Bionomy of Macrobenthic Polychaetes in the Evros Delta (North Aegean Sea)

The composition and distribution of the macrobenthic polychaete fauna in the Evros Delta (North Aegean Sea) have been investigated by means of 4 replicate quantitative samples collected at 35 sites. 10 species were found and, in additional qualitative samples, the sedentary species Ficopomatus enigmaticus was collected. On the basis of the similarity in distribution among stations, 3 groups of species have been distinguished. One of these groups includes the species Spio decoratus and Hediste diversicolor which were both dominant and present at almost all stations. The distribution of species in the study area seems to depend on factors such as salinity, granulometric composition and organic matter of the sediment and interspecific competition, but mainly on the degree of “confinement”, namely the degree of exchange with the open sea. At the most isolated stations, the lowest number of species and the highest values of abundance and biomass were recorded.     

Distribution,ecology and conservation survey on Trifolium michelianum Savi (Fabaceae) in Sicily (Italy)

We report the identification of four residual stations for Trifolium michelianum Savi (Fabaceae) in Sicily, whereas the species was documented to be extinct at the Gorgo Cerro station (western Sicily), the only locality previously reported in the literature. In addition to an update on the distribution of the species, a survey on the new Sicilian populations led to their biological, ecological and phytosociological characterization, as well as to an assessment of the risk factors. The species, here relegated to the limit of its distribution area, occurs in particularly sensitive and vulnerable environments, such as the “Mediterranean temporary ponds”, considered “priority” by the Council Directive 92/43/EEC. Moreover, a new Sicilian association (Trifolio micheliani–Glycerietumspicatae ass. nova), framed in the alliance Glycerio-Sparganion (class Phragmito-Magnocaricetea), is described.     

Phylogenetic relationships in the Sceloporus variabilis (Squamata: Phrynosomatidae) complex based on three molecular markers,continuous characters and geometric morphometric data

The monophyly of the Sceloporus variabilis group is well established with five species and two species complexes, but phylogenetic relationships within species complexes are still uncertain. We studied 278 specimens in 20 terminals to sample all taxa in the “variabilis group,” including three subspecies in the “variabilis complex,” and two outgroups (Sceloporus grammicus and Sceloporus megalepidurus). We assembled an extensive morphological data set with discrete and continuous characters (distances and scale counts), including geometric morphometric data (landmark coordinates of three shapes), and a three‐marker molecular data set as well (ND4, 12S and RAG1). We conducted parsimony and Bayesian phylogenetic inferences on these data, including several partitioning and weighting schemes. We suggest elevating three subspecies to full species status. Therefore, we recommend recognition of nine species in the “variabilis group.” First, S. variabilis is sister to Sceloporus teapensis. In turn, Sceloporus cozumelae is sister to Sceloporus olloporus. These four species are a monophyletic group, which is sister to Sceloporus smithi. Finally, Sceloporus marmoratus is sister of the clade of five species. The other species in the “variabilis group” (Sceloporus chrysostictus, Sceloporus couchii and Sceloporus parvus) are a paraphyletic grade at the base of the tree. Our analyses reject the existence of the “variabilis complex.” We conducted a parsimony‐based ancestral reconstruction on body size (snout–vent length), femoral pores and dorsal scales and related morphological changes to geographic distribution of the species. Our phylogenetic hypothesis will allow best designs of comparative studies with species in the “variabilis group,” one of the earliest divergent lineages in the genus.     

Biological availability and humic properties of dissolved organic carbon in Lake Balaton (Hungary)

The nursery role of the Mondego estuary for marine fish species was studied between June 2003 and May 2004. The spatial and temporal distribution and abundance patterns of 0-group Dicentrarchus labrax (Linnaeus, 1758), Platichthys flesus (Linnaeus, 1758) and Solea solea (Linnaeus, 1758) were analyzed based on monthly sampling surveys in five stations along the estuarine gradient. Fishing took place during the night at low water of spring tides, using a 2 m beam trawl. The spatial patterns of estuarine colonization were different according to species. D. labrax showed a wider distribution, but the main nursery ground was the same as for S. solea. Highest densities of S. solea juveniles were found in oligohaline areas, with muddy bottoms and high benthic invertebrates availability, while P. flesus occurred mainly in the sandy uppermost areas. D. labrax was found in both these areas. Fish abundance in the estuary mainly reflected seasonal changes.     

