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1.
Here, multi‐locus sequence data are coupled with observations of live colouration to recognize a new species, Eviota punyit from the Coral Triangle, Indian Ocean and Red Sea. Relaxed molecular clock divergence time estimation indicates a Pliocene origin for the new species, and the current distribution of the new species and its sister species Eviota sebreei supports a scenario of vicariance across the Indo‐Pacific Barrier, followed by subsequent range expansion and overlap in the Coral Triangle. These results are consistent with the ‘centre of overlap’ hypothesis, which states that the increased diversity in the Coral Triangle is due in part to the overlapping ranges of Indian Ocean and Pacific Ocean faunas. These findings are discussed in the context of other geminate pairs of coral reef fishes separated by the Indo‐Pacific Barrier.  相似文献   

2.
Aim To provide evidence suggesting the existence of a dynamic system of extinction and replacement. Location The Indo-West Pacific Ocean. Methods Utilization of species distribution patterns produced by detailed systematic works. Results The distribution patterns appear to suggest a sequence of events that is consistent with the centre of origin hypothesis. The East Indies centre is considered to operate according to the centrifugal speciation model. Main conclusions Disjunct patterns appear to have originated in the East Indies and spread out from there. In cases where the vacated area is occupied by a sibling species, competitive (sympatric) speciation may have occurred. Over time the extinction pattern will gradually extend outward until it is played out among small populations far from their centre of origin  相似文献   

3.
Towards a panbiogeography of the seas   总被引:3,自引:0,他引:3  
A contrast is drawn between the concept of speciation favoured in the Darwin–Wallace biogeographic paradigm (founder dispersal from a centre of origin) and in panbiogeography (vicariance or allopatry). Ordinary ecological dispersal is distinguished from founder dispersal. A survey of recent literature indicates that ideas on many aspects of marine biology are converging on a panbiogeographic view. Panbiogeographic conclusions supported in recent work include the following observations: fossils give minimum ages for groups and most taxa are considerably older than their earliest known fossil; Pacific/Atlantic divergence calibrations based on the rise of the Isthmus of Panama at 3 Ma are flawed; for these two reasons most molecular clock calibrations for marine groups are also flawed; the means of dispersal of taxa do not correlate with their actual distributions; populations of marine species may be closed systems because of self‐recruitment; most marine taxa show at least some degree of vicariant differentiation and vicariance is surprisingly common among what were previously assumed to be uniform, widespread taxa; mangrove and seagrass biogeography and migration patterns in marine taxa are best explained by vicariance; the Indian Ocean and the Pacific Ocean represent major biogeographic regions and diversity in the Indo‐Australian Archipelago is related to Indian Ocean/Pacific Ocean vicariance; distribution in the Pacific is not the result of founder dispersal; distribution in the south‐west Pacific is accounted for by accretion tectonics which bring about distribution by accumulation and juxtaposition of communities; tectonic uplift and subsidence can directly affect vertical distribution of marine communities; substantial parallels exist between the biogeography of terrestrial and marine taxa; biogeographically and geologically composite areas are tractable using panbiogeographic analysis; metapopulation models are more realistic than the mainland/island dispersal models used in the equilibrium theory of island biogeography; and regional biogeography is a major determinant of local community composition. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 84 , 675–723.  相似文献   

