The biogeographical study of the freshwater fish fauna of Hiroshima Prefecture in the Chugoku and Shikoku Districts

It is important for studies of Japanese urban systems to investigate the present features of firm activities in cities of each hierarchical order. Particularly, branch offices of firms play an important role within firm activities of provincial and prefectural capitals in non-metropolitan regions. In this paper the author attempts to examine the functions and roles of branch offices of wholesale trades and producer services located in Hiroshima City as a case study by analyzing about 530 postal questionnaires answered from these branch offices. The main results are summarized as follows:1. Most of the branch offices located in Hiroshima have their headquarters in Tokyo or Osaka. The firms of wholesale trades were mainly established in the period before or just after World War II and set their branch offices during the period of high economic growth (1960 to 1973) in Hiroshima. On the other hand, many branch offices of producer services were established after the 1980's, while the firms they belong to were founded dominantly during the 1970's and 1980's.2. Although the firms of both types identify Hiroshima as the provincial capital in the Chugoku District, many of them regard the future development of Hiroshima as stagnated or slightly declining. At the same time, many branch offices of wholesale trades consider that the future development of Hiroshima depends on the development of Mazda, Inc., an automobile company headquartered in Hiroshima which has recently suffered from severe damage in the business depression. On the other hand, they expect the future development of rival city Okayama in the Chugoku District. But even if Hiroshima were to slightly decline and Okayama were to be developed in the future, few firms have said that they will move their branch offices from Hiroshima to Okayama.3. The main reason why most firms have established their branch offices in Hiroshima is due to its being the provincial capital with the largest service area in the Chugoku or the Chugoku and Shikoku District. And then-branch offices of wholesale trades refer to“a large amount of trade within Hiroshima”as the second most frequent answer, while those of producer services mainly point to the“favorable situation for managing the Chugoku District”.Branch offices of both types are concentrated in the four old wards including the city center (57.0 percent of 2, 134 branch offices in total). This is because of the favorable accessibility and the better conditions of face-to-face contact. Added to large opportunities for business in the city center, this accounts for about 70 percent of total answers. Although the location movement of offices from city centers to suburban areas is developing considerably in metropolitan areas of Europe and North America, branch offices do not act in such a way in Hiroshima. If such a phenomenon would occur, they would suffer not only from teir unprofitable businesses because of less accessibility but also from a shortage of labor because of unfavorable commuting conditions.4. The managing areas of branch offices in Hiroshima mainly consist of the Chugoku District or its western part (Hiroshima, Yamaguchi and Shimane Prefectures); 66 percent of branch offices in wholesale trades and 59 percent of those in producer services occupy the whole area or western part of the Chugoku District as their managing areas, respectively. But in some cases not only the Chugoku but also the Shikoku District belong to their managing areas. They consist of somewhat larger areas compared to the trade areas before the period of the rapid economic growth. Most branch offices usually carry out their intensive business activities within smaller areas than their managing areas, especially in the main urban areas.

The freshwater and marine fish faunas of South America are the most diverse on Earth, with current species richness estimates standing above 9100 species. In addition, over the last decade at least 100 species were described every year. There are currently about 5160 freshwater fish species, and the estimate for the freshwater fish fauna alone points to a final diversity between 8000 and 9000 species. South America also has c. 4000 species of marine fishes. The mega-diverse fish faunas of South America evolved over a period of >100 million years, with most lineages tracing origins to Gondwana and the adjacent Tethys Sea. This high diversity was in part maintained by escaping the mass extinctions and biotic turnovers associated with Cenozoic climate cooling, the formation of boreal and temperate zones at high latitudes and aridification in many places at equatorial latitudes. The fresh waters of the continent are divided into 13 basin complexes, large basins consolidated as a single unit plus historically connected adjacent coastal drainages, and smaller coastal basins grouped together on the basis of biogeographic criteria. Species diversity, endemism, noteworthy groups and state of knowledge of each basin complex are described. Marine habitats around South America, both coastal and oceanic, are also described in terms of fish diversity, endemism and state of knowledge. Because of extensive land use changes, hydroelectric damming, water divergence for irrigation, urbanization, sedimentation and overfishing 4-10% of all fish species in South America face some degree of extinction risk, mainly due to habitat loss and degradation. These figures suggest that the conservation status of South American freshwater fish faunas is better than in most other regions of the world, but the marine fishes are as threatened as elsewhere. Conserving the remarkable aquatic habitats and fishes of South America is a growing challenge in face of the rapid anthropogenic changes of the 21st century, and deserves attention from conservationists and policy makers.