IDENTIFICATION OF PFIESTERIA PISCICIDA (DINOPHYCEAE) AND PFIESTERIA‐LIKE ORGANISMS USING INTERNAL TRANSCRIBED SPACER‐SPECIFIC PCR ASSAYS1

The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida (Steidinger et Burkholder), frequently co‐occurs with other morphologically similar species collectively known as Pfiesteria‐like organisms (PLOs). This study specifically evaluated whether unique sequences in the internal transcribed spacer (ITS) regions, ITS1 and ITS2, could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit or large subunit rRNA genes and more likely to contain species‐specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida, Pfiesteria shumwayae (Glasgow et Burkholder), Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum (Leadbetter et Dodge). These PCR assays had a minimum sensitivity of 100 cells in a 100‐mL sample (1 cell·mL^?1) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA. DNA purification and aspects of PCR assay development, PCR optimization, PCR assay controls, and collection of field samples are discussed.     

Results of a food addition experiment in a north-central Chile small mammal assemblage: evidence for the role of "bottom-up" factors

Since 1989, effects of biotic interactions including predation and herbivory have been examined in a replicated experimental study in a north‐central Chilean semiarid thorn scrub community. Strong responses of small mammals and plants to El Niño Southern Oscillations (ENSO) have also been documented suggesting that “bottom‐up” factors related to high rainfall are important. To simulate increased primary productivity effects on small mammals, ad lib rabbit pellet additions were initiated in mid‐1997 on unfenced grids near the experimental complex. Following the 1997 El Niño event with three times normal precipitation, numbers of small mammals during pre‐addition months and the first treatment year were similar on control and food addition grids. During the second year (1998–1999), a period of severe drought, food additions had significant positive effects on numbers of two predominantly herbivorous “core” (resident) species, Octodon degus and Phyllotis darwini, and an omnivorous “quasi‐core” (resident but highly fluctuating) species, Akodon olivaceus; however, all three species declined towards the end of the second treatment year. Two “opportunistic” (temporarily resident) species, Abrothrix longipilis (an insectivore) and Oligoryzomys longicaudatus (a granivore), showed no responses to food additions. An insectivorous marsupial, Thylamys elegans (also a “core species”), had significantly lower numbers on food addition grids. Changes in body weight distributions and proportions of reproductive individuals particularly in O. degus indicate in situ responses. Whereas no differences in residency, numbers of stations visited, and trappability were observed, energy compensation ratios greater than one suggest significant immigration in the second year. Thus, food additions elicited strong responses by herbivorous/omnivorous “core” and “quasi‐core species” whereas they had no effects on “opportunistic species”. These results reinforce the view that “bottom‐up” factors influencing food availability exert prevailing control on numerically important small mammal species by temporarily increasing carrying capacity, and that “top‐down” factors (i.e., biotic interactions) become important when small mammal numbers are at or near their carrying capacity. Spatial dynamics may be important in explaining declines of species populations exhibiting initially positive responses to food additions.     

Polychaete distribution on the southwestern Atlantic continental shelf

Diversity and distribution of polychaetes on the southeastern Brazilian Shelf (SBS) adjacent to the city of Santos were studied. The study area is situated in the vicinity of Santos Bay with its estuarine complex and other small rivers along the coast. A total of 16,274 specimens belonging to 214 polychaete species were found at 21 sampling stations during two different periods. Two communities occur along the shelf and were related firstly to sediment characteristics. Prionospio dayi (Spionidae) was dominant in the inner shelf community that was characterized by well-sorted, very fine sand. The outer shelf community was found in muddy sediments with high organic matter content and was dominated by subsurface deposit feeders, like Petersenaspis capillata (Sternaspidae) and Leitoscoloplos kerguelensis (Orbiniidae), and by large carnivores such as Aglaophamus sp. (Nephtyidae) and Sigambra sp. (Pilargidae). A transition zone of mixed sediments presenting high diversity and richness was found between these communities. The characteristics of bottom water and food quality in the sediment were important to divide the inner shelf into two sub-areas. Nearshore sampling stations (A group) were more influenced by freshwater input, mainly during summer. This influence is not conspicuous at stations close to 30?m depth (B group). However the effect of South Atlantic Central Water mass (SACW) intrusion on the benthic system was observed on the inner shelf – B group during the summer. The summer intrusion of SACW onto the inner shelf may explain the higher quality of organic matter that resulted in an increase in polychaete abundance and richness.     

