Molecular phylogeny of the lionfish genera Dendrochirus and Pterois (Scorpaenidae, Pteroinae) based on mitochondrial DNA sequences

This study investigates the molecular phylogeny of seven lionfishes of the genera Dendrochirus and Pterois. MP, ML, and NJ phylogenetic analysis based on 964 bp of partial mitochondrial DNA sequences (cytochrome b and 16S rDNA) revealed two main clades: (1) “Pterois” clade (Pterois miles and Pterois volitans), and (2) “Pteropterus–Dendrochirus” clade (remainder of the sampled species). The position of Dendrochirus brachypterus either basal to the main clades or in the “Pteropterus–Dendrochirus” clade cannot be resolved. However, the molecular phylogeny did not support the current separation of the genera Pterois and Dendrochirus. The siblings P. miles and P. volitans are clearly separated and our results support the proposed allopatric or parapatric distribution in the Indian and Pacific Ocean. However, the present analysis cannot reveal if P. miles and P. volitans are separate species or two populations of a single species, because the observed separation in different clades can be either explained by speciation or lineage sorting. Molecular clock estimates for the siblings P. miles and P. volitans suggest a divergence time of 2.4–8.3 mya, which coincide with geological events that created vicariance between populations of the Indian and Pacific Ocean.     

Ecological impacts of an invasive mesopredator do not differ from those of a native mesopredator: lionfish in Caribbean Panama

Coral Reefs - The impacts of invasive lionfish (Pterois volitans/miles) on native coral reef populations in the Western Atlantic Ocean and Caribbean Sea can be enormous. However, how much lionfish...     

Mitochondrial cytochrome b analysis reveals two invasive lionfish species with strong founder effects in the western Atlantic

Lionfish (Scorpaenidae, Pteroinae) are venomous predatory fish that are native to the Indo-Pacific region and have recently become established in the western Atlantic Ocean. Since the invasion was first documented in 2000, the number of lionfish in the Atlantic has increased substantially and spurred a series of investigations regarding their biology and potential impacts on the ecosystem. The present study uses haplotypes from the mitochondria-encoded cytochrome b (cyt b ) locus to determine the number of lionfish species involved in the Atlantic invasion and the decrease in genetic diversity that accompanied the invasion. The cyt b data reveal that Pterois volitans along with a small number of Pterois miles are present in the Atlantic Ocean and that a strong founder effect has resulted in a large decrease in genetic diversity compared with native lionfish populations.     

First record of a digenean from invasive lionfish, Pterois cf. volitans, (Scorpaeniformes: Scorpaenidae) in the northwestern Atlantic Ocean

Adults of Lecithochirium floridense (Digenea: Hemiuridae) parasitized the stomach in each of 22 necropsied lionfish, Pterois cf. volitans (Scorpaeniformes: Scorpaenidae) (prevalence = 100%, mean intensity = 11), captured in the northwestern Atlantic Ocean off Beaufort, North Carolina (34°14.83'N, 76°35.25'W). This is the first report of a digenean from the invasive lionfish and that of L. floridense from a species of Pterois. The leech specimen previously identified as Myzobdella lugubris from P. volitans in the northwestern Atlantic Ocean is re-identified as Trachelobdella lubrica based on a study of the original voucher specimen.     

Indo-Pacific population structure and evolutionary history of the coconut crab Birgus latro

Mitochondrial DNA variation was used to examine population structure in a widespread, marine-dispersed species, Birgus latro . Crabs were collected from eight locations throughout the species' Indo-Pacific distribution. Purified mtDNA from 160 individuals was cut with five restriction enzymes, revealing high haplotype diversity (0.96) and moderate nucleotide diversity (0.75%). Island populations from the Indian Ocean (Christmas I.) and Pacific Ocean were significantly different ( G _ST= 0.37) and had distinct mtDNA lineages with a net sequence divergence of 1.4%. Pacific island populations had diverged in a manner consistent with isolation by distance, with only the most peripheral populations being significantly different. The results for mtDNA are largely concordant with those from allozymes, although estimates of gene flow between the Indian and Pacific Oceans were much lower when based on mtDNA. The mtDNA phylogeny also permitted a deeper examination of the evolutionary and demographic history of Birgus latro . Long-term separation of populations is evident in the complete phylogenetic subdivision of mtDNA lineages between the Indian and Pacific Ocean populations sampled. The starlike phylogeny of alleles from the Pacific suggests a rapid population expansion in the Pacific during the Pleistocene. Including information about allele phylogeny, as well as distribution and frequency, obscured contemporary population structure, but provided unique insights into the evolutionary history of the species.     

