Freshwater habitats in the Indo-Pacific Islands are colonised by amphidromous fish, which undergo a marine larval phase while the rest of the life cycle takes place in the riverine habitat. These fish are mainly represented by Gobiiformes. Among these, Stenogobius genivittatus (Valenciennes, 1837) is widely distributed in the Indo-Pacific Region, from South Africa to French Polynesia. We studied elements of the life history of S. genivittatus to better understand the processes contributing to its vast distribution: we analysed population genetic structure based on partial mitochondrial DNA sequences ( COI and ND6 ) and we used otolith microstructural analysis to estimate the duration of the marine pelagic larval phase (PLD). The analysis indicates the presence of a unique population broadly distributed across the Indo-Pacific Ocean, from South Africa to French Polynesia, while individuals from Hawaii appear to constitute a potentially distinct population. Also, our results show a homogeneous PLD in the West Indo-Pacific Region, except for Hawaii where it is longer and the Central Pacific Ocean (French Polynesia and the Marquesas) where it is shorter.

Insular biodiversity hotspots of Southeast Asia are remarkable for their biodiverse faunas. With a marine larval phase lasting up to several months, the freshwater fish subfamily Sicydiinae has colonized most islands of these hotspots. However, Sicydiinae diversity is still poorly understood in Southeast Asia. With the objective of estimating intraspecific genetic diversity and inferring past demography, we conducted the molecular inventory of Sicydiinae species in Sundaland and Wallacea using 652 bp of the mitochondrial cytochrome oxidase I gene, species delimitation methods, and Bayesian Skyline plot reconstructions. In total, 24 Molecular Operational Taxonomic Units are delimited among the 603 sequences belonging to 27 species and 5 genera. Two cases of discordance between morphology and mitochondrial sequence are observed, suggesting ongoing speciation and/or introgression in 2 genera. Multiple new occurrences are reported, either for a single biodiversity hotspot or both, some of which correspond to observations of a few individuals far from the range distribution of their conspecifics. Among the 10 species or species groups whose intraspecific diversity was examined, high levels of genetic diversity and past population expansion are revealed by Tajima’s D tests and Bayesian Skyline Plot reconstructions. Together, these results indicate that long-distance dispersal is common and suggest that most endemic species originated through founder events followed by population expansion. Patterns of sexual dimorphism and males’ coloration among diverging species pairs seem to point to sexual selection as an important mechanism contributing to speciation in the Sicydiinae of Sundaland and Wallacea.

Freshwater habitats in Indo-Pacific tropical islands are mainly inhabited by amphidromous fish, which display a marine larval phase while the rest of their life cycle takes place in rivers. Gobiiformes are the most diversified fish component in these ecosystems. In this study, we focused on the status of the widespread Stenogobius genus (Gobioidei). This genus is distributed from the Indian Ocean to French Polynesia. Recently, a first revision of Stenogobius was undertaken leading to the redescription of S. genivittatus (Valenciennes, 1837) and the placement of 12 species names as synonyms of this species. This paper focuses on the status of nine Stenogobius species supposedly present in Indonesia, a country well known as one of the freshwater hotspots of biodiversity. The present study is based on 95 specimens, and includes morphomeristic data and partial mito-chondrial COI sequences. Our results show that, at least four species occur in Indonesia, including the wide-spread species S. genivittat

This PCR protocol has been used to amplify the Cytochrome Oxydase I gene of neo-caledonian genera Boeckella, Lynceus, Eulimnadia and Streptocephalus with several primers.

The species of Eleotris from Indonesia are reviewed and compared to the known species described from the area. Nine species are recognized including three new species in the 'melanosoma' neuromast pattern group. These are described using genetic and morpho-meristic approaches. The new species differ by a high percentage of genetic divergence in partial COI gene (652 bp) and by several characters including the number of pectoral fin rays, the number of scales in lateral, predorsal, forward and zigzag series. The main characteristics of the other known species in the area in the 'melanosoma' group, Eleotris melanosoma Bleeker, 1853 and Eleotrismacrolepis (Bleeker, 1875), both belonging to this group, are given for comparison. A key for Eleotris species from Indonesia is provided.

