Genetic isolation between coastal and fishery‐impacted,offshore bottlenose dolphin (Tursiops spp.) populations

The identification of species and population boundaries is important in both evolutionary and conservation biology. In recent years, new population genetic and computational methods for estimating population parameters and testing hypotheses in a quantitative manner have emerged. Using a Bayesian framework and a quantitative model‐testing approach, we evaluated the species status and genetic connectedness of bottlenose dolphin (Tursiops spp.) populations off remote northwestern Australia, with a focus on pelagic ‘offshore’ dolphins subject to incidental capture in a trawl fishery. We analysed 71 dolphin samples from three sites beyond the 50 m depth contour (the inshore boundary of the fishery) and up to 170 km offshore, including incidentally caught and free‐ranging individuals associating with trawl vessels, and 273 dolphins sampled at 12 coastal sites inshore of the 50 m depth contour and within 10 km of the coast. Results from 19 nuclear microsatellite markers showed significant population structure between dolphins from within the fishery and coastal sites, but also among dolphins from coastal sites, identifying three coastal populations. Moreover, we found no current or historic gene flow into the offshore population in the region of the fishery, indicating a complete lack of recruitment from coastal sites. Mitochondrial DNA corroborated our findings of genetic isolation between dolphins from the offshore population and coastal sites. Most offshore individuals formed a monophyletic clade with common bottlenose dolphins (T. truncatus), while all 273 individuals sampled coastally formed a well‐supported clade of Indo‐Pacific bottlenose dolphins (T. aduncus). By including a quantitative modelling approach, our study explicitly took evolutionary processes into account for informing the conservation and management of protected species. As such, it may serve as a template for other, similarly inaccessible study populations.     

Cranial morphology and taxonomic resolution of some dolphin taxa (Delphinidae) in Australian waters,with a focus on the genus Tursiops

Phylogenetic relationships in the family Delphinidae have been widely debated. We examined 347 skulls of Tursiops, Stenella, Delphinus, Steno, Lagenodelphis, and Sousa in order to resolve the phylogenetic position of Australian species of Tursiops. Five Tursiops type specimens were included. Cranial morphology was described using 2‐dimensional (2‐D) and 3‐dimensional geometric morphometrics (3‐GM), counts and categorical data. Analyses showed a clear morphological separation of Tursiops, including type specimens, from other genera. The three Stenella species did not cluster together. Stenella attenuata clustered with Delphinus delphis, and Stenella coeruleoalba with Lagenodelphis hosei. Length and width of the skull and rostrum were important discriminators in both methods. For 3‐D data, round vs. angular posterior skull shape distinguished some genera. Taxa that overlapped in the multivariate analyses had different mean tooth counts. Our study challenges genetic studies that identified Tursiops as polyphyletic, with T. aduncus closer to S. attenuata.     

Will climate change impact the potential distribution of a native vine (Merremia peltata) which is behaving invasively in the Pacific region?

Merremia peltata is a species with uncertain status in the island nations of the Pacific region. It has been designated introduced and invasive in some countries whereas it is considered native in others. Recent increase in its abundance across some island landscapes have led to calls for its designation as an invasive species of environmental concern with biological control being suggested as a control strategy. Climate change will add to the complications of managing this species since changes in climate will influence its range limits. In this study, we develop a process‐oriented niche model of M. peltata using CLIMEX to investigate the impacts of climate change on its potential distribution. Information on the climatic requirements of M. peltata and its current geographic distribution were used to calibrate the model. The results indicate that under current climate, 273,132 km² of the land area in the region is climatically unsuitable or marginal for M. peltata whereas 664,524 km² is suitable to highly suitable. Under current climate, areas of climatic suitability for M. peltata were identified on the archipelagos of Fiji, Papua New Guinea, Solomon Islands and Vanuatu. By the end of the century, some archipelagos like Fiji, Hawaii, New Caledonia and Vanuatu will probably become more suitable while PNG and Solomon Islands become less suitable for M. peltata. The results can be used to inform biosecurity planning, management and conservation strategies on islands.     

