In the tropics, crustose calcifying red algae (Corallinophycidae and Peyssonneliales; CCRA) are dominant and important reef builders that serve a suite of ecological functions affecting reef health. However, CCRA taxa have historically...
moreIn the tropics, crustose calcifying red algae (Corallinophycidae and Peyssonneliales; CCRA) are dominant and important reef builders that serve a suite of ecological functions affecting reef health. However, CCRA taxa have historically been overlooked in floristic and ecological studies because of their high degrees of phenotypic plasticity and morphological convergence that impede reliable identifications based on morphology. This study provides an update of the CCRA diversity of Guam (Mariana Islands) based on a recent DNA barcoding effort. This account of CCRA taxa is compared to (1) the most current species inventories for Guam based on morphological identifications and (2) similar floristic accounts of CCRA from other regions using DNA barcoding. 492 CCRA specimens were collected from Guam for which two markers, COI-5P andpsbA, were used for phylogenetic analysis and species delimitation. Phylogenetic relationships were inferred using maximum likelihood. Species richness estima...
Gibsmithia hawaiiensis is a peculiar red alga characterized by furry gelatinous lobes arising from a cartilaginous stalk. The species has been recorded from tropical reef systems throughout the Indo-Pacific. A multilocus phylogeny (UPA,...
moreGibsmithia hawaiiensis is a peculiar red alga characterized by furry gelatinous lobes arising from a cartilaginous stalk. The species has been recorded from tropical reef systems throughout the Indo-Pacific. A multilocus phylogeny (UPA, rbcL, COI-5P) of 36 specimens collected throughout the species distribution range, showed high genetic diversity at species level. Two major groups were identified, each consisting of multiple lineages. Genetic variability was low in the Hawaiian Islands and the northern Red Sea and high in the Western Indian Ocean and the Coral Triangle, where lineages overlap in distribution. Genetic distances suggest that G. hawaiiensis represents a complex of five cryptic species, with no difference observed in the external morphology corresponding to separate lineages. Anatomical and reproductive differences were observed at the microscopic level for the lineage from the Red Sea, which is here described as G. eilatensis sp. nov. The geographic range of the speci...
We identify the gorgonian Echinomuricea sp. as a keystone species in subtidal benthic communities in the Gulf of Oman, this being the first record of Echinomuricea in the northwestern Indian Ocean. An otherwise undisturbed Echinomuricea...
moreWe identify the gorgonian Echinomuricea sp. as a keystone species in subtidal benthic communities in the Gulf of Oman, this being the first record of Echinomuricea in the northwestern Indian Ocean. An otherwise undisturbed Echinomuricea dominated community at Qalhat (Gulf of Oman) underwent a marked change in community structure over a two year period. Upon the onset of marine construction activities, an outbreak of the diatom Chrysanthemodiscus floriatus Mann was an early indicator of a change in community structure. C. floriatus is a wide-spread yet enigmatic tropical species, and is a common component in damselfish gardens. Diatoms are generally overlooked in monitoring studies but here we demonstrate their potential value in monitoring hard-bottom benthic communities following sudden environmental changes, including natural disasters like tsunamis. Although records are few, Chrysanthemodiscus floriatus Mann is a widespread benthic diatom in tropical coastal communities (Round et...
FIG. 1. Map displaying the Indian Ocean countries and islands included in the biogeography affinity analysis. The countries and islands are ordered from the southwestern Indian Ocean, over the Arabian Sea, to the south-eastern Indian...
moreFIG. 1. Map displaying the Indian Ocean countries and islands included in the biogeography affinity analysis. The countries and islands are ordered from the southwestern Indian Ocean, over the Arabian Sea, to the south-eastern Indian Ocean: 1, South Africa; 2, Mozambique; 3, Madagascar; 4, Réunion; 5, Mauritius; 6, Tanzania; 7, Seychelles; 8, Kenya; 9, Somalia; 10, Yemen; 11, Oman; 12, Pakistan; 13, Maldives; 14, Sri Lanka; 15, Indonesia; 16, Australia. Inset shows a detailed image of Rodrigues with its surrounding coral reef system (striped ridges), redrawn from Wells (1988).
