The southwestern Atlantic reef fish fauna: composition and zoogeographic patterns

The Brazilian coast, the Caribbean and the tropical South Atlantic oceanic islands reef ichthyofauna separated into two major clusters: (1) the western Atlantic continental margin and Bermuda, further divided into (1a) the western North Atlantic, and (1b) the Brazilian coast; and (2) the South Atlantic oceanic islands, also divided in (2a) the Brazilian offshore islands, and (2b) Ascension and St Helena. Species geographic ranges suggest the recognition of only two western Atlantic zoogeographic provinces for tropical marine shore fishes. A Brazilian Province, including the offshore localities of Atol das Rocas, Fernando de Noronha, Trindade and St Paul's Rocks, and an expanded West Indian Province that includes Bermuda. Ascension and St Helena should be regarded as a separated Central Atlantic Province.     

The shore fishes of Ascension Island

Seventy-one species of shore fishes are recorded from Ascension in a checklist which includes notes on ecology and behaviour. The extraordinary abundance of blackfish, Melichlhys niger , and the aggressive nature of moray eels, Lycodontis moringa , towards man are briefly mentioned. The number of species recorded is low for a tropical island and seems to reflect Ascension's geographical isolation and lack of habitat diversity; 15·7% of Ascension shore fishes (excluding one fish not identified to species level) appear to be endemic to the island, with a further 17·1% known only from Ascension and St Helena; 30·0% are recorded only from the western and central Atlantic, while 7·1% are recorded from the eastern and central Atlantic; 30·0% are widespread Atlantic species. Two new species are described: Taenioconger camelopardalis and Helcogramma ascensionis.     

Lichens of St Helena and Ascension Island

Lichens are the dominant organisms on most of the South Atlantic island of St Helena. In total, 220 different species were found during a recent survey, most of which have never been reported from the island. Previously, less than 50 lichen species were reported from the island, one half of which are most probably incorrect records. The total number of lichens known from the island now stands at 225. Most species could be identified, but the following, most probably endemic, species are described as new to science: Dolichocarpus seawardii , which is only the second species in this genus, the type being from Chile; Dermatiscum pusillum , which is only the third species in this African genus; Dimelaena triseptata ; Xanthoparmelia beccae ; and four Ramalina species, Ramalina geniculatella , R. ketner‐oostrae , R. rigidella , and R. sanctae‐helenae . The lichen flora has many species in common with that of the geologically much younger Ascension Island, where just under 100 species were recently found by the author, most of which are equally new to that island. Lecanora sanctae‐helenae, previously known as the only endemic lichen of St Helena, was also found to be abundant on Ascension Island. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 147–171.     

The fishes of Saint Paul's Rocks

Fifty species of fishes are recorded from Saint Paul's Rocks in a checklist which includes notes on ecology and behaviour. The poor species diversity, which is the lowest of any tropical island studied to date, seems to result from the isolation of the Rocks and also their small size and lack of habitat diversity. Large pelagic and semi-pelagic predators, especially Galapagos sharks, are unusually common; 12.1% of identified shore fishes at St Paul's appear to be endemic to the Rocks, while 6.1% are known only from the tropical islands of the mid-Atlantic ridge (St Paul's, Ascension, St Helena); 15.2% are recorded only from Brazil and St Paul's 30.3% are widespread western Atlantic forms that have the central Atlantic as the eastern limit of their range; a further 36.4% are widely distributed throughout the tropical Atlantic. Three new species are described: Anthias salmopunctatus, Stegastes sanctipauli and Enneanectes smithi .     