Mudwhelks and mangroves: the evolutionary history of an ecological association (Gastropoda: Potamididae)

Most of the 29 living species of Potamididae show a close association with mangroves. The trees provide the snails with shelter, protection from predators, a solid substrate and sometimes food. Using sequences from three genes (nuclear 18S rRNA and 28S rRNA, mitochondrial COI) we derive a molecular phylogeny and recognize six living genera (Terebralia, Telescopium, Tympanotonos, Cerithidea, Cerithideopsis, Cerithideopsilla). The oldest modern genera (Terebralia, Cerithideopsis) appeared in the Tethyan realm in the Middle Eocene, shortly after the origin of mangrove trees. Whereas most potamidid genera are now restricted to either the Indo-West Pacific (IWP) or to the eastern Pacific plus Atlantic (EPA), sister clades of Cerithideopsis survive in both realms. Based on a reinterpretation of the fossil record (particularly of the monotypic Tympanotonos and extinct Potamides), and parsimonious reconstruction of ancestral habitats, we suggest that the living potamidids are an adaptive radiation that has always been closely associated with mangroves. The specialized tree-climbing groups Cerithidea and Cerithideopsis were independently derived from mud-dwelling ancestors. Cerithideopsilla cingulata (a species complex in the IWP) and 'Potamides' conicus (in the Mediterranean and Indian Ocean) form a single clade within the genus Cerithideopsilla. This refutes the hypothesis that 'P.'conicus is the sole relict of the Tethyan Potamides that has occurred in the Mediterranean region since the Palaeocene. Instead, the phylogeny and fossil record suggest that an ancestor of Cerithideopsilla conica with planktotrophic larvae dispersed from the IWP to the Mediterranean in the Middle Miocene, that its direct development evolved in the Mediterranean during the Pliocene, and that it reinvaded the Indian Ocean during the Plio-Pleistocene.     

Phylogenetic relationships within the tropical soft coral genera Sarcophyton and Lobophytum (Anthozoa, Octocorallia)

Abstract. The alcyonacean soft coral genera Sarcophyton and Lobophytum are conspicuous, ecologically important members of shallow reef communities throughout the Indo-West Pacific. Study of their ecology is, however, hindered by incomplete knowledge of their taxonomy: most species cannot be identified in the field and the two genera cannot always be distinguished reliably. We used a 735-bp fragment of the octocoral-specific mitochondrial protein-coding gene msh1 to construct a phylogeny for 92 specimens identified to 19 species of Lobophytum and 16 species of Sarcophyton . All phylogenetic methods used recovered a tree with three strongly supported clades. One clade included only morphologically typical Sarcophyton species with a stalk distinct from the polypary, poorly formed club-shaped sclerites in the colony surface, and large spindles in the interior of the stalk. A second clade included only morphologically typical Lobophytum colonies with lobes and ridges on the colony surface, poorly formed clubs in the colony surface, and interior sclerites consisting of oval forms with regular girdles of ornamental warts. The third distinct clade included a mix of Sarcophyton and Lobophytum nominal species with intermediate morphologies. Most of the species in this mixed clade had a polypary that was not distinct from the stalk, and the sclerites in the colony surface were clubs with well-defined heads. Within the Sarcophyton clade, specimens identified as Sarcophyton glaucum belonged to six very distinct genetic sub-clades, suggesting that this morphologically heterogeneous species is actually a cryptic species complex. Our results highlight the need for a complete taxonomic revision of these genera, using molecular data to help confirm species boundaries as well as to guide higher taxonomic decisions.     

Inferring the mode of speciation in Indo-West Pacific Conus (Gastropoda: Conidae)

