Phylogeography of <Emphasis Type="Italic">Eleotris fusca</Emphasis> (Teleostei: Gobioidei: Eleotridae) in the Indo-Pacific area reveals a cryptic species in the Indian Ocean

Indo-Pacific insular freshwater systems are mainly dominated by amphidromous species. Eleotris fusca is a widespread one, its life cycle is characterised by a marine pelagic larval phase allowing the species to disperse in the ocean and then to recruit to remote island rivers. In the present study, the population structure of E. fusca over its Indo-Pacific distribution range (Western Indian Ocean to French Polynesia, Pacific Ocean) was evaluated. We analysed a section of mitochondrial COI of 557 individuals sampled from 28 islands to visualise the population structure. Haplotypes diversity (Hd) was between 0.458 and 1 and, nucleotide diversity (π) was between 0.001 and 0.02. Two distinct genetic groups appeared, one in the Indian Ocean and the other in the Pacific Ocean (F_ST mean?=?0.901; 5.2% average divergence). Given these results, complete mitogenomes (mtDNA) were sequenced and combined with the nuclear Rhodopsin (Rh) gene for a subset of individuals. The two phylogenetic trees based on each analysis showed the same genetic pattern: two different groups belonging to the Indian and the Pacific oceans (6.6 and 1.6% of divergence for mtDNA and Rh gene respectively), which supported species level differentiation. These analyses revealed the presence of two sister species confounded until present under the name of Eleotris fusca. One of them is cryptic and endemic of the Indian Ocean and the other one is the true E. fusca, which keeps, nevertheless, its status of widespread species.     

Length–weight and length–length relationships of 139 Indo‐Pacific fish species (Teleostei) from the Davao Gulf,Philippines

Length–weight relationships (LWRs) of 139 coral reef and pelagic fish species (representing 34 fish families) were calculated based on 3806 individuals measured at local fish markets near the Davao Gulf in the southern Philippines during weekly visits between March 2009 and July 2011, as well as in June 2012. Fishes were caught with a variety of fishing methods, corroborated by abrasions and injuries. Forty‐seven of 139 LWRs were firstly reported and new to science. The mean slope b of the LWRs was 3.035, indicating that the majority of studied species followed isometric growth. Standard length – total length relationships were calculated for all measured fish species. Additionally, standard length – fork length relationships are presented for 108 species. Moreover, fifteen new records of maximum fish length and weight are reported.     

Complete mitochondrial genome of spined sleeper Eleotris oxycephala (Perciformes,Eleotridae) and phylogenetic consideration

The complete mitochondrial genome of Eleotris oxycephala was determined to be 16,527 bp in length with (A + T) content of 53%, and it consists of 13 protein-coding genes, 22 tRNAs, 2 ribosomal RNAs, and a control region. The gene composition and the structural arrangement of the E. oxycephala complete mtDNA were identical to most of other vertebrates. Phylogenetic analysis based on different sequences of species of the Gobioidei suborder and different methods showed that E. oxycephala formed a cluster with Eleotris acanthopoma and Eleotridae were divided into two clades. Furthermore, extensive taxon sampling and more molecular information are needed to confirm the phylogenetic relationships among the Gobioidei.     

Review of the Acanthopagrus latus complex (Perciformes: Sparidae) with descriptions of three new species from the Indo‐West Pacific Ocean

Acanthopagrus latus, long considered a single valid Indo‐West Pacific Ocean species, characterized by having yellow pelvic, anal and caudal fins, is reviewed and separated into A. latus (east Asian shelf) and Acanthopagrus longispinnis (Bengal Bay), and three new species: Acanthopagrus morrisoni sp. nov. (north‐western Australia), Acanthopagrus arabicus sp. nov. [Middle East (except for the Red Sea) to coasts of Iran and Pakistan, and western Indian coast] and Acanthopagrus sheim sp. nov. (The Gulf). Although A. latus as redefined considerably varies in morphology and colouration, it can be recognized as a discrete east Asian endemic, with the following nominal species being junior synonyms: Chrysophrys auripes, Chrysophrys xanthopoda, Chrysophrys rubroptera and Sparus chrysopterus. Chrysophrys novaecaledoniae, known only from the holotype (type locality: Nouméa, New Caledonia), is a questionable junior synonym of A. latus, the lack of subsequent collections suggesting that the type locality is erroneous. Acanthopagrus longispinnis is differentiated from the other species in the complex by consistently having 12 dorsal‐fin spines and a much larger second anal‐fin spine, 21–26% (mean 23%) of standard length (L_S) (v. 14–24%, mean 18–21% in the other four species). Acanthopagrus morrisoni sp. nov. has the entire caudal fin yellow with a wide black posterior margin (persisting in preserved specimens) and consistently 3 ½ scale rows between the fifth dorsal‐fin spine base and the lateral line. Acanthopagrus sheim sp. nov. has the pelvic, anal and lower caudal fins vivid yellow, with two (rarely three) small black blotches on the lower inter‐radial membranes between the spinous and soft dorsal‐fin rays. Acanthopagrus arabicus sp. nov. consistently has 4 ½ scale rows between the fifth dorsal‐fin spine base and the lateral line, whereas A. latus always has black streaks proximally on the inter‐radial membranes between the yellow anal‐fin rays. A neotype and lectotye, respectively, are designated for A. latus and A. longispinnis. The p‐distance (net nucleotide substitutions per site) of partial mitochondrial 16s ribosomal RNA genes (538 bp) among the above species (except A. longispinnis) and three other congeners (Acanthopagrus berda, Acanthopagrus pacificus and Acanthopagrus bifasciatus) strongly indicates that each is a distinct species. A key is provided for the 20 species of Acanthopagrus currently known from the Indo‐West Pacific Ocean.     