AimHuman‐mediated species introductions and extirpations have resulted in the homogenization of biotas over time. However, there remains considerable uncertainty in our understanding of homogenization process for megadiverse regions of the world. Here, we investigate the consequences of widespread species invasions and extirpations for the biogeography of China's unique freshwater fish fauna.LocationChina.MethodsBy assembling a comprehensive dataset for distribution of Chinese freshwater fishes, we quantify how non‐native fish species, from both overseas introductions and domestic translocations, has led to taxonomic homogenization of fish faunas at watershed, basin, ecoregion and country scales. We explore how the observed patterns in homogenization vary geographically, and identify those species most responsible for the faunal changes. Lastly, we simulate how China's fish fauna may continue to homogenize according to different scenarios of anticipated species introductions and extirpations.ResultsWe demonstrate that species introductions and extirpations have homogenized freshwater fish faunas across China. Overall compositional similarity of watersheds increased by 7.0% (from a historical 14.9% to 21.9% in the present day; Sørensen index). Compositional similarity of 96 of 103 (93.2%) watersheds increased, with western basins exhibiting the highest magnitude. Translocated non‐native species associated with aquaculture practices contributed the most to faunal homogenization when compared to alien species (7.3% and 0.4%, respectively). Furthermore, faunal homogenization is predicted to intensify an additional 0.5–4.2% with increasing numbers of new non‐native species introductions and the extirpation of native species.Main conclusionsSpecies introductions and extirpations have resulted in the significant impoverishment, and thus the loss of antiquity, of China's freshwater fish fauna over the past century. In the light of the growing realization that species composition (not richness) defines the role that biodiversity plays in maintaining ecosystem function, our study highlights the need for conservation strategies in China that consider changing patterns of β diversity.

Aim This paper describes known patterns in the distributions and relationships of Hawaiian freshwater fishes, and compares these patterns with those exhibited by Hawaii's terrestrial biota.Location The study is based in Hawaii, and seeks patterns across the tropical and subtropical Indo‐west Pacific.Methods The study is based primarily on literature analysis.Results The Hawaiian freshwater fish fauna comprises five species of goby in five different genera (Gobiidae). Four species are Hawaiian endemics, the fifth shared with islands in the western tropical Pacific Ocean. All genera are represented widely across the Indo‐west Pacific. All five species are present on all of the major Hawaiian islands. All five species are amphidromous – their larval and early juvenile life being spent in the sea. Although there has been some local phyletic evolution to produce Hawaiian endemics, there has been no local radiation to produce single‐island endemics across the archipelago. Nor is there evidence for genetic structuring among populations in the various islands.Main conclusions In this regard, the freshwater fish fauna of Hawaii differs from the well‐known patterns of local evolution and radiation in Hawaiian Island terrestrial taxa. Amphidromy probably explains the biogeographical idiosyncrasies of the fish fauna – dispersal through the sea initially brought the fish species to Hawaii, and gene flow among populations, across the archipelago, has hitherto inhibited the evolution of local island endemics, apparently even retarding genetic structuring on individual islands.

Pre-Columbian use of freshwater fish in the Santa Maria Biogeographical Province, Panama