The endemic plant families and the palms of New Caledonia: a biogeographical analysis

This paper provides a panbiogeographical analysis of the endemic plant families and the palms of New Caledonia. There are three endemic plant families in New Caledonia and several genera that were previously recognized as endemic families. Of these taxa, some are sister to widespread Northern Hemisphere or global groups (Canacomyrica, Austrotaxus, Amborella). The others belong to trans‐Indian Ocean groups (Strasburgeria), trans‐tropical Pacific groups (Oncotheca) or Tasman Sea/Coral Sea groups (Phelline, Paracryphia) that are sister to widespread Northern Hemisphere or global groups. In palms, the four clades show allopatric regional connections in, respectively: (1) western Indonesia, Malaysia and Thailand; (2) Vanuatu/Fiji and the southern Ryukyu Islands near Taiwan; (3) the western Tasman/Coral Sea (eastern Australia, New Guinea and the Solomon Islands); and (4) the eastern Tasman/Coral Sea (Lord Howe and Norfolk Islands, New Zealand, Vanuatu, Fiji and the Solomon Islands). The four clades thus belong to different centres of endemism that overlap in New Caledonia. The patterns are attributed not to chance dispersal and adaptive radiation but to the different histories of the eight terranes that fused to produce modern New Caledonia. Trans‐tropical Pacific connections can be related to the Cretaceous igneous plateaus that formed in the central Pacific and were carried, with plate movement, west to the Solomon Islands and New Zealand, and east to Colombia and the Caribbean.     

Unexpectedly complex gradation of coral population structure in the Nansei Islands,Japan

To establish effective locations and sizes of potential protected areas for reef ecosystems, detailed information about source and sink relationships between populations is critical, especially in archipelagic regions. Therefore, we assessed population structure and genetic diversity of Acropora tenuis, one of the dominant stony coral species in the Pacific, using 13 microsatellite markers to investigate 298 colonies from 15 locations across the Nansei Islands in southwestern Japan. Genetic diversity was not significant among sampling locations, even in possibly peripheral locations. In addition, our results showed that there are at least two populations of A. tenuis in the study area. The level of genetic differentiation between these populations was relatively low, but significant between many pairs of sampling locations. Directions of gene flow, which were estimated using a coalescence‐based approach, suggest that gene flow not only occurs from south to north, but also from north to south in various locations. Consequently, the Yaeyama Islands and the Amami Islands are potential northern and southern sources of corals. On the other hand, the Miyako Islands and west central Okinawa Island are potential sink populations. The Kerama Islands and the vicinity of Taketomi Island are potential contact points of genetic subdivision of coral populations in the Nansei Islands. We found that genetic population structure of A. tenuis in the Nansei Islands is more complex than previously thought. These cryptic populations are very important for preserving genetic diversity and should be maintained.     

Genetic diversity and structure of the invasive tree Miconia calvescens in Pacific islands

