Substrate switches,phenotypic innovations and allopatric speciation formed taxonomic diversity within the lichen genus Blastenia

Blastenia is a widely distributed lichen genus in Teloschistaceae. We reconstructed its phylogeny in order to test species delimitation and to find evolutionary drivers forming recent Blastenia diversity. The origin of Blastenia is dated to the early Tertiary period, but later diversification events are distinctly younger. We recognized 24 species (plus 2 subspecies) within 6 infrageneric groups. Each species strongly prefers a single type of substrate (17 species occur on organic substrates, 7 on siliceous rock), and most infrageneric groups also show a clear substrate preference. All infrageneric groups tend to have the Mediterranean and Macaronesian distribution, but some epiphytic species have much larger geographic ranges and some evolved after a long‐distance dispersal outside the region. Chlorinated and nonchlorinated anthraquinone chemosyndromes co‐occur in apothecia of most species, but the chemotype has been secondarily reduced in some lineages. One infrageneric group has a marked reduction in apothecial size, associated with a substrate shift to twigs. Only seven species have vegetative diaspores; they also produce apothecia but have smaller ascospores. Genome sizes (22‐35 Mb in Blastenia) are significantly higher in epilithic species. Within‐species genetic variation is low in widely distributed species but high in some epilithic species with small geographical ranges. New taxa are: B. afroalpina, B. anatolica, B. caucasica, B. gennargentuae, B. herbidella subsp. acidophila, B. lauri, B. monticola, B. palmae, B. psychrophila, B. purpurea, B. relicta, B. remota, B. xerothermica, and B. xerothermica subsp. macaronesica. New combinations are: B. festivella and B. subathallina; both names and B. catalinae are lectotypified.     

Systematic revision of the living species of Bullidae (Mollusca: Gastropoda: Cephalaspidea), with a molecular phylogenetic analysis

Bullidae are a worldwide family of marine shelled cephalaspidean gastropods with a mainly tropical distribution, but also with some representatives in temperate waters. The taxonomy of the group has in the past been based only on shell characters, and the few anatomical accounts available have not addressed more than one to three species, so there has been no agreement about the number of valid species. Seventy‐two specific names and 16 varietal names have been proposed worldwide. The systematics of the family Bullidae are revised, based not only on shells but also on anatomy of all extant species and on DNA sequence data. Twelve species are recognized worldwide, including one new species here described, and all are assigned to the genus Bulla. Two species occur in the eastern Atlantic, B. striata and B. mabillei; two in the western Atlantic, B. occidentalis and B. solida; two in the eastern Pacific, B. gouldiana and B. punctulata; and six in the Indo‐West Pacific, B. ampulla, B. arabica sp. nov. , B. orientalis, B. peasiana, B. quoyii and B. vernicosa. Full synonymies and taxonomic histories are provided for each species. In order to promote taxonomic stability, neotypes are designated for B. striata, B. solida, B. nebulosa (valid name B. gouldiana) and B. vernicosa, and lectotypes for B. occidentalis, B. mabillei, B. punctulata, B. ampulla and B. quoyii. The type locality of B. ampulla is restricted to Mauritius. Bullidae show a general morphological stasis, with anatomy being very similar between species. However, there are high levels of intraspecific variability in the shell, radula and male genital system. In some cases species could only be separated based on molecular data . After defining the characters and geographical range of each species it became clear that sympatric species (a maximum of three) show distinctive shells and reproductive structures, which makes identification straightforward. This study employs an integrative approach, combining information on shells, anatomy, DNA and geographical distribution, in order to resolve the systematics of a difficult taxonomic group. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 153 , 453–543.     