4.
The finless porpoise (genus Neophocaena) is a poorly known cetacean of great conservation concern. Within its range, from western Pacific to northwestern Indian Ocean, there are currently two species recognized (N. asiaeorientalis and N. phocaenoides), thought to be reproductively isolated since last glacial maximum, with the only sympatric overlap zone in Taiwan Strait. However, the genetic variation across the genus’ distribution has not yet been extensively studied, especially in the Indian Ocean. We performed an exhaustive review of molecular data of the finless porpoise across its range. Neighbor-net networks analyses based on two mitochondrial loci (control region/CR and cytochrome b/cyt b) suggest that finless porpoises from the Indian and Pacific Ocean constitute two distinct clades, well-defined by fixed mutations at both loci. A molecular clock analyses indicate early split (CR: 13.1 Ma, cyt b: 12.9 Ma) between these two oceanic lineages, while spatial genetic analyses further suggest that in the Pacific the divergence was primarily due to the taxon from Japanese waters rather than inter-species divergence across the Taiwan Strait. As extinction risks can be substantially underestimated if threatened species are pooled together with non-threatened, especially in the absence of long-distance migration, we suggest that the present 2-species taxonomy of the genus Neophocaena should be given further examination, with concerted sampling effort in the Western Indian Ocean. More research effort and genomic information is needed before taxonomic revisions can be considered; such further studies are strongly recommended as they may affect the current status classification of the species constituting the genus Neophocaena. Most notably, the narrow-ridged finless porpoise off Japan merits urgent conservation attention.  相似文献   

5.
Understanding stock and age-specific seasonal migrations of Pacific salmon during ocean residence is essential to both the conservation and management of this important resource. Based upon 11 microsatellites assayed on 265 individuals collected aboard international research surveys during winter 2009, we found substantial differences in the age-specific origin of chum salmon (Oncorhynchus keta) in the North Pacific Ocean. Overall, Asian stocks dominated the collections, however, ocean age 1 fish were primarily of Japanese origin and ocean age 2–3+ fish were predominantly of Russian origin. These results suggest that cohorts of chum salmon stocks migrate nonrandomly in the North Pacific Ocean and adjacent seas.  相似文献   

6.
The Pacific Ocean evolved from the Panthalassic Ocean that was first formed ca 750 Ma with the rifting apart of Rodinia. By 160 Ma, the first ocean floor ascribed to the current Pacific plate was produced to the west of a spreading centre in the central Pacific, ultimately growing to become the largest oceanic plate on the Earth. The current Nazca, Cocos and Juan de Fuca (Gorda) plates were initially one plate, produced to the east of the original spreading centre before becoming split into three. The islands of the Pacific have originated as: linear chains of volcanic islands on the above plates either by mantle plume or propagating fracture origin, atolls, uplifted coralline reefs, fragments of continental crust, obducted portions of adjoining lithospheric plates and islands resulting from subduction along convergent plate margins. Out of the 11 linear volcanic chains identified, each is briefly described and its history summarized. The geology of 10 exemplar archipelagos (Japan, Izu-Bonin, Palau, Solomons, Fiji, New Caledonia, New Zealand, Society, Galápagos and Hawaii) is then discussed in detail.  相似文献   

7.
Nuclear deoxyribonucleic acid sequences from approximately 15,000 salmon louse expressed sequence tags (ESTs), the complete mitochondrial genome (16,148bp) of salmon louse, and 16S ribosomal ribonucleic acid (rRNA) and cytochrome oxidase subunit I (COI) genes from 68 salmon lice collected from Japan, Alaska, and western Canada support a Pacific lineage of Lepeophtheirus salmonis that is distinct from that occurring in the Atlantic Ocean. On average, nuclear genes are 3.2% different, the complete mitochondrial genome is 7.1% different, and 16S rRNA and COI genes are 4.2% and 6.1% different, respectively. Reduced genetic diversity within the Pacific form of L. salmonis is consistent with an introduction into the Pacific from the Atlantic Ocean. The level of divergence is consistent with the hypothesis that the Pacific form of L. salmonis coevolved with Pacific salmon (Onchorhynchus spp.) and the Atlantic form coevolved with Atlantic salmonids (Salmo spp.) independently for the last 2.5–11 million years. The level of genetic divergence coincides with the opportunity for migration of fish between the Atlantic and Pacific Ocean basins via the Arctic Ocean with the opening of the Bering Strait, approximately 5 million years ago. The genetic differences may help explain apparent differences in pathogenicity and environmental sensitivity documented for the Atlantic and Pacific forms of L. salmonis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