Aim This study investigates the amount and distribution of genetic variation within and among populations of the highly invasive tree, Miconia calvescens (Melastomataceae; hereafter miconia), in tropical island habitats that are differently impacted (distribution and spread) by this weed. Location Invasive populations were included from northern and southern Pacific islands including the Hawaiian Islands (Hawaii, Kauai and Maui), Marquesas Islands (Nuku Hiva), Society Islands (Tahiti, Tahaa, Moorea, Raiatea) and New Caledonia. Methods We used 9 codominant microsatellite and 77 highly variable dominant intersimple sequence repeat markers (ISSRs) to characterize and compare genetic diversity among and within invasive miconia populations. For the codominant microsatellite data we calculated standard population genetic estimates (heterozygosity, number of alleles, inbreeding coefficients, etc.) and described population genetic structure using AMOVA, Mantel tests (to test for isolation by distance), unweighted pair‐group method with arithmetic averages (UPGMA) cluster analysis and principal components analysis (PCA). We also tested for the presence of a population bottleneck and used a Bayesian analysis of population structure in combination with individual assignment tests. For the dominant ISSR data we used AMOVA, PCA, upgma and a Bayesian approach to investigate population genetic structure. Results Both markers types showed little to no genetic differentiation among miconia populations from northern and southern Pacific hemispheres (AMOVA: microsatellite, 3%; ISSR, 0%). Bayesian and frequency‐based analysis also failed to support geographical genetic structure, confirming considerable low genetic differentiation throughout the Pacific. Molecular data furthermore showed that highly successful miconia populations throughout the Pacific are currently undergoing severe bottlenecks and high levels of inbreeding (f = 0.91, ISSR; F_IS = 0.27, microsatellite). Main conclusions The lack of population genetic structure is indicative of similar geographical sources for both hemispheres and small founding populations. Differences in invasive spread and distribution among Pacific islands are most likely the result of differences in introduction dates to different islands and their accompanying lag phases. Miconia has been introduced to relatively few tropical islands in the Pacific, and the accidental introduction of a few or even a single seed into favourable habitats could lead to high invasive success.     

Signature whistles in free‐ranging populations of Indo‐Pacific bottlenose dolphins,Tursiops aduncus

Common bottlenose dolphins (Tursiops truncatus) use individually distinctive signature whistles which are highly stereotyped and function as contact calls. Here we investigate whether Indo‐Pacific bottlenose dolphins (T. aduncus) use signature whistles. The frequency trace of whistle contours recorded from three genetically distinct free‐ranging populations was extracted and sorted into whistle types of similar shape using automated categorization. A signature whistle identification method based on the temporal patterns in signature whistle sequences of T. truncatus was used to identify signature whistle types (SWTs). We then compared the degree of variability in SWTs for several whistle parameters to determine which parameters are likely to encode identity information. Additional recordings from two temporarily isolated T. aduncus made during natural entrapment events in 2008 and 2009 were analyzed for the occurrence of SWTs. All populations were found to produce SWTs; 34 SWTs were identified from recordings of free‐ranging T. aduncus and one SWT was prevalent in each recording of the two temporarily isolated individuals. Of the parameters considered, mean frequency and maximum frequency were the least variable and therefore most likely to reflect identity information encoded in frequency modulation patterns. Our results suggest that signature whistles are commonly used by T. aduncus.     

Assessment of genetic diversity and population structure in cultured Australian Pacific oysters

The recent development of Pacific oyster (Crassostrea gigas) SNP genotyping arrays has allowed detailed characterisation of genetic diversity and population structure within and between oyster populations. It also raises the potential of harnessing genomic selection for genetic improvement in oyster breeding programmes. The aim of this study was to characterise a breeding population of Australian oysters through genotyping and analysis of 18 027 SNPs, followed by comparison with genotypes of oyster sampled from Europe and Asia. This revealed that the Australian populations had similar population diversity (H_E) to oysters from New Zealand, the British Isles, France and Japan. Population divergence was assessed using PCA of genetic distance and revealed that Australian oysters were distinct from all other populations tested. Australian Pacific oysters originate from planned introductions sourced from three Japanese populations. Approximately 95% of these introductions were from geographically, and potentially genetically, distinct populations from the Nagasaki oysters assessed in this study. Finally, in preparation for the application of genomic selection in oyster breeding programmes, the strength of LD was evaluated and subsets of loci were tested for their ability to accurately infer relationships. Weak LD was observed on average; however, SNP subsets were shown to accurately reconstitute a genomic relationship matrix constructed using all loci. This suggests that low‐density SNP panels may have utility in the Australian population tested, and the findings represent an important first step towards the design and implementation of genomic approaches for applied breeding in Pacific oysters.     

