Dictyopteris jamaicensis Taylor (Phaeophyceae, Dictyotales): new occurrence for the Atol das Rocas reef and for the Brazilian coast

Abstract

A project about several aspects of the ecology of marine macroalgae was carried out in the Atol das Rocas reef in the last two years. Some new occurrences of macroalgae have been recorded for the Atol, for the Brazilian coast or for both. Dictyopteris jamaicensis is herein recorded for the first time in Brazilian waters. This macroalga was collected on a large sandbank of foliose macroalgae, mainly brown algae, on the bottom around the reef, between 6 and 12 meters deep. Dictyopteris jamaicensis is very similar to D. plagiogramma and D. polypodioides, but differs from the first by the absence of lateral veins and from either by possessing clearly serrated margins. Sporangia sori, parallel to the central mibrid, were observed in this species for the first time. Even though the characters used clearly distinguish D. jamaicensis from the others species described from Brazil, a more careful study based on chemosystematics or molecular biology may show D. jamaicensis and D. polypodioides to be the same species.