Since 1962, the University of Guam has housed the GUAM herbarium collection, which comprises important collections of terrestrial and marine plants from the tropical western Pacific. This herbarium contains 57,647 archived specimens,...
moreSince 1962, the University of Guam has housed the GUAM herbarium collection, which comprises important collections of terrestrial and marine plants from the tropical western Pacific. This herbarium contains 57,647 archived specimens, mostly from Micronesia, an expanse in the western Pacific the size of the continental United States and encompassing over 2,000 islands. Specimens include comprehensive collections from the region as well as the entire terrestrial and marine flora of the Mariana Islands (of which the territory of Guam is the largest and southernmost island). Unique amongst U.S. herbaria, GUAM's focal area of research is situated entirely within the Paleotropics, e.g., with lateritic soils and uplifted limestone habitats. The remote, insular and oceanic setting has also resulted in a herbarium that, for its size, has a high proportion of rare, endangered and newly discovered species. The herbarium also contains unique vouchers from island areas that have been devasta...
obpyriformis sp. nov., with comments on the family Naccariaceae. Phycologia 42: 44–55. Reticulocaulis obpyriformis Schils, sp. nov. is described from the south coast of Socotra Island (Yemen), and a second species, R. mucosissimus, is...
moreobpyriformis sp. nov., with comments on the family Naccariaceae. Phycologia 42: 44–55. Reticulocaulis obpyriformis Schils, sp. nov. is described from the south coast of Socotra Island (Yemen), and a second species, R. mucosissimus, is recorded from a similar upwelling area in the Arabian Sea (Masirah Island, Oman). These are the first published records of Naccariaceae for the Indian Ocean and end the monospecific, Hawaiian-endemic status of Reticulocaulis. Features distinguishing R. obpyriformis from R. mucosissimus include its more sparsely branched thallus, obpyriform rather than cylindrical inner cortical cells, the presence of short moniliform laterals of small spherical cells on the cortical filaments, monoecious rather than dioecious gametophytes, and the direct development of spermatangia from catenate mother cells. The morphology and anatomy of the gametophytes of this heteromorphic genus are discussed in relation to those of other naccariacean genera.
The genus Izziella Doty is reassessed based on an examination of a speci- men of Liagora orientalis J. Agardh (the species into which Izziella abbottiae Doty has been subsumed) from the Socotra Archipelago, Yemen. This species shows...
moreThe genus Izziella Doty is reassessed based on an examination of a speci- men of Liagora orientalis J. Agardh (the species into which Izziella abbottiae Doty has been subsumed) from the Socotra Archipelago, Yemen. This species shows marked dif- ferences from the type species of Liagora (L. viscida (Forsskal) C. Agardh), Ganonema (G. farinosum (Lamouroux) Fan et Wang), and Trichogloea (T. requienii (Montagne) Kutzing) and we therefore propose that Izziella be restored as an independent genus. It is our contention that Liagora, as presently constituted, displays considerable varia- tion in reproductive morphology and should probably be divided into several smaller genera.
Among the hammerhead sharks, scalloped hammerheads (Sphyrna lewini) have undergone the steepest population declines worldwide. Due to their high susceptibility to exploitation, the species is now classified as ‘critically endangered’, the...
moreAmong the hammerhead sharks, scalloped hammerheads (Sphyrna lewini) have undergone the steepest population declines worldwide. Due to their high susceptibility to exploitation, the species is now classified as ‘critically endangered’, the most threatened category listed by the International Union for Conservation of Nature. There is an urgent need for data on the distribution of S. lewini to inform the design and implementation of effective conservation management strategies, and mitigate the risk of global extinction. Environmental DNA (eDNA) is emerging as a powerful method to monitor the geographic distribution, population trends, and habitat usage of rare and endangered species. In comparison to traditional survey methods, eDNA methods offer lower cost, higher detection rates, and are non-invasive. At present, there is no targeted eDNA assay for the detection of S. lewini and existing methods to assess their distribution are either fisheries-dependent, leading to bias, or costly...
This study reports on the gelatinous red algae of the Arabian Sea (Masirah Island, Oman and Socotra Island, Yemen) belonging to the families Dumontiaceae, Nemastomataceae and Schizymeniaceae. Dudresnaya capricornica, Gibsmithia larkumii,...
moreThis study reports on the gelatinous red algae of the Arabian Sea (Masirah Island, Oman and Socotra Island, Yemen) belonging to the families Dumontiaceae, Nemastomataceae and Schizymeniaceae. Dudresnaya capricornica, Gibsmithia larkumii, Predaea laciniosa, P. weldii and Titanophora pikeana are new records for the region. The morphological and reproductive features of these species are presented, with emphasis on post-fertilization events. Platoma heteromorphum Schils sp. nov. is described from an upwelling region along the eastern coast of Masirah Island. Based on similarities in morphology and postfertilization events, this species is closely related to P. ardreanum, P. cyclocolpum (the generitype) and P. izunosimense. The connecting filament initiation in P. heteromorphum is comparable to Titanophora, but the post-fertilization processes observed in P. heteromorphum and T. pikeana clearly demarcate both genera within the Schizymeniaceae. A first impression of the gelatinous red al...