Genome‐wide SNP analysis unveils genetic structure and phylogeographic history of snow sheep (Ovis nivicola) populations inhabiting the Verkhoyansk Mountains and Momsky Ridge (northeastern Siberia)

Insights into the genetic characteristics of a species provide important information for wildlife conservation programs. Here, we used the OvineSNP50 BeadChip developed for domestic sheep to examine population structure and evaluate genetic diversity of snow sheep (Ovis nivicola) inhabiting Verkhoyansk Range and Momsky Ridge. A total of 1,121 polymorphic SNPs were used to test 80 specimens representing five populations, including four populations of the Verkhoyansk Mountain chain: Kharaulakh Ridge–Tiksi Bay (TIK, n = 22), Orulgan Ridge (ORU, n = 22), the central part of Verkhoyansk Range (VER, n = 15), Suntar‐Khayata Ridge (SKH, n = 13), and Momsky Ridge (MOM, n = 8). We showed that the studied populations were genetically structured according to a geographic pattern. Pairwise F_ST values ranged from 0.044 to 0.205. Admixture analysis identified K = 2 as the most likely number of ancestral populations. A Neighbor‐Net tree showed that TIK was an isolated group related to the main network through ORU. TreeMix analysis revealed that TIK and MOM originated from two different ancestral populations and detected gene flow from MOM to ORU. This was supported by the f3 statistic, which showed that ORU is an admixed population with TIK and MOM/SKH heritage. Genetic diversity in the studied groups was increasing southward. Minimum values of observed (Ho) and expected (He) heterozygosity and allelic richness (Ar) were observed in the most northern population—TIK, and maximum values were observed in the most southern population—SKH. Thus, our results revealed clear genetic structure in the studied populations of snow sheep and showed that TIK has a different origin from MOM, SKH, and VER even though they are conventionally considered a single subspecies known as Yakut snow sheep (Ovis nivicola lydekkeri). Most likely, TIK was an isolated group during the Late Pleistocene glaciations of Verkhoyansk Range.     

Molecular determination of kleptoplast origins from the sea slug Plakobranchus ocellatus (Sacoglossa,Gastropoda) reveals cryptic bryopsidalean (Chlorophyta) diversity in the Hawaiian Islands

The sacoglossan sea slug species complex Plakobranchus ocellatus is a common algivore throughout the tropical Pacific, including the Hawaiian Islands. Plakobranchus ocellatus is kleptoplastic—it sequesters and retains algal chloroplasts—a characteristic that can be exploited to molecularly characterize diminutive bryopsidalean algae that are typically difficult to locate, collect, and identify. Previous DNA barcode analyses of both P. ocellatus and its kleptoplasts have been conducted primarily in the western Pacific and have only minimally sampled the most eastern populations in the Hawaiian Islands. Using two chloroplast markers, rbcL and tufA, kleptoplast samples from an Oahu population of P. ocellatus were amplified and cloned to identify their algal sources. Plakobranchus ocellatus sequester chloroplasts from up to 11 bryopsidalean algal species, all but one being diminutive in thallus size. Notably, eight of the detected algal species were new records to the Hawaiian Islands. A sequestration preference study demonstrated that the O‘ahu population of P. ocellatus preferentially sequesters chloroplasts from diminutive, epilithic taxa. Using coxI barcoding of P. ocellatus, we showed the O‘ahu population to be part of a clade that includes sequences from the neighboring island Maui, Australia, and the Philippines. The use of P. ocellatus as a novel sampling tool allows the exploration of the green algal community diversity and composition at a fine scale.     

