Trophic levels in community food webs

Summary Four concepts are considered for the trophic level of a species in a community food web. The long-way-up-level (or LU-level) of species A is the length of the longest simple food chain from a basal species (one with no prey in the web) to A. (A simple chain is a chain that does not pass through any given species more than once.) The short-way-up-level (SU-level) of species A is the length of the shortest chain from a basal species to A. The long-way-down-level (LD-level) of species A is the length of the longest simple chain from species A to a top species (one with no consumers in the web). The short-way-down-level (SD-level) of species A is the length of the shortest chain from species A to a top species. The stratigraphy of a web is the analogue for species of the pyramid of numbers for individuals: it is the frequency distribution of species according to level. The LU-, SU-, LD-, and SD-stratigraphies of the seven webs in the Briand-Cohen collection with 30 or more trophic species reveal no species with LU-level or LD-level more than 6, no species with SU-level more than 3, and no species with SD-level more than 2. In all seven webs, SD-levels are stochastically less than SU-levels: species tend to be closer to a top predator than to a basal species. Two stochastic models of food web structure (the cascade model and the homogeneous superlinear model) correctly predict that 95% or more of species should have LU-level and LD-level in the range 0–6. The models also correctly predict some details of the distribution of species in the SU- and SD-stratigraphies, particularly the fraction of species in level 1. The models do not, in general, correctly predict the distribution of species within the range 0–6 of LU-levels and LD-levels.     

New species and new records of recently described species of the coral genus Acropora (Scleractinia: Astrocoeniina: Acroporidae) from Indonesia

Six new species of the coral genus Acropora arc described from Indonesia. These include a species which is remarkable for tubercular cocnostcal structures similar to those of the confamilial genus Montipora. The new species include three regional endemics (A. togianensis and A. batunai from central east Sulawesi and A. derawanensis from east Kalimantan), one species with broad distribution across the southern island chains (A. sukarnoi) and two species which occur throughout most of the Indonesian archipelago (A. Indonesia and A. hoeksemai). A further two species described from Western Australia and Papua New Guinea in 1994 (A. turaki and A. jacquelineae respectively) are recorded from Indonesia for the first time, as common members of an unusual assemblage type in the Togian Islands. The range of another species described from Lombok in 1994 (A. suharsonoi) is extended into Bali. With A. desalwii, A. lokani and A. indiana , this brings to 12 the number of Acropora species newly recorded as being endemic to the Indonesian archipelago or to Indonesia and one adjoining region (either the Indian Ocean or the western Pacific).     

假丝酵母一新种——北京假丝酵母

本文研究了一株从水果表皮分离到的假丝酵母,它与至今已发表的所有已知假丝酵母均不相同,定名为北京假丝酵母(Candida beijingensis)。     

Biodiversity of Asterina species on Neotropical host plants: new species and records from Panama

Two new species of the genus Asterina are described from living leaves collected in provinces Chiriquí and Bocas del Toro in western Panama. Asterina alloplecti on Alloplectus ichtyoderma (Gesneriaceae) differs from other Asterina on Gesneriaceae by its stalked appressoria and host relationship. Asterina compsoneurae on Compsoneura sprucei (Myristicaceae) can be distinguished from other members of Asterina on Myristicaceae by its larger ascomata, larger, prominently spinose ascospores and host relationship. New records for Panama are Asterina corallopoda from a new host plant species (Solanum trizygum, Solanaceae), A. diplopoda, A. ekmanii from a new host plant species (Gonzalagunia rudis, Rubiaceae), A. siphocampyli from a new host plant genus and species (Burmeistera vulgaris, Campanulaceae) and A. styracina from a new host-plant species (Styrax argenteus, Styracaceae). This study increases the number of species of Asterina known for Panama from 12 to 19 and the number of Asterinaceae from 14 to 21. Asterina corallopoda, A. diplopoda, A. ekmanii, A. siphocampyli and A. styracina are illustrated for the first time. A phylogeny inferred from the analysis of LSU rDNA sequences of species of Asterina is presented. The diversity and host-plant patterns of known Neotropical species of Asterina are discussed.     