Phylogeny and evolution of shallow‐water squat lobsters (Decapoda,Galatheoidea) from the Indo‐Pacific

Squat lobsters have a worldwide distribution and are highly visible crustaceans living in a broad range of habitats. In this study, partial sequences of two mitochondrial DNA genes (16S rRNA and COI) and a nuclear gene (H3) were obtained for all but one of the known species of the shallow‐water genera Sadayoshia (Munididae) and Lauriea, Macrothea and Triodonthea (Galatheidae). Lauriea siagiani appeared to be phylogenetically closer to Triodonthea and Macrothea than to other Lauriea species, suggesting the need for taxonomic re‐evaluation of these taxa. All species of Sadayoshia formed a monophyletic group that would have diverged during the Paleogene (around 50 Mya). Our results support the hypothesis that the late Paleogene–Neogene transition was a period of rapid diversification for shallow‐water species of both Galatheidae and Munididae in the Indo‐Pacific region. This is probably related to high tectonic activity among the Eurasian, Philippine Sea, Indo‐Australian and Pacific plates and corresponding changes in distribution of habitats and ocean currents during the late Paleogene. Finally, the tropical south‐west Pacific province is identified as a major diversification centre for shallow‐water squat lobsters, from where species dispersed to other Pacific and Indian Ocean regions.     

Gill‐derived glands in species of Astyanax (Teleostei: Characidae)

The presence of a gill‐derived gland is herein reported for the first time in males of species of Astyanax and related genera; they are described through histological cuts and SEM. The gill‐derived glands described for the Characidae, when fully developed, present a similar structure in different species. The main external feature of gill‐derived glands is the fusion of anteriormost gill filaments on the ventral branch of first gill arch. This fusion is caused by squamous stratified epithelial tissue that covers adjacent filaments, forming a series of chambers. In the region where the gill‐derived gland develops, the secondary lamellae of the gill filaments are much reduced or completely atrophied being characterized by the presence of glandular cells forming nests.     

Resurrection of Mesoplodon hotaula Deraniyagala 1963: A new species of beaked whale in the tropical Indo‐Pacific

We present genetic and morphological evidence supporting the recognition of a previously synonymized species of Mesoplodon beaked whale in the tropical Indo‐Pacific, Mesoplodon hotaula. Although the new species is closely‐related to the rare ginkgo‐toothed beaked whale M. ginkgodens, we show that these two lineages can be differentiated by maternally (mitochondrial DNA), biparentally (autosomal), and paternally (Y chromosome) inherited DNA sequences, as well as by morphological features. The reciprocal monophyly of the mtDNA genealogies and the largely parapatric distribution of these lineages is consistent with reproductive isolation. The new lineage is currently known from at least seven specimens: Sri Lanka (1), Gilbert Islands, Republic of Kiribati (1+), Palmyra Atoll, Northern Line Islands, U.S.A. (3), Maldives (1), and Seychelles (1). The type specimen (Sri Lanka) was described as a new species, M. hotaula, in 1963, but later synonymized with M. ginkgodens. This discovery brings the total number of Mesoplodon species to 15, making it, by far, the most speciose yet least known genus of cetaceans.     

Mosaics in the mangroves: allopatric diversification of tree‐climbing mudwhelks (Gastropoda: Potamididae: Cerithidea) in the Indo‐West Pacific

The Indo‐Australian Archipelago (IAA) is the richest area of biodiversity in the marine realm, yet the processes that generate and maintain this diversity are poorly understood and have hardly been studied in the mangrove biotope. Cerithidea is a genus of marine and brackish‐water snails restricted to mangrove habitats in the Indo‐West Pacific, and its species are believed to have a short pelagic larval life. Using molecular and morphological techniques, we demonstrate the existence of 15 species, reconstruct their phylogeny and plot their geographical ranges. Sister species show a pattern of narrowly allopatric ranges across the IAA, with overlap only between clades that show evidence of ecological differentiation. These allopatric mosaic distributions suggest that speciation may have been driven by isolation during low sea‐level stands, during episodes preceding the Plio‐Pleistocene glaciations. The Makassar Strait forms a biogeographical barrier hindering eastward dispersal, corresponding to part of Wallace's Line in the terrestrial realm. Areas of maximum diversity of mangrove plants and their associated molluscs do not coincide closely. © 2013 The Natural History Museum. Biological Journal of the Linnean Society © 2013 The Linnean Society of London, 2013, 110 , 564–580.     