F. Igoe e-mnail: igoeashrfb.com), Irish Char Conservation Group, 1i Poddle Green, Kimmage, Dublin 12. Some 17,000 years ago, as the last Ice Age finally retreated from Ireland (Bowen et al. 2002), freshwater fish species first reached the country's newly forming loughs and rivers, following cordors of saline waters or travelling directly by sea. For millennia these native fish species, the oldest of Ireland's surviving animal species, were the sole fish species in the country's freshwaters. The formation of the Irish sea between Britain and Ireland acted as barrier to fish species with more sedentary habits and lower salinity tolerance, prematurely severing their natural colonisation pathways (Charlesworth 1930), and it was not until sometime during the miiddle of the last millennium that these non-native species were introduced to Ireland by Homo sapiens (McCormick 1999). Much of this early postglacial fauna, which still persists in many Irish loughs, must have been prevalent throughout north-westem Europe immediately after the last Ice Age (Ferguson 1986) before more warm water species moved in from the south and east. These com munities pretty much reflect the Irish freshwater fish fauna first encountered by our early ancestors dunrng the Megalithic penrod. As such, these native freshwater fish species are highly significant, not just for Ireland, but also for much of western Europe, where in many such communities have been lost or altered. The Inrsh environment has changed since these early times, as humans made their mark on the landscape and waterscape. These changes have accelerated during the last few decades (Stapleton et al. 2000). A decline in water quality in many areas, the impacts of introduced non-native fish species, alteration to habitats, and changes in a range of land-use practices have modified and changed the complexion and composition of our freshwater fish fauna. However, even today, much of the country holds aboriginal postglacial fish com munities, particularly in mountain loughs and loughs in the south-west and north-west, reflecting the early period before the arrival of humans. Whether we value our native fish communities from a heritage, cultural, recreational or economical perspective, one thing is clear: currently we are losing discrete populations of some species (e.g. Arctic char) and, if we are not careful, we will lose actual species and/or unique genetic vanants soon, and by default lose a precious link to our past. From a conservation perspective some of these fish species are important internationally and in a European context. The importance of other fish species should be considered in the national context. In fact some of our native fish species (e.g. pollan, Killarney shad, ferox, gillaroo and sonaghen trout) are among the most unique components of the entire Irish fauna, not just the fish fauna. Consider the following:

AimAssessing the consequences of a future increase in non‐native species introductions and native species extirpations on taxonomic similarity among fish faunas.LocationWorld‐wide.MethodsWe designed 42 scenarios of future species introductions and extirpations to simulate future fish composition for 1054 river basins. Using these simulated future compositions, we computed the change in taxonomic similarity among pairs of fish faunas from historical to future situation at the river basin, biogeographic realm and world scales.ResultsAccording to all our scenarios, taxonomic similarity among fish faunas will strongly increase in the future at the three spatial scales considered. Fish faunas from the Southern Hemisphere, which are currently the less affected by taxonomic homogenization, are forecasted to show the steepest changes. Our scenarios also reveal that non‐native species introductions will account for most of the predicted changes, whereas the effect of native species extirpations will be weak.Main conclusionsThe predicted future taxonomic homogenization will blur the current high level of taxonomic dissimilarity among freshwater fish faunas, and therefore, imperil the conservation programmes based on beta‐diversity mapping.

While the modern freshwater fish fauna of Africa has been the subject of considerable biological attention, there are few studies on the biogeography that include recent fossil reports. Since the publication of comprehensive reviews of Cenozoic freshwater fish faunas in Africa by Greenwood in the mid 1970s and updates in the late 1970s by Van Couvering, considerable collection and reporting of Cenozoic Africa fish has occurred. These specimens and reports have provided a considerable database from which to derive zoogeographical and biogeographical inferences. A pan‐African fish fauna can be documented at the generic level throughout the Miocene in northern, central and eastern Africa, including Protopterus, Polypterus, Labeo, Alestes/Brycinus, Clarias/Heterobranchus, Synodontis, and Lates. The extinct genus Semlikiichthys (formerly Lates) may also be included in this pan‐African fauna. Where the Miocene fish records were widely distributed through much of the African continent and were primarily fluvial‐derived faunas, the Early Pliocene record is strictly a central and eastern one, mainly from lacustrine deposits. These reflect the new lacustrine habitats created through severe tectonic change, in the form of rifting and volcanism. The Pliocene faunas are characterised both by extinct taxa not previously recorded, and by immigrant taxa. By the Pleistocene the Rift systems were completely formed. However, ongoing volcanism and tectonics continued to alter the hydrological systems. In the Early and Middle Pleistocene, Lakes Albert and Edward both still had the widespread modern genera Lates and Synodontis, and several taxa known from previous deposits. However, all extinct taxa had disappeared, except Sindacharax (Characidae), which was still found in Lake Edward. In the Turkana Basin, there is continuity of most taxa from the Pliocene (except for Semlikiichthys, which is absent), as well as Miocene and Pliocene Sindacharax species. In the Middle Pleistocene, Sindacharax disappears from the African fossil record. Also, in the Pleistocene, several hydrological systems lose their pan‐African faunas, including Lake Edward, Lake Victoria and the Maghreb. The modern faunas are not as diverse at the family level as previously. This history of the Neogene African fish fauna is necessarily incomplete without fossil records from many regions of Africa, particularly in the west and south.