A new species of Bricelochlorops Paganelli and the first record of Urubambina rufa (Duda) (Diptera: Chloropidae) from Brazil

The subfamily Chloropinae comprises about 442 described species, with only one species recorded from the Brazilian Amazon. The genus Bricelochlorops Paganelli was represented by a unique species from Rio de Janeiro, Brazil. The species Urubambina rufa (Duda) is the only species of the genus Urubambina Paganelli and has been recorded only from Peru. A new species of Bricelochlorops, B. celutae sp. nov., is described here and Urubambina rufa is recorded for the first time in Brazil. Both species were collected in the state of Acre. A key to species of Bricelochlorops is provided.     

A new species of Anisakis Dujardin, 1845 (Nematoda, Anisakidae) from beaked whales (Ziphiidae): allozyme and morphological evidence

Larvae and adults of Anisakis, recovered from the beaked whales Mesoplodon layardii and Ziphius cavirostris from the Mediterranean Sea and South African waters, were analysed morphologically and by molecular markers (allozymes). A new Anisakis species was identified, showing fixed allele differences at a number of loci from the other Anisakis spp. tested (A. simplex complex, A. physeteris). The lack of hybrid or recombinant genotypes in mixed infections with A. pegreffii, A. simplex C and A. physeteris, as well as the high values of genetic distance (average D_Nei = 1.65 from the members of the A. simplex complex, and D_Nei = 3.09 from A. physeteris) showed that the new species is reproductively isolated. This new Anisakis species is morphologically different from the other Anisakis retained by Davey (1971) as either good species or species inquirendae. The name Anisakis ziphidarum n. sp. is proposed for the new species.     

中国海鼓虾科角鼓虾属分类研究(甲壳亚门,十足目)

对中国海鼓虾科角鼓虾属系统分类进行了研究.角鼓虾全世界共记录34种,其中中国海记录了9种.本文中记录中国海分布的角鼓虾属Athanas 8种,其中对中国海2新纪录种A.polymorphus Kemp和A.squillophilus Hayashi,进行了描记,并提供了中国角鼓虾种检索表.在中国的材料中:A.japonicus、A.ohsimai、A.polymorphus及A.squillophilus 4种的螯足表现了多态性,A.ohsimai和A.squillophilus的螯足多态性也是首次发现和记载.所有研究测量标本均保存在中国科学院海洋研究所.     

Taxonomy of the Neotropical Genus Americabaetis,New Status (Insecta: Ephemeroptera: Baetidae)

Americabaetis (Insecta: Ephemeroptera: Baetidae), previously considered synonymous with Acerpenna, is reinstated and given generic rank. The genus differs from Acerpenna in lacking hindwings, gills on abdominal segment 1, and a conical process between the male genital forceps, and in possessing apically rounded gills on abdominal segment 7. The genus has a general Neotropical distribution with a northern limit in east-central Mexico. Five new species of Americabaetis are described from South America: A. alphus, new species, from Argentina, Bolivia, Brazil, Chile, and Paraguay; A. labiosus, new species, from Brazil, Paraguay, and Uruguay; A. longetron, new species, from Brazil, Paraguay, and Uruguay; A. maxifolium, new species, from Paraguay; and A. titthion, new species, from Brazil. Americabaetis boriquensis, new combination; A. intermedius, new combination; A. naranjoi, new combination; A. pleturus, new combination; and A. robacki, new combination, are reviewed.     

中国西北地区维特疣(虫兆)属一新种(弹尾纲,疣(虫兆)科)

描述了采自中国西北地区的维特疣属Vitronura1新种——陕西维特疣,模式标本保存在中国科学院上海生命科学研究院。新种与属内其它种的区别在于上颚具有7齿,上唇有4根毛,头部背面毛的数量明显少于其它种类,An疣上有2根毛,胸部第2～3节的Di疣上分别有3根毛,腹部第1～4节De疣上分别有3根普通毛和1根感觉毛,腹部第5节的Di疣互相分离。文中同时还编制了该属中国种类检索表。     

Description of Culicoides pseudoheliconiae sp.n. from Peruvian Amazon and revalidation of Culicoides contubernalis Ortiz & Leon (Diptera: Ceratopogonidae)

A new species of the Culicoides hylas species group, Culicoides pseudoheliconiae Felippe-Bauer is described and illustrated based on female specimens from Peruvian Amazon, and Culicoides contubernalis Ortiz & Leon from Ecuador is resurrected and redescribed as a valid species. A systematic key, table with numerical characters of females of species of the Culicoides hylas group are given.     