8.
The lower Mokelumne River (LMR), located in the California Central Valley, supports a population of natural-origin Oncorhynchus mykiss. In addition, the Mokelumne River Fish Hatchery (Hatchery) contributes hatchery produced O. mykiss to the system annually. We conducted a 3 year acoustic tagging study to evaluate the migratory characteristics of LMR hatchery and natural-origin O. mykiss to the Pacific Ocean. Specifically, we analyzed downstream movement and migration rates, routes, and success of acoustically tagged O. mykiss of hatchery and natural origin under variable release locations in non-tidal and tidal habitats. Results from our study suggest there are significant differences in the proportion of hatchery and natural O. mykiss that demonstrate downstream movement. Fish origin, size, and release location all had a significant effect on whether an individual demonstrated downstream movement. Mokelumne origin O. mykiss that initiated downstream movement utilized numerous migration routes throughout the Delta during their migration towards the Pacific Ocean. We identified four primary migration pathways from the lower Mokelumne River through the Sacramento-San Joaquin Delta while the Delta Cross Channel was closed. However, several other pathways were utilized. Origin had a significant effect on O. mykiss success in reaching key points in the Delta and through the Estuary. Fish size had a significant effect on whether an individual reached the marine environment. Of the 467 O. mykiss tagged, 34 successfully reached the Pacific Ocean (Golden Gate Bridge), and of these, 33 were hatchery-origin and 1 was natural-origin. A higher proportion of hatchery-origin fish (10% of tagged) migrated to the ocean compared to natural-origin fish (<1%). Our study provides valuable information on the differences between hatchery and natural-origin O. mykiss migration characteristics as well as unique insight into the migratory behavior of little studied non-Sacramento River origin salmonids.  相似文献   

9.
Climate change is one of the top three global threats to seabirds, particularly species that visit polar regions. Arctic terns migrate between both polar regions annually and rely on productive marine areas to forage, on sea ice for rest and foraging, and prevailing winds during flight. Here, we report 21st-century trends in environmental variables affecting arctic terns at key locations along their Atlantic/Indian Ocean migratory flyway during the non-breeding seasons, identified through tracking data. End-of-century climate change projections were derived from Earth System Models and multi-model means calculated in two Shared Socioeconomic Pathways: ‘middle-of-the-road’ and ‘fossil-fuelled development’ scenarios. Declines in North Atlantic primary production emerge as a major impact to arctic terns likely to affect their foraging during the 21st century under a ‘fossil-fuelled development’ scenario. Minimal changes are, however, projected at three other key regions visited by arctic terns (Benguela Upwelling, Subantarctic Indian Ocean and the Southern Ocean). Southern Ocean sea ice extent is likely to decline, but the magnitude of change and potential impacts on tern survival are uncertain. Small changes (<1 m s−1) in winds are projected in both scenarios, but with minimal likely impacts on migration routes and duration. However, Southern Ocean westerlies are likely to strengthen and contract closer to the continent, which may require arctic terns to shift routes or flight strategies. Overall, we find minor effects of climate change on the migration of arctic terns, with the exception of poorer foraging in the North Atlantic. However, given that arctic terns travel over huge spatial scales and live for decades, they integrate minor changes in conditions along their migration routes such that the sum effect may be greater than the parts. Meeting carbon emission targets is vital to slow these end-of-century climatic changes and minimise extinction risk for a suite of polar species.  相似文献   