Aim This study aims to initially explore the mode of speciation in Indo‐West Pacific Conus. Location The Indo‐West Pacific island arc, Indian and Pacific Oceans. Methods Relating evolutionary divergence in a molecular phylogeny [T.F. Duda & S.R. Palumbi (1999) Proceedings of the National Academy of Science USA, 96 , 10272] using node height with modern range extents as a possible measure of allopatric or sympatric speciation following that of T.G. Barraclough, A.P. Vogler & P.H. Harvey [(1999) Evolution of Biological Diversity. Oxford University Press, Oxford] models of sympatric and allopatric speciation. Results The analysis seems to indicate that the relationship of sympatry with node height is not informative. Species that have diverged quite recently show 100% sympatry with the sister species. A clearer signal of recent allopatric speciation is observed in species whose distribution is at the edge of the Indian and Pacific Ocean basins. In the widely distributed Conus ebraeus clade, the relationships of node heights and range extents of the member species support a key prediction of sympatric speciation. In highly ecologically specialized species, there is a smaller degree of sympatry than those species that are less specialized. Main conclusions The modes of speciation models presented in this study are not informative. This suggests that there had been large and possibly rapid changes in range size after speciation in the various clades. This could have been due to the fact that the wide dispersal life‐history strategy in the genus had been largely conserved in Conus evolution. There is evidence of sympatric and parapatric speciation in one Conus clade. Overall, the patterns of phylogeny and range distribution when related to the timing of speciation lend circumstantial support to a Neogene centre of origin hypothesis but not to speciation on the Pacific Plate. Speciation is likely to have been associated with the Tethys Sea closure event, with rapid speciation occurring after closure.     

Molecular phylogeny of the Robust clade (Faviidae, Mussidae, Merulinidae, and Pectiniidae): An Indian Ocean perspective

Recent phylogenetic analyses have demonstrated the limits of traditional coral taxonomy based solely on skeletal morphology. In this phylogenetic context, Faviidae and Mussidae are ecologically dominant families comprising one third of scleractinian reef coral genera, but their phylogenies remain partially unresolved. Many of their taxa are scattered throughout most of the clades of the Robust group, and major systematic incongruences exist. Numerous genera and species remain unstudied, and the entire biogeographic area of the Indian Ocean remains largely unsampled. In this study, we analyzed a portion of the mitochondrial cytochrome c oxidase subunit 1 gene and a portion of ribosomal DNA for 14 genera and 27 species of the Faviidae and Mussidae collected from the Indian Ocean and New Caledonia and this is the first analysis of five of these species. For some taxa, newly discovered evolutionary relationships were detected, such as the evolutionary distinctiveness of Acanthastrea maxima, the genetic overlap of Parasimplastrea omanensis and Blastomussa merleti, and the peculiar position of Favites peresi in clade XVII together with Echinopora and Montastraea salebrosa. Moreover, numerous cases of intraspecific divergences between Indian Ocean and Pacific Ocean populations were detected. The most striking cases involve the genera Favites and Favia, and in particular Favites complanata, F. halicora, Favia favus, F. pallida, F. matthaii, and F. rotumana, but divergence also is evident in Blastomussa merleti, Cyphastrea serailia, and Echinopora gemmacea. High morphological variability characterizes most of these taxa, thus traditional skeletal characteristics, such as corallite arrangement, seem to be evolutionary misleading and are plagued by convergence. Our results indicate that the systematics of the Faviidae and the Mussidae is far from being resolved and that the inclusion of conspecific populations of different geographical origin represents an unavoidable step when redescribing the taxonomy and systematics of scleractinian corals. More molecular phylogenies are needed to define the evolutionary lineages that could be corroborated by known and newly discovered micromorphological characters.     

The evolutionary history of seahorses (Syngnathidae: Hippocampus): molecular data suggest a West Pacific origin and two invasions of the Atlantic Ocean

Sequence data derived from four markers (the nuclear RP1 and Aldolase and the mitochondrial 16S rRNA and cytochrome b genes) were used to determine the phylogenetic relationships among 32 species belonging to the genus Hippocampus. There were marked differences in the rate of evolution among these gene fragments, with Aldolase evolving the slowest and the mtDNA cytochrome b gene the fastest. The RP1 gene recovered the highest number of nodes supported by >70% bootstrap values from parsimony analysis and >95% posterior probabilities from Bayesian inference. The combined analysis based on 2317 nucleotides resulted in the most robust phylogeny. A distinct phylogenetic split was identified between the pygmy seahorse, Hippocampus bargibanti, and a clade including all other species. Three species from the western Pacific Ocean included in our study, namely H. bargibanti, H. breviceps, and H. abdominalis occupy basal positions in the phylogeny. This and the high species richness in the region suggests that the genus evolved somewhere in the West Pacific. There is also fairly strong molecular support for the remaining species being subdivided into three main evolutionary lineages: two West Pacific clades and a clade of species present in both the Indo-Pacific and the Atlantic Ocean. The phylogeny obtained herein suggests at least two independent colonization events of the Atlantic Ocean, once before the closure of the Tethyan seaway, and once afterwards.     