Genetic diversity and phylogeography of Siberian roe deer,Caproulus pygargus,in central and peripheral populations

Current understanding of phylogeographical structure and genetic diversity of Siberian roe deer remains limited mainly due to small sample size and/or low geographical coverage in previous studies. Published data suggest at least two phylogroups: western (Ural Mountains and Western Siberia) and eastern (east from lake Baikal, including the Korean peninsula), but their phylogenetic relationship remains unclear. Combined sequences of cytochrome b (1140 bp) and the mtDNA control region (963 bp) were analyzed from 219 Siberian roe deer from 12 locations in Russia, Mongolia, and South Korea, which cover a large part of its range, to assess genetic diversity and phylogeographical status. Special emphasis was placed on the demographic history and genetic features of central, peripheral, and isolated populations. Results of median‐joining network and phylogenetic tree analyses indicate that Siberian roe deer from the Urals to the Pacific Ocean are genetically diverse and that geographical distribution and composition of haplogroups coincide with previously described ranges of the subspecies Capreolus pygargus pygargus and Capreolus pygargus tianschanicus. We found that peripheral populations in the northwestern parts of the species range (Urals), as well as the isolated population from Jeju Island, are genetically distinct from those in the core part of the range, both in terms of genetic diversity and quantitative composition of haplogroups. We also found that northwestern (Urals) and northern (Yakutia) peripheral populations share the same haplogroup and fall into the same phylogenetic clade with the isolated population from Jeju Island. This finding sheds light on the taxonomic status of the Jeju Island population and leads to hypotheses about the discordance of morphological and genetic evolution in isolated populations and specific genetic features of peripheral populations.     

High genetic diversity in a small population: the case of Chilean blue whales

It is generally assumed that species with low population sizes have lower genetic diversities than larger populations and vice versa. However, this would not be the case for long‐lived species with long generation times, and which populations have declined due to anthropogenic effects, such as the blue whale (Balaenoptera musculus). This species was intensively decimated globally to near extinction during the 20th century. Along the Chilean coast, it is estimated that at least 4288 blue whales were hunted from an apparently pre‐exploitation population size (k) of a maximum of 6200 individuals (Southeastern Pacific). Thus, here, we describe the mtDNA (control region) and nDNA (microsatellites) diversities of the Chilean blue whale aggregation site in order to verify the expectation of low genetic diversity in small populations. We then compare our findings with other blue whale aggregations in the Southern Hemisphere. Interestingly, although the estimated population size is small compared with the pre‐whaling era, there is still considerable genetic diversity, even after the population crash, both in mitochondrial (N = 46) and nuclear (N = 52) markers (H_d = 0.890 and H_o = 0.692, respectively). Our results suggest that this diversity could be a consequence of the long generation times and the relatively short period of time elapsed since the end of whaling, which has been observed in other heavily‐exploited whale populations. The genetic variability of blue whales on their southern Chile feeding grounds was similar to that found in other Southern Hemisphere blue whale feeding grounds. Our phylogenetic analysis of mtDNA haplotypes does not show extensive differentiation of populations among Southern Hemisphere blue whale feeding grounds. The present study suggests that although levels of genetic diversity are frequently used as estimators of population health, these parameters depend on the biology of the species and should be taken into account in a monitoring framework study to obtain a more complete picture of the conservation status of a population.     

Sebdenia cerebriformis sp. nov. (Sebdeniaceae, Sebdeniales) from the south and western Pacific Ocean

A new species of red alga, Sebdenia cerebriformis N'Yeurt et Payri sp. nov. (Sebdeniaceae, Sebdeniales), is described from various localities in the south and western Pacific including Fiji, New Caledonia, the Solomon Islands, Vanuatu, and Indonesia (Java Sea). The new species is characterized by a ruffled thallus with multiple perennial stipitate holdfasts, large conspicuous inner cortical stellate cells, and a lax filamentous medulla.     