Abundance and Distribution of Native and Alien Grasses in a “Cerrado” (Brazilian Savanna) Biological Reserve1

Several species of African grasses brought to Brazil as cattle forage have spread widely, outcompeting native herb species. The open forms of Brazilian savanna (“campo cerrado” and “campo sujo”) are the most affected by such invasions, because their structure is open, permitting enough sunlight into the lower strata. The invasion of alien forage grasses occurs in almost every cerrado nature reserve. This study was carried out in the “Cerrado de Hmas Biological Reserve”, Pirassununga, São Paulo State, Brazil, with the following objectives: (a) to compare the abundance of native and alien grass species; (b) to verify the importance of such alien grasses in the community; (c) to identity distribution patterns for the alien grass species in a gradient from the edge (highly disturbed) to the center (less disturbed) of the reserve; and (d) to explore the distribution of native and alien grasses in the search for possible competitive interactions. Using the “point method,” a total of 260 points was sampled and 52 species were recorded. The four most frequent species (FA = absolute frequency) were two native (Echinolaena inflexa [Poir.J Chase [FA = 38.85%] and Diandrostachya chrysotrix [Nees] Jacues Felix [FA = 15.38%]) and two alien African species (Melinis minutiflora Beauv. [FA = 33.08%] and Brachiaria decumbens Stapf [FA = 13.85%]). M. minutiflora and E. inflexa had higher values of absolute vigor (67.69 and 59.62%, respectively), relative vigor (28.16 and 24.80%, respectively), and cover (100.77 and 98.47, respectively), indicating higher biomasses and densities and their dominance in the community. B. decumbens presented the highest number of contacts per point, showing the highest stratification. To detect possible edge–center distribution gradients, correspondence analysis was done, initially using all the recorded species and subsequently only the four more frequent grasses, with similar results: (a) the alien grasses, especially M. minutiflora, did not show a distinct distribution gradient from edge to center, but occurred over the whole reserve; (b) no distinct ecotonal band around the reserve (edge–belt) was detected, the whole reserve seeming to be “ecotonal”; and (c) E. inflexa and M. minutiflora showed similar phytosociological patterns, and spatial distribution; association between these two species was statistically significant.     

Mitochondrial gene rearrangements suggest a new genus in the subfamily Cantharinae (Coleoptera)

The Cephalomalthinus semifumatus species group, referred to as the “semifumatus” group henceforth, is interesting because of its heterogeneous morphology resembling either Cephalomalthinus Pic, 1921 or Rhagonycha Eschscholtz, 1830. To elucidate its phylogenetic status, mitochondrial genomes of four species of the “semifumatus” group, 11 Cephalomalthinus species, and 11 Rhagonycha species were sequenced and examined. All analysed mitogenomes were similar with respect to genome size, nucleotide composition, and AT content. Surprisingly, a rearrangement of the trnW-trnC and trnY genes was detected in the “semifumatus” group, presumably caused by tandem duplication and random loss events. Furthermore, genetic distance analyses showed that the proximity of the “semifumatus” group to Cephalomalthinus and to Rhagonycha was comparable to that between the latter two. Moreover, the produced phylogeny strongly supported the monophyly of the “semifumatus” group, and molecular clock analyses dated its divergence from Cephalomalthinus to 32.52 Ma. Thus, the new genus Amphimorphus gen. nov. is suggested to comprise the “semifumatus” group, in which the observed gene rearrangement was a synapomorphy. Moreover, morphological evidence regarding the unique structure of the aedeagus supported this separation. These results indicate that mitochondrial gene rearrangement provide important phylogenetic implications for revising Cephalomalthinus, a speciose genus that is puzzling in the morphology-based taxonomy.     

