Lozada-Troche, C.

The genus Ramicrusta (Peyssonneliales, Rhodophyta) in the Caribbean Sea, including Ramicrusta bonairensis sp. nov. and Ramicrusta monensis sp. nov.

Two new species of Ramicrusta (Peysson- neliaceae, Rhodophyta), Ramicrusta bonairensis from Bonaire, The Netherlands Antilles and Puerto Rico and Ramicrusta monensis from Puerto Rico are described on the basis of both morphological and genetic criteria. Both grow closely appressed to their substrata, a characteristic that differs from their Caribbean congener, Ramicrusta tex- tilis, which forms flared or broadly fluted, expanded erect tissue, and is not closely appressed throughout. The new species also share with each other, the character, seen in microscopic sections, of appearing layered due to an abrupt decrease in cell size that occurs in the perithallus. Ramicrusta bonairensis is thicker than R. monensis, form- ing crusts up to 840 μm thick and carposporangia that measure up to 80 μm in length. Ramicrusta monensis is less thick, 585–650 μm, and produces smaller carposporangia, 40–50 μm in length. Overgrowing thalli in R. monensis are commonly observed, frequently resulting in gaps visible in transverse microscopic sections. Irregular perithallial growth may also result in hollow regions. Male gameto- phytes are reported for the first time in R. textilis and in R. monensis. Mixed reproductive phases in individual thalli, with both male gametophytic structures and tetrasporan- gial nemathecia, are also observed in R. monensis. 

Date
2016
Data type
Research report
Theme
Research and monitoring
Geographic location
Bonaire

Wrangelia gordoniae, a new species of Rhodophyta (Ceramiales, Wrangeliaceae) from the tropical western Atlantic

 

Abstract

On the basis of comparative morphological and molecular analyses, a new red algal species in the genus Wrangelia(Wrangeliaceae, Ceramiales) is described from the tropical western Atlantic. Distinctive characteristics of the proposed new species, W. gordoniae, include: overall habit; built up pseudoparenchymatous cortex that is composed of 2, and in localized sites up to 3, layers of cortical cells, with the outermost layer incomplete, composed of smaller, irregular-shaped cells; and spermatangial heads with 5–6 (–7) involucres, each consisting of a single elongate cell. Analyses of SSU sequences of specimens of Wrangelia from Puerto Rico further support the presence of four genetically distinct entities. In addition to numerous recent collections, a number of herbarium specimens from different Caribbean locales previously identified as “W. penicillata” are now recognized to be W. gordoniae. The new species is compared morphologically with other Wrangelia species that also have 5 whorl branchlets per segment and a cortex that partially or wholly covers their axes. A key to the tropical western Atlantic species of Wrangelia is provided.

Date
2014
Data type
Scientific article
Theme
Research and monitoring
Journal
Geographic location
Curacao