Evolution of nuclear rDNA ITSsequences in the Cladophora albida/sericea clade (Chlorophyta)

Ribosomal DNA ITS sequences were compared among 13 different species and biogeographic isolates from the monophyletic albida/sericea clade in the green algal genus Cladophora. Six distinct ITS sequence types were found, characterized by multiple insertions and deletions and high levels of nucleotide substitution. Conserved domains within the ITS regions indicate the presence of ITS secondary structure. Low transition/transversion ratios among the six types and nearly symmetrical tree-length frequency distributions indicate some saturation, and low phylogenetic signal. Although branching order among five of the six ITS sequence types could not be resolved, estimates of ITS sequence divergence as compared with 18S divergence in a subset of the taxa suggests that the origin of the different ITS types is probably in the mid-Miocene (12 Ma ago) but that biogeographic isolates within a single ITS type (including both Pacific and Atlantic representatives) have probably dispersed on a time scale of thousands rather than millions of years

Clorofíceas marinhas bentônicas da Praia de Serrambi, Pernambuco, Brasil Benthic marine Chlorophyceae from Serrambi Beach, Pernambuco, Brazil

É apresentado o levantamento florístico sobre as clorofíceas marinhas bentônicas encontradas na Praia de Serrambi, litoral Sul do Estado de Pernambuco. O material estudado foi coletado em três estações, as quais foram visitadas mensalmente durante o período de abril de 1986 a setembro de 1987. As clorofíceas foram representadas na flora local por 39 espécies, três variedades e uma forma, pertencentes às ordens Ulotrichales, Ulvales, Siphonocladales, Cladophorales, Caulerpales e Dasycladales. Acetabularia calyculus Quoy & Gaimard. In Freycinet, Bryopsis pennata Lamouroux, Bryopsis plumosa (Hudson) C. Agardh, Caulerpa ambigua Okamura, Caulerpa serrulata (Forsskål) J. Agardh emend Børgesen, Chaetomorpha brachygona Harvey, Cladophora coelothrix Kützing, Cladophoropsis membranacea (C. Agardh) Børgesen, Codium intertextum Collins & Hervey, Ernodesmis verticillata (Kützing) Børgesen são novas referências para a flora do litoral de Pernambuco. Pringsheimiella scutata (Reinke) von Höhnel ex Marchewianka o é também para o litoral continental do Brasil. Halimeda opuntia (L.) Lamouroux foi hospedeira de maior número de epífitas, enquanto Bryopsis plumosa, quando epífita, foi a que cresceu sobre maior número de hospedeiros.<br>This survey presents studies about benthics marine chlorophyceae found in the Serrambi Beach, South coast of Pernambuco. The material studied was collected in three stations, which were visited monthly during the period from April, 1986 to September, 1987. The chlorophyceae were represented in this flora by 39 species, three varieties and one form, from orders Ulotrichales, Ulvales, Siphonocladales, Cladophorales, Caulerpales and Dasycladales. Acetabularia calyculus Quoy & Gaimard. In Freycinet, Bryopsis pennata Lamouroux, Bryopsis plumosa (Hudson) C. Agardh, Caulerpa ambigua Okamura, Caulerpa serrulata (Forsskål) J. Agardh emend Børgesen, Chaetomorpha brachygona Harvey, Cladophora coelothrix Kützing, Cladophoropsis membranacea (C. Agardh) Børgesen, Codium intertextum Collins & Hervey, Ernodesmis verticillata (Kützing) Børgesen are refered by first time from Pernambuco coast. Pringsheimiella scutata (Reinke) von Höhnel ex Marchewianka is for the continental Brazilian coast too. Halimeda opuntia (L.) Lamouroux was the host with the major number of epiphytes, while Bryopsis plumosa, when epiphyte, was the one that grew over the great number of hosts