A new species of Schismatogobius, a freshwater goby, is described from Sulawesi (Indonesia). It differs from other species belonging to the genus by a high percentage of genetic divergence in partial COI gene (652 bp) and by several characters, including the number of pectoral fin rays, the pectoral fin colour pattern, the jaw length/head length ratio and the preanal length.

ten-Abstract . – a new species of Schismatogobius, a freshwater goby, is described from Sulawesi (indonesia). it differs from other species belonging to the genus by a high percentage of genetic divergence in partial COI gene (652 bp) and by several characters, including the number of pectoral fin rays, the pectoral fin colour pattern, the jaw length/head length ratio and the preanal length. résumé . – une nouvelle espèce

Sundaland 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. Here, we established a DNA barcode reference library of the Rasborinae in Sundaland to examine species boundaries and range distributions through DNA-based species delimitation methods. A checklist of the Rasborinae of Sundaland was compiled based on online catalogs and used to estimate the taxonomic coverage of the present study. We generated a total of 991 DNA barcodes from 189 sampling sites in Sundaland. Together with 106 previously published sequences, we subsequently assembled a reference library of 1097 sequences that covers 65 taxa, including 61 of the 79 known Rasborinae species of Sundaland. Our library indicates that Rasborinae species are defined by distinct molecular lineages that are captured by species delimitation methods. A large overlap between intraspecific and interspecific genetic distance is observed that can be explained by the large amounts of cryptic diversity as evidenced by the 166 Operational Taxonomic Units detected. Implications for the evolutionary dynamics of species diversification are discussed.

Abstract The 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. Biomass, however, is a poor proxy of species richness, and automated methods of species identification are required to move beyond biomass‐based approaches. Recent meta‐analyses have demonstrated that species richness peaks at intermediary levels of biomass. Consequently, preserving biomass is not equal to preserving biodiversity. We present the results of a survey to estimate the shore fish diversity retailed at the harbor of Ambon Island, an island located at the center of the CT that display exceptionally high biomass despite high levels of threat, while building a DNA barcode reference library of CT shore fishes targeted by artisanal fisheries. We sampled 1,187 specimens and successfully barcoded 696 of the 760 selected specimens that represent 202 species. Our results show that DNA barcodes were effective in capturing species boundaries for 96% of the species examined, which opens new perspectives for the routine monitoring of the CT fisheries.

DNA 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. Here, we used DNA-based species delimitation and specimen assignment methods iteratively to tackle the inventory of the Indo-Australian Archipelago grey mullets, a notorious case of taxonomic complexity that requires DNA-based identification methods considering that traditional morphological identifications are usually not repeatable and sequence mislabeling is common in international sequence repositories. We first revisited a DNA barcode reference library available at the global scale for Mugilidae through different DNA-based species delimitation methods to produce a robust consensus scheme of species delineation. We then used this curated library to assign unknown specimens collected throughout the Indo-Australian Archipelago to known species. A second iteration of OTU delimitation and specimen assignment was then performed. We show the benefits of using species delimitation and specimen assignment methods iteratively to improve the accuracy of specimen identification and propose a workflow to do so.

Indonesian Giuris species are reviewed and compared to the known species described from the area. Three species are recognized including one new species, which is described in this paper using genetic and morphomeristic approaches. The three species differ by a high percentage of divergence in partial COI gene (652 bp) and by several characters including the number of pectoral fin rays, the scales in transverse forward series, the scales around the eye and the interorbital length.

Biodiversity hotspots have provided useful geographic proxies for conservation efforts. Delineated from a few groups of animals and plants, biodiversity hotspots do not reflect the conservation status of freshwater fishes. With hundreds of new species described on a yearly basis, fishes constitute the most poorly known group of vertebrates. This situation urges for an acceleration of the fish species inventory through fast and reliable molecular tools such as DNA barcoding. The present study focuses on the freshwater fishes diversity in the Sundaland biodiversity hotspot in Southeast Asia. Recent studies evidenced large taxonomic gaps as well as unexpectedly high levels of cryptic diversity, particularly so in the islands of Java and Bali. The Cypriniformes genera Rasbora and Nemacheilus account for most of the endemic species in Java and Bali, however their taxonomy is plagued by confusion about species identity and distribution. This study examines the taxonomic status of the Rasbora and Nemacheilus species in Java, Bali and Lombok islands through DNA barcodes, with the objective to resolve taxonomic confusion and identify trends in genetic diversity that can be further used for conservation matters. Several species delimitation methods based on DNA sequences were used and confirmed the status of most species, however several cases of taxonomic confusion and two new taxa are detected. Mitochondrial sequences argue that most species range distributions currently reported in the literature are inflated due to erroneous population assignments to the species level, and further highlight the sensitive conservation status of most Rasbora and Nemacheilus species on the islands of Java, Bali and Lombok.