The land fauna of Ascension Island: new data from caves and lava flows,and a reconstruction of the prehistoric ecosystem

Abstract. Terrestrial arthropods were investigated in 1990 and 1995 on Ascension, a young and extremely isolated volcanic island in the equatorial Atlantic. Three new genera (of Araneae, Oribatida and Psocoptera) were discovered and the number of apparently endemic species was increased from fourteen to about twenty-nine. Some 311 species of land animals (a few now extinct) are known to have established themselves on the island; in a few groups there may be significant numbers of unrecorded species. About ninety-five endemic and non-endemic species are considered to be native (including two marine turtles, twelve seabirds and two extinct landbirds); seventy-eight are of doubtful status; and at least 138 were probably introduced by humans. Natural colonists arrived mainly by air (drifting with the wind during migratory movements) but some evidently travelled on floating objects or attached to birds or other animals. Natural colonization was almost entirely from Africa. Before the arrival of humans, Ascension had an early successional ecosystem. The fauna in the lava and cinder deserts of the lowlands—both on the surface and in subterranean cracks and caves—was dominated by taxonomically varied scavengers and mainly arachnid predators. The scattered angiosperms here and in the foothills supported some host-specific herbivores with associated predators; they were also exploited (especially after exceptional rains) by a number of Orthoptera, Hemiptera and Lepidoptera derived from migratory African populations and perhaps reinforced at intervals by additional groups of colonists. The more extensive and largely cryptogamic vegetation on the central peak had a poor fauna probably composed mainly of micro-arthropods. Along coasts, on islets and in the extensive seabird colonies there were additional arthropod species and also a flightless rail and a night heron (both now extinct). Invertebrate stocks that colonized Ascension underwent a variety of evolutionary changes including phyletic evolution leading to endemic status, adaptation to subterranean life (Araneae, Pseudoscorpiones, Collembola and Psocoptera), character release (phorid Diptera), and probably splitting of lineages (speciation) within the island (Isopoda, Collembola and gryllid Orthoptera). The relatively high diversity of Pseudoscorpiones (five species in five genera) and their 100% apparent endemicity is notable. The indigenous fauna of Ascension provides a view of an early stage in the processes of colonization, adaptive evolution and radiation which—over much longer periods—give rise to the richer and more distinctive faunas of older oceanic islands such as Ascension's nearest neighbour, St Helena, where a few invertebrate clades have undergone repetitive speciation and some adaptive radiation.     

PHYLOGEOGRAPHY OF THE PANTROPICAL SEA URCHIN EUCIDARIS IN RELATION TO LAND BARRIERS AND OCEAN CURRENTS

The pantropical sea urchin genus Eucidaris contains four currently recognized species, all of them allopatric: E. metularia in the Indo-West Pacific, E. thouarsi in the eastern Pacific, E. tribuloides in both the western and eastern Atlantic, and E. clavata at the central Atlantic islands of Ascension and St. Helena. We sequenced a 640-bp region of the cytochrome oxidase I (COI) gene of mitochondrial DNA to determine whether this division of the genus into species was confirmed by molecular markers, to ascertain their phylogenetic relations, and to reconstruct the history of possible dispersal and vicariance events that led to present-day patterns of species distribution. We found that E. metularia split first from the rest of the extant species of the genus. If COI divergence is calibrated by the emergence of the Isthmus of Panama, the estimated date of the separation of the Indo-West Pacific species is 4.7–6.4 million years ago. This date suggests that the last available route of genetic contact between the Indo-Pacific and the rest of the tropics was from west to east through the Eastern Pacific Barrier, rather than through the Tethyan Sea or around the southern tip of Africa. The second cladogenic event was the separation of eastern Pacific and Atlantic populations by the Isthmus of Panama. Eucidaris at the outer eastern Pacific islands (Galapagos, Isla del Coco, Clipperton Atoll) belong to a separate clade, so distinct from mainland E. thouarsi as to suggest that this is a different species, for which the name E. galapagensis is revived from the older taxonomic literature. Complete lack of shared alleles in three allozyme loci between island and mainland populations support their separate specific status. Eucidaris galapagensis and E. thouarsi are estimated from their COI divergence to have split at about the same time that E. thouarsi and E. tribuloides were being separated by the Isthmus of Panama. Even though currents could easily convey larvae between the eastern Pacific islands and the American mainland, the two species do not appear to have invaded each other's ranges. Conversely, the central Atlantic E. clavata at St. Helena and Ascension is genetically similar to E. tribuloides from the American and African coasts. Populations on these islands are either genetically connected to the coasts of the Atlantic or have been colonized by extant mitochondrial DNA lineages of Eucidaris within the last 200,000 years. Although it is hard to explain how larvae can cross the entire width of the Atlantic within their competent lifetimes, COI sequences of Eucidaris from the west coast of Africa are very similar to those of E. tribuloides from the Caribbean. F_ST statistics indicate that gene flow between E. metularia from the Indian Ocean and from the western and central Pacific is restricted. Low gene flow is also evident between populations of E. clavata from Ascension and St. Helena. Rates of intraspecific exchange of genes in E. thouarsi, E. galapagensis, and E. tribuloides, on the other hand, are high. The phylogeny of Eucidaris confirms Ernst Mayr's conclusions that major barriers to the dispersal of tropical echinoids have been the wide stretch of deep water between central and eastern Pacific, the cold water off the southwest coast of Africa, and the Isthmus of Panama. It also suggests that a colonization event in the eastern Pacific has led to speciation between mainland and island populations.     

