title: New diagnostic characters for the order Sporolithales (Corallinophycidae, Rhodophyta).
abstract: The diagnosis of the order Sporolithales is currently restricted to tetrasporangial anatomy. Until recently, there were few reports about gametangial, and more specifically carposporangial material for the Sporolithales. This study provides the first detailed observations of the anatomy of the mature carposporophyte phase from three species of Sporolithales commonly found in rhodolith beds from Brazil: Sporolithon episporum, S. ptychoides, and Sporolithon sp. Using these observations, along with previously published descriptions and illustrations from other representative species in the order, a comparison was made with the other three orders (Corallinales, Hapalidiales, and Rhodogorgonales) of the Corallinophycidae. We amend the diagnosis of the order Sporolithales to include the anatomy of the mature carposporophyte as follows: carposporangial conceptacles that lack a central fusion cell, but instead with numerous, short, one to two-celled, filaments that bear oblong terminal carposporangia that are distributed across the conceptacle chamber floor and walls.
authors.affiliation: Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Diretoria de Pesquisa Científica, Rua Pacheco Leão 915, Rio de Janeiro, RJ, 22460-030, Brazil.
authors.forename: Ricardo G
authors.initials: RG
authors.lastname: Bahia
authors.affiliation: Department of Biodiversity and Conservation Biology, University of the Western Cape, P. Bag X17, Bellville, 7535, South Africa.
authors.forename: Gavin W
authors.initials: GW
authors.lastname: Maneveldt
authors.affiliation: Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Diretoria de Pesquisa Científica, Rua Pacheco Leão 915, Rio de Janeiro, RJ, 22460-030, Brazil.
authors.forename: Gilberto M
authors.initials: GM
authors.lastname: Amado-Filho
authors.affiliation: Departamento de Botânica, Instituto de Biologia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ), Ilha do Fundão. Av. Brigadeiro Trompowsky, s.n., Rio de Janeiro, RJ, 21941-900, Brasil.
authors.forename: Yocie
authors.initials: Y
authors.lastname: Yoneshigue-Valentin
keywords: Sporolithon; anatomy; carposporangial conceptacles; coralline algae; taxonomy