Deciphering patterns of transoceanic dispersal: the evolutionary origin and biogeography of coastal lizards (Cryptoblepharus) in the Western Indian Ocean region

Aim Cryptoblepharus is a genus of small arboreal or rock‐dwelling scincid lizards, widespread through the Indo‐Pacific and Australian regions, with a disjunct outlier in the Malagasy region. The taxonomy within this genus is controversial, with different authors ranking the different forms (now some 36) at various levels, from different species to subspecies of a single species, Cryptoblepharus boutonii. We investigated the biogeography and genetic differentiation of the Cryptoblepharus from the Western Indian Ocean region, in order to understand their origin and history. Location Western Indian Ocean region. Methods We analysed sequences of mitochondrial DNA (partial 12s and 16s rRNA genes, 766 bp) from 48 specimens collected in Madagascar, Mauritius, the four Comoros islands and East Africa, and also in New Caledonia, representing the Australo‐Pacific unit of the distribution. Results Pairwise sequence divergences of c. 3.1% were found between the New Caledonian forms and the ones from the Western Indian Ocean. Two clades were identified in Madagascar, probably corresponding to the recognized forms cognatus and voeltzkowi, and two clades were identified in the Comoro islands, where each island population formed a distinct haplotype clade. The East African samples form a monophyletic unit, with some variation existing between Pemba, Zanzibar and continental Tanzania populations. Individuals from Mauritius form a divergent group, more related to populations from Moheli and Grand Comore (Comoros islands) than to the others. Main conclusions The level of divergence between the populations from the Western Indian Ocean and Australian regions and the geographic coherence of the variation within the Western Indian Ocean group are concordant with the hypothesis of a colonization of this region by a natural transoceanic dispersal (from Australia or Indonesia). The group then may have diversified in Madagascar, from where it separately colonized the East African coast, the Comoros islands (twice), and Mauritius. The genetic divergence found is congruent with the known morphological variation, but its degree is much lower than typically seen between distinct species of reptiles.     

POPULATION STRUCTURE AND SPECIATION IN TROPICAL SEAS: GLOBAL PHYLOGEOGRAPHY OF THE SEA URCHIN DIADEMA

Abstract.— The causes of speciation in the sea are rarely obvious, because geographical barriers are not conspicuous and dispersal abilities or marine organisms, particularly those of species with planktonic larvae, are hard to determine. The phylogenetic relations of species in cosmopolitan genera can provide information on the likely mode of their formation. We reconstructed the phylogeny of the pantropical and subtropical sea urchin genus Diadema, using sequences of mitochondrial DNA from 482 individuals collected around the world, to determine the efficacy of barriers to gene flow and to ascertain the history of possible dispersal and vicariance events that led to speciation. We also compared 22 isozyme loci between all described species except D. palmeri. The mitochondrial DNA data show that the two deepest lineages are found in the Indian and West Pacific Oceans. (Indo‐Pacific) Diadema setosum diverged first from all other extant Diadema, probably during the initiation of wide fluctuations in global sea levels in the Miocene. The D. setosum clade then split 3‐5 million years ago into two clades, one found around the Arabian Peninsula and the other in the Indo‐West Pacific. On the lineage leading to the other species of Diadema, the deepest branch is composed of D. palmeri, apparently separated when the climate of New Zealand became colder and other tropical echinoids at these islands went extinct. The next lineage to separate is composed of a currently unrecognized species of Diadema that is found at Japan and the Marshall Islands. Diadema mexicanum in the eastern Pacific separated next, whereas D. paucispinum, D. savignyi, and D. antillarum from the western and central Atlantic, and (as a separate clade) D. antillarum from the eastern Atlantic form a shallow polytomy. Apparently, Indo‐Pacific populations of Diadema maintained genetic contact with Atlantic ones around the southern tip of Africa for some time after the Isthmus of Panama was complete. Diadema paucispinum contains two lineages: D. paucispinum sensu stricto is not limited to Hawaii as previously thought, but extends to Easter Island, Pitcairn, and Okinawa; A second mitochondrial clade of D. paucispinum extends from East Africa and Arabia to the Philippines and New Guinea. A more recent separation between West Indian Ocean and West Pacific populations was detected in D. setosum. Presumably, these genetic discontinuities are the result of water flow restrictions in the straits between northern Australia and Southeast Asia during Pleistocene episodes of low sea level. Diadema savignyi is characterized by high rates of gene flow from Kiribati in the central Pacific all the way to the East African Coast. In the Atlantic, there is a biogeographic barrier between the Caribbean and Brazil, possibly caused by fresh water outflow from the Amazon and the Orinoco Rivers. Diadema antillarum populations of the central Atlantic islands of Ascension and St. Helena are genetically isolated and phylogenetically derived from Brazil. Except for its genetic separation by the mid‐Atlantic barrier, Diadema seems to have maintained connections through potential barriers to dispersal (including the Isthmus of Panama) more recently than did Eucidaris or Echinometra, two other genera of sea urchins in which phylogeography has been studied. Nevertheless, the mtDNA phylogeography of Diadema includes all stages expected from models of allopatric differentiation. There are anciently separated clades that now overlap in their geographic distribution, clades isolated in the periphery of the genus range that have remained in the periphery, clades that may have been isolated in the periphery but have since spread towards the center, closely related clades on either side of an existing barrier, and closely related monophyletic entities on either side of an historical barrier that have crossed the former barrier line, but have not attained genetic equilibrium. Except for D. paucispinum and D. savignyi, in which known hybridization may have lodged mtDNA from one species into the genome of the other, closely related clades are always allopatric, and only distantly related ones overlap geographically. Thus, the phylogenetic history and distribution of extant species of Diadema is by and large consistent with allopatric speciation.     

