PHENOLOGY AND MORPHOLOGY ON A NEW MEMBER OF JAPANESE GRACILARIA IN TOSA BAY, SOUTHERN JAPAN

Changes in morphological characteristics and thallus fragmentation pat terns of a new member of Japanese Gracilaria, G. lemaneiformis, were i nvestigated. The Gracilaria species occurs in abundant quantities all year round on the coast of Uranouchi Inlet in Tosa Bay, southern Japan . This Gracilaria species occurs mainly in the form of fragmented thal li. The thalli were categorized into two types: fragments possessing a holdfast (A) and fragments without a holdfast (B). The maximum length attained by A-type thalli was 123 +/- 36 cm in July, while the maximu m length of B-type thalli (121 +/- 23 cm) was obtained in September. T he highest occurrence of A-type thalli (25.41%) was in January. Howeve r, the B-type thalli occurred in greater proportions than the A-type t halli throughout the sampling period. Seasonal changes by fragmentatio n, mostly without holdfast, and free floating forms with no reproducti ve organs, are specific characteristics of this Gracilaria species in Japan that have not been found in other species of Gracilaria.