10.
A lone petrel was shot from the decks of an Italian warship (the ‘Magenta’) while it was sailing the South Pacific Ocean in 1867, far from land. The species, unknown to science, was named the ‘Magenta petrel’ (Procellariiformes, Procellariidae, Pterodroma magentae). No other specimens of this bird were collected and the species it represented remained a complete enigma for over 100 years. We compared DNA sequence of the mitochondrial cytochrome b gene from the Magenta petrel to that of other petrels using phylogenetic methods and ancient DNA techniques. Our results strongly suggest that the Magenta petrel specimen is a Chatham Island taiko. Furthermore, given the collection location of the Magenta petrel, our finding indicates that the Chatham Island taiko forages far into the Pacific Ocean (near South America). This has implications for the conservation of the taiko, one of the world's rarest seabirds.  相似文献   

11.
Conventional and electronic tags were used to investigate social segregation, distribution, movements and migrations of salmon sharks Lamna ditropis in Prince William Sound, Alaska. Sixteen salmon sharks were tagged with satellite transmitters and 246 with conventional tags following capture, and were then released in Prince William Sound during summer 1999 to 2001. Most salmon sharks sexed during the study were female (95%), suggesting a high degree of sexual segregation in the region. Salmon sharks congregated at adult Pacific salmon Oncorhynchus spp. migration routes and in bays near Pacific salmon spawning grounds in Prince William Sound during July and August. Adult Pacific salmon were the principal prey in 51 salmon shark stomachs collected during summer months in Prince William Sound, but the fish appeared to be opportunistic predators and consumed sablefish Anoplopoma fimbria, gadids, Pacific herring Clupea pallasi, rockfish Sebastes spp. and squid (Teuthoidea) even when adult Pacific salmon were locally abundant. As Pacific salmon migrations declined in late summer, the salmon sharks dispersed; some continued to forage in Prince William Sound and the Gulf of Alaska into autumn and winter months, while others rapidly moved south‐east thousands of kilometres toward the west coasts of Canada and the U.S. Three movement modes are proposed to explain the movement patterns observed in the Gulf of Alaska and eastern North Pacific Ocean: ‘focal foraging’ movements, ‘foraging dispersals’ and ‘direct migrations’. Patterns of salmon shark movement are possibly explained by spatio‐temporal changes in prey quality and density, an energetic trade‐off between prey availability and water temperature, intra‐specific competition for food and reproductive success. Transmissions from the electronic tags also provided data on depth and water temperatures experienced by the salmon sharks. The fish ranged from the surface to a depth of 668 m, encountered water temperatures from 4·0 to 16·8° C and generally spent the most time above 40 m depth and between 6 and 14° C (60 and 73%, respectively).  相似文献   

12.
From the first movements of people towards the Pacific Islands millennia ago to recent transnational migration in a globalised world, translocal mobility has been a central aspect of the social lives, cultures and histories of many Pacific Islanders. While Oceania has always been an area of migration as well as cultural and economic exchange, current transnational Pacific movements are deeply embedded in a twentieth- and twenty-first-century global phenomenon, which Castles and Miller [2009. The Age of Migration. International Population Movements in the Modern World. Houndsmill: MacMillan Press. (1993 1st edition)] have called the ‘age of migration’. This essay gives an overview of Pacific Islander migration and its patterns and motives as presented in previous studies. It shows how useful cultural categories can be for a deeper understanding of notions of moving and staying, two pluralistic and not contradictorily perceived concepts for Pacific Islanders that are crucial in transnational migration. With its focus on transnational migration and the challenges experienced by Fijians in the UK and Japan, and Micronesian Chuukese in Guam, Hawai'i, and the US mainland, this introduction concludes by analysing how the case studies presented in this special issue contribute to and complement current anthropological perspectives on Pacific Islanders’ multiple and complex forms of transnationalism.  相似文献   

13.
The spatial evolution of South American Syncarida (Anaspidacea and Bathynellacea) and related taxa is evaluated applying a panbiogeographic approach, where Ocean basins are used to identify major patterns of intercontinental distribution. The Pacific basin, corresponding to a southern temperate track, is identified as the major evolutionary centre for Stygocaris (Stygocarididae), Bathynella (Bathynellidae), Atopobathynellu , and Chilibathynella (Parabathynellidae), whereas distribution of Nannobathynella (Bathynellidae) and Cteniobathynella (Parabathynellidae) is centred on the Atlantic Ocean, belonging to a northern tropical track. It is concluded that the biotic origin of the South American Syncarida is complex, implying the existence of at least two ancestral biotas.  相似文献   

