Decomposition of four macrophytes in wetland sediments: Organic matter and nutrient decay and associated benthic processes

Decomposition rates of Phragmites australis, Carex riparia, Nuphar luteum and Salvinia natans and benthic processes were measured from December 2003 to December 2004 in a shallow wetland (Paludi di Ostiglia, Northern Italy) by means of litter bags and intact cores incubations. Decay rate was highest for N. luteum (k = 0.0152 d⁻¹), intermediate for S. natans (k = 0.0041 d⁻¹) and similar for P. australis (k = 0.0027 d⁻¹) and C. riparia (k = 0.0028 d⁻¹).Benthic metabolism followed a seasonal pattern with summer peaks of O₂ demand and TCO₂, CH₄ and NH₄⁺ efflux whilst soluble reactive phosphorus (SRP) fluxes were negligible also under hypoxic conditions, indicating that P was mainly retained by sediment. The initial C:P ratio was similar in N. luteum and S. natans (170) and significantly lower than that of P. australis and C. riparia (360). During the detritus decay P was progressively lost by N. luteum and S. natans tissues, whereas, after an initial leaching, it was probably re-used during the microbial decomposition of the more refractory P. australis and C. riparia detritus. Nuphar luteum, P. australis and S. natans had comparable initial C:N mass ratio (15), significantly lower than that of C. riparia (26). The C:N ratio was rather constant for N. luteum (12.9 ± 1.5) and S. natans (14.6 ± 0.9), decreased slightly to below 20 for C. riparia and increased up to 30 for P. australis. Overall, differences among species were likely due to the recalcitrance of decomposing detritus, whilst process rates were controlled by limitation of microbial processes by nutrients and electron acceptor availability.     

Demographic and phylogeographic histories of two venomous North American snakes of the genus Agkistrodon

Many studies have revealed that lineages currently inhabiting formerly glaciated areas were pushed into southern glacial refugia and have expanded into their modern range since the last glacial maximum. There have been few studies that compare the effects of glacial cycles on lineage diversification and historical demography in closely related species with overlapping ranges. In this study we compare phylogeographic structure, historical demography, and approximate lineage age in two closely related and broadly co-occurring venomous snakes in eastern North America, the cottonmouth (Agkistrodon piscivorus) and copperhead (A. contortrix) using sequences from the mtDNA gene cytochrome b. We inferred three geographic lineages of A. contortrix and two of A. piscivorus with no common geographic or temporal pattern of lineage diversification identified for these species. Lineage diversification occurred in the Late Pliocene for A. piscivorus (2.5 mya) and in the Early Pleistocene for A. contortrix (1.5 mya). Demographic estimates revealed population expansion following the last glacial maximum (20,000 years ago) in two lineages of A. contortrix (the Central clade and Eastern clade) and one lineage of A. piscivorus (the Continental clade). The Florida clade of A. piscivorus is the only lineage for which constant population size through time was inferred, possibly due to stable populations persisting in areas unaffected by glacial advances. Our data suggest that unique habitat preferences may have shaped both the phylogeographic and demographic histories of each species.     

Fine structure characterization of amylopectins from grain amaranth starch

The aim of this study was to determine the fine structure of amylopectin from grain amaranth. Amaranthus amylopectin was hydrolyzed with α-amylase, and single clusters and a group of clusters (domain) were isolated by methanol precipitation. The domain and the clusters were treated with phosphorylase a and then β-amylase to remove all external chains, whereby the internal structure was obtained. The ,β-limit dextrins were analyzed on Sepharose CL 6B. The average DP (degree of polymerization) and peak-DP values of fractions of clusters were 57 and 82, respectively; the values of the domain were 137 and 309, respectively. The unit chain length profiles were analyzed by high-performance anion-exchange chromatography with pulsed amperometric detector (HPAEC–PAD). The results showed that the domain fraction contained 2.2 clusters, and single clusters were composed of 13 chains. The ,β-limit dextrins of the clusters were further hydrolyzed with α-amylase to characterize their building block composition. The average DP of the branched blocks was 11 and they contained on average 2.5 chains. Their average chain length, internal chain length, and degree of branching were approximately 4.3, 2.8, and 14, respectively. A cluster consisted of 6 branched blocks, and the internal chain length between the blocks was 6.8.     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Radiation and species limits in the Asian Pallas’s warbler complex (Phylloscopus proregulus s.l.)*

