Cultivation of Grateloupia filicina (Rhodophyta, Cryptonemiales) by Regeneration of Crusts

Abstract

Grateloupia filiclna (Lamouroux) C. Agardh, Rhodophyta, Cryptonemiales, is one of the edible marine algae used as “seaweed salad” in Japan. The carpospores and tetraspores of this alga germinate into circular crusts from which erect thalli grow up and develop to Grateloupia-thalli. When the crusts were cut into many fragments in a Petri-dish, cut fragments regenerated into similar new crusts. The crusts grew to about 1.2mm in diameter after 35 days culture. The regeneration of crusts by cutting could be repeated throughout the year, making propagation of crusts very easy. For cultivation in the sea, the cut fragments of crusts were scattered on oyster shells and synthetic twine of Nori-net and cultured for about one month in the laboratory. The substrata with regenerated crusts were transferred into the sea from October to December. Many erect thalli grew up from the substrata and developed into about 15cm in length 2 months after transfer into the sea.