The Kuroshio Current influences genetic diversity and population genetic structure of a tropical seagrass,Enhalus acoroides

Information on genetic diversity and differentiation of seagrass populations is essential for the conservation of coastal ecosystems. However, little is known about the seagrasses in the Indo‐West Pacific Ocean, where the world's highest diversity of seagrasses occurs. The influence of sea currents on these populations is also unknown. We estimated the genetic diversity and population genetic structure and identified reproductive features in Enhalus acoroides populations from the Yaeyama Islands, Hainan Island and the Philippines. The Philippines are situated at the centre of the E. acoroides range, Yaeyama and Hainan are peripheral populations, and the Yaeyama population is at the northern limit of the species range. The powerful Kuroshio Current flows from the Philippines to Yaeyama. Genetic analyses using nine microsatellite markers indicated that reproduction of E. acoroides is mostly sexual. Clonal diversity does not decrease in northern populations, although genetic diversity does. However, the genetic diversity of the Yaeyama populations is greater than that of the Hainan populations. Significant genetic differentiation among most populations was evident; however, the Yaeyama and north‐east Philippines populations were genetically similar, despite being separated by ~1100 km. An assignment test suggested that recruitment occurs from the north‐east Philippines to Yaeyama. The strong current in this region is probably responsible for the extant genetic diversity and recruitment patterns.     

Increases in crop pests caused by Wasmannia auropunctata in Solomon Islands subsistence gardens

The impacts of Wasmannia auropunctata (the little fire ant) on the native biota and subsistence agriculture in the Solomon Islands are poorly understood. This species was originally introduced as a biological control against nut‐fall bugs (Amblypelta sp.) around 30 years ago and in the intervening time has spread throughout the Solomon Islands, aided movement of produce and planting material. It is now itself a major pest of coconut, cocoa and subsistence agriculture. In this study, we show the negative effects of this invasive ant on subsistence agriculture in the Solomon Islands. We do this by (i) assessing the presence of insect pests that develop a mutual relationship with W. auropunctata on four common subsistence crops; and (ii) measuring the impact of a significant pest (Tarophagus sp.) and its natural predator the bug Cyrtohinus fulvus, in the presence and absence of W. auropunctata on taro crops. The existence of insect pests that form a mutual relationship with W. auropunctata was measured in a total of 36 gardens of the four subsistence crops. This was conducted through standardized visual searches, plus identification and collecting from randomly selected plants within the gardens. A number of additional insect pests causing major problems to subsistence crops have also developed mutual relationships with W. auropunctata. Infested taro gardens have more Tarophagus sp. compared with taro plants that are free of the little fire ant. The presence and abundance of Wasmannia therefore has the potential to inflict considerable crop loss in rural subsistence gardens in the Solomon Islands.     

Genetic footprints of habitat fragmentation in the extant populations of Sinojackia (Styracaceae): implications for conservation

Sinojackia, a member of the family Styracaceae, is an endangered genus endemic to China. The number of populations and population size of Sinojackia have decreased sharply because of habitat fragmentation and destruction. We studied the genetic diversity of extant populations in two different cohorts (adult and seedling) using eight microsatellite markers to investigate the genetic footprints of habitat fragmentation in four recognized Sinojackia spp. and to develop appropriate conservation measures. Data on intrapopulational genetic diversity suggest that Sinojackia populations have maintained relatively high levels of genetic diversity and low levels of genetic differentiation despite severe fragmentation. The high genetic diversity may be explained by the outcrossing mating system and high longevity of Sinojackia spp. The amount of genetic variation is not associated with population size, which was also supported by bottleneck analysis. In the species studied, there was no significant difference in the genetic diversity between the two cohorts analysed. However, inbreeding increased from adult trees to seedling populations, suggesting that the higher proportion of biparental inbreeding in the recent generations of seedlings is the result of restricted current genetic flow caused by habitat fragmentation. Average seed set per population was not significantly correlated with either population size or genetic diversity. Conservation management should aim to monitor inbreeding and outbreeding depression carefully to ensure the in situ and ex situ conservation of Sinojackia spp. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ?? , ??–??.     

