Phycological Research 1998; 46: 57-61 Porphyra lilliputiana sp. nov. (Bangiales, Rhodophyta): A diminutive New Zealand endemic with novel reproductive biology Wendy A. Nelson,' Glenys A. Knight' and Michael W. Hawkes Museum of New Zealand Te Papa Tongarewa, PO Box 467, Wellington, New Zealand and ^'Department of Botany, University of British Columbia, #3529-6270 University Blvd., Vancouver, B.C. V6T 1Z4, Canada SUMMARY A new species of Porphyra, Porphyra lilliputiana, is de- scribed for the New Zealand region. This species is very small {[5] 10-20 [35] mm) and is found growing epi- phytically, epilithically and epizoically on upper inter- tidal shores of moderate exposure. Field-collected ma- terial of P. lilliputiana possessed archeosporangia, endosporangia, spermatangia and zygotosporangia. In culture, archeospores vi/ere released and germinated to form thalli. Endosporangia either developed directly into thalli or released endospores v^'hich individually formed thalli. Zygotospores developed into the concho- celis phase, which formed conchosporangia. Released conchospores formed thalli. This species is distin- guished by its small size, arrangement of reproductive cells, occurrence of endosporangia, dentate margin and habitat. Key words: Bangiales, endosporangia, new species, New Zealand, Porphyra lilliputiana, Rhodophyta. INTRODUCTION A systematic study of the genus Porphyra C.Agardh (Bangiales, Rhodophyta) in New Zealand has revealed a number of undescribed species (Nelson and Adams 1990; Nelson 1993). Life history studies are assisting our understanding of species limits within the genus in New Zealand {Nelson and Knight 1996). in earlier work {Nelson and Knight 1995), we presented the first report of endosporangia for the genus Porphyra, discovered in an undescribed species from the New Zealand region. In this paper, we describe this species of Porphyra and present the results of culture studies. MATERIALS AND METHODS Collections of Porphyra have been made from through- out the New Zealand region (Fig, 1), and deposited in the herbarium of the Museum of New Zealand Te Papa Tongarewa (WELT) (Holmgren et al. 1990). Cultures established from field-collected material have been maintained in f/2 grov^'th medium (Guillard and Ryther 1962) under the following conditions: 10"0, 9:15 h L:D cycle; 12X, 12:12 h L:D cycle; 15X, 15: 9 h L:D cycle; and at room temperature (ca. 20X) 12: 12 h L:D cycle. An Olympus CK2 inverted microscope and Olympus SC35 (Type II) camera were used for ob- serving and photographing specimens. Voucher speci- mens of cultured material are deposited in WELT, Spermatangiai regions of thalli were fixed in 3:1 eth- anol: glacial acetic acid. Chromosomes were stained us- ing aceto-iron-haematoxylin-chioral hydrate {Wittmann 1965) and photographed using an Olympus BH2 mi- croscope, RESULTS Description Porphyra lilliputiana W.A.Nelson, G.A.Knight et M.W.Hawkes {Fig. 2) Thallus minutus, usque ad 20 (35) mm altus, roseo- lus usque aeneus, ovatus usque cordatus usque re- niformis, lamina plana molli; monostromaticus; margo microscopice dentatus. Thalli monoecii; spermatan- gia in pannis secus marginem superum laminae; zy- gotosporangia in areas dispersas secus marginem la- minae; endosporangia ad basim et marginem inferum thalli praesentia; archeosporae vulgares In margine supero laminae. Epillthicae vel epiphyticae in hos- pitibus varlis vel epizoicae in conchis lampredarum bernacarumque. Thallus minute, up to 20 (35) mm in height, pink to bronze, ovate to cordate to reniform, with flat soft-tex- tured blade; monostromatic; margin microscopically dentate. Thalli monoecious; spermatangia in patches along the upper margin of the blade; zygotosporangia in scattered areas along blade margin; endosporangia occurring at the base and lower margin of the thalli; archeospores common on upper blade margin. Epilith- Communicating editor: S. Lindstrom Received 22 August 1997; accepted 11 November 1997.