Pallass Warbler (Phylloscopus proregulus) of the Eastern Palaearctic (Siberia, China, Himalayas) resolves into a complex of four closely related but distinct allospecies forming a superspecies, P. [proregulus]. Assignment of species rank is based on cytochrome-b gene sequences and on vocalisations (territorial song and calls). Morphological divergence is poor, as is typical in Phylloscopus. It applies to size (nominate Siberian proregulus as opposed to the Sino-Himalayan taxa), and slight coloration differences among the latter taxa do not correspond to the cyt-b topology and are considered to be adaptive. Vocal differences relate to syntax (verse song vs endless song), frequency (broad vs narrow bandwidth, allocation of elements within the frequency band), form of elements (ascending vs descending parts, combination of these), and repertoire size. Strong premating isolating mechanisms are assigned to vocalisations. Contrary to current taxonomy, we propose the following constituent taxa of the Phylloscopus [proregulus] complex: Phylloscopus proregulus s.str. (Siberia, disjunct from the following taxa), P. kansuensis (China: Gansu, Qinghai), P. forresti (W/SW China, part of E Himalayas?), P. chloronotus with two subspecies: P. c. simlaensis (W Himalayas), and P. c. chloronotus (C and E Himalayas). Contact zones and possible hybridisation between the Sino-Himalayan taxa remain undetermined. A closely related isospecies is Phylloscopus yunnanensis (syn. P. sichuanensis), which is locally sympatric with and extremely similar morphologically to P. forresti and P. kansuensis. Cyt-b distance values range from 3.1% to 4.6% within the P. proregulus complex and from 7.5% to 8.4% between the latter and P. yunnanensis. This corresponds to differentiation times of 4.1 to 5.5 Myears (P. proregulus complex vs P. yunnanensis) and 1.7 to 3.2 Myears (within the P. proregulus complex).Electronic Supplementary Material Supplementary material is available in the online version of this article at Communicated by A. Helbig*Results of the Himalaya Expeditions of J. Martens, No. 247. – For No. 246 see: Ann Zool Warszawa, 2004.This revised version was published online in July 2004 with corrections to a heading and species names.     