Species proliferate through evolutionary mechanisms but coexist through ecological dynamics. As such, it might be expected that mechanisms of speciation and species maintenance jointly influence the settlement of ecological communities, a process called community assembly. Disentangling the relative contribution of evolutionary and ecological dynamics might be a difficult task, particularly so for the tropical biotas due to their extreme diversity and large knowledge gaps. Here, we explore genetic diversity and distribution of 23 freshwater shrimp species of the genera Caridina and Macrobrachium in Sundaland to examine patterns of species co-occurrence based on 1583 observations across 19 sites in Java and Bali islands. DNA-based species delimitation methods applied to 204 cytochrome oxidase I sequences detected 30 operational taxonomic units and a few cases of deep intraspecific divergence. Species co-occurrence and phylogenetic community structure show no departure from expectations under a random distribution of species in landscapes and support a lottery model of community assembly. Species age estimates expand beyond the geological settlement of Sundaland, suggesting that species proliferation and community assembly are driven by mechanisms acting at distinct spatial and temporal scales.

Delineating Evolutionary Significant Units for conservation purposes is a crucial step in conservation. Across a distribution range, species frequently display population structure that drives the distribution of genetic diversity. These patterns of genetic structure and diversity result from intricate interactions between biogeographic history and demographic dynamics. Prior biogeographic knowledge, however, is scarcely available, a trend particularly pronounced in the tropics where the taxonomic impediment is hampering biogeographic studies and conservation efforts. DNA barcoding has been initially proposed to foster taxonomic studies through the development of an automated molecular system of species identification. While its utility for species identification is increasingly acknowledged, its usefulness for fast and large-scale delineation of ESU remains to be explored. If proved to be useful for that purpose, DNA barcoding may also open new perspectives in conservation by quickly providing preliminary information about population conservation status. The present study aims at assessing the utility of DNA barcoding for the delineation of ESUs among the most common freshwater fish species of Java and Bali through the comparison of population genetic structures and diversification patterns across multiple species. Substantial levels of cryptic diversity are discovered among the three widely distributed freshwater fish species analyzed with a total of 21 evolutionary independent mitochondrial lineages (BINs) observed in Barbodes binotatus, Channa gachua and Glyptothorax platypogon. The maximum genetic distance for each coalescent tree ranges from 6.78 to 7.76 K2P genetic distances for C. gachua and G. platypogon, respectively. Diversification and population genetic analyses support a scenario of allopatric differentiation. The analysis of the BINs spatial distribution indicates concordant distribution patterns among the three species that allow identifying 18 ESUs. Implications for the conservation genetics of these species are discussed at the light of the history of the region.

Among the 899 species of freshwater fishes reported from Sundaland biodiversity hotspot, nearly 50% are endemics. The functional integrity of aquatic ecosystems is currently jeopardized by human activities, and landscape conversion led to the decline of fish populations in several part of Sundaland, particularly in Java. The inventory of the Javanese ichthyofauna has been discontinuous, and the taxonomic knowledge is scattered in the literature. This study provides a DNA barcode reference library for the inland fishes of Java and Bali with the aim to streamline the inventory of fishes in this part of Sundaland. Owing to the lack of available checklist for estimating the taxonomic coverage of this study, a checklist was compiled based on online catalogues. A total of 95 sites were visited, and a library including 1046 DNA barcodes for 159 species was assembled. Nearest neighbour distance was 28-fold higher than maximum intraspecific distance on average, and a DNA barcoding gap was observed. The list of species with DNA barcodes displayed large discrepancies with the checklist compiled here as only 36% (i.e. 77 species) and 60% (i.e. 24 species) of the known species were sampled in Java and Bali, respectively. This result was contrasted by a high number of new occurrences and the ceiling of the accumulation curves for both species and genera. These results highlight the poor taxonomic knowledge of this ichthyofauna, and the apparent discrepancy between present and historical occurrence data is to be attributed to species extirpations, synonymy and misidentifications in previous studies.

A new species of Stiphodon, an amphidromous goby, is described from streams of three islands in Indonesia, Java, Bali and Lombok. It differs from other species of the genus by a combination of characters including 14-15 pectoral rays, a second dorsal fin with nine segmented rays, fewer scales in predorsal, transverse forward and transverse back series, and a diagnostic golden and black pattern in male. Cybium, Vol. 39, No. 3. Hal. 219-225

A new species of Sicyopterus, freshwater goby, is described from Sumatra and Java, Indonesia. It differs from other species belonging to the genus by a combination of characters including two lateral clefts on the crenulated upper lip, a second dorsal fin with one spine and 10 segmented rays, second and third rays of the first dorsal fin filamentous, more lateral, predorsal and transverse back scales, and a reddish caudal fin in male with a slight blue line on the upper and lower parts.

With 1172 native species, the Indonesian ichthyofauna is among the world's most speciose. Despite that the inventory of the Indonesian ichthyofauna started during the eighteen century, the numerous species descriptions during the last decades highlight that the taxonomic knowledge is still fragmentary. Meanwhile, the fast increase of anthropogenic perturbations during