A review of the West Palaearctic aphidiines (Hymenoptera: Braconidae: Aphidiinae) parasitic on Uroleucon spp., with the description of a new species

A review of aphidiine wasps (Hymenoptera: Braconidae) parasitizing the Uroleucon species in the West Palaearctic is presented. Eleven species are keyed and illustrated. In addition, a new hymenopteran parasitoid species: Praon nonveilleri n. sp. from Uroleucon inulicola (Hille Ris Lambers) infesting Inula ensifolia L., is described. The new species is diagnosed and illustrated. It belongs to the “dorsale-yomenaé” species group and was collected from the Djetinja canyon in Serbia and Montenegro. The aphidiines presented in this work were identified from 97 aphid taxons occurring on 236 plant taxons. Furthermore, 361 original parasitoid – host aphid – host plant associations of the species mentioned in the key are presented. Finally, phylogenetic relationships inside the “dorsale-yomenae” species group and related species were reconstructed using cladistic distance methods.     

How much does climate change threaten European forest tree species distributions?

Although numerous species distribution models have been developed, most were based on insufficient distribution data or used older climate change scenarios. We aimed to quantify changes in projected ranges and threat level by the years 2061–2080, for 12 European forest tree species under three climate change scenarios. We combined tree distribution data from the Global Biodiversity Information Facility, EUFORGEN, and forest inventories, and we developed species distribution models using MaxEnt and 19 bioclimatic variables. Models were developed for three climate change scenarios—optimistic (RCP2.6), moderate (RCP4.5), and pessimistic (RPC8.5)—using three General Circulation Models, for the period 2061–2080. Our study revealed different responses of tree species to projected climate change. The species may be divided into three groups: “winners”—mostly late‐successional species: Abies alba, Fagus sylvatica, Fraxinus excelsior, Quercus robur, and Quercus petraea; “losers”—mostly pioneer species: Betula pendula, Larix decidua, Picea abies, and Pinus sylvestris; and alien species—Pseudotsuga menziesii, Quercus rubra, and Robinia pseudoacacia, which may be also considered as “winners.” Assuming limited migration, most of the species studied would face a significant decrease in suitable habitat area. The threat level was highest for species that currently have the northernmost distribution centers. Ecological consequences of the projected range contractions would be serious for both forest management and nature conservation.     

Redefinition and taxonomic revision of the “buqueti” species-group,Dichotomius Hope, 1838 (Coleoptera: Scarabaeidae: Scarabaeinae)

On the basis of external morphology and genitalia of males, as well as a comparison between different species belonging to other groups of Dichotomius, we propose a redefinition of the “buqueti” species group separated by Luederwaldt (1929). Six species are excluded from this group and transferred to other groups: D. ribeiroi (Pereira, 1954) in the “cotopaxi” group; D. camposeabrai Martínez, 1974 in the “bitiensis” group; D. reclinatus (Felsche, 1901), D. horridus (Felsche, 1911), D. quadrinodosus (Felsche, 1901) and D. nimuendaju (Luederwaldt, 1925) (revalidated species) forming the newly defined “reclinatus” group. The other species kept in the “buqueti” group include D. buqueti (Lucas, 1857) from Brazil (lectotype here designated), D. haroldi (Waterhouse, 1891) from Argentina and D. nutans (Harold, 1867) from Brazil, Argentina and Uruguay. The taxonomic revision of the “buqueti” group are presented, including a history of the included species, a determination key, illustrations of the structures of external morphology, male genitalia and sclerites of the internal sac, and a distribution map.     

Larvae of uncommon caridean decapods in the German Bight: Species composition,distribution and abundance

Typically, the most abundant group of shrimp larvae in the German Bight is formed by representatives of the family Crangonidae. Larvae of the remaining species have been largely ignored, and only scarce information concerning their ecology is available. Thus, the purpose of the present study was to determine the species composition, distribution and abundance of noncrangonid shrimp larvae in the German Bight in July 1990, after the mildest winter of the century. The material is based upon plankton samples collected at 77 stations, covering the entire German Bight. Eight species were identified, as well as larvae of Palaemonidae andProcessa-juveniles.Processa nouveli holthuisi (53.0%) andP. modica (31.3%) were predominant in the collection. The distribution of the two species was clearly separated: the main concentration ofP. nouveli holthuisi (peak concentration of 1.94 larvae per m³) was confined to the northwest corner of the German Bight, while a majority ofP. modica larvae (peak concentration of 0.54 larvae per m³) occurred at the southwesterly stations. The spatial distribution ofCaridion steveni andEualus occultus around Helgoland indicates the presence of an adult population at the only rocky island in the study area. Other taxa, such as larvae of Palaemonidae and juvenilePandalina brevirostris were collected exclusively in estuarine habitats. Based upon both the results of the present study and comparable data, we conclude that developmental stages of ten non-crangonid species, as well as representatives of Palaemonidae, can be expected to occur in the plankton of the German Bight. The extremely mild temperatures of the preceding winter may have been, in part, responsible for the relatively high densities of some taxa encountered during our plankton survey. We assume that warm winter temperatures favour the immigration, reproduction and survival of cold-sensitive species.     