The biogeography of littoral Lecane Rotifera

Little is known on the biogeography of Rotifera, particularly regarding the littoral taxa. Here, the biogeography of the most specious group of littoral Rotifera, Lecane, is discussed based on a recent revision of the group, and considering only verified records.Only 41.3% of all 167 Lecane morphospecies are widely distributed. Of these, 21 (12.6%) are cosmopolitan (sensu strictu), 26 (15.6%) are Tropicopolitan. There are 6 (3.6%) Arctic-temperate and Pantropical taxa. These categories of widely distributed taxa are not clear-cut, as differences in latitudinal distribution are largely gradual. Ten taxa have odd distributions. Most of these are insufficiently known and some may be recent introductions.All the major zoogeographical regions have their share of endemic taxa, with endemicity rates varying from 6.5% to 21.8%. Thirteen Holarctic, one widespread Eastern hemisphere, eleven Palaearctic, six Palaeotropical, one Australasian and five widespread Western hemisphere taxa have circumscribed ranges encompassing more than one region. The Palaeotropical and Holarctic components are particularly noteworthy, and may result from relatively recent faunal exchange between the Palaearctic and Nearctic, and between the African, Oriental and Australian regions. The different orientation of the major mountain chains of the Eastern and Western hemisphere, and the presence of extensive arid regions in Northern Africa, Arabia and Asia may explain the difference in faunal similarity between the tropical and temperate faunas of the Eastern and Western hemispheres. Ornithochoric dispersal and human introductions may have played a role in the exchange of faunas.The analysis of pairs or groups of closely related taxa only rarely reveals a causal relation between tectonical events and phylogeny. Most vicariant distributions are readily explained by climatological rather than by tectonical considerations. The ranges of some closely related taxa indicate that they have different capacities of dispersal.When compared to pelagic Rotifera, littoral Lecane exhibit a relatively wide variety of distribution patterns, and relatively many have restricted distributions. This may be a consequence of, either or both, their lower abundance, or be related to the littoral habitat which, being less predictable, implies more specific adaptations. Lecane is tropic-centred, which may be a consequence of avoidance of competition and/or predation by Cladocera and, eventually, Ostracoda.The most striking feature in rotifer chorology is the large range of many morphospecies. As such, the group's biogeography is more similar to that of freshwater algae than to that of other freshwater zooplankton. The likely explanations for this are the group's great ability for passive dispersal, combined with a short life-cycle and high fecundity, which are consequences of their parthenogenetic reproduction. So, relatively recent long-distance dispersal defines the ranges of the morphospecies. Vicariance plays a role in the distribution of Rotifera, but its importance is generally subordinate to that of dispersal. However, insufficient taxonomic resolution may be responsible for the apparently large ranges of some morphospecies.     

Inoculative releases of Trichogramma ostriniae for suppression of Ostrinia nubilalis (European corn borer) in sweet corn: field biology and population dynamics

The effectiveness of inoculative releases of Trichogramma ostriniae Pang and Chen for suppression of Ostrinia nubilalis (Hübner) in sweet corn was assessed. Early-season, low-density (75,000 females ha⁻¹) releases were made, and establishment, levels of parasitism and sex ratios of emerging T. ostriniae quantified. T. ostriniae established effectively for each season that they were released, but appeared to be unable to overwinter. Parasitism levels tracked egg mass numbers closely, and T. ostriniae persisted in fields even where insecticides were applied. Parasitism by indigenous Trichogramma species was 3%. Field populations of T. ostriniae were distinctly female biased (78%), with males produced in the majority of broods. Numbers of males did not increase linearly with number of O. nubilalis eggs parasitized, but appeared to remain constant above an egg mass size of about 20 eggs. A Type-I functional response to increasing egg and egg mass density was found under field conditions, where the proportion of egg masses parasitized remained constant with increasing egg mass density. A relatively consistent percentage of eggs per egg mass was parasitized, with a linear increase in number of eggs parasitized with increasing number of eggs per egg mass. These results show that T. ostriniae established viable reproductive populations in sweet corn following inoculative release, with the potential to contribute to reduced dependence on insecticides for the control of O. nubilalis in an integrated pest management program.     

Multi-locus phylogeny of the family Acrocephalidae (Aves: Passeriformes) – The traditional taxonomy overthrown

We present the first study of the warbler family Acrocephalidae based on one mitochondrial and three nuclear DNA loci, in total 2900 bp, including most or all of the species in three (Acrocephalus, Hippolais and Chloropeta) of the four genera and one species in the fourth genus (Nesillas) in this family. All three genera were suggested to be non-monophyletic, although the non-monophyly of Acrocephalus is not fully convincingly demonstrated. Six major clades were found, which agreed largely with the results from two earlier mitochondrial studies, and for which the names Hippolais, Iduna, Acrocephalus, Calamocichla, Notiocichla and Calamodus have been used. However, the results also revealed some new constellations, due to better resolution of deeper nodes and the inclusion of more taxa. The taxonomic implications are discussed.     

