Diatomáceas epífitas em Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux (Rhodophyta) no Arquipélago de Fernando de Noronha, PE, Nordeste do Brasil

Abstract

Exemplares de Galaxaura rugosa (J. Ellis & Solander) J.V. Lamouroux foram coletados nos meses de junho/2006 e junho/2007, em três localidades do Arquipélago de Fernando de Noronha (Atalaia, Porto e Cagarras), com o objetivo de identificar a flora das diatomáceas epífitas que habita o talo da alga. Foram identificados 52 táxons distribuídos nas classes: Coscinodiscophyceae (19%), Fragilariophyceae (21%) e Bacillariophyceae (60%) denotando uma dominância de indivíduos com simetria bilateral, os quais corresponderam a 81% da flora identificada. As seguintes espécies caracterizaram a estrutura florística das diatomáceas, pois foram encontradas em mais de 70% das amostras analisadas: Amphora sp., Biddulphia biddulphiana (J.E. Smith) Boyer, Cocconeis scutellum Ehrenberg, Diploneis bombus Ehrenberg, Grammatophora marina (Lyngbye) Kützing, Mastogloia binotata (Grunow) Cleve, Navicula longa Grunow, Nitzschia sp., Psammodiscus nitidus (Gregory) Round in Mann, Rhabdonema adriaticum Kützing, Trachyneis aspera (Ehrenberg) Cleve e Tryblionella coarctata (Grunow) Mann. A diversidade específica variou entre média à alta, com os menores valores correspondendo aos florescimentos de Amphora sp. (49,3%), Mastogloia binotata (42,1%) e Nitzschia sp. (62,5%).

Quantitative variation of epiphytic diatoms in Galaxaura rugosa (Nemaliales: Rhodophyta)

“…The fragments were dried on absorbent paper, weighed on an analytic scale and submitted to direct oxidation with sodium hypochlorite at 1% for 24 hours to remove diatoms from the host. The oxidized material underwent successive washings with distilled water in a centrifuge at 1000 rpm for approximately two minutes (Costa et al, 2009). The supernatant was removed until the sample reached 15 ml, and the sediment was preserved with 1 ml of formaldehyde at 4%.…”

Ecological guilds of epiphytic diatoms (Bacillariophyta) on Acrostichum danaeifolium Längst. & Fisch in a subtropical wetland in southern Brazil

“…The vast majority of studies of epiphytic diatoms are focused on macroalgae and the under growth of marine vegetation (Costa et al, 2009). In Brazil, there are records of diatoms in angiosperms, such as Polygonum hydropiperoides Michaux.…”