Geographic variation in the age of temperate-zone reptile and amphibian species: Southern Hemisphere species are older

Despite controversy over alternative definitions, the species is the fundamental operational unit of biodiversity, and species are the building-blocks of conservation. But is a ‘species’ from one part of the world the same as a ‘species’ from elsewhere? Our meta-analysis of molecular phylogenetic data reveals that reptile and amphibian species distributed in temperate-zone areas of the Northern Hemisphere are younger than taxa from the Southern Hemisphere, probably reflecting the greater impact of past climatic variation on Northern Hemisphere habitats. Because a species'' age may influence its vulnerability to anthropogenic threats, geographical variation in species ages should be incorporated into conservation planning.     

Phylogeny and biogeography of Anthopleura in the North Atlantic Ocean

Two species of Anthopleura, A. ballii and A. thallia, co-occur in Northern Europe with Bunodosoma biscayensis, a species closely allied to Anthopleura. The historical factors underlying their distribution are here investigated as part of a preliminary phylogenetic analysis of morphological data. Based on this analysis, Bunodosoma is nested within Anthopleura, and B. biscayensis is more closely related to members of Anthopleura than to other members of Bunodosoma. Because B. biscayensis also has adhesive verrucae, rather than non-adhesive, rounded vesicles, it is transferred to Anthopleura.The tree consists of two major clades, each of which includes species from the Atlantic and the Pacific. The tree shows geographic structure: one clade includes species found only in the Northern Hemisphere, and the other includes widespread species and species found only in the Southern Hemisphere. Although all of the European species of Anthopleura are part of the Northern Hemisphere clade, none are one another’s closest relative.     

Multiple origins of Southern Hemisphere Anemone (Ranunculaceae) based on plastid and nuclear sequence data

 Using two molecular data sets, the plastid atpB-rbcL intergenic spacer region and the nuclear ribosomal internal transcribed spacer regions (ITS), the taxonomic affinities of two newly available Anemone species from the Southern Hemisphere were tested. From previous work based on morphology and geographic distribution, it was assumed that A. tenuicaulis from New Zealand was most closely related to the Tasmanian A. crassifolia, whereas the affinity of A. antucensis from Chile and Argentina was regarded as uncertain. Analyses of molecular sequence data from these and 18 other species of Anemone s.lat. (with Clematis as outgroup) result in trees largely congruent with past analyses based on morphology and plastid restriction site data. They strongly support A. richardsonii and A. canadensis (with boreal distributions in the Northern Hemisphere) as paraphyletic to a well supported Southern Hemisphere clade consisting of A. antucensis and A. tenuicaulis. This group of four species is part of an otherwise predominantly Northern Hemisphere assemblage (subgenus Anemonidium s.lat., chromosome base number x=7), including A. narcissiflora, A. obtusiloba, A. keiskeana and A. (=Hepatica) americana. All other austral species included in the present sampling, A. crassifolia (Tasmania), A. knowltonia (=Knowltonia capensis), and A. caffra (both South African), form a separate clade, sister to A. (=Pulsatilla) occidentalis and other Northern Hemisphere anemones (subgenus Anemone s.lat., x=8). Possible phytogeographical links of the Southern Hemisphere species are discussed. Received April 23, 2001 Accepted October 4, 2001     

An exploration of factors influencing lotic insect species richness

An understanding of factors that influence species richness of lotic insects is generally lacking. We present comparative data on aquatic insect species richness from several North American and other streams. Factors such as large sample numbers and drainage area (species area relationships) are not significant predictors of species richness across the streams we examined. We explore several hypotheses regarding the origins and maintenance of species richness using Upper Three Runs Creek (UTR), South Carolina, USA, as a reference stream. UTR has the highest species richness of any stream in the Western Hemisphere. Hypotheses examined included historical, regional and local processes such as: (1) Evolutionary time, (2) disturbance regime/environmental variability, (3) temperature/evolutionary-speed, (4) productivity, and (5) habitat heterogeneity. Of these hypotheses, we suggest that productivity and habitat heterogeneity appear to contribute most to the high species richness found in UTR. We believe that multidisciplinary analysis of other streams is necessary because without this crucial information our knowledge of, and desire to protect biodiversity in streams will be wanting.     

A molecular investigation of the genus Ecklonia (Phaeophyceae,Laminariales) with special focus on the Southern Hemisphere

Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.     