14.
Similarities of mid-Jurassic bivalve faunas between the European and the Ethiopian faunal province are very high at the genus-level. At the species-level, however, it is shown that during the Bathonian and Callovian 35% of the bivalves occurring in the Ethiopian faunal province are restricted to this province. In the region of Kachchh (W-India) in the same time-interval 25% of all bivalves are endemic. In the Ethiopian faunal province a clear tendency of increasing endemism from the Bathonian to the Tithonian/Lower Cretaceous at the genus-level and, even more obviously, at the species-level exists. Endemism and provincialism are most marked within the orders Arcoida, Trigonioida, and Nuculoida. The degree of endemism is lower within the Veneroida, but still very high. The orders Mytiloida, Pterioida, and Pholadomyoida hold the largest portion of cosmopolitan species. The rise of endemism and provincialism in Kachchh and m the Ethiopian faunal province from the Bathonian onwards can be explained only partly by the increasing broadening of the Tethys and its effect as an oceanic barrier. The steep increase of endemism in the Upper Jurassic of Kachchh is essentially caused by a radiation within the astartids and trigoniids, accompanied by a reduction of facies-types, due to a regional regression. The very southerly palaeogeographic position of India, the opening of the ‘South African Seaway’, and a change in the marine current system in the uppermost Jurassic led to an increasing differentiation of the Ethiopian faunal province in an ‘Ethiopian-Tethyan’ subprovince to the north and an ‘Ethiopian-Austral’ subprovince to the south. A migration of bivalves in mid-Jurassic times can be reconstructed along the southern margin of the Tethys mainly from east to west. On the other hand, an easternward migration of bivalves along the northern margin of the Tethys from Europe to China and Japan can be documented especially in the Upper Jurassic. This corroberates the existence of a clock-wise marine current system in the northern hemisphere in the Jurassic. The distribution patterns of bivalves in Kachchh and the Ethiopian faunal province are essentially characterized by ‘migration’ of bivalves. The opening of the ‘Hispanic Corridor’ in the Pliensbachian gave way to the immigration of East Pacific bivalves via the western Tethys as far as Kachchh and Madagascar. The dispersal ofPisotrigonia, Seebachia, Tendagurium, andMegacucullaea in the uppermost Jurassic/lowermost Cretaceous from Kachchh and East-Africa respectively to South-Africa and South-America documents the establishment of a ‘South-African Seaway’ and favours migration. However, ‘migration’ and ‘vicariance’ do not exclude each other. On the contrary, both are important mechanisms for creating distributional patterns of bivalves, although within different geological dimensions. Vicariance events produce faunal provinces which last for a long time and within this time-interval, migration seems to be the more important mechanism affecting palaeobiogeographic distribution of bivalves. There is no evidence that the distribution patterns of bivalves in Kachchh and in the Ethiopian faunal province are governed by eustatic sea-level changes. The dominating factors have been a change of the palaeogeographic constellation as a consequence of the break-up of Gondwana, and the local facies distribution. The number of bivalve species known from Europe is much larger than the number of species of the Ethiopian faunal province. A comparison of rarefaction curves of associations, however, shows that this is not a primary feature, but is a consequence of a greater number of different facies types and is due to a far more intense collecting activity in Europe. The bivalves of the Spiti Shales are unequivocal Ethiopian-Tethyan in character. The composition of the fauna indicates the deposition on the deeper shelf of the southern margin of the Tethys. All occurring ‘European’ faunal elements are not significant because of their more or less cosmopolitan distribution.  相似文献   