Robert (Bob) McDowall died in Christchurch, New Zealand on 20 February 2011 after a short illness. Bob was a widely published author and an acknowledged world authority on the taxonomy and biogeography of freshwater fishes. In a preface to Bob’s recent magnum opus on the osteology of the galaxiids and allied genera (McDowall and Burridge 2011), the series editor, Peter Bartsch called him “a complete zoologist” and listed his knowledge and experience ranged from “taxonomy, biogeography and systematics to reproductive biology, behaviour, ecology, evolution, fisheries and conservation biology”. So, how did this talented and productive fisheries scientist come to acquire a profound knowledge of not only the freshwater fish fauna of New Zealand but of the southern hemisphere? Bob was born on 15 September 1939 in Palmerston North in 1939, the second youngest in a family of five. Bob attended Victoria University of Wellington (1958–62), completing an M. Sc. in zoology. As a young scientist, Bob recognised he had available to him a virtually unstudied fish fauna, the native freshwater fishes of New Zealand. The fauna is sparse (~ 40 species) and characterised by a high degree of diadromy. Bob soon realised that this fauna offered an opportunity to “explore pattern and process, cause and effect, evolution and biogeography, in a way that would have been much more difficult in areas with more speciose faunas” (McDowall 2010). One of the earliest papers he wrote on the origins of the New Zealand freshwater fish fauna (McDowall 1964) was probably instrumental in his gaining the opportunity to study at the Museum of Comparative Zoology, Harvard University USA (1965–68) where he was exposed to the teachings of the likes of Ernst Mayr, P J Darlington, Giles Mead, Alfred Romer and other luminaries of that era. His Ph. D. was on the systematics and phylogeny of the New Zealand galaxiids. The family Galaxiidae comprises a group of southern hemisphere fishes whose wide geographic range and the diversity of habitats they have colonised are somewhat akin to the northern hemisphere salmonids. The galaxiids were destined to become a major research focus for Bob. Upon completion of his doctorate and return to New Zealand, Bob was instructed to commence research on the diet of brown trout, Salmo trutta, something he regarded of much lesser importance than understanding the ecology of native species. With a dogmatism that often characterised his dealings with authority, he ignored this directive and established an extensive field Environ Biol Fish DOI 10.1007/s10641-011-9877-0

Effects of urbanization on California’s fish diversity: Differentiation, homogenization and the influence of spatial scale

More than 300 species of freshwater fishes are present in Japan. Because their distribution is expected to reflect geological history consequent to their low dispersal ability, they are a suitable group for studying historical relationships between land and biota. The strictly freshwater fish fauna in the Japanese Archipelago is primarily separated into two groups: those in northeastern Hokkaido, and those in other southwestern areas. The latter is further divided into two endemic faunas in the eastern and western regions across the Fossa Magna area. Recent phylogenetic and phylogeographic studies, primarily using mitochondrial DNA markers, support the importance of the Fossa Magana area in isolating related forms or intraspecific populations since the Late Miocene–Pliocene. This isolation, however, is not a primary one in some species. In western Japan, which has a rich and endemic freshwater fish fauna, both similar and different phylogeographic patterns have been observed among species, which may reflect differences in distribution histories and ecological traits of species. Further analyses using nuclear DNA loci, or genomic data, are necessary to elucidate the true processes of distribution, demography, and adaptation. Currently, 181 species/subspecies that depend heavily on freshwater environments are recognized in the Japanese Archipelago, but at least 244 evolutionary units (i.e., deep lineages with a long, unique history) are included in its freshwater fish fauna. The introduction of nonindigenous species is the primary driver for the decrease in β-diversity among regions, but the effects of species transplanted from other regions within Japan (i.e., the mixture and loss of endemic evolutionary units) remain underevaluated. Evolutionarily distinct units of freshwater fishes are historical legacies and should be maximally protected and passed on to future generations.