Comparative analysis of two algicidal bacteria active against the red tide dinoflagellate Karenia brevis

The red tide dinoflagellate Karenia brevis blooms annually along the eastern Gulf of Mexico, USA, and is often linked to significant economic losses through massive fish kills, shellfish harvest closures, and the potential threat to humans of neurotoxic shellfish poisonings as well as exposure to aerosolized toxin. As part of an effort to enhance the strategies employed to manage and mitigate these events and their adverse effects, several approaches are being investigated for controlling blooms. Previous studies have established the presence of algicidal bacteria lethal to K. brevis in these waters, and we aim to characterize bacterial–algal interactions, evaluate their role as natural regulators of K. brevis blooms, and ultimately assess possible management applications. Herein, the algicidal activity of a newly isolated Cytophaga/Flavobacterium/Bacteroidetes (CFB)-bacterium, strain S03, and a previously described CFB-bacterium, strain 41-DBG2, was evaluated against various harmful algal bloom (HAB) and non-HAB species (23 total), including multiple clones of K. brevis, to evaluate algal target specificity. Strains S03 and 41-DBG2, which employ direct and indirect modes of algicidal lysis, respectively, killed 20% and 40% of the bacteria-containing isolates tested. Interestingly, no bacteria-free algal cultures were resistant to algicidal attack, whereas susceptibility varied occasionally among bacteria-containing isolates of a single algal taxon originating from either the same or different geographic location. The dynamics of K. brevis culture death appeared to differ according to whether the algicidal bacterium did or did not require direct contact with algal cells, with the former most rapidly affecting K. brevis morphology and causing cell lysis. Both bacterial strains promoted the formation of a small number of cyst-like structures in the K. brevis cultures, possibly analogous to temporary cysts formed by other dinoflagellates exposed to certain types of stress. Results were also consistent with earlier work demonstrating that bacterial assemblages from certain cultures can confer resistance to attack by algicidal bacteria, again indicating the complexity and importance of microbial interactions, and the need to consider carefully the potential for using such bacteria in management activities.     

The avian malaria parasite Plasmodium gallinaceum causes marked structural changes on the surface of its host erythrocyte

Using a combination of atomic force, scanning and transmission electron microscopy, we found that avian erythrocytes infected with the avian malaria parasite Plasmodium gallinaceum develop 60 nm wide and 430 nm long furrow-like structures on the surface. Furrows begin to appear during the early trophozoite stage of the parasite’s development. They remain constant in size and density during the course of parasite maturation and are uniformly distributed in random orientations over the erythrocyte surface. In addition, the density of furrows is directly proportional to the number of parasites contained within the erythrocyte. These findings suggest that parasite-induced intraerythrocytic processes are involved in modifying the surface of host erythrocytes. These processes may be analogous to those of the human malaria parasite P. falciparum, which induces knob-like protrusions that mediate the pathogenic adherence of parasitized erythrocytes to microvessels. Although P. gallinaceum-infected erythrocytes do not seem to adhere to microvessels in the host chicken, the furrows might be involved in the pathogenesis of P. gallinaceum infections by some other mechanism involving host-pathogen interactions.     

Bottom-up controls on a mixed-species HAB assemblage: A comparison of sympatric Chattonella subsalsa and Heterosigma akashiwo (Raphidophyceae) isolates from the Delaware Inland Bays, USA