Patterns of diversity of the north-eastern Atlantic blenniid fish fauna (Pisces: Blenniidae)

This paper presents an analysis of the distributional patterns of blenniids (Pisces: Blenniidae) in the north‐eastern Atlantic. Two peaks of species diversity were found, both in terms of number of species and number of endemics: one in the tropical African coast and another in the Mediterranean Sea. A cluster analysis of similarity values (Jaccard coefficient) among the eastern Atlantic zoogeographical areas, revealed the following groups: a north temperate group, a tropical group formed by the tropical African coast and Mauritania, another group formed by the islands of Cape Verde, a south temperate group (South Africa), and a southern Atlantic group formed by the islands of Ascension and St Helena. Within the north temperate group, the subgroups with higher similarities were: Azores and Madeira, Canary Islands and Morocco, and the Mediterranean and the Atlantic coast of the Iberian Peninsula. Based on affinity indices, the probable directions of faunal flows were inferred. The tropical coast of Africa and the Mediterranean emerged from this analysis as probable speciation centres of the north‐eastern Atlantic blenniid fauna. The Mediterranean may have also acted as a refuge during glacial periods.     

Wood anatomy of the endemic woody Asteraceae of St Helena I: phyletic and ecological aspects

Quantitative and qualitative data are given for samples of mature wood of all eight species of woody Asteraceae, representing three tribes, of St Helena I. The quantitative features of all except one species are clearly mesomorphic, corresponding to their mesic central ridge habitats. Commidendrum rugosum has more xeromorphic wood features and occurs in dry lowland sites. Commidendrum species are alike in their small vessel pits and abundant axial parenchyma. Melanodendrum agrees with Commidendrum in having fibre dimorphism and homogeneous type II rays. The short fibres in both genera are storied and transitional to axial parenchyma. Elongate crystals occur in ray cells of only two species of Commidendrum , suggesting that they are closely related. Wood of Commidendrum and Melanodendrum is similar to that of the shrubby genus Felicia , thought closely related to Commidendrum on molecular bases. Commidendrum and Melanodendrum have probably increased in woodiness on St Helena, but are derived from shrubby ancestors like today's species of Felicia. Petrobium wood is paedomorphic and indistinguishable from that of Bidens , from which Petrobium is likely derived. The two senecionid species (Senecio leucadendron = Pladaroxylon leucadendron; and Senecio redivivus = Lachanodes arborea , formerly Lachanodes prenanthiflord) also show paedomorphic wood. Wood of the various St Helena Asteraceae is consonant with relationship to African or South American ancestors that reached St Helena via long distance dispersal. Derivation from genera of Pacific islands or Austromalesian regions is considered less likely. However, DNA evidence is needed to clarify origins, times of colonization on St Helena and divergence from closest relatives, and the nature of evolutionary patterns.     

