Abstract

BRANCO, Luis Henrique Zanini; MOURA, Ariadne do Nascimento; SILVA, Adriana Cristina da  and  BITTENCOURT-OLIVEIRA, Maria do Carmo. Biodiversity and biogeographical considerations of Cyanobacteria from a Mangrove area of Pernambuco State, Brazil. Acta Bot. Bras. [online]. 2003, vol.17, n.4, pp. 585-596. ISSN 0102-3306.  http://dx.doi.org/10.1590/S0102-33062003000400010.

Mangroves are characterized by their wide environmental variations (mainly of salinity, irradiance and oxygen content) and by the relatively unstable substratum. These conditions demand specific adaptations of the organisms to successfully inhabit this environment. The main objective of the present study was to contribute with the knowledge of the biodiversity, focusing the cyanobacteria flora of some mangrove areas of Pernambuco State. Fortnightly samplings were carried out in four different sites along Paripe River, between August and December/1998, totaling 27 collected samples. The identification of the most representative cyanobacteria of the communities revealed the presence of 16 species, distributed in 11 genera, seven families and two orders. The genus Phormidium revealed the highest species number (four) and some taxa could not be identified at specific level (Myxohyella sp. and Oscillatoria sp.). The dominance of Oscillatoriales over other orders, in terms of number of species, was observed as well as the absence of heterocytous organisms, agreeing with the tendency verified in similar studies. Considering biogeographical aspects, most of the found taxa has been recorded in brackish or even marine environments from other areas, evidencing the wide geographical distribution and adaptability of these organisms. Some species found, as Microcoleus chthonoplastes Gomont, are worldwide distributed in marine or brackish habitats, while other taxa are limited to more restricted geographical areas.

Keywords : Cyanobacteria; Mangrove; taxonomic survey; biogeography; Pernambuco State.