Recent novel mixed blooms of several species of toxic raphidophytes have caused fish kills and raised health concerns in the highly eutrophic Inland Bays of Delaware, USA. The factors that control their growth and dominance are not clear, including how these multi-species HAB events can persist without competitive exclusion occurring. We compared and contrasted the relative environmental niches of sympatric Chattonella subsalsa and Heterosigma akashiwo isolates from the bays using classic Monod-type experiments. C. subsalsa grew over a temperature range from 10 to 30 °C and a salinity range of 5–30 psu, with optimal growth occurring from 20 to 30 °C and 15 to 25 psu. H. akashiwo had similar upper temperature and salinity tolerances but also lower limits, with growth occurring from 4 to 30 °C and 5 to 30 psu and optimal growth between 16 and 30 °C and 10 and 30 psu. These culture results were confirmed by field observations of bloom occurrences in the Inland Bays. Maximum nutrient-saturated growth rates (μ_max) for C. subsalsa were 0.6 d⁻¹ and half-saturation concentrations for growth (K_s) were 9 μM for nitrate, 1.5 μM for ammonium, and 0.8 μM for phosphate. μ_max of H. akashiwo (0.7 d⁻¹) was slightly higher than C. subsalsa, but K_s values were nearly an order of magnitude lower at 0.3 μM for nitrate, 0.3 μM for ammonium, and 0.2 μM for phosphate. H. akashiwo is able to grow on urea but C. subsalsa cannot, while both can use glutamic acid. Cell yield experiments at environmentally relevant levels suggested an apparent preference by C. subsalsa for ammonium as a nitrogen source, while H. akashiwo produced more biomass on nitrate. Light intensity affected both species similarly, with the same growth responses for each over a range from 100 to 600 μmol photons m⁻² s⁻¹. Factors not examined here may allow C. subsalsa to persist during multi-species blooms in the bays, despite being competitively inferior to H. akashiwo under most conditions of nutrient availability, temperature, and salinity.     

Phylogeography of the frog Leptodactylus validus (Amphibia: Anura): Patterns and timing of colonization events in the Lesser Antilles

The frog Leptodactylus validus occurs in northern South America, Trinidad and Tobago, and the southern Lesser Antilles (Grenada and St. Vincent). Mitochondrial DNA sequences were used to perform a nested clade phylogeographic analysis (NCPA), to date colonization events, and to analyze colonization patterns using on a relaxed molecular clock and coalescent simulations. L. validus originated on the mainland and first colonized Trinidad with subsequent independent colonizations of Tobago and the Lesser Antilles from Trinidad. The NCPA suggests a historical vicariant event between populations in Trinidad and Tobago from those in the Lesser Antilles. The colonization of Trinidad occurred 1 million years ago (mya) and the colonization of the Lesser Antillean islands occurred 0.4 mya. The coalescent approach supported the scenario where L. validus dispersed from Trinidad to St. Vincent and from there to Grenada, a dispersal event that could have been mediated by human introduction as recent as 1600 years ago.     

Adult Brugia malayi 34 kDa (BMT-5) antigen offers Th1 mediated significant protection against infective larval challenge in Mastomys coucha

We earlier reported a sizeable protection conferred by ‘mitochondria rich’ (MT) fraction of adult B. malayi and the present study was planned to locate the candidate protective molecule/s in the active fraction. The MT fraction was subjected to sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and the antigen bands showing strong immune-reactivity with the resistant mastomys sera were assayed for their lymphoproliferative response using splenocytes of protected animals. Of the eight such protein bands, one sub fraction with a molecular weight of  34 kDa (BMT-5) produced utmost cellular proliferation and was therefore exploited for vaccination study. BMT-5 emulsified in Freund's adjuvant produced discernible protection causing 69 and 67% reductions in microfilaraemia and adult worm burden respectively along with sterilization of 68% of the recovered female parasites. Significant levels of filaria-specific and non-specific lymphoproliferation along with enhanced release of Th1 cytokines (TNF-α, IFN-γ and IL-2) by splenocytes were observed in the vaccinated mastomys in addition to elevated levels of antigen-specific IgG, IgG2a, IgG2b and IgA. The peritoneal macrophages of immunized animals also revealed enhanced nitric oxide production in the presence of BMT-5. The findings suggest that  34 kDa (BMT-5) molecules present in the MT fraction of adult B. malayi provided sizeable protection against infective larval challenge by generating a Th1 biased milieu in the host.     