Biological control of an exotic scale, Orthezia insignis Browne (Homoptera: Ortheziidae), saves the endemic gumwood tree, Commidendrum robustum (Roxb.) DC. (Asteraceae) on the island of St. Helena

St. Helena is a small South Atlantic island with a highly degraded, but internationally significant, terrestrial flora. The 2500 remaining gumwoods, Commidendrum robustum, are an important part of this remnant flora. In 1991, a South American scale insect, Orthezia insignis, was identified attacking the gumwood trees. By 1993, severe infestations had killed over 100 trees. If the number of dead trees had continued to increase exponentially, all 2500 trees would have died by 1995. This outcome was likely given abundant alternative host plants, and lack of natural enemies of O. insignis. Host range tests showed that the other members of the endemic genus Commidendrum were also at risk. The coccinellid predator, Hyperaspis pantherina, was released on St. Helena in 1993. H. pantherina numbers increased from 1994, coinciding with a 30× decrease in scale numbers. Scale outbreaks have not been reported on St Helena since 1995, and culturing of H. pantherina was discontinued because insufficient O. insignis prey could be found in the field. Extensive blackening from sooty molds on the surviving trees in 1995 suggested that the predator was effective just in time to prevent death of most trees. H. pantherina appears to have saved the field population of a rare endemic plant from extinction.     

Comparative feeding strategies of yellowfin tuna around St Helena and adjacent seamounts of the South Atlantic Ocean

Yellowfin tuna are the mainstay of the traditional tuna fisheries in St Helena waters, but there is limited knowledge of their ecology and feeding behaviour in the area. In this study yellowfin tuna stomach contents were used to assess spatio-temporal changes in feeding strategy and consider the role of tuna in the local ecosystem. Comparisons of the feeding spectra of yellowfin tuna between inshore regions of St Helena and oceanic seamounts demonstrated that in both areas the species was largely piscivorous. In inshore waters yellowfin consumed more neritic fauna, including significant numbers of crab megalopa, whereas around seamounts the diet included a greater diversity of epi- and mesopelagic fish and squids. The most important fish prey species in inshore waters was the St Helena butterflyfish Chaetodon sanctahelenae, and around seamounts was the pufferfish Lagocephalus lagocephalus. Results indicate that the diet spectrum of yellowfin tuna in St Helena waters is relatively similar to those of conspecifics living in waters with relatively low productivity, with strategies indicative of food-poor ecosystems. The availability of coastal fauna may make areas around islands and seamounts more attractive for feeding aggregations of yellowfin tuna, compared to the open ocean. The relatively unselective feeding of yellowfin tuna means that stomachs can provide valuable data on the species diversity, particularly in remote areas with limited opportunities for dedicated research expeditions.     

The gracilarioids in South Africa: long-term monitoring of a declining resource

In South Africa, gracilarioid red algae have been collected as wash-up to be dried and sold for agar extraction for at least 50 years. Despite much research, there is currently no commercial mariculture of the algae locally although this has been carried out in neighboring Namibia for a number of years. The industry is traditionally confined to Saldanha Bay on the west coast, although small wash-ups of Gracilariopsis longissima have been collected in nearby St Helena Bay. In Saldanha Bay, wash-ups of Gracilaria. gracilis have been very sporadic over the last few decades, with human alteration of the bay configuration possibly responsible for an initial major decline in 1974. This unpredictability in the amounts of wash-up has made the industry unstable and increasingly unprofitable. We compiled the results of previous surveys (some unpublished) of gracilariod populations in St Helena Bay and the Saldanha-Langebaan sytem, and re-surveyed these populations to examine long-term fluctuations. In Saldanha Bay and Langebaan Lagoon, standing stock of G. gracilis was estimated at 538 tons fresh weight and 71 tons fresh weight respectively. Less than 4 tons of gracilarioids are estimated to remain in St Helena Bay. We discuss the fluctuations in biomass and distribution of these South African gracilarioid populations.     

Bryophytes of St Helena,South Atlantic Ocean. 4. Kurzia nemoides (Hook.f. et Taylor) Grolle and Lepidozia africana Steph. (Jungermanniales,Lepidoziaceae) described from the island

Abstract

The little known species Kurzia nemoides (Hook.f. et Taylor) Grolle and Lepidozia africana Steph. (Lepidoziaceae) are described and illustrated from St Helena, South Atlantic Ocean. Details are given of their distributions on the island, and the differences between related species are discussed. This is the first report of the genus Lepidozia from St Helena.     