Island hopping across the central Pacific: mitochondrial DNA detects sequential colonization of the Austral Islands by crab spiders (Araneae: Thomisidae)

Aim Phylogenetic studies concerning island biogeography have been concentrated in a fraction of the numerous hot‐spot archipelagos contained within the Pacific Ocean. In this study we investigate relationships among island populations of the thomisid spider Misumenops rapaensis Berland, 1934 across the Austral Islands, a remote and rarely examined southern Pacific hot‐spot archipelago. We also assess the phylogenetic position of M. rapaensis in relation to thomisids distributed across multiple Polynesian archipelagos in order to evaluate the proposed hypothesis that thomisid spiders colonized Polynesia from multiple and opposing directions. The data allow an examination of genetic divergence and species accumulation in closely related lineages distributed across four Polynesian archipelagos. Location The study focused on four Polynesian hot‐spot archipelagos: the Austral, Hawaiian, Marquesan and Society islands. Methods Mitochondrial DNA sequences comprising c. 1400 bp (portions of cytochrome oxidase subunit I, ribosomal 16S and NADH dehydrogenase subunit I) were obtained from thomisid spiders (64 specimens, representing 33 species) collected in the Australs, the Hawaiian Islands, the Society Islands, the Marquesas, Tonga, Fiji, New Zealand, New Caledonia and North and South America. Phylogenetic analyses using parsimony, maximum‐likelihood and Bayesian approaches were employed to resolve relationships of M. rapaensis to other Polynesian Misumenops and across the Austral Islands. Results Rather than grouping with other Misumenops spp. from the archipelagos of the Society Islands, Marquesas and Hawaiian Islands, M. rapaensis appears more closely related to Diaea spp. from Tonga, Fiji, New Zealand and New Caledonia. Phylogenetic analyses strongly support M. rapaensis as monophyletic across the Austral Islands. Misumenops rapaensis sampled from the two older islands (Rurutu and Tubuai) form reciprocally monophyletic groups, while individuals from the younger islands (Raivavae and Rapa) are paraphyletic. Across the Austral Islands, M. rapaensis exhibits a surprising level of genetic divergence (maximally 11.3%), an amount nearly equivalent to that found across the 16 examined Hawaiian species (14.0%). Main conclusions Although described as a single morphologically recognized species, our results suggest that M. rapaensis comprises multiple genetically distinct lineages restricted to different Austral Islands. Phylogenetic relationships among the island populations are consistent with sequential colonization of this lineage down the Austral archipelago toward younger islands. Analyses support the hypothesis that thomisid spiders colonized the central Pacific multiple times and suggest that M. rapaensis arrived in the Austral Islands from a westward direction, while Misumenops found in neighbouring archipelagos appear to be more closely related to New World congeners to the east. Finally, our data detect asymmetrical rates of morphological evolution and species diversification following colonization of four different Polynesian archipelagos.     

Population structure, mitochondrial polyphyly and the repeated loss of human biting ability in anopheline mosquitoes from the southwest Pacific

Australia and New Guinea contain high levels of endemism and biodiversity, yet there have been few evaluations of population‐level genetic diversity in fauna occurring throughout the Australo‐Papuan region. Using extensive geographical sampling, we examined and compared the phylogenetic relationships, phylogeography and population structure of Anopheles farauti, An. hinesorum and An. irenicus throughout their ranges in the southwest Pacific using mitochondrial (mtDNA COI) and nuclear (ribosomal protein S9 and ribosomal DNA ITS2) loci. Phylogenetic analyses suggest that the ability to utilize humans as hosts has been lost repeatedly, coincident with independent colonizations of the Solomon Islands. As some of the species under investigation transmit malaria in the region, this is a medically important finding. Maximum likelihood and Bayesian phylogenetic analyses of nuclear loci also showed that the three species are monophyletic. However, putative introgression of An. hinesorum mtDNA onto a nuclear background of An. farauti was evident in populations from Queensland, Torres Strait and southern New Guinea. Haplotype networks and pairwise F_ST values show that there is significant genetic structure within New Guinea and Australia in both An. farauti and An. hinesorum, consistent with a long‐term history of low gene flow among populations.     