Albian－Campanian钙质超微化石描述生物地理学研究

本文以Ａｌｂｉａｎ－Ｃａｍｐａｎｉａｎ的钙质超微化石为例,介绍了一种描述生物地理学研究的新方法──运用计算机绘制化石种的分布图（包括平面图和立体图两种）,并运用这一方法对该时间段的近２００个种进行了具体研究,归纳出六种分布类型,即：广布型,南半球分布型,北半球分布型,赤道海域缺失型,赤道海域分布型,迁移型。并且对每个种在这一时间段中的分布作了具体阐述。     

Molecular phylogeny of the antitropical genus Pseudolabrus (Perciformes: Labridae): evidence for a Southern Hemisphere origin

The genus Pseudolabrus comprises 11 species of marine nearshore fishes which are antitropically distributed: two species occur in East Asia, the remaining nine species being distributed in the Southern Hemisphere, mainly in the temperate Pacific. The distributions of their closely allied genera, collectively called "pseudolabrines" are, however, restricted to the Australia-New Zealand region. The molecular phylogeny of six of the 11 Pseudolabrus species from both Hemispheres and four of the five other pseudolabrine genera was reconstructed from nucleotide sequence data from mitochondrial DNA 12S rRNA, tRNAVal, and 16S rRNA genes. Both parsimony and Bayesian analyses were performed. Results are not consistent with a previous phylogenetic hypothesis based on osteological data, particularly in the relationship between Pseudolabrus and Notolabrus, indicating a probable need for reviewing the status of Notolabrus (or the delimitations of both Pseudolabrus and Notolabrus). The two Northern Hemisphere species of Pseudolabrus were monophyletic and nested deep into the clade of the Southern Hemisphere pseudolabrines, which indicates that both pseudolabrines and Pseudolabrus originated in the Southern Hemisphere. A dispersal rather than vicariance explanation for the antitropical distribution of Pseudolabrus is more parsimonious given the number of dispersal events, extinctions, and evolutionary adaptations required under the phylogeny. Based on molecular clock calibrations, the transequatorial divergence was suggested to be early to mid Pliocene at the earliest.     

AN EARLY CENOZOIC NEOSELACHIAN SHARK FAUNA FROM THE SOUTHWEST PACIFIC

Abstract: An early Cenozoic shark fauna, comprising at least 16 taxa, is described from Paleocene sedimentary rocks on the South Island of New Zealand. Although representing a remote Southern Hemisphere location, the fauna includes forms closely comparable to contemporary species from the Northern Hemisphere, in addition to the new species Chlamydoselachus keyesi and Centroselachus goordi. Comparison with closely related extant species suggests the fauna may be interpreted as a deep water one, typical of the outer continental shelf and upper slope. However, after palaeogeography, sedimentology and mineralogy of the enclosing rock, and the nature of similar faunas from elsewhere are taken into consideration, the fauna is interpreted to have occupied a mid‐shelf environment.     

Invasive blue mussels threaten regional scale genetic diversity in mainland and remote offshore locations: the need for baseline data and enhanced protection in the Southern Ocean

Human‐mediated biological transfers of species have substantially modified many ecosystems with profound environmental and economic consequences. However, in many cases, invasion events are very hard to identify because of the absence of an appropriate baseline of information for receiving sites/regions. In this study, use of high‐resolution genetic markers (single nucleotide polymorphisms – SNPs) highlights the threat of introduced Northern Hemisphere blue mussels (Mytilus galloprovincialis) at a regional scale to Southern Hemisphere lineages of blue mussels via hybridization and introgression. Analysis of a multispecies SNP dataset reveals hotspots of invasive Northern Hemisphere blue mussels in some mainland New Zealand locations, as well as the existence of unique native lineages of blue mussels on remote oceanic islands in the Southern Ocean that are now threatened by invasive mussels. Samples collected from an oil rig that has moved between South Africa, Australia, and New Zealand were identified as invasive Northern Hemisphere mussels, revealing the relative ease with which such non‐native species may be moved from region to region. In combination, our results highlight the existence of unique lineages of mussels (and by extension, presumably of other taxa) on remote offshore islands in the Southern Ocean, the need for more baseline data to help identify bioinvasion events, the ongoing threat of hybridization and introgression posed by invasive species, and the need for greater protection of some of the world's last great remote areas.     