应用鱼类完整性指数(FAII)评价长江口沿岸碎波带健康状况

基于2006年11月-2007年10月在长江口的13个站点的周年调查,探索了鱼类完整性指数（FAII）在河口水域鱼类栖息地环境评价中的应用。结果显示各站点FAII值介于0-46之间,表明碎波带健康状况全年处于一般到极差的水平。系统聚类（Hierarchical Cluster）将所有站点分为四组,第一组St.1,Sts.12-13;第二组为Sts.2- 3,St.5;第三组为St.6,St.11;第四组为St.4,Sts.7- 10。健康状况差的站点FAII值全年波动较大,由于夏季水温升高,部分站点出现大量的洄游性和海洋性种类,FAII值出现季节性的升高;其中河口外段的St.1,St.11-St.13的完整性等级分别在7月和8月达到一般水平。St.4,St.10因位于水源保护区外侧,St.9位于西沙湿地公园,受人为影响较小,这三个站点的FAII值相对比较稳定且在所有站位点中处于较高水平。FAII与Margalef丰富度指的周年变化有一定的相似性,但与Shannon-Wiener多样性指数的变化却有很大的差异。     

Feather damage due to mycotic infections in wild turkeys

Wild turkeys (Meleagris gallopavo) from Pearl River Wildlife Management Area, St. Tammany Parish and from adjacent St. Helena Parish, Louisiana (USA) were observed to have broken and frayed rectrices. The condition was noted in 21% of 90 wild turkeys harvested by hunters during the springs of 1985 through 1988 from the Pearl River Wildlife Management Area. Damage to feathers ranged from mild to severe. Histologic and microbiologic study of five birds disclosed colonization and invasion of the rachis sheath and pulp by fungi of the genera Aspergillus, Curvularia, Cladosporium, Dactylella, Exophiala, Helminthosporium and Trichophyton and by Streptomyces. Sterilized normal rectrices from wild turkeys were inoculated with these organisms and subsequently developed damage that was histologically compatible with field cases. The condition was diagnosed as a multiple etiology mycosis. Successful colonization and invasion of experimentally inoculated feathers required addition of moisture and elevation of relative humidity within the cultures. The apparent high moisture requirements of the fungi suggest that late winter and early spring flooding may be a probable predisposing factor for this condition.     

Growth rates and agar properties of three gracilarioids in suspended open-water cultivation in St. Helena Bay, South Africa

Relative growth rates (RGRs), yields and agar characteristics of threegracilarioid isolates (Gracilariopsis sp. from St. Helena Bay, and Gracilaria gracilis isolates from Langebaan Lagoon and Saldanha Bay) weremeasured to assess the suitability of a site in St. Helena Bay for suspendedcultivation. The gracilarioids were grown on polypropylene ropes and`netlon' lines, and the RGRs were 4.0–11.0% d<sup>-1</sup> and 5.0–7.0%d<sup>-1</sup>, respectively. The RGR of the Langebaan isolate of G. gracilis grown on ropes was significantly higher than the RGR of otherisolates. The mean net yield for the Langebaan isolate grown on `netlon'lines was 2.6 ± 0.9 kg wet wt m^-2 30 day^-1. Thecultured gracilarioids were extracted for native and alkali treated agars. Themean native agar yield over the entire period was 39.0% dry wt. Alkalipretreatment reduced the yield by 55%, but significantly increased gelstrength. High gel strengths (>750 g cm^-2) were measured inagars from Gracilariopsis sp. and Saldanha Gracilaria gracilis inmid-summer and winter. The dynamic gelling and melting temperatures ofnative and alkali treated agars varied among the gracilarioids. The meangelling and melting temperatures of agars were about 39.0 ^°C and86.0 ^°C, respectively. The 3,6-AG content ranged from 29% to38% for native agars and 34–45% for alkali treated agars. While theseresults indicate that this site is suitable for gracilarioid cultivation, occasionallow-oxygen events in St. Helena Bay lead to production of hydrogensulphide in the sea water (`black tides'). Such events killed most inshorebiota (including seaweeds) in 1994 and 1998. This frequency (on average1–2 per decade) and duration (maximum 2 weeks) would have to beconsidered in planning commercial seaweed farming in St. Helena Bay.     