AimTo compile an inventory of freshwater fish species in China, and to investigate these data to determine spatial patterns in species richness, endemism and threatened species for the purpose of facilitating conservation.LocationChinaMethodsLiterature, databases and fish collections were examined to create an inventory database of freshwater fishes of China. This list was analysed to determine species richness, endemism and threatened species.spssandoriginsoftware were used to determine relationships between these three parameters across the area and length of river basins. Coefficients of fish diversity for each major river were calculated using the Gleason Index.ResultsChinese freshwater fish fauna is comprised of 1323 species; the majority of species belong to Cypriniformes and Cyprinidae. Of 877 species endemic to China, 161 of 199 threatened species are endemic, with most classified as ‘endangered’ (85 species) or ‘vulnerable’ (70). Species endemism and the number of threatened species correlate positively with species richness. River basin area and length have no direct bearing on either species richness or endemism. The Pearl River was identified as the most species‐rich system. It also has the most endemic and threatened fish species.Main conclusionsChina's vast size, variable geography and climate influence patterns in species diversity and endemism. Its freshwater fish fauna is rich and largely endemic and a significant number of these endemic species are threatened. Dam construction, water pollution, overfishing and invasive species pose threats to native biodiversity. National assessment of threatened species is urgently needed. The Yangtze, Yellow and Pearl rivers require prioritized national protection. Environmental effects of development require serious consideration and, potentially, proactive conservation efforts and mitigation. Development on international rivers needs to consider environmental policies of all countries owning spans of the systems, particularly the wishes and concerns of nations with lower spans of a system.

The freshwater fish fauna occurring in Brazilian small streams comprises 34 families of teleosts. The knowledge about its sistematic and biogeography is characterized by great heterogeneity among taxonomic groups. For some groups there are identification keys and phylogenetic hypotheses available which can be used for detailed biogeographic studies. Over the last few years, the biogeographic studies of small stream fish faunas reflect a general trend of rejection of dispersalist ideas as the primary explanation for the spatial diversity of the neotropical fish fauna and of simple inventaries of arcas of endemism. Recent biogeographic studies rely on the formulation of hypotheses about the biogeographic history of river drainages based on the identification of geographic barriers associated with geologic, climatic and eustatic events of the past. Such events are the primary cause of vicariant differentiation of the fish fauna.

The freshwater fish fauna occurring in Brazilian small streams comprises 34 families of teleosts. The knowledge about its sistematic and biogeography is characterized by great heterogeneity among taxonomic groups. For some groups there are identification keys and phylogenetic hypotheses available which can be used for detailed biogeographic studies. Over the last few years, the biogeographic studies of small stream fish faunas reflect a general trend of rejection of dispersalist ideas as the primary explanation for the spatial diversity of the neotropical fish fauna and of simple inventaries of arcas of endemism. Recent biogeographic studies rely on the formulation of hypotheses about the biogeographic history of river drainages based on the identification of geographic barriers associated with geologic, climatic and eustatic events of the past. Such events are the primary cause of vicariant differentiation of the fish fauna.

Fishes are appropriate indicators of trends in aquatic biodiversity because their enormous variety reflects a wide range of environmental conditions. Fish also have a major impact on the distribution and abundance of other organisms in waters they inhabit. Examination of trends in freshwater fish faunas from different parts of the world indicate that most faunas are in serious decline and in need of immediate protection. Species most likely to be threatened with immediate extinction are either specialized for life in large rivers or are endemic species with very small distributions. We conservatively estimate that 20 percent of the freshwater fish species of the world (ca. 1800 species) are already extinct or in serious decline. Evidence for serious declines in marine fishes is limited largely to estuarine fishes, reflecting their dependence on freshwater inflows, or to fishes in inland seas. The proximate causes of fish species’ decline can be divided into five broad categories: (1) competition for water, (2) habitat alteration, (3) pollution, (4) introduction of exotic species, and (5) commercial exploitation. Although one or two principal causes of decline can be identified for each species, the decline is typically the result of multiple, cumulative, long-term effects. Ways to protect aquatic biodiversity include the implementation of landscape-level management strategies, the creation of aquatic preserves, and the restoration of degraded aquatic habitats. Without rapid adoption of such measures we are likely to experience an accelerated rate of extinctions in aquatic environments as human populations continue to expand.