mateo-Cid, 1996:64, 67, 76, 88, pl. 28: figs. 126–128; Bucio-Pacheco and Dreckmann, 1998:43; Mendoza-González and Mateo-Cid, 1998:25; Servière-Zaragoza et al., 1998:168; Yoshida, 1998:139; L. Aguilar-Rosas et al., 2000:133, 134, 136, 137; Mateo-Cid et al., 2000a:70; Cruz-Ayala et al., 2001:190; Abbott and Huisman, 2004:96, fig. 33A; Wysor, 2004:219; Pedroche et al., 2005:58; Mateo-Cid et al., 2006:59; Dreckmann et al., 2006:154.

Algae tufted, up to 2–4 cm tall; main axes 200–250(–400) µm in diameter, branching often profuse, usually radial or sometimes irregular; branches become progressively narrower and smaller distally; ultimate branchlets up to 50 µm in diameter and up to 5 mm long, abruptly constricted at the base, and gradually tapered at upper end. Rhizoids grow downward from base of primary branches.

HABITAT. On rocks or shells; epiphytic on Gelidium pusillum (L. Aguilar-Rosas et al., 2000); mid to low intertidal.

DISTRIBUTION. Gulf of California: Puerto Peñasco to Guaymas; Bahía Concepción to Cabo Pulmo. Pacific coast: British Columbia to Chiapas; Panama; Chile; Hawaiian Islands; Japan.

TYPE LOCALITY. Near Cette, Mediterranean coast of France.