ATTRIBUTES OF CHLOROCOCCUM SPECIES: A NUMERICAL ANALYSIS2

From previously published data, 73 characteristics of 17 species of Chlorococcum were compiled. Comparisons of character states of each character were made, and simple matching coefficients were calculated for each species by following the procedure of Sokal & Michener. From a data matrix of the matching coefficients, a phenogram was constructed according to the unweighted pair group method of Sokal & Sneath. Arithmetic averages were used in transferring data from one matrix to another. The frequency of each character state was calculated, and the character states of the highest frequency (the modes) were used to describe a “typical” Chlorococcum species. Comparisons were made between the “typical” Chlorococcum species and each of the 17 species studied. Simple matching coefficients were also calculated from these comparisons. All of the species had a relatively high affinity for the data of the calculated “typical”. Suggestions are made about the use of a “typical” taxonomic unit, and questions are raised about the taxonomic relationship among species of the genus Tetracystis and the genus Chlorococcum.     

Phylogenetic and phenotypic relationships among Triatoma carcavalloi (Hemiptera: Reduviidae: Triatominae) and related species collected in domiciles in Rio Grande do Sul State,Brazil

Triatoma carcavalloi is considered a rare Chagas disease vector often collected inside domiciles in Rio Grande do Sul State. In this Brazilian state, T. carcavalloi has been collected in the same ecotope (rock piles) with two other species (T. rubrovaria and T. circummaculata), with which it also shares morphological characteristics. Previous morphological studies placed T. carcavalloi in the same species complex (“infestans complex”) and subcomplex (“rubrovaria subcomplex”) as T. rubrovaria, whereas T. circummaculata was placed in the “circummaculata complex.” The phylogeny of a group composed of 16 species of triatomines was revaluated with the inclusion of T. carcavalloi by Bayesian analysis using mtDNA sequences of subunits 12S and 16S of the ribosomal RNA, and the cytochrome oxidase I (COI) genes. The phenotypic relationship among T. carcavalloi and related triatomines was also inferred from morphometrics. Phylogenetic results indicate that T. carcavalloi is a sister species of T. rubrovaria, and both were recovered as closely related to T. circummaculata. Morphometric studies confirmed the closeness among T. carcavalloi, T. rubrovaria, and T. circummaculata, prompting the placement of the latter species in the “infestans complex” and “rubrovaria subcomplex.”     

Phylogeographic patterns and species delimitation in the endangered silverside “humboldtianum” clade (Pisces: Atherinopsidae) in central Mexico: understanding their evolutionary history

The Atherinopsidae is the second largest group of freshwater fishes occupying central Mexico and is one of biological, cultural, and economic importance. The “humboldtianum” clade (Genus Chirostoma) is a “species flock” of nine described species that inhabit lacustrine ecosystems in central Mexico. The high morphological polymorphism within the group makes species identification difficult and thereby limits the development of research and management projects focusing on this group. In this study, we used phylogeographic and coalescent-based methods to understand the evolution of genetic variation among these species. The results revealed taxonomic inaccuracies and genetic admixture among species. Genetic variation was structured geographically, rather than taxonomically, and five closely related genetic groups were recovered. Two evolutionary pathways were found. First, a novel geographical arrangement of haplotypes was recovered that gave rise to the five recently (Pleistocene, <?1 Myr) derived genetic groups. The second pathway showed a recent intra-lacustrine genetic differentiation that could be associated with sympatric or ecological speciation. The current classification of the group is revised and includes a reduction in the number of valid species in the “humboldtianum” clade. Moreover, this study provides new insight into the biogeography and evolutionary history of this important group of fishes.