Seeing green bacteria in a new light: genomics-enabled studies of the photosynthetic apparatus in green sulfur bacteria and filamentous anoxygenic phototrophic bacteria

Based upon their photosynthetic nature and the presence of a unique light-harvesting antenna structure, the chlorosome, the photosynthetic green bacteria are defined as a distinctive group in the Bacteria. However, members of the two taxa that comprise this group, the green sulfur bacteria (Chlorobi) and the filamentous anoxygenic phototrophic bacteria (Chloroflexales), are otherwise quite different, both physiologically and phylogenetically. This review summarizes how genome sequence information facilitated studies of the biosynthesis and function of the photosynthetic apparatus and the oxidation of inorganic sulfur compounds in two model organisms that represent these taxa, Chlorobium tepidum and Chloroflexus aurantiacus. The genes involved in bacteriochlorophyll (BChl) c and carotenoid biosynthesis in these two organisms were identified by sequence homology with known BChl a and carotenoid biosynthesis enzymes, gene cluster analysis in Cfx. aurantiacus, and gene inactivation studies in Chl. tepidum. Based on these results, BChl a and BChl c biosynthesis is similar in the two organisms, whereas carotenoid biosynthesis differs significantly. In agreement with its facultative anaerobic nature, Cfx. aurantiacus in some cases apparently produces structurally different enzymes for heme and BChl biosynthesis, in which one enzyme functions under anoxic conditions and the other performs the same reaction under oxic conditions. The Chl. tepidum mutants produced with modified BChl c and carotenoid species also allow the functions of these pigments to be studied in vivo.     

Pronase digestion of brush border membrane-bound Cry1Aa shows that almost the whole activated Cry1Aa molecule penetrates into the membrane

Bacillus thuringiensis insecticidal proteins, Cry toxins, following ingestion by insect larvae, induce insecticidal effect by penetrating the brush border membranes (BBM) of midgut epithelial cells. Purified, activated B. thuringiensis Cry1Aa bound to Bombyx mori BBMV or unbound Cry1Aa were vigorously digested with Pronase. Both digests were compared by Western blotting. Free Cry1Aa was digested to α-helix and/or to amino acids at 1 mg Pronase/mL within 2.4 h at 37 °C. Whereas, BBMV-bound Cry1Aa was very resistant to Pronase digestion and even at 2 mg for 24 h, 7.5 kDa and 30 kDa peptide were detected by α-2,3 antiserum, and α-4,5 and α-6,7 antisera, respectively. Another 30 kDa peptide was also detected by β-6-11 and domain III antisera. These fragments are believed either to be embedded in or to strongly interact with the BBMV. The 7.5 and former 30 kDa peptides are thought to be derived from α-2,3 helix and stretch of α-4 to α-7 helices. Furthermore the latter 30 kDa was thought to include the stretch of β-6 to domain III. Moreover, the embedded Cry1Aa molecule appears to be segregated in some areas of β-1-5 sheets, resulting in the above two 30 kDa peptides. From these digestion patterns, we proposed new membrane insertion model for single Cry1Aa molecule. On the other hand, in digestion of BBMV-bound Cry1Aa, 15 kDa peptide which was recognized only by α-4,5 antiserum was observed. This fragment must be dimeric α-4,5 helices and we discussed the origin of this peptide.     

Historical biogeography, phylogenetic relationships and intraspecific diversity of agamid lizards in the Central Asian deserts of Kazakhstan and Uzbekistan

The Central Asian agamid lizards are ecologically and morphologically diverse, occurring across a broad range of desert environments in this biogeographically important region. It is probable that past climatic shifts have significantly influenced the diversification patterns and distributions of the agamid lizards of this region. To assess this within a phylogenetic framework we sequenced a 1200 bp region of mitochondrial DNA and a 1200 bp nuclear gene (RAG-1), incorporating both inter- and intraspecific sampling across Central Asian agamids. Our topology and divergence time estimates support an Eocene origin of the Agaminae subfamily on the Indian subcontinent, coinciding with the collision of India into Eurasia. The onset of aridification in Central Asia during the Late Oligocene, resulting from the retreat of the Paratethys Sea and the intensified uplift of the Tibetan–Himalayan complex, probably played an important role in the diversification of Phrynocephalus, one of the three genera studied. Intensification of aridity and geologic events in the Plio-Pleistocene and Quaternary glacial cycling probably had a significant influence on intraspecific diversification patterns within Phrynocephalus.     