The genus Ramicrusta (order Peyssonneliales) is a new record for Micronesia, with range expansions of Ramicrusta fujiiana and R. lateralis to Guam. In addition, four species (Ramicrusta adjoulanensis, R. asanitensis, R. labtasiensis, and...
moreThe genus Ramicrusta (order Peyssonneliales) is a new record for Micronesia, with range expansions of Ramicrusta fujiiana and R. lateralis to Guam. In addition, four species (Ramicrusta adjoulanensis, R. asanitensis, R. labtasiensis, and R. taogamensis) are newly described from Guam using molecular and anatomical characters. Ramicrusta lateralis specimens from Guam share most anatomical features with the holotype description from Vanuatu, but the plants from Guam are more tightly adherent, rigid, and robust than those of Vanuatu. Ramicrusta adjoulanensis possesses a well-developed epithallus with frequent cell fusions, secondary pit connections, and lacking hair bases or trichocytes, similar to Ramicrusta bonairensis. Ramicrusta adjoulanensis differs from other Ramicrusta species in having occasionally free margins and being attached by frequently produced, relatively long rhizoids (75–100 μm long). Ramicrusta asanitensis shares features with many other species, but the thickness of...
Successful recruitment of invertebrate larvae to reef substrates is essential to the health of tropical coral reef ecosystems and their capacity to recover from disturbances. Crustose calcifying red algae (CCRA) have been identified as...
moreSuccessful recruitment of invertebrate larvae to reef substrates is essential to the health of tropical coral reef ecosystems and their capacity to recover from disturbances. Crustose calcifying red algae (CCRA) have been identified as important recruitment substrates for scleractinian corals. As such, CCRA as a whole or subgroups (e.g., crustose coralline algae, CCA) are often used at the functional group level in experimental, ecological, and monitoring studies. Species of CCRA, however, differ in their ecological roles and their value as coral recruitment substrates. Here, we (1) investigate the species richness and community composition of CCRA on experimental coral recruitment tiles, and (2) assess if there is a recruitment preference of the coral Acropora surculosa for any of these CCRA species. 27 species of two orders of CCRA (Corallinales and Peyssonneliales) were identified from the recruit tiles. None of the DNA sequences of these species matched released sequences in Gen...
ABSTRACT The gelatinous, calciferous red alga Renouxia antillana was described in 1995 based on material from Guadeloupe, French West Indies, and accommodated in a new family and order (Rhodogorgonaceae, Rhodogorgonales) along with the...
moreABSTRACT The gelatinous, calciferous red alga Renouxia antillana was described in 1995 based on material from Guadeloupe, French West Indies, and accommodated in a new family and order (Rhodogorgonaceae, Rhodogorgonales) along with the genus Rhodogorgon from Belize and Caribbean Panama. For more than 20 years, Renouxia has remained monotypic, with rare reports in the Caribbean and the Indo-Pacific (from Réunion Island to French Polynesia). DNA-based analyses of recently collected Renouxia specimens from Egypt showed that they are not conspecific with the Caribbean R. antillana and are described as R. marerubra sp. nov. Uncorrected p-distances between the Red Sea specimens and the generitype were 8.0% for COI, 6.5-7.3% for rbcL and 3.1% for UPA. Morphological and anatomical features are also presented for the newly described species and compared to its congener, with the first documented report of monoecism in the Rhodogorgonales. Besides the new record of Renouxia from the Red Sea, the geographic distribution of the genus is here extended with additional records from Sri Lanka, Indonesia, as well as the islands of Guam and Kosrae in the Western Pacific. The UPA phylogeny suggests that these new distribution records may also represent undescribed species, with representatives in two distinct genetic groups.
Abstract: Codium pulvinatum sp. nov. (Bryopsidales, Chlorophyta) is described from the southern shores of Oman and from the Mediterranean shore of Israel. The new species has a pulvinate to mamillate–globose habit and long narrow...
moreAbstract: Codium pulvinatum sp. nov. (Bryopsidales, Chlorophyta) is described from the southern shores of Oman and from the Mediterranean shore of Israel. The new species has a pulvinate to mamillate–globose habit and long narrow utricles. Molecular data from the rbcL gene show that the species is distinct from closely related species, and concatenated rbcL and rps3–rpl16 sequence data show that it is not closely related to other species with similar external morphologies. The recent discovery of well-established populations of C. pulvinatum along the central Mediterranean coast of Israel suggests that it is a new Lessepsian migrant into the Mediterranean Sea. The ecology and invasion success of the genus Codium, now with four alien species reported for the Levantine Sea, and some ecological aspects are also discussed in light of the discovery of the new species.