Toward an inordinate fondness for stars,beetles and Lobophora? Species diversity of the genus Lobophora (Dictyotales,Phaeophyceae) in New Caledonia

Until the recent use of molecular markers, species diversity of Lobophora, an ecologically important brown algal genus with a worldwide distribution in temperate and tropical seas, has been critically underestimated. Using a DNA‐based taxonomic approach, we re‐examined diversity of the genus from New Caledonia in the Southwest Pacific Ocean. First, species were delineated using general mixed Yule coalescent‐based and barcoding gap approaches applied to a mitochondrial cox3 data set. Results were subsequently confirmed using chloroplast psbA and rbcL data sets. Species delimitation analyses agreed well across markers and delimitation algorithms, with the barcoding gap approach being slightly more conservative. Analyses of the cox3 data set resulted in 31–39 molecular operational taxonomic units (MOTUs), four of which are previously described species (L. asiatica, L. crassa, L. nigrescens s.l., L. pachyventera). Of the remaining MOTUs for which we obtained a representative number of sequences and results are corroborated across analyses and genes, we described 10 species de novo: L. abaculusa, L. abscondita, L. densa, L. dimorpha, L. gibbera, L. hederacea, L. monticola, L. petila, L. rosacea, and L. undulata. Our study presents an excellent case of how a traditional morphology‐based taxonomy fails to provide accurate estimates of algal diversity. Furthermore, the level of Lobophora diversity unveiled from a single locality in the Pacific Ocean raises important questions with respect to the global diversity of the genus, the distributions and range sizes of the individual species, as well as the mechanisms facilitating coexistence.     

Molecular phylogeography of the fruit bat genus Melonycteris in northern Melanesia

Aim To investigate patterns of genetic divergence between populations of the fruit bat genus Melonycteris Dobson 1877 in relation to the possible effects on dispersal of the geological history of water barriers within and between northern Melanesian archipelagos. Location The genus is found only in the Bismarck Archipelago and Solomon Islands of northern Melanesia. Methods Up to 935 aligned bases of cytochrome b and cytochrome c oxidase subunit I DNA sequences were determined for specimens of most species and subspecies of Melonycteris. Measures of genetic distance, analysis of molecular variation and phylogenetic investigations (using maximum parsimony, maximum likelihood and Bayesian approaches) were conducted to assess the evolutionary relationships amongst populations. Results The deepest divergences within Melonycteris separate the genus into two reciprocally monophyletic clades from first, the Bismarck Archipelago, and secondly, the Solomon Islands. Within the Solomon Islands, five major clades received strong support. Listed in a generally north‐western to south‐eastern direction these were: (1) specimens from Choiseul and Santa Isabel; (2) specimens from New Georgia and Kolombangara; (3) specimens from Malaita; (4) specimens from Guadalcanal; and (5) specimens from Makira. Outgroup rooting suggested that the clade from Makira was the most basal within the Solomon Islands, being shown as the sister group to all other Melonycteris from this archipelago. Main conclusions Patterns of genetic variation within Melonycteris were generally consistent, given current knowledge of northern Melanesian geological history, with the hypothesis that the dispersal of these fruit bats is strongly inhibited by water barriers. Within the Solomon Islands the main genetic clades were each restricted to a single island or to a group of islands that are thought to have belonged to larger landmasses (Greater Gatumbangara and Greater Bukida) formed by land bridges during the Pleistocene. The high genetic distance between specimens from the Bismarck Archipelago and from the Solomon Islands reflects the persistently large geographic distance between these archipelagos. The unexpected phylogenetic position of the Makira specimens suggests either that this island was the first colonized by Melonycteris in the Solomon Islands or that this population is the relict of a clade that was previously more widely distributed.