Contrasting demographic history and phylogeographical patterns in two Indo-Pacific gastropods

Marine species with ranges that span the Indo-Australian Archipelago (IAA) exhibit a range of phylogeographical patterns, most of which are interpreted in the context of vicariance between Indian and Pacific Ocean populations during Pliocene and Pleistocene low sea-level stands. However, patterns often vary among ecologically similar taxa, sometimes even within genera. This study compares phylogeographical patterns in two species of highly dispersive neritid gastropod, Nerita albicilla and Nerita plicata, with nearly sympatric ranges that span the Indo-Pacific. Mitochondrial COI sequences from >1000 individuals from 97 sites reveal similar phylogenies in both species (two divergent clades differing by 3.2% and 2.3%, for N. albicilla and N. plicata, respectively). However, despite ecological similarity and congeneric status, the two species exhibit phylogeographical discordance. N. albicilla has maintained reciprocal monophyly of Indian and Pacific Ocean populations, while N. plicata is panmictic between oceans, but displays a genetic cline in the Central Pacific. Although this difference might be explained by qualitatively different demographic histories, parameter estimates from three coalescent models indicate that both species have high levels of gene flow between demes (2Nem>75), and share a common history of population expansion that is likely associated with cyclical flooding of continental shelves and island lagoons following low sea-level stands. Results indicate that ecologically similar, codistributed species may respond very differently to shared environmental processes, suggesting that relatively minor differences in traits such as pelagic larval duration or microhabitat association may profoundly impact phylogeographical structure.     

Molecular phylogeny of the spiny lobster genus Palinurus (Decapoda: Palinuridae) with hypotheses on speciation in the NE Atlantic/Mediterranean and SW Indian Ocean

Sequence data derived from the mitochondrial DNA 16S rRNA and COI genes were used to determine the phylogenetic relationships among six Palinurus spiny lobster species. Three species (P. charlestoni, P. elephas, and P. mauritanicus) occur in the northeastern Atlantic/Mediterranean, and the others (P. barbarae, P. delagoae and P. gilchristi) inhabit the southwestern Indian Ocean. Parsimony and model based phylogenetics strongly supported the monophyly of the genus. A combined parsimony analysis based on 1001bp and 274 parsimony informative characters recovered the most resolved phylogeny with >70% bootstrap support for associations among species. The Atlantic P. charlestoni consistently clusters nested within the Indian Ocean clade, and the mtDNA sequence divergence between the two most distant species is 8.24%. If the northward collision of Africa with Eurasia in the Miocene caused the final physical separation between the Atlantic and Indian Ocean taxa, then the Palinurus mtDNA (COI and 16S combined) evolved no faster than 0.18% (lower bound) to 0.36% (upper bound) per lineage per million years. The six extant species occur in the pathways of the North Atlantic and South Indian Ocean gyres, and hypotheses on their radiation are developed relative to the strengthening of boundary currents in the Miocene and life history traits congruent with survival in strong ocean currents.     