Isolation and characterization of microsatellite markers from malaria vector,Anopheles culicifacies

Anopheles culicifacies, an important vector in the Indian subcontinent is a complex of five sibling species of which four are vectors. We describe the isolation of 31 microsatellite markers from the recently recognized isomorphic species A of which 13 were characterized in sympatric populations of Anopheles culicifacies isomorphic species A and B. The allele frequencies ranges from two to 12 in species A and two to seven in species B. Species A being a vector, and that these markers can be used in closely related species, makes the isolation of these markers important to study population structure of all sibling species in this complex.     

A new species of Acanthostigma (Tubeufiaceae, Dothideomycetes) from the southern hemisphere

A new species belonging to the Dothideomycete genus Acanthostigma is described from bark of two Nothofagus species from Argentina. Its identity as a new species is based on both morphology and molecular sequence data. Acanthostigma patagonica differs from other species in the genus by having larger ascomata and setae and wider, asymmetrical ascospores. An amended key to Acanthostigma species is provided along with a discussion of other species previously described from South America.     

Some species of the genus Phyllodoce (Polychaeta) from Southern California

Five species of the genus Phyllodoce from Southern California are reviewed. A new subgenus (Aponaitides) is proposed and a new species, Phyllodoce cuspidata , is described. A key to the Southern California species is included.     

A new species of <Emphasis Type="Italic">Prohatschekia</Emphasis> Nunes-Ruivo, 1954 (Copepoda: Hatschekiidae) parasitic on <Emphasis Type="Italic">Scorpaena elongata</Emphasis> (Cadenat) off Algeria

A new species of parasitic copepod, Prohatschekia mediterranea n. sp. (Siphonostomatoida: Hatschekiidae), is described from a scorpaenid fish, Scorpaena elongata, collected off Algeria. This is the seventh species of Prohatschekia Nunes-Ruivo, 1954 to be described and the first record of the genus from the Mediterranean Sea. The new species is most closely related to P. cremouxi Nunes-Ruivo, 1954, known from a congeneric host collected in Senegal. A key is provided to distinguish the new species from other members of the genus.     

Systematics and biogeography of the genus Actenodia (Coleoptera: Meloidae: Mylabrini)

Abstract.  The genus Actenodia Laporte de Castelnau (Meloidae: Mylabrini) is revised. It includes 18 species distributed in the Mediterranean and Saharo-Arabian regions, and in eastern and southern Africa; A. carpanetoi sp.n. from Mozambique is described. The bionomics of the genus is summarized, according to a collection of records on phenology, elevation, habitat preference and host plants. A classification of the genus is proposed after a morphological cladistic analysis: one Afrotropical lineage clearly emerged with three distinct groups of species, whereas other taxa, all Palaearctic except A. mirabilis , remained unresolved. The analysis of the nuclear internal transcribed spacer 2 rDNA sequences of some Palaearctic and Afrotropical species supports the distinction of the Afrotropical lineage. The first instar larvae of two species, A. chrysomelina from southern Africa and A. denticulata from Arabia, are described for the first time and compared with two other Palaearctic species described previously; inferences from larval morphology are discussed. The adult morphology of all species is described briefly and illustrated, and a key to the species is provided, as well as locality data. Three new synonymies are proposed: A. extera Dvořák, 1993 syn.n. = A. septempunctata Baudi di Selve, 1878; A. sexpunctata Pic, 1948 syn.n . = A. curtula Fähraeus, 1870 ; A. unimaculata lanzai Kaszab, 1973 syn.n . = A. unimaculata Pic, 1908. The biogeography of the genus is discussed within the framework of a more general analysis of the disjunct distribution models.     

A new species of Ascocotyle (Trematoda: Heterophyidae) from the South American sea lion, Otaria flavescens, off Patagonia, Argentina

We describe a new heterophyid species, Ascocotyle (Ascocotyle) patagoniensis n. sp., based on specimens collected from the intestines of the South American sea lion Otaria flavescens from Patagonia (Argentina). Ascocotyle (A.) patagoniensis n. sp. is distinguished from the other species of the subgenus by the number of circumoral spines, which are arranged in 2 rows of 18 to 23. The new species also differs from the other species in having a gonotyl without papillae. The specimens exhibited the widest seminal receptacle described for a species of this subgenus. Species of the subgenus Ascocotyle usually infect fish-eating birds or mammals in freshwater or brackish habitats. Ascocotyle (A.) patagoniensis n. sp. is the first species of the subgenus described from a marine mammal. However, no metacercariae of Ascocotyle spp. were found in 542 marine teleosts from 20 species collected in the same locality. The life cycle of the marine species from the Ascocotyle -complex infecting pinnipeds remains elusive.     

