Marine algal flora of French Polynesia III. Rhodophyta, with additions to the Phaeophyceae and Chlorophyta

This third paper in a monographic series on the marine macroalgae of French Polynesia gives a detailed coverage of the species of Rhodophyta occurring in these islands. A total of 197 taxa are presented (195 Rhodophyceae, 1 Phaeophyceae and 1 Chlorophyta; of these, 84 (or 43%) represent new records for the flora, while 7 (or 3.6%) are new species. The new combination Jania subulata (J. Ellis et Solander) N’Yeurt et Payri is made for Haliptilon subulatum (J. Ellis et Solander) W. H. Johansen. Padina stipitata Tanaka et Nozawa (Phaeophyceae) and Codium saccatum Okamura (Chlorophyceae) are notable additions to the flora from deepwater habitats in the southern Australs; 56 taxa (or 28.7%) occur only in the Austral archipelago. The flora has most affinities with that of the Hawaiian Islands (Sørensen Index = 0.30), followed by the Cook Islands and Samoa (SI = 0.26 each) and the Solomon Islands (SI = 0.25). There are some disjunct distribution patterns for several subtropical to temperate species, possibly suggesting special oceanic current routes between the southern Australs, Hawaii and the Southern Australian region

Grammephora peyssonnelioides gen. et sp. nov. (Rhodophyta, Rhodymeniaceae) from the Solomon Islands, South Pacific

A new genus and species of red alga in the Rhodymeniaceae, Grammephora peyssonnelioides, is described from both shallow and deepwater habitats in the Solomon Islands, South Pacific. The new genus and species is characterized by prostrate overlapping lobes with a strongly cartilaginous flexible texture, distinct surface linear markings perpendicular to the growing margins, and a compact three to four celled medulla of relatively small refractive cells. Tetrasporangia are elongate and decussately divided, and occur in large scattered dorsal surface sori. Cystocarps are prominent and conical, on the dorsal surface of the blade, with a network of nutritive filaments and basal nutritive tissue around the suspended, centrally located carposporophyte, with all gonimoblast initials becoming carposporangia. The columnar fusion cell is uniquely crowned by a ring of discoid cells of nonalgal origin

Liste des algues de l'expedition Santo 2006 (Vanuatu)- list of algae from the Santo 2006 expedition (Vanuatu)

During the month of August 2006, 7 participants of the workshop 'Algae' SANTO 2006 Expedition have prospected exclusively in the South of the island of Santo. Nearly 1,500 samples of calcareous algae and 'soft' algae were collected in 41 stations divided in different habitats from the coast up to 60 m deep. The results of the taxonomic study are 284 species (excluding calcareous red algae) including 8 marine phanerogams, and 4 cyanobacteria. 272 species of algae are divided into 164 Rhodophyta, Chlorophyta 82 and 26 Ochrophyta. Nine taxa would be new to science. This inventory is in addition to those already made to the Solomons (2004) and Fiji (2007) under the CRISP programme and in New Caledonia and French Polynesia for projects funded by communities themselves. South of Santo, appears as a relatively rich site and is part of the diversity gradient that extends from the most species-rich area located in the indo-Malay region the poorest area in the region is the Pacific. This study is the first inventory of marine flora of Vanuatu

Clipperton: La flore marine du complexe récifal et quelques aspects de la biodiversité et de la géomorphologie de l’île

The marine flora of the reef flats and outer slopes of Clipperton were studied by SCUBA from the surface down to a depth of 60m and reef walks on 18 sites distributed around the island. About 100 samples of algae have been collected and pressed as herbarium specimens which will be deposited at the MNHN in Paris. Sixty one species have been identified, increasing the number of species recorded from Clipperton to 83 .The results of morphological analyses confirm that the algal flora of Clipperton belongs to the Indo-Pacific biogeographical area with 75% of the species widely distributed in the West and Central Pacific and 4% species from the East Pacific side. About 14% of the species are not yet identified and could be species new science or endemic

Myriogramme melanesiensis and M. heterostroma (Delesseriaceae, Rhodophyta), two new species from the Solomon Islands and Vanuatu

Two new species of the red algal genus Myriogramme, M. melanesiensis and M. heterostroma, are described from subtidal habitats in the Solomon Islands and Vanuatu, South Pacific. Myriogramme melanesiensis is characterized by a tristromatic thallus with layers composed of subrectangular cells of approximately equal height, smooth margins lacking any spines or proliferations, and multiple ovoid to elongate two-layered, submarginal tetrasporangial sori. Myriogramme heterostroma is distinguished by its tri- to pentastromatic thallus, with a single large layer of clear medullary cells and smaller pigmented cortical cells, and tetrasporangia occurring in single, large, median sori

Pinnatiphycus menouana gen. et sp. nov. (Rhodophyta: Dicranemataceae) from New Caledonia and Fiji (South Pacific): vegetative and reproductive morphology and molecular phylogeny

A new tropical genus and species belonging to the family Dicranemataceae, Pinnatiphycus menouana, is described from lagoon and outer reef-slope habitats in New Caledonia and Fiji. The new genus differs from other members of the family by the unique combination of the following characters: (1) tetrasporangia borne in terminal nemathecia on lateral cylindrical branchlets; and (2) the disposition of cystocarps along lateral branchlets rather than on the main axis itself. The new species differs from Peltasta australis J. Agardh by the presence of cylindrical lateral branchlets along the flattened main axes and the occurrence of reproductive structures in terminal, subterminal or basal positions on the lateral branchlets. It differs from subtropical Reptataxis rhizophora (Lucas) Kraft from Lord Howe Island by the presence of both yellowish refractive medullary cell clusters and cylindrical lateral branches bearing subapical tetrasporangial sori and cystocarps, as well as a central fusion cell and the production of carposporangia in chains of two to three rather than four to six. rbcL molecular analysis of Fijian samples unequivocally places the genus in the family Dicranemataceae with 100% bootstrap support, strongly relating it to two species of Tylotus. The family itself, however, received only weak bootstrap support (66%) for distinguishing it from the clade containing the virtually Australian-endemic families Mychodeaceae and Acrotylaceae. Pinnatiphycus favors deepwater habitats (65–70 m) with low light intensities or shallower (, 30 m) but turbid high-current areas, which may have contributed to it being overlooked in the past