Reproductive biology of skates, Bathyraja(Ishiyama), along the eastern Bering Sea continental slope

Eight Bathyraja skate species, Bathyraja aleutica, Bathyraja interrupta, Bathyraja lindbergi, Bathyraja maculata, Bathyraja minispinosa, Bathyraja parmifera, Bathyraja taranetzi and Bathyraja trachura, collected along the eastern Bering Sea continental slope were examined for reproductive features. The sex ratio for six of eight Bathyraja skate species studied was c. 1 : 1 with males dominating for B. interrupta and B. parmifera. Five of eight species examined, B. aleutica, B. lindbergi, B. parmifera, B. taranetzi and B. trachura approximately equalled or exceeded the maximum reported total length, L_T. Maximum L_T for three species (B. interrupta, B. minispinosa and B. parmifera) revealed that the largest individuals were males and that in three other species (B. lindbergi, B. maculata and B. trachura) both females and males grew to approximately the same size. Both females and males matured at approximately the same L_T for seven of eight species. Only female B. aleutica matured at a much larger size than males. All species matured within a narrow size range following a protracted juvenile stage and once mature these skates appeared to grow very little. First maturity for all species occurred at ≥80% of their maximum L_T. The number of oocytes did not significantly differ between the left and right ovary for any species. The total number of mature oocytes increased with L_T for six of eight species examined. The number of oocytes for one species, B. aleutica, increased in number until 145 cm L_T, then declined in those individuals greater in length. The egg cases of all species are described, of which four (B. lindbergi, B. parmifera, B. taranetzi and B. trachura) have never been previously reported. Evidence is presented that suggest skates may be limited to as little as one and as many as 13 spawning seasons, depending on the species, and that senescence may occur in older individuals.     

Effects of waterlogging on growth and some physiological parameters of four Brassica species

Waterlogging tolerance of four Brassica species, Brassica campestris L., B. carinata A. Br., B. juncea (L.) Czern and Coss., and B. napus L. was assessed after 4 weeks growth in greenhouse at two waterlogging treatments, unflooded control soil, and fully waterlogged soil.Shoot fresh and dry biomass, in both mean and relative terms, was highest in B. juncea and lowest in B. napus at waterlogging treatment. B. carinata was as good as B. juncea in mean shoot fresh and dry matter but it had almost same relative shoot fresh matter as that in B. campestris, but was second highest in relative shoot dry weight.Waterlogging treatment caused a marked reduction in chlorophyll content in all four species but the species difference was not evident. However, B. juncea and B. napus had lower relative total chlorophyll than the other species.A marked increase in soluble protein content of B. juncea and a significant increase in total amino acids in B. carinata was observed under waterlogged conditions as compared to the other species.At the waterlogging regime, an increase in iron content in both shoots and roots was observed in all four species. B. juncea accumulated lower amount of iron in both shoots and roots as compared to the other species, whereas B. carinata had also lower iron in the roots. The species did not differ for shoot manganese content but B. carinata had significantly higher manganese in the roots as compared to the other species.     

Zooplankton of Lake Peipsi-Pihkva in 1909–1987

164 taxa were identified in the net zooplankton of the pelagial of L. Peipsi-Pihkva in 1909–1987, including 3 species of protozoans, 74 species of rotifers, 58 species of cladocerans, 28 species of copepods and 1 mollusc. One rotifer species, Ploesoma peipsiense Mäemets et Kutikova, has been described as new for science here. The zooplankton of L. Peipsi-Pihkva is remarkably rich in species including rarities in Estonia: Limnosida frontosa, Drepanothrix dentata, Bythotrephes longimanus, B. cederstroemi etc. Due to its large surface area, L. Peipsi-Pihkva provides a large scale of biotopes of a diverse trophic state and humic content, which support species with different ecological requirements. Most of the aquatory of the lake has lately been mesotrophic, favouring the coexistence of indicators of oligo- and mesotrophic state and species preferring a higher trophic state. The occurrece of 10 species of the genus Bosmina including B. berolinensis, B. gibbera, B. lilljeborgi, B. thersites and B. crassicornis, sparse in Estonian lakes, is the most noteworthy feature of the zooplankton of L. Peipsi-Pihkva. The coexistence of B. coregoni and B. berolinensis, B. gibbera, B. lilljeborgi etc. which were earlier regarded as subspecies of B. c. coregoni proves that they are different species producing usually no hybrids. The species composition was subjected to certain changes during the years under consideration. Larvae of Dreissena were first found in zooplankton in 1962. The oligo-mesotrophic indicator Holopedium gibberum occurred in the lake in 1909–1964, but was lacking in later samples.     