Redescription of Pennella sagitta (Copepoda: Pennellidae) from Histrio histrio (Pisces) in the North-west Atlantic Ocean with a provisional review of the genus Pennella

Pennella sagitta (L.) is redescribed from fresh specimens recovered from Histrio histrio (L.) and from material in the collection of the Smithsonian Institution. A small, delicate parasitic copepod, P. sagitta is shown to be a valid species, found only on fishes of the family Antennariidae. Attempts of earlier workers to synonymize P. diodontis with P. sagitta are rejected, and the distinguishing features of both species are presented. A neotype is proposed from material described herein, due to a lack of the original holotype. A provisional review of the genus Pennella Oken, 1816 is provided, and the taxonomic status of 31 species is discussed. Pennella exocoetus is described from material in museum collections. Seven species, P. balaenoptera, P. diodontis, P. exocoetus, P.filosa, P. instructa, P. makaira and P. sagitta are considered as valid members of the genus. The remaining species are reduced to synonymy with valid species or accorded the status of species inquirendae.     

Three new phylogenetic lineages are the closest relatives of the widespread species Albugo candida

White blister rust caused by the obligate biotroph Albugo candida (Albuginaceae; Oomycota) is one of the most notorious and common diseases of Brassicaceae. During the past 5 y, A. candida specimens collected from about 30 host genera were phylogenetically and morphologically investigated in several studies. These not only revealed that A. candida s.str. has a broad host range, encompassing a large number of host plants belonging to Brassicales, but also the presence of previously overlooked species of Albugo with hosts in this order. In this study, we examined specimens from Alyssum, Barbarea, and Rorippa, of which many species were commonly recorded as host plants of A. candida but could not be included in previous works due to the paucity of specimens available. It was revealed that Albugo specimens from Alyssum montanum, Barbarea vulgaris, and various Rorippa species, were placed in three phylogenetically distinct clades, but closer to A. candida s.str. than any previously reported species. Oospores were observed from Albugo specimens parasitic to Rorippa and could be distinguished morphologically from A. candida. Therefore, Albugo rorippae sp. nov. is described and illustrated here. In addition, a key of Albugo species described previously from Brassicales is given. The present study reveals that a large number of Albugo species remain still undiscovered, and that species close to A. candida exist. This could help elucidating the basis of the broad host range of A. candida as opposed to the narrow specialisation that is seemingly present in other species of Albugo on the Brassicaceae.     

Acacia species and rhizobial interactions: Implications for restoration of native vegetation

Summary For successful restoration of native vegetation on nitrogen-depauperate soils, an understanding of nitrogen-fixing relationships between plant host species and their bacterial symbionts is critical. Each of three geographically restricted Acacia species ( A. fulva , A. nano-dealbata , and A. trachyphloia ) and three widely distributed species ( A. dealbata , A. implexa , and A. melanoxylon ) were inoculated with 20 different rhizobial ( Bradyrhizobium spp.) strains. The strains comprised two obtained from each of 10 different host species, including the six Acacia species listed above plus a further four species, A. cangaiensis , A. cincinnata , A. deanei , A. mearnsii . Neither restricted nor widely distributed species grew more effectively with their own strains than with strains isolated from other species. Thus, host species with restricted geographical ranges did not demonstrate greater specialization in their symbiotic associations with rhizobia than widespread species. Highly significant variation was observed between the strains obtained from each host species with respect to their ability to promote effective plant growth across all host species. In many cases, strains that were highly effective at promoting growth for one host species, were comparatively ineffective in combination with other host species. Strains thus exhibited host specificity in their ability to fix nitrogen. These findings indicate that choosing appropriate rhizobial strains for inoculation prior to revegetation is critical and should be made carefully for both restricted and widespread species.
Key words distribution, nitrogen fixation, revegetation, symbiotic interactions.