Fruit differentiation, palynology, and systematics in theScabiosa group of genera andPseudoscabiosa (Dipsacaceae)

Fruits ofDipsacaceae are single-seeded, have bristle-shaped calyx segments and are tightly enclosed by four fused bracts forming an epicalyx. Comparative morphological and anatomical studies reveal a great diversity of epicalyx and calyx, often relevant to fruit dispersal. The present contribution deals with theScabiosa group of genera, the core of theScabioseae tribe. Most of its taxa develop a diaphragma from a meristem on the inside of the epicalyx. This diaphragma, together with the lower part of the epicalyx encloses the fruit proper, whereas the upper parts form a so-called epi-diaphragma (ed) and a ± hyaline corona. Differences of the epicalyx with respect to the size and position of the ed, elaboration of the corona, origin of pits (=foveoles) and other morphological and anatomical specializations can be demonstrated. Together with palynological and karyological data these new facts support an improved concept of relationships and systematics for the taxa studied:Scabiosa sect.Scabiosa and sect.Cyrtostemma are closely related and should be united to form the genusScabiosa s. str.;Pycnocomon can be maintained as an independent genus, sister toScabiosa sect.Trochocephalus which then has to be treated as a genus,Lomelosia. In contrast, the following genera have to be included inLomelosia:Tremastelma asLomelosia sect.Callistemma, andScabiosiopsis as part ofLomelosia sect.Lomelosia. Pseudoscabiosa deviates in so many features that it has to be excluded from the redefinedScabioseae s. str.     

Basin-scale Patterns in the Drift of Embryonic and Larval Fishes and Lamprey Ammocoetes in two Coastal Rivers

We studied the distribution and abundance of drifting embryonic and larval fishes and lampreys in the Smith and Van Duzen rivers of northern California, U.S.A. We collected seven fish species in four families and at least one lamprey species in the drift. All taxa drifted almost exclusively at night. Sculpins, Cottus aleuticus and C. asper, outnumbered all other taxa, comprising 63% of the catch in the Van Duzen River and 90% of the catch in the Smith River. We estimated that sculpin drift reached 3×10⁷ individualsh^–1 during the relatively high flow period from late winter through early summer. Most sculpin in these two rivers appeared to drift to the estuaries; we estimated 2.5×10⁹ sculpin embryos and larvae reached the Smith River estuary in 1995. In contrast to the sculpins, the patterns in the drift of other taxa suggest limited transport to the estuaries. Suckers, Catostomus occidentalis in the Van Duzen River, C. rimiculus in the Smith River, threespine stickleback, Gasterosteus aculeatus, and lamprey, Lampetra tridentata and possibly L. richardsoni, drifted at much lower rates and later in the year than sculpins. In the Van Duzen River, drift appeared to serve as a dispersal mechanism for only one of three introduced cyprinids. California roach, Lavinia symmetricus, drifted at low rates throughout the summer while we captured only seven Sacramento pikeminnow, Ptychocheilus grandis, and no speckled dace, Rhynichthys osculus. The information gathered on the drift of early life history phases is germane to both the conservation of native fishes and management of non-indigenous species in coastal rivers.     

Seven new calochroid and fulvoid species of Cortinarius

We describe seven new European species of Cortinarius. All species are based on analyses of morphological and DNA sequence data. They all belong to a well-supported clade comprising most species traditionally treated in Cortinarius subgenus Phlegmacium sections Fulvi and Calochroi (i.e. the/Calochroi clade). All taxa are either fulvoid (containing anthraquinoid pigments) or calochroid (without these pigments). Morphological and ecological data are presented for all species and compared with similar species. A dichotomous key is presented for C. calochrous and similar species, including all six newly described calochroid species. The calochroid species C. albertii, C. chailluzii, C. cisticola, C. sancti-felicis, C. selandicus and C. vesterholtii spp. nov., and the fulvoid species C. langeorum sp. nov. are described.