A cladistic phylogeny of the family Patellidae (Mollusca: Gastropoda)

A phylogenetic hypothesis for the patellid limpets is reconstructed by cladistic analysis of morphological characters from 37 species, representing all but one of the living members of the family. Characters included in the analysis are derived from shell shape and microstructure, headfoot and pallial complex, radula and sperm. The species fall into four clades, providing the basis for a new phylogenetic classification into four monophyletic genera: Helcion (four species; southern Africa), Cymbula (eight species; southern Africa, eastern Atlantic, southern Indian Ocean), Scutellastra (17 species; southern and southwestern Africa, Australia, Indo-West Pacific, Eastern Pacific) and Patella (nine species; northeastern Atlantic and Mediterranean). The analysis suggests sister-group relationships between Helcion and Cymbula, and between Scutellastra and Patella. In combination with present-day patterns of geographical distribution, this phylogenetic hypothesis is used to discuss the historical biogeography of the Patellidae. Scutellastra may have originated in southern Africa and dispersed across the Pacific, or alternatively may be a primitively Tethyan group. Both Helcion and Cymbula appear to have originated in southern Africa, but three Cymbula species have dispersed respectively to northwest Africa, St Helena and the southern Indian Ocean. The patellids of the northeastern Atlantic form a single clade, Patella (including P. pellucida), which may have arrived by northward dispersal of an ancestor from southern Africa, or possibly by vicariance of a widespread ancestral Tethyan distribution. The known fossil record of patellids is too fragmentary to permit choice between these alternatives.     

Review of Indo-Pacific dwarf lionfishes (Scorpaenidae: Pteroinae) in the <Emphasis Type="Italic">Dendrochirus brachypterus</Emphasis> complex,with description of a new species from the western Indian Ocean

A taxonomic review of the Dendrochirus brachypterus complex resulted in the recognition of five species, including Dendrochirus barberi (Steindachner 1900), Dendrochirus bellus (Jordan and Hubbs 1925), Dendrochirus brachypterus (Cuvier in Cuvier and Valenciennes 1829), Dendrochirus hemprichi sp. nov. and Dendrochirus tuamotuensis Matsunuma and Motomura 2013. The complex is defined as having usually 9 dorsal-fin soft rays, usually 5 anal-fin soft rays, 17–20 (rarely 20) pectoral-fin rays, no ocellated spots on the soft-rayed portion of the dorsal fin and usually 2 (sometimes none) barbels on the snout tip. Dendrochirus barberi, known from the Hawaiian Islands and Johnston Atoll, is characterized by usually 18 pectoral-fin rays, a relatively high number of scale rows in the longitudinal series (modally 51 vs. 39–49 in other species) and mottled markings on the pectoral fin in large specimens. Dendrochirus bellus, restricted to the northwestern Pacific Ocean from the South China Sea north to southern Japan, is characterized by usually 17 pectoral-fin rays, a relatively low number of scale rows in the longitudinal series (modally 38 vs. 44–51 in other species), and the absence of skin flaps on the orbit surface and uppermost preopercular spine base. Dendrochirus tuamotuensis, recorded only from the Tuamotu Archipelago, is characterized by 19 pectoral-fin rays, the posterior margin of the pectoral fin strongly notched, and a relatively shallow and narrow head and body. Dendrochirus hemprichi sp. nov. is distributed in the western Indian Ocean, including the Red Sea. Although previously confused with a closely related congener (D. brachypterus, known from the northern and eastern Indian Ocean and western Pacific), D. hemprichi can be distinguished from the former by having fewer scale rows between the last dorsal-fin spine base and lateral line, and between the sixth dorsal-fin spine base and lateral line [4–7 (5) in D. hemprichi vs. 5–7 (6) in D. brachypterus, in both cases], a slightly greater interorbital width at the mid-orbit [5.5–10.7 (mean 7.8) % SL vs. 4.5–8.9 (6.8) % of SL] and at preocular spine base [4.4–9.1 (6.6) % SL vs. 3.5–7.8 (5.7) % of SL], and slightly shorter posteriormost (usually 13th) dorsal-fin spine length [11.8–19.9 (15.3) % SL vs. 13.3–21.3 (17.2) % of SL]. Moreover, D. hemprichi tends to have relatively more spinous points on the head spines and ridges, compared with D. brachypterus. Notwithstanding the morphological similarity between the two species, an obvious genetic difference was observed between D. hemprichi and D. brachypterus. Dendrochirus chloreus Jenkins 1903 and Dendrochirus hudsoni Jordan and Evermann 1903 were synonymized under Pterois barberi, as in some previous studies. Scorpaena koenigii Bloch 1789 was regarded as conspecific with D. brachypterus, which it predated. However, the former name should be suppressed under Reversal of Precedence.     

