Search

Phylogenetic analyses resolved that specimens from Manawatāwhi/Three Kings Islands in northern New Zealand, formerly identified as Sonderophycus coriaceus, belong to the genus Agissea (Peyssonneliales). This species is dark red, prostrate and robust, with leathery, fan-shaped lobes and is described here as Agissea teruruhau. It was found to serve as a host to a very small red algal epiphyte described here as Piriora waewaiti gen. & sp. nov. While phylogenetic analyses have placed Piriora in the Gigartinales, the familial placement of this genus has been unable to be resolved. Manawatāwhi/Three Kings Islands is a group of small islands known to harbour a rich marine biota with many endemic species, and the description of these taxa has increased the reported endemic algal flora of the islands. In addition, the phylogenetic analyses have confirmed the presence of Olokunia boudouresquei and a further three species of Peyssonneliales in the New Zealand flora, belonging to the genera Olokunia, Peyssonnelia and Seiria. [ABSTRACT FROM AUTHOR]

The ecological consequences of ocean acidification are unclear due to varying physiological properties of macroalgae and species-specific responses. Therefore, in the present study, we used a laboratory culture experiment to analyse the eco-physiological responses of the Mediterranean subtidal red alga Peyssonnelia squamaria to CO2-induced lower pH. Our results showed an increase in the photosynthetic performance and growth rate of P. squamaria, despite the reduction in CaCO3 content in the low pH treatment. According to our results, we believe that samples exposed to elevated CO2 could be regulated own nitrogen metabolism to support increased growth rate and it may be down-regulated nitrate uptake. As a result, we hypothesize that P. squamaria may benefit from ocean acidification. [ABSTRACT FROM AUTHOR]

An encrusting red alga ( Ramicrusta sp., Peyssonneliaceae) present in Lac Bay, Bonaire, overgrows and kills corals and other sessile organisms. Living coral tissue comprises 7.2 % of the benthic composition of the shallow reef, while Ramicrusta sp. covers 18.7 % of the substratum. Of 1374 coral colonies surveyed, 45.8 % were partially overgrown by Ramicrusta sp., with P. porites, P. astreoides and M. complanata being the most susceptible to overgrowth. Mean Ramicrusta sp. maximum overgrowth rates ± SD were 0.08 ± 0.05 mm d, 0.07 ± 0.03 mm d and 0.06 ± 0.02 mm d for M. complanata, P. porites and P. astreoides, respectively. None of the 71 coral recruits surveyed were growing on Ramicrusta sp. Ramicrusta sp. is an immediate threat to corals, reduces the area of suitable substratum for coral settlement and may have the ability to influence coral species composition. [ABSTRACT FROM AUTHOR]