15.
Aim We address questions about trans‐Pacific distributions of marine organisms and the North Pacific Ocean as a centre of marine biodiversity through a phylogenetic and biogeographical study of a pan‐Pacific genus of Northern Hemisphere smelts (Hypomesus, Pisces: Osmeridae). Location North Pacific Ocean. Methods Relationships of the five species of Hypomesus from throughout the North Pacific were reconstructed through maximum likelihood and Bayesian phylogenetic analyses of sequence data from two mitochondrial (cytb, 16S) and three nuclear (ITS2, S71, RAG1) gene regions of five to 25 individuals per species, totalling 3588 characters. The resulting phylogenies were used to test hypotheses of species relationships and geographical origins using both dispersal‐based and maximum likelihood methods for inferring ancestral areas (lagrange ). Cytb sequence divergence and a Bayesian approach (beast ) were used to estimate the timeframe of Hypomesus evolution, which was compared with work on similarly distributed taxa. Results Hypothesized trans‐Pacific Ocean relationships based on lateral line scale counts were not supported by the phylogeny, suggesting parallel evolution of this phenotype, although we found one such relationship between the western H. japonicus and the two eastern Pacific species (H. pretiosus and H. transpacificus). Dispersalist approaches rejected an early proposal of a double‐compression vicariant mechanism as well as an eastern Pacific origin. Results from the lagrange analysis suggested a more widespread ancestor, although also supporting a role for the western Pacific. Divergence estimates suggested that most splits between species occurred in the mid‐Miocene, and the most recent speciation event, between the eastern Pacific species, occurred in the Pliocene to early Pleistocene. Main conclusions Our molecular data indicate that the character historically used to define relationships within Hypomesus, lateral line scale count, does not reflect ancestry within the genus. Biogeographical reconstructions suggest an important role for the western North Pacific in the diversification of Hypomesus. While uncertainty remains over the date of origin for this genus, estimates place the divergences during periods of climatic cooling that have been important in generating diversity in a number of similarly distributed organisms. Additional comparative data will provide further insight into the relative importance of the western region in generating diversity in the North Pacific Ocean.  相似文献   

16.
Migrations are often influenced by seasonal environmental gradients that are increasingly being altered by climate change. The consequences of rapid changes in Arctic sea ice have the potential to affect migrations of a number of marine species whose timing is temporally matched to seasonal sea ice cover. This topic has not been investigated for Pacific Arctic beluga whales (Delphinapterus leucas) that follow matrilineally maintained autumn migrations in the waters around Alaska and Russia. For the sympatric Eastern Chukchi Sea (‘Chukchi’) and Eastern Beaufort Sea (‘Beaufort’) beluga populations, we examined changes in autumn migration timing as related to delayed regional sea ice freeze‐up since the 1990s, using two independent data sources (satellite telemetry data and passive acoustics) for both populations. We compared dates of migration between ‘early’ (1993–2002) and ‘late’ (2004–2012) tagging periods. During the late tagging period, Chukchi belugas had significantly delayed migrations (by 2 to >4 weeks, depending on location) from the Beaufort and Chukchi seas. Spatial analyses also revealed that departure from Beaufort Sea foraging regions by Chukchi whales was postponed in the late period. Chukchi beluga autumn migration timing occurred significantly later as regional sea ice freeze‐up timing became later in the Beaufort, Chukchi, and Bering seas. In contrast, Beaufort belugas did not shift migration timing between periods, nor was migration timing related to freeze‐up timing, other than for southward migration at the Bering Strait. Passive acoustic data from 2008 to 2014 provided independent and supplementary support for delayed migration from the Beaufort Sea (4 day yr?1) by Chukchi belugas. Here, we report the first phenological study examining beluga whale migrations within the context of their rapidly transforming Pacific Arctic ecosystem, suggesting flexible responses that may enable their persistence yet also complicate predictions of how belugas may fare in the future.  相似文献   