Identification of species in tribe Brassiceae by dot-blot hybridization using species-specific ITS1 probes

Simple, reliable methods for identification of species are required for management of many species and lines in a plant gene bank. Species-specific probes were designed from published sequences of the ITS1 region in rDNA of 16 species in Brassica and its related genera, and used as probes for dot-blot hybridization with plant genomic DNA. All the probes detected species-specific signals at dot-blots of genomic DNAs of the 16 species in Brassica, Diplotaxis, Eruca, and Raphanus. Signals of the Brassica digenomic species in the U’s triangle, i.e., B. napus, B. juncea, and B. carinata, were detected by the probes of their parental monogenomic species, i.e., B. rapa, B. nigra, and B. oleracea. The probe for B. oleracea showed signals of B. balearica, B. cretica, B. incana, B. insularis, and B. macrocarpa, which have the C genome as B. oleracea. Eruca vesicaria DNA was detected by the probe for E. sativa, which has been classified as a subspecies of E. vescaria. DNA of leaf tissue extracted by an alkaline solution and seed DNA prepared by the NaI method can be used directly for dot-blotting. Misidentification of species was revealed in 20 accessions in the Tohoku University Brassica Seed Bank. These results indicate dot-blot hybridization to be a simple and efficient technique for identification of plant species in a gene bank.     

A NUMERICAL–TAXONOMIC STUDY OF THE GENUS BULNESIA (ZYGOPHYLLACEAE): CLUSTER ANALYSIS,ORDINATION AND SIMULATION OF EVOLUTIONARY TREES

Cluster analysis by four methods, ordination by principal component analysis (PCA) and simulation of evolutionary trees (Wagner Trees) were performed on morphological data from 43 characters of eight species of the South American genus Bulnesia (Zygophyllaceae). The results of cluster analysis and principal component analysis in general agree and show that there are three pairs of taxa that appear, or obviously are, closely related. These are the pairs B. arborea–B. carrapo, B. foliosa–B. schickendantzii and B. retama–B. chilensis. These methods also indicate that the southern species B. bonariensis occupies an intermediate position between the pair of northern tropical species (B. arborea, B. carrapo) and the remaining southern species. From the beginning it was assumed that these three multifoliolate species with large flowers may be rather primitive. The Prim network indicates that these three species are closely related among themselves. Also in two of the three Wagner Trees they are placed in a group. In all cases B. sarmientoi is shown as the more remote and isolated of all species. It is regarded as a unique, specialized arboreal species showing extreme reduction in number of leaflets and carpels, leaf and flower size, etc. All graphic representations (Fig. 1–3) show the phenetic similarity or the close phylogenetic relationships of the pairs B. foliosa–B. schickendantzii and B. retama–B. chilensis to each other. These four species would represent a rather advanced group. The most xerophytic species B. retama and B. chilensis are regarded as the most advanced taxa and the most specialized histophysiologically. These occupy extreme and distant positions in PCA diagrams and Prim network, and top positions in the Wagner Trees.     

Soil water exploitation after fire: competition between Bromus tectorum (cheatgrass) and two native species

Summary Causes for the widespread abundance of the alien grass Bromus tectorum (cheatgrass) after fire in semiarid areas of western North America may include: (1) utilization of resources freed by the removal of fireintolerant plants; and (2) successful competition between B. tectorum and individual plants that survive fire. On a site in northwestern Nevada (USA), measurements of soil water content, plant water potential, aboveground biomass production, water use efficiency, and B. tectorum tiller density were used to determine if B. tectorum competes with either of two native species (Stipa comata and Chrysothamnus viscidiflorus) or simply uses unclaimed resources. Soil water content around native species occurring with B. tectorum was significantly lower (P<0.05) than around individuals without B. tectorum nearby. Native species had significantly more negative plant water potential when they occurred with B. tectorum. Aboveground biomass was significantly higher for native species without B. tectorum. However, the carbon isotope ratio of leaves for native species with B. tectorum was not significantly different from individuals without B. tectorum. Thus, B. tectorum competes with native species for soil water and negatively affects their wate status and productivity, but the competition for water does not affect water use efficiency of the native species. These adverse effects of B. tectorum competition on the productivity and water status of native species are also evident at 12 years after a fire. This competitive ability of B. tectorum greatly enhances its capability to exploit soil resources after fire and to enhance its status in the community.     