Bryophytes of St Helena,South Atlantic Ocean. 1. Three new species of Cololejeunea (Jungermanniales,Lejeuneaceae), C. dianae sp. nov., C. sanctae-helenae sp. nov. and C. grossestyla sp. nov.

Abstract

Three new species of Cololejeunea, C. dianae M. Wigginton, C. sanctae-helenae M. Wigginton and C. grossestyla M. Wigginton are described and illustrated from St Helena, South Atlantic Ocean. Details of their distributions are provided, and differences between the new taxa and other species of Cololejeunea are discussed. This is also the first report of the genus Cololejeunea from St Helena.     

Evolution of St Helena arborescent Astereae (Asteraceae): relationships of the genera Commidendrum and Melanodendron

The cladistic relationships of endemic Commidendrum (four species) and Melanodendron (one species) from St Helena were inferred from sequences of ITS1 and ITS2 of nuclear ribosomal DNA. Despite showing a range of morphological and ecological variation, the four species of Commidendrum , C. spurium , C. robustum , C. rotundifolium , and C. rugosum , form a closely related monophyletic group with percentage sequence divergence between 0.2 and 0.9%. Melanodendron integrifolium is sister to Commidendrum indicating that the two genera may have evolved from a common ancestor that arrived in St Helena via a single dispersal event. The closest relatives of Commidendrum and Melanodendron appear to be South African, in the predominantly shrubby genus Felicia , although further sampling of South African Astereae is required. We discuss the evolution and adaptive radiation of these rare and threatened species with particular reference to the possible role of heterochrony.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 69–83.     

Shigeru Tsuiki: a pioneer in the research fields of complex carbohydrates and protein phosphatases

Dr Tsuiki made three major contributions during his illustrious career as a biochemist. First, he developed the procedure for mucin isolation from bovine submaxillary glands. His work became the basis for mucin biochemistry. Second, he identified four distinct molecular species of mammalian sialidase. Subsequent studies based on his work led to the discovery that sialidase plays a unique role as an intracellular signalling factor involved in the regulation of a variety of cellular functions. Finally, he established the molecular basis for the diversity of mammalian protein phosphatases through protein purification and molecular cloning. His work prompted the functional studies of protein phosphatases.     

Phylogeography of Ophioblennius: the role of ocean currents and geography in reef fish evolution

Many tropical reef fishes are divided into Atlantic and East Pacific taxa, placing similar species in two very different biogeographic regimes. The tropical Atlantic is a closed ocean basin with relatively stable currents, whereas the East Pacific is an open basin with unstable oceanic circulation. To assess how evolutionary processes are influenced by these differences in oceanography and geography, we analyze a 630-bp region of mitochondrial cytochrome b from 171 individuals in the blenniid genus Ophioblennius. Our results demonstrate deep genetic structuring in the Atlantic species, O. atlanticus, corresponding to recognized biogeographic provinces, with divergences of d = 5.2-12.7% among the Caribbean, Brazilian, St. Helena/Ascension Island, Gulf of Guinea, and Azores/Cape Verde regions. The Atlantic phylogeny is consistent with Pliocene dispersal from the western to eastern Atlantic, and the depth of these separations (along with prior morphological comparisons) may indicate previously unrecognized species. The eastern Pacific species, O. steindachneri, is characterized by markedly less structure than O. atlanticus, with shallow mitochondrial DNA lineages (dmax = 2.7%) and haplotype frequency shifts between locations in the Sea of Cortez, Pacific Panama, Clipperton Island, and the Galapagos Islands. No concordance between genetic structure and biogeographic provinces was found for O. steincdachneri. We attribute the phylogeographic pattern in O. atlanticus to dispersal during the reorganization of Atlantic circulation patterns that accompanied the shoaling of the Isthmus of Panama. The low degree of structure in the eastern Pacific is probably due to unstable circulation and linkage to the larger Pacific Ocean basin. The contrast in genetic signatures between Atlantic and eastern Pacific blennies demonstrates how differences in geology and oceanography have influenced evolutionary radiations within each region.