Global diversity of crayfish (Astacidae, Cambaridae, and Parastacidae––Decapoda) in freshwater

The freshwater crayfishes are distributed across all but the Indian and Antarctic continents with centers of diversity in the southeastern Appalachian Mountains in the Northern Hemisphere and in south–east Australia in the Southern Hemisphere. There are currently over 640 described species of freshwater crayfishes with an average of 5–10 species still being described each year. Freshwater crayfishes can serve as keystone species in aquatic habitats, but a few species are also significantly invasive and can cause impressive damage to the fragile freshwater habitat. Crayfishes inhabit caves, burrows, streams, lakes and strong burrowers can even be found in terrestrial habitats where they have burrowed to the water table or where rainfall is sufficiently abundant to provide the needed moisture. The freshwater crayfishes, like the habitats in which they are encountered, are generally endangered to some degree and conservation efforts would do well to focus on them as key elements of the freshwater ecosystem. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

A CLADISTIC ANALYSIS OF THE EVOLUTION AND BIOGEOGRAPHY OF DURVILLAEA (PHAEOPHYTA)1

The genus Durvillaea currently has four recognized species found along many exposed, rocky coastlines of the temperate to sub-Antarctic regions in the Southern Hemisphere. We propose that the current species distributions are related primarily to vicariance events and subsequent speciation associated with the breakup of Gondwana between 40 and 100 Ma. From an ancestral species, a stipitate species developed in the Tasman basin, with separation and speciation resulting in the D. potatorum/ D. willana complex in southeastern Australia and New Zealand. A second line of evolution led to D. chathamensis and D. antarctica characterized by a honeycombed medulla. The extensive distribution of D. antarctica throughout the Southern Hemisphere is related to both vicariance and dispersal events. The status of D. chathamensis as a species distinct from D. antarctica is questioned. The affinities of an as yet undescribed taxon from the Antipodes Islands are thought to be with the D. potatorum complex but require further study before they can be defined more precisely .     

Molecular and morphological identification of truffle-producing <Emphasis Type="Italic">Tuber</Emphasis> species in New Zealand

Molecular and morphological techniques were used to examine New Zealand ascomycetous truffle (Tuber spp.) samples deposited in the Plant & Food Research and Landcare Research Fungi Herbarium collections. Truffles have been found on the roots of many Northern Hemisphere tree species growing in New Zealand, but not on indigenous plant species. Comparisons of ribosomal DNA sequences proved to be a simple and rapid method to identify the Tuber species. Tuber maculatum was by far the predominant species in New Zealand, and was distributed throughout the country. A single truffle sample from Christchurch was identified as T. rufum. Two other groups of truffle samples from Pinus spp. were closely related to anonymous Northern Hemisphere Tuber sequences. Ascocarps with these sequences have not previously been described. Specific primers for the PCR detection of these Pinus isolates were developed. None of these Tuber species accidentally introduced to New Zealand is of economic value.     

栲属(壳斗科)植物的现代和地史分布

根据文献资料和标本馆及化石记录,讨论了壳斗科栲属植物的现代分布和地史分布。现代栲属植物有110～134种,主要分布在东亚及东南亚,其中印度支那地区有82种栲属植物,是世界栲属植物分布最集中的地区,马来西亚地区是栲属特有种最丰富的事实是支持马来西亚地区与其它地区的区系交流十分有限的论据。中国栲属植物最丰富的地区是滇黔桂地区（29种）。栲属植物现代多样化中心在马来西亚和中南半岛。排除Chrysolepis后,栲属的分布类型应属热带亚洲分布。栲属在地质历史上有着比现在广泛的分布,最早、最可靠的栲属化石记录发现于北美始新世地层,欧洲和日本始新世也有栲属的化石记录,化石记录表明栲属起源的时间不晚于古新世,所有的壳斗科及栲属的化石都发现于北半球,现代分布也主要在北半球,壳斗科及栲属起源于北半球可以确认,由于化石证据与现代植物学的研究结果有较大差异以及关键地区化石证据的不足,具体的起源地尚不能肯定。     

Present patterns and future prospects for biodiversity in the Western Hemisphere

Creating networks of nature reserves to protect areas rich in biodiversity from the adverse impacts of anthropogenic change is a critical and urgent task. We illustrate the skewed geographical and size distributions of protected areas in the Western Hemisphere. For instance, 811 of 1413 reserves in the Western Hemisphere are smaller than 10 km², and 35% of the total area of these reserves is in Alaska. We compile ranges for all bats in the continental Western Hemisphere and find that 82% of threatened and small‐range species are not protected adequately. Many of the most vulnerable species occur in the areas of highest human density. We provide maps delineating areas where conservation investments may have the greatest impact in preventing biodiversity losses.     