New species and new records of Callionymus from the Pacific Ocean (Teleostei: Callionymidae)

Recently obtained material of Callionymus from the Pacific Ocean includes: Callionymus marquesensis sp. n. (Marquesas Islands), characterized within the C. variegatus-group of the subgenus Calliurichthys by its preopercular spine formula of with an upcurved main tip and a bony keel between the points on the dorsal margin, and a spotted dorsal fin without filaments which is higher than the 1st D₂ ray in both sexes; C. pleurostictus Fricke, 1982, record from New Britain and Solomon Islands, with a discussion of competition with C. delicatulus; C.simplicicornis Valenciennes, 1837, record from Society Islands and Marquesas Islands, with a discussion of competition with C. marquesensis; C. obscurus sp. n. (Ambon, Indonesia) which is characterized within the subgenus Spini-capitichthys by its preopercular spine formula with an upcurved main tip and very small ventral serrae, its weakly armed head, and its 7 anal fin rays.     

Phylogeny of Indo‐West Pacific pontoniine shrimps (Crustacea: Decapoda: Caridea) based on multilocus analysis

The phylogenetic relationships and evolutionary processes within the subfamily Pontoniinae, a speciose group of shrimps with diverse lifestyles (free living, semi‐symbiotic and symbiotic) inhabiting the coral reefs of tropical oceans, are an interesting and undeveloped subject of study. In this work, two mitochondrial ribosomal genes (12S rRNA and 16S rRNA) and two protein‐coding nuclear genes (Histone 3 and the sodium–potassium ATPase α‐subunit) were employed to reconstruct the phylogenetic relationships of 42 genera and 101 species within Pontoniinae. Compared to previous studies, ten additional genera were shown to be monophyletic groups, and the genera Dactylonia and Periclimenaeus were shown to be paraphyletic. The shallow‐water crinoid‐associated pontoniines were divided into several groups which were mostly consistent with the morphological analysis. The studied bivalve‐associated taxa exhibited ancestries that were traceable to different lineages, and two groups could be distinguished: Anchiopontonia + Conchodytes and Anchistus. The similar situation occurred in other echinoderm‐associated pontoniines. These results suggest that pontoniines sharing the same hosts may have different evolutionary origins resulting from multiple intrusions of their hosts by morphologically plastic ancestral groups.     

Cryptic diversity in flathead fishes (Scorpaeniformes: Platycephalidae) across the Indo‐West Pacific uncovered by DNA barcoding

Identification of taxonomical units underpins most biological endeavours ranging from accurate biodiversity estimates to the effective management of sustainably harvested, protected or endangered species. Successful species identification is now frequently based on a combination of approaches including morphometrics and DNA markers. Sequencing of the mitochondrial COI gene is an established methodology with an international campaign directed at barcoding all fishes. We employed COI sequencing alongside traditional taxonomic identification methods and uncovered instances of deep intraspecific genetic divergences among flathead species. Sixty‐five operational taxonomic units (OTUs) were observed across the Indo‐West Pacific from just 48 currently recognized species. The most comprehensively sampled taxon, Platycephalus indicus, exhibited the highest levels of genetic diversity with eight lineages separated by up to 16.37% genetic distance. Our results clearly indicate a thorough reappraisal of the current taxonomy of P. indicus (and its three junior synonyms) is warranted in conjunction with detailed taxonomic work on the other additional Platycephalidae OTUs detected by DNA barcoding.     

Comparative population structure of three snook species (Teleostei: Centropomidae) from the eastern central Pacific

Three snook species, Centropomus viridis, Centropomus medius, and Centropomus robalito, from the eastern central Pacific, representing three of the four proposed phyletic lineages in the genus, were analyzed for genetic variability by means of allozyme and RAPD to evaluate the divergence between populations at different levels of dispersal ability and to evaluate the importance of barriers to dispersal in the population subdivision and genetic diversity. Levels of genetic diversity among species estimated by allozymes were similar and consistent with the observed levels of differentiation in marine fish species. Mean heterozygosity ranged from 0.089 for C. viridis to 0.10 for C. robalito. Genetic diversity for the snook species studied was slightly higher than the mean estimation reported in allozymes for 106 marine fish (0.055) and for anadromous fish species (0.043 to 0.057). Multilocus allele frequency homogeneity tests and population-subdivision estimates for both allozyme and RAPD markers revealed the existence of population structure in C. viridis and C. medius, in coincidence with geographic separation of samples, whereas no divergence was detected in C. robalito. This finding may be attributed to the greater population size of C. robalito, which originated by a recent population range expansion, and hence the potential for dispersal is mediated by larval drift. Fluctuations in population size and population range expansion are used to explain discrepancies between levels of genetic diversity and population structure in the studied species. Supplementary material to this paper is available in electronic format at