The tropical alga previously recognized as Gibsmithia hawaiiensis (Dumontiaceae, Rhodophyta) was recently suggested to represent a complex of species distributed throughout the Indo-Pacific Ocean and characterized by a peculiar...
moreThe tropical alga previously recognized as Gibsmithia hawaiiensis (Dumontiaceae, Rhodophyta) was recently suggested to represent a complex of species distributed throughout the Indo-Pacific Ocean and characterized by a peculiar combination of hairy (pilose) gelatinous lobes growing on cartilaginous stalks. Phylogenetic reconstructions based on three genetic markers are presented here with the inclusion of new samples. Further diversity is reported within the complex, with nine lineages spread in four major phylogenetic groups. The threshold between intra- and interspecific relationships was assessed by species delimitation methods, which indicate the existence of 8-10 putative species in the complex. Two species belonging to the Gibsmithia hawaiiensis complex are described here: G. malayensis sp. nov. from the Coral Triangle and G. indopacifica sp. nov., widely distributed in the Central and Eastern Indo-Pacific. Morphological differences in the vegetative and reproductive structure...
Increased sedimentation due to anthropogenic activities is a threat to many nearshore coral reefs. The effects on adult corals have been studied extensively and are well known. Studies about the impact of sedimentation on the early life...
moreIncreased sedimentation due to anthropogenic activities is a threat to many nearshore coral reefs. The effects on adult corals have been studied extensively and are well known. Studies about the impact of sedimentation on the early life stages of scleractinian corals, however, are rare although recruitment is essential for conserving and restoring coral reefs. Laboratory and in situ experiments with recruits of different age classes focused on the broadcast-spawning species Acropora hyacinthus and the brooding coral Leptastrea purpurea. Recruits were exposed to different sediment loads over three to five weeks. Applied sediment loads were more than one order of magnitude lower than those known to affect survival of adult coral colonies. Growth and survival of newly settled recruits were negatively affected by sediment loads that had no effect on the growth and survival of one-month-old recruits. All experiments indicated that newly settled coral recruits are most sensitive to sedimentation within the first two to four weeks post settlement. The co-occurrence of moderate sedimentation events during and immediately after periods of coral spawning can therefore reduce recruitment success substantially. These findings provide new information to develop comprehensive sediment management plans for the conservation and recovery of coral reefs affected by chronic or acute sedimentation events.
Abstract The Pacific Island region is an ideal setting for case studies on the invasion history of macroalgae in tropical coastal waters. Many textbook examples of algal invasions in this region demonstrate their significant ecological...
moreAbstract The Pacific Island region is an ideal setting for case studies on the invasion history of macroalgae in tropical coastal waters. Many textbook examples of algal invasions in this region demonstrate their significant ecological impacts on native reef communities. In light of increased maritime traffic as a potential anthropogenic dispersal mechanism for nonindigenous marine algae between tropical North Pacific Islands, a risk assessment was conducted to (1) quantify floristic disparities between marine ecoregions based on three subsets of species inventories, (2) evaluate the environmental and spatial distribution characteristics of island floras that are conducive to new introductions, and (3) establish a baseline with which future risk assessments based on a molecularly-assisted alpha taxonomy concept may be compared. The results of the environmental and floristic analyses showed that the “potentially invasive species” (i.e., species belonging to genera with known invasive representatives) constitute the best taxonomic subset for future risk assessments of marine macroalgae as this group (1) consists of an adequate—yet manageable—number of species, (2) is characterized by environmental and distribution parameters similar to that of the entire flora, (3) alleviates the deficit of non-indigenous species detection in tropical waters due to a historical bias toward temperate waters, and (4) closely mimics proportional differences in species composition between entire floras.
This paper presents a comprehensive quantitative baseline assessment of in situ net calcium carbonate accretion rates (g CaCO3 cm-2 yr-1) of early successional recruitment communities on Calcification Accretion Unit (CAU) plates deployed...
moreThis paper presents a comprehensive quantitative baseline assessment of in situ net calcium carbonate accretion rates (g CaCO3 cm-2 yr-1) of early successional recruitment communities on Calcification Accretion Unit (CAU) plates deployed on coral reefs at 78 discrete sites, across 11 islands in the central and south Pacific Oceans. Accretion rates varied substantially within and between islands, reef zones, levels of wave exposure, and island geomorphology. For forereef sites, mean accretion rates were the highest at Rose Atoll, Jarvis, and Swains Islands, and the lowest at Johnston Atoll and Tutuila. A comparison between reef zones showed higher accretion rates on forereefs compared to lagoon sites; mean accretion rates were also higher on windward than leeward sites but only for a subset of islands. High levels of spatial variability in net carbonate accretion rates reported herein draw attention to the heterogeneity of the community assemblages. Percent cover of key early success...
The primary objective of the present paper is to quantify the biogeographic affinity of the marine flora of Rodrigues within the Indian Ocean by means of the Simpson Similarity Coefficient. A second topic explores the observation that...
moreThe primary objective of the present paper is to quantify the biogeographic affinity of the marine flora of Rodrigues within the Indian Ocean by means of the Simpson Similarity Coefficient. A second topic explores the observation that certain widespread m
The 62nd Annual Meeting of the Phycological Society of America. New Orleans, Louisiana, EUA, 27-30 de Julho de 2008.