A molecular phylogeny for the Tribe Dacini (Diptera: Tephritidae): systematic and biogeographic implications

With well over 700 species, the Tribe Dacini is one of the most species-rich clades within the dipteran family Tephritidae, the true fruit flies. Nearly all Dacini belong to one of two very large genera, Dacus Fabricius and Bactrocera Macquart. The distribution of the genera overlap in or around the Indian subcontinent, but the greatest diversity of Dacus is in Africa and the greatest diversity of Bactrocera is in south-east Asia and the Pacific. The monophyly of these two genera has not been rigorously established, with previous phylogenies only including a small number of species and always heavily biased to one genus over the other. Moreover, the subgeneric taxonomy within both genera is complex and the monophyly of many subgenera has not been explicitly tested. Previous hypotheses about the biogeography of the Dacini based on morphological reviews and current distributions of taxa have invoked an out-of-India hypothesis; however this has not been tested in a phylogenetic framework. We attempted to resolve these issues with a dated, molecular phylogeny of 125 Dacini species generated using 16S, COI, COII and white eye genes. The phylogeny shows that Bactrocera is not monophyletic, but rather consists of two major clades: Bactrocera s.s. and the 'Zeugodacus group of subgenera' (a recognised, but informal taxonomic grouping of 15 Bactrocera subgenera). This 'Zeugodacus' clade is the sister group to Dacus, not Bactrocera and, based on current distributions, split from Dacus before that genus moved into Africa. We recommend that taxonomic consideration be given to raising Zeugodacus to genus level. Supportive of predictions following from the out-of-India hypothesis, the first common ancestor of the Dacini arose in the mid-Cretaceous approximately 80mya. Major divergence events occurred during the Indian rafting period and diversification of Bactrocera apparently did not begin until after India docked with Eurasia (50-35mya). In contrast, diversification in Dacus, at approximately 65mya, apparently began much earlier than predicted by the out-of-India hypothesis, suggesting that, if the Dacini arose on the Indian plate, then ancestral Dacus may have left the plate in the mid to late Cretaceous via the well documented India-Madagascar-Africa migration route. We conclude that the phylogeny does not disprove the predictions of an out-of-India hypothesis for the Dacini, although modification of the original hypothesis is required.     

Molecular phylogeography reveals island colonization history and diversification of western Indian Ocean sunbirds (Nectarinia: Nectariniidae)

We constructed a phylogenetic hypothesis for western Indian Ocean sunbirds (Nectarinia) and used this to investigate the geographic pattern of their diversification among the islands of the Indian Ocean. A total of 1309 bp of mitochondrial sequence data was collected from the island sunbird taxa of the western Indian Ocean region, combined with sequence data from a selection of continental (African and Asian) sunbirds. Topological and branch length information combined with estimated divergence times are used to present hypotheses for the direction and sequence of colonization events in relation to the geological history of the Indian Ocean region. Indian Ocean sunbirds fall into two well-supported clades, consistent with two independent colonizations from Africa within the last 3.9 million years. The first clade contains island populations representing the species Nectarinia notata, while the second includes Nectarinia souimanga, Nectarinia humbloti, Nectarinia dussumieri, and Nectarinia coquereli. With respect to the latter clade, application of Bremer's [Syst. Biol. 41 (1992) 436] ancestral areas method permits us to posit the Comoros archipelago as the point of initial colonization in the Indian Ocean. The subsequent expansion of the souimanga clade across its Indian Ocean range occurred rapidly, with descendants of this early expansion remaining on the Comoros and granitic Seychelles. The data suggest that a more recent expansion from Anjouan in the Comoros group led to the colonization of Madagascar by sunbirds representing the souimanga clade. In concordance with the very young geological age of the Aldabra group, the sunbirds of this archipelago have diverged little from the Madagascar population; this is attributed to colonization of the Aldabra archipelago in recent times, in one or possibly two or more waves originating from Madagascar. The overall pattern of sunbird radiation across Indian Ocean islands indicates that these birds disperse across ocean barriers with relative ease, but that their subsequent evolutionary success probably depends on a variety of factors including prior island occupation by competing species.