REPRODUCTIVE-BIOLOGY AND POLYSACCHARIDE CHEMISTRY OF THE RED ALGA CATENELLA (CAULACANTHACEAE, GIGARTINALES)

The reproductive, biology of five isolates of Catenella caespitosa fro m France, Puerto Rico and Brazil and seven isolates of C. nipae from A ustralia and the Philippines was investigated in culture. Most isolate s exhibited a Polysiphonia-type life history and bisexual gametophytes . Mixed-phase reproduction occurred in one C. caespitosa isolate from Puerto Rico and one C. nipae isolate from Australia in which female se gments of bisexual gametophytes developed zonately-divided tetrasporan gia. In C. caespitosa, male and female segments were very similar in s ize and shape, whereas in C. nipae the segments were sexually dimorphi c: the male segments being long, narrow and ringed by successive sperm atangial sori, the female segments being short and round. Male and fem ale gametangia were rarely produced together on individual segments. T etrasporophytes and gametophytes of all isolates of C. caespitosa and C. nipae from field and culture samples contained iota-carrageenan, in contrast to C. nipae from Burma that Zablackis and Santos based their initial description of alpha-carrageenan.