<Emphasis Type="Italic">Mycena haushoferi</Emphasis>, a new species of section <Emphasis Type="Italic">Intermediae</Emphasis> from Germany

Mycena haushoferi, a new species of the section Intermediae collected in Bavaria, is described and compared with four other species of the sect. Intermediae known from the Northern Hemisphere and with M. cystidiosa and M. metuloidifera, two species of sect. Metuloidiferae. The five known species of Northern Hemisphere of section Intermediae are keyed out.     

EVOLUTION OF THE ANTARCTIC MARINE BENTHIC ALGAL FLORA

There are many logistic difficulties associated with studying Antarctic marine algae and, as a consequence, the taxonomic information available is far from comprehensive and any generalizations should be regarded with caution. The Antarctic marine benthic flora is characterized by a low species richness. Biogeographical characteristics of the flora are outlined. There is a high degree of endemism, possibly around 35–40%. Other major floristic elements are a group of species with a distribution extending to Tierra del Fuego and subantarctic islands, a group spread through temperate regions of the Southern Hemisphere, and a cosmopolitan group. Ecological observations show that ice has a major effect on the occurrence and distribution of algae, and ecophysiological studies indicate that Antarctic macroalgae possess various adaptations to ice, low temperatures, and strongly seasonal light conditions. Possible trends in the evolution of the Antarctic benthic marine flora, including a reduction in species richness and the origins of biogeographical links with subantarctic and temperate regions of the Southern Hemisphere, are discussed in the context of tectonic and climatic changes over the past 100 million years. A comparison is made with studies on the evolution of shallow-water marine fauna.     

Bioinvasion threatens the genetic integrity of native diversity and a natural hybrid zone: smooth‐shelled blue mussels (Mytilus spp.) in the Strait of Magellan

Smooth‐shelled blue mussels of the Mytilus edulis species complex are widely distributed bivalve molluscs whose introductions threaten native marine biodiversity (non‐indigenous species – NIS). The aim of the present study was to identify the species and hybrids of Mytilus present in the Magellan Region (southern Chile). Results indicate that three mussel species of the Mytilus edulis complex are found in the region – M. edulis, M. chilensis (or the Southern Hemisphere lineage of Mytilus galloprovincialis), and M. galloprovincialis of Northern Hemisphere origin. For the first time, alleles of the introduced M. trossulus are reported from the Southern Hemisphere. In the Strait of Magellan the native Pacific blue mussel, Mytilus chilensis and the native Atlantic blue mussel, Mytilus edulis, meet and mix at a natural hybrid zone (about 125 km in length). This is the first record of a natural Mytilus hybrid zone in the Southern Hemisphere and is also the first record of the co‐occurrence of genes from all four Mytilus species in any one region. These results contribute to the knowledge of the biodiversity and delimitation of mussel species in southern South America, and highlight how introduced species may threaten the genetic integrity of native species through hybridization and introgression.     

Hidden diversity in high-latitude Southern Hemisphere environments: Reinstatement of the genus Rama and description of Vandenhoekia gen. nov. (Cladophoraceae,Ulvophyceae, Chlorophyta), two highly variable genera

The continental coasts and remote islands in the high-latitude Southern Hemisphere, including the subantarctic region, are characterized by many endemic species, high abundance of taxa, and intermediate levels of biodiversity. The macroalgal flora of these locations has received relatively little attention. Filamentous green algae are prolific in the intertidal of southern islands, but the taxonomy, distribution, and evolutionary history of these taxa are yet to be fully explored, mostly due to the difficulty of access to some of these locations. In this study, we examined specimens of the order Cladophorales from various locations in the high-latitude Southern Hemisphere including the subantarctic (the Auckland Islands, Bounty Islands, Campbell Island, Macquarie Island, and Kerguelen Islands), as well as mainland New Zealand, the Chatham Islands, Chile, and Tasmania. The analyses of the rDNA sequences of the samples revealed the existence of two new clades in a phylogeny of the Cladophoraceae. One of these clades is described as the novel genus Vandenhoekia gen. nov., which contains three species that are branched or unbranched. The amended genus Rama is reinstated to accommodate the other clade, and contains four species, including the Northern Hemisphere “Cladophora rupestris.” In Rama both branched and unbranched morphologies are found. It is remarkable that gross morphology is not a predictor for generic affiliations in these algae. This study illustrates that much can still be learned about diversity in the Cladophorales and highlights the importance of new collections, especially in novel locations.     

Wittina gen. n., a New Genus of Neotropical Moths (Lepidoptera,Megalopygidae)

Entomological Review - A new genus, Wittinia gen. n., is proposed for Megalopygidae moths restricted to the Western Hemisphere. Two species are included: Wittinia cremor sp. n., the type species...