Tropical insular systems have long attracted biologists, stimulating some important controversies in ecology and evolution. Eustatic fluctuations during the Pleistocene have been invoked to explain species dispersal and proliferation in these fragmented systems by controlling the extent of landmasses and their temporary connections. In ancient archipelagos, the Pleistocene represents only a small slice of their history so long-standing configurations might better explain insular diversity patterns.
View Article and Find Full Text PDFThe blenniids of the genus Scartichthys are one of the most common fishes of Central and South American Pacific coastal reefs. This being said, Scartichthys spp. remain difficult to identify in the field, and identification is particularly challenging across the c.
View Article and Find Full Text PDFBiodiversity knowledge is widely heterogeneous across the Earth's biomes. Some areas, due to their remoteness and difficult access, present large taxonomic knowledge gaps. Mostly located in the tropics, these areas have frequently experienced a fast development of anthropogenic activities during the last decades and are therefore of high conservation concerns.
View Article and Find Full Text PDFPleistocene climatic fluctuations (PCF) are frequently highlighted as important evolutionary engines that triggered cycles of biome expansion and contraction. Although there is ample evidence of the impact of PCF on biodiversity of continental biomes, the consequences in insular systems depend on the geology of the islands and the ecology of the taxa inhabiting them. The idiosyncratic aspects of insular systems are exemplified by the islands of the Sunda Shelf in Southeast Asia (Sundaland), where PCF-induced eustatic fluctuations had complex interactions with the geology of the region, resulting in high species diversity and endemism.
View Article and Find Full Text PDFDNA barcoding opens new perspectives on the way we document biodiversity. Initially proposed to circumvent the limits of morphological characters to assign unknown individuals to known species, DNA barcoding has been used in a wide array of studies where collecting species identity constitutes a crucial step. The assignment of unknowns to knowns assumes that species are already well identified and delineated, making the assignment performed reliable.
View Article and Find Full Text PDFElucidating demographic history during the settlement of ecological communities is crucial for properly inferring the mechanisms that shape patterns of species diversity and their persistence through time. Here, we used genomic data and coalescent-based approaches to elucidate for the first time the demographic dynamics associated with the settlement by endemic reef fish fauna of one of the most remote peripheral islands of the Pacific Ocean, Rapa Nui (Easter Island). We compared the demographic history of nine endemic species in order to explore their demographic responses to Pleistocene climatic fluctuations.
View Article and Find Full Text PDFThe Coral Triangle (CT), a region spanning across Indonesia and Philippines, is home to about 4,350 marine fish species and is among the world's most emblematic regions in terms of conservation. Threatened by overfishing and oceans warming, the CT fisheries have faced drastic declines over the last decades. Usually monitored through a biomass-based approach, fisheries trends have rarely been characterized at the species level due to the high number of taxa involved and the difficulty to accurately and routinely identify individuals to the species level.
View Article and Find Full Text PDFSundaland constitutes one of the largest and most threatened biodiversity hotspots; however, our understanding of its biodiversity is afflicted by knowledge gaps in taxonomy and distribution patterns. The subfamily Rasborinae is the most diversified group of freshwater fishes in Sundaland. Uncertainties in their taxonomy and systematics have constrained its use as a model in evolutionary studies.
View Article and Find Full Text PDFThe emergence of DNA barcoding and metabarcoding opened new ways to study biological diversity, however, the completion of DNA barcode libraries is fundamental for such approaches to succeed. This dataset is a DNA barcode reference library (fragment of Cytochrome Oxydase I gene) for 2,190 specimens representing at least 540 species of shore fishes collected over 10 years at 154 sites across the four volcanic archipelagos of French Polynesia; the Austral, Gambier, Marquesas and Society Islands, a 5,000,000 km area. At present, 65% of the known shore fish species of these archipelagoes possess a DNA barcode associated with preserved, photographed, tissue sampled and cataloged specimens, and extensive collection locality data.
View Article and Find Full Text PDFRapa Nui, commonly known as Easter Island (Chile), is one of the most isolated tropical islands of the Pacific Ocean. The island location of Rapa Nui makes it the easternmost point of the geographic ranges for many western Pacific fish species that are restricted to the subtropical islands south of 20°S latitude. The blenniid fish species has been thought to have one of the most extensive geographic distribution ranges among these southern subtropical fish species, extending from the southern Great Barrier Reef to Rapa Nui.
View Article and Find Full Text PDFDespite the unique nature of endemic species, their origin and population history remain poorly studied. We investigated the population history of 28 coral reef fish species, close related, from the Gambier and Marquesas Islands, from five families, with range size varying from widespread to small-range endemic. We analyzed both mitochondrial and nuclear sequence data using neutrality test and Bayesian analysis (EBSP and ABC).
View Article and Find Full Text PDFProc Biol Sci
December 2014
Endemic species are frequently assumed to have lower genetic diversity than species with large distributions, even if closely related. This assumption is based on research from the terrestrial environment and theoretical evolutionary modelling. We test this assumption in the marine environment by analysing the mitochondrial genetic diversity of 33 coral reef fish species from five families sampled from Pacific Ocean archipelagos.
View Article and Find Full Text PDFA new species of wrasse, Macropharyngodon pakoko, is described from the Marquesas Islands, bringing the total number of species of the genus Macropharyngodon to 12. Macropharyngodon pakoko was found at depths from 0-42 m and is endemic to the Marquesas Islands. Macropharyngodon pakoko is similar to M.
View Article and Find Full Text PDFTwo new species of anthiine fishes are described from the Marquesas Islands, French Polynesia. Plectranthias flammeus was found at depths from 20-45 m and is characterized by dorsal rays X, 14 or 15, with spines 1-6 bearing fleshy white tabs at their tips, longest fleshy tab on spine 4; 14 unbranched pectoral rays; lateral line incomplete with 16-17 tubed scales; preopercle with 8-10 small spines along posterior margin and 2 antrorse spines on ventral margin; broad, fiery red-orange streak across lower cheek; head and body with irregularly spaced maroon-ringed yellow blotches on a white background; pair of small dark oblong spots (red with black centers in life) on the bases of the middle rays of the caudal fin. Pseudanthias oumati was found on the outer reef slope of Fatu Hiva at a depth of 50-55 m and is characterized by 3rd dorsal spine elongate and tipped with fleshy yellow filament extending beyond tip of spine; lateral-line scales 43; gill rakers 10 + 28; no papillae on posterior edge of orbit; front of upper lip not thickened (male condition unknown); caudal fin lunate; color of female yellow, all fins yellow with narrow magenta margin (except pectoral fin, which lacks magenta); no stripe from snout to pectoral base; small scales located on basal quarter of soft-dorsal fin from segmented rays 1-12; dorsal profile of head slightly concave.
View Article and Find Full Text PDFA reference collection of COI barcode (650 bp) for the Pacific Society Islands has been constituted for 22 species of Acanthuridae and 16 species of Holocentridae. Divergence between congeneric species was on average 20-fold to 87-fold higher than divergence between conspecific sequences and this set of DNA-identifiers was used to identify 40 larvae of both families. All larvae sequenced could be identified to species using DNA-barcodes.
View Article and Find Full Text PDF