Reproductive structures in Curdiea coriacea (Gracilariales, Rhodophyta) including the first report of spermatangia for the genus

Abstract

Curdiea coriacea (Gracilariales, Rhodophyta) is endemic to New Zealand, with its distribution restricted to northern North Island. It has been collected relatively infrequently because of its subtidal habitat and the patchy distribution of populations. Commercial interest in this agarophyte species has raised questions about its reproduction and life history. Curdiea coriacea is found to possess an isomorphic alternation of generations. This report describes reproductive morphology of carpo-sporophyte, tetrasporophyte, and spermatangial plants. This is the first record of spermatangia for any member of this genus. The formation of spermatangial nemathecia distinguishes Curdiea coriacea from all other species in the Gracilariaceae for which spermatangia have been described. Tetrasporangia are also produced in nemathecia, in common with members of the closely related Australasian genus Melanthalia. In C. coriacea the carposporangia are formed in long files, the cystocarp cavity is completely filled by gonimoblast tissue, and there is no sterile vacuolated gonimoblast tissue.

Keywords:

• Curdiea coriacea
• spermatangia
• tetrasporangia
• carposporophyte
• Gracilariales
• Rhodophyta
• New Zealand
• North Island
• endemic