La macroflore marine de l'archipel des Marquises

Until the Pakaihi i te Moana 2011 expedition, there were only ten known species of marine plants from the Marquesas Islands. Following this survey, 144 additional records (excluding Corallinales and Peyssonnelia spp.) were identified from the nine islands studied. These include 94 Rhodophyta (red algae), 38 Chlorophyta (green algae) and 12 Phaeophyceae (brown algae), with several undescribed species. Due to the dynamic water motion around these wave-swept islands, the dominant flora, from the surface until about 40 meters depth, consists of red encrusting coralline algae. The broad types of habitats seen include sedimentary plains, rubble, coralline habitats dominated by the genera Porites and Millepora, bare vertical drop-offs and escarpments, and algal beds. The latter consist mainly of several species of Halimeda, notably H. distorta, H. melanesica, H. heteromorpha and H. discoidea. Species richness varies within the archipelago and from one island to the other, with a higher number of species in the central and southern islands. Half of the species were recorded only from a single island, and only 16% of the species were recorded from four or more of the nine surveyed islands. The islands of Ua Huka and Nuku Hiva show the highest diversity, notably because of a greater number of habitats, including rock pools and crevices of the basalt ledges. It is in these habitats, that are particularly rich in algal diversity, that the inhabitants of the Marquesas still collect today various edible species for use as food. The Marquesas Islands stand out from the rest of Polynesia by quite a number of aspects, and show biogeographical affinities with the Hawaiian Islands, as well as the Eastern Pacific (Guadelupe, Revillagigedo and Galápagos islands). The natural and ecological characteristics of the marine flora, together with traditional cultural practices still very much alive today, impart a special place to this archipelago within Polynesian society. These unique characteristics contribute towards supporting a regional conservation program

High metabolic variation for seaweeds in response to environmental changes: a case study of the brown algae <i>Lobophora</i> in coral reefs

In the marine environment, macroalgae face changing environmental conditions and some species are known for their high capacity to adapt to the new factors of their ecological niche. Some macroalgal metabolites play diverse ecological functions and belong to the adaptive traits of such species. Because algal metabolites are involved in many processes that shape marine biodiversity, understanding their sources of variation and regulation is therefore of utmost relevance. This work aims at exploring the possible sources of metabolic variations with time and space of four common algal species from the genus Lobophora (Dictyotales, Phaeophyceae) in the New Caledonian lagoon using a UHPLC-HRMS metabolomic fingerprinting approach. While inter-specific differences dominated, a high variability of the metabolome was noticed for each species when changing their natural habitats and types of substrates. Fatty acids derivatives and polyolefins were identified as chemomarkers of these changing conditions. The four seaweeds metabolome also displayed monthly variations over the 13-months survey and a significant correlation was made with sea surface temperature and salinity. This study highlights a relative plasticity for the metabolome of Lobophora species

A preliminary annotated checklist of the marine algae and seagrasses of the Wallis Islands (French Overseas Territory of Wallis and Futuna), South Pacific

A total of 194 species of marine algae (14 Cyanobacteria, 41 Chlorophyta, 11 Heterokontophyta and 128 Rhodophyta), as well as three species of seagrasses, represent the first published records for the isolated island of Wallis, South Pacific. The flora has its strongest affinities with Fiji and Rotuma, followed by Samoa and French Polynesia. The lack of diverse habitats and its geographical location are invoked to explain the relatively low species richness compared with localities such as Fiji and Samoa. The flora has a typically tropical component dominated by encrusting coralline red algae, the calcified green algal genera Halimeda, and assemblages of Cyanobacteria. Normally ubiquitous species such as Halimeda discoidea, and the brown algal genera Hydroclathrus, Colpomenia, Rosenvingea, Asteronema, and Chnoospora are notably absent from the island, perhaps due to seasonality and the lack of suitable habitats. The minute epiphytic red alga Acrochaetium kurogii is reported for the first time outside of its type locality in Japan, while two as yet unidentified species of red algae (Gracilaria sp. and Sebdenia sp.) could represent new taxa if further useful material is found

Four new species of Rhodophyceae from Fiji, Polynesia and Vanuatu, South Pacific

Four new species of Rhodophyceae are described from the South Pacific, with type localities in Fiji, French Polynesia and Vanuatu. Chondria bullata from the Tuamotus (French Polynesia), Vanuatu, Palmerston Atoll (Cook Islands) and Fiji is unique owing to its nonconstricted axes with markedly protruding, bubble-like cortical cells. Halymenia nukuhivensis, from the Marquesas Islands in French Polynesia, is distinguished from others in the genus by its dichotomous, papery blades issued from a strap-shaped basal region, and the equal proportion of anti-clinal, periclinal and oblique filaments in its medullary layer. Jania articulata, so far known only from the Tuamotus in French Polynesia and Manihiki in the Northern Cook Islands, superficially resembles the genus Amphiroa with its articulated branches with numerous genicula between successive dichotomies, and its large axis diameter. Meristotheca peltata from the Fiji Islands is unique among the genus by its distinctly peltate, erect habit. The recent high number of newly described species from the South Pacific region emphasizes the need for more in-depth surveys, particularly in deeper outer reef slope habitats, which remain for the most part unexplored and could yield particularly interesting new taxa or distributional records