17.
Three isolates ofFusarium avenaceum are pathogenic on spotted knapweed(Centaurea maculosa), a major weed plant of pasturelands and rangelands of the Pacific Northwestern USA. One isolate (no. 1) obtained from the European centre of origin of knapweed and isolate no. 365 native to Montana, did not significantly affect knapweed seed germination. However,F. avenaceum no. 1003, another Montana native isolate, caused a 100% decrease in seed germination and hence, no seedling emergence. When formulated, isolate no. 1003, could be recovered from treated soils after 7 days and caused a significant reduction in seedling emergence or seedling dry weight. This organism had no effect on the germination ofTriticum aestivum orMedicago sativa, but did affect the germination of other plant species.F. avenaceum appears to be a candidate for the biocontrol of spotted knapweed, however, a native isolate is potentially more effective than an isolate obtained from the centre of origin ofC. maculosa.  相似文献   

18.
We used a population genetic approach to quantify major population subdivisions and patterns of migration within a broadly distributed Indo-Pacific parrotfish. We genotyped 15 microsatellite loci in Scarus rubroviolaceus collected from 20 localities between Africa and the Americas. A STRUCTURE model indicates the presence of four major populations: Eastern Pacific, Hawaii, Central-West Pacific and a less well-differentiated Indian Ocean. We used the isolation and migration model to estimate splitting times, population sizes and migration patterns between sister population pairs. To eliminate loci under selection, we used BayeScan to select loci for three isolation and migration models: Eastern Pacific and Central-West Pacific, Hawaii and the Central-West Pacific, and Indian Ocean and the Central-West Pacific. To test the assumption of a stepwise mutation model (SMM), we used likelihood to test the SMM against a two-phase model that allowed mutational complexity. A posteriori, minor departures from SMM were estimated to affect ≤2% of the alleles in the data. The data were informative about the contemporary and ancestral population sizes, migration rates and the splitting time in the eastern Pacific/Central-West Pacific comparison. The model revealed a splitting time ~17,000 BP, a larger contemporary N(e) in the Central-West Pacific than in the eastern Pacific and a strong bias of east to west migration. These characteristics support the Center of Accumulation model of peripatric diversification in low-diversity peripheral sites and perhaps migration from those sites to the western Pacific diversity hotspot.  相似文献   

19.
A systematic revision of flying fishes of the subgenus Hirundichthys s.str was carried out based on a study of meristic and morphometric traits and characteristics of pigmentation of fishes from the local populations of species belonging to the subgenus. It is found out that the subgenus includes four species: oceanic H. speculiger from the Atlantic, Pacific and Indian Oceans, oceanic H. indicus sp.n. from the waters of the Indian Ocean, nerito-oceanic H. oxycephalus from the waters of the Indo-West Pacific and nerito-oceanic H. affinis from the Atlantic Ocean. The first part of the review focuses on two oceanic species with a large “mirror” on the pectoral fins: H. speculiger and H. indicus. A comparison of local populations showed that the species H. indicus is polytypic and consists of two subspecies. One of the subspecies—nominative H. indicus indicus—is distributed in the western and the central parts of the Indian Ocean and the other—H. indicus orientalis ssp.n.—in the Eastern Indian Ocean. Maps showing a geographical distribution of the species and the subspecies in the World Ocean are drawn up.  相似文献   

20.
Three oligo-raker species (?19 rakers on the first gill arch) of the genus Melamphaes out of the “M. typhlops” group are considered. The validity of M. indicus Ebeling is restored. This species inhabits equatorial and tropical waters of the Indian Ocean and the western part of the Pacific Ocean. M. eurous sp. n., which is related to M. indicus, is described from equatorial waters of the eastern part of the Pacific Ocean. M. typhlops (Lowe) inhabiting the northern part of the Atlantic Ocean, from the equatorial zone about to 45° N, is redescribed.  相似文献   

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