Species composition and distribution patterns of baetid nymphs (Baetidae: Ephemeroptera) in a Japanese stream

Species composition and distributional patterns among nymphs of five baetid genera (Ephemeroptera), Baetis, Tenuibaetis, Labiobaetis, Nigrobaetis and Alainites were investigated in Yura Stream, Kyoto Prefecture. I collected 13 species: B. sahoensis, B. thermicus, B. sp. F, B. sp. J, B. sp. M1, B. sp. S1, T. sp. E, T. sp. H, L. sp. G, N. chocoratus, N. sp. D, N. sp. I and A. yoshinensis, among which B. thermicus, B. sp. S1 and T. sp. E were dominant, whereas B. sahoensis, B. sp. F, B. sp. M1 and N.sp. I were scarce. Based on their longitudinal distribution patterns, the 13 species were classified into upper species, upper-middle species, middle species, middle-lower species and lower species. Baetis thermicusand A. yoshinensis showed long downstream tails. Baetis sp. J and N. sp. D extended their longitudinal distribution upstream in summer. With regard to habitat preference, Alainites and Labiobaetis were restricted to riffle and vegetated zones, respectively. Tenuibaetis consisted of riffle-vegetated zone species, whereas Baetis and Nigrobaetiscontained both riffle species and ubiquitous species. Habitat partitioning (`sumiwake') along the watercourse (macro-sumiwake) was evident in Tenuibaetis, and that between habitat types (micro-sumiwake) in Labiobaetis vs. Baetis (rhodanigroup species) and Labiobaetis vs. Alainites.     

Enzymatic characterization of oral and non-oral black-pigmented Bacteroides species

The purpose of this study was to investigate the production of various enzymes by oral and non-oral black-pigmented Bacteroides species using chromogenic substrates. The 19 substrates present in the API ZYM system did not differentiate between B. melaninogenicus, B. denticola, B. loescheii and B. levii. The asaccharolytic black-pigmented Bacteroides species showed each species specific enzyme activity, however, differences were based on one enzyme only as far as B. asaccharolyticus and B. endodontalis are concerned. An extended number of 40 chromogenic substrates were tested in order to find more species specific enzyme. With a set of 20 substrates it appeared to be possible to discriminate between all species tested. The possibility to use enzymes for the identification of black-pigmented Bacteroides is discussed.     

Competitive displacement of the native species <Emphasis Type="Italic">Bursaphelenchus mucronatus</Emphasis> by an alien species <Emphasis Type="Italic">Bursaphelenchus xylophilus</Emphasis> (Nematoda: Aphelenchida: Aphelenchoididae): a case of successful invasion

The presence of alien invasive species has serious negative impact on endemic biodiversity, especially on native species that occupy the same niche in the ecosystem. To study the influence of the alien invasive species Bursaphelenchus xylophilus on its native sister species B. mucronatus, the two nematode species were mix-cultured in a fungal mat and mix-inoculated into a susceptible host. By comparing the propagation parameters of both species under competitive and noncompetitive conditions it was shown that the propagation level of B. xylophilus was clearly higher than that of B. mucronatus under laboratory culture. Furthermore, the propagation capacity of B. xylophilus under competitive conditions was much higher than that under noncompetitive conditions, both in laboratory culture and with host inoculation. Bursaphelenchus xylophilus also excluded B. mucronatus when the two species were cultured as a mixture for a longer time. The relative abundance ratios of the two species in natural pinewoods were also determined by random sampling of dying pine trees from regions with different invasion histories. It was noted that with an increase in invasion years the distribution frequency of B. xylophilus increased while that of B. mucronatus decreased. Experimental tests verified our hypothesis that because of its high fecundity and strong competitive ability, the invasive species B. xylophilus out-competed the native species B. mucronatus and displaced it in natural ecosystems. The successful invasion of B. xylophilus is attributed to competitive displacement, which may be one of the ecological invasive mechanisms.     

Accessing and exploiting genes of breeding value of distant relatives of crop Brassicas

The Brassicas are an important group of crops in India yielding edible oils and many vegetables. For improving cultivated Brassicas, the wild relatives are of considerable value. The Brassica group of seed oil and vegetables comprises six cultivated species, out of which three are diploids and three are digenomic tetraploids. Brassica juncea is the major seed oil crop in India which can be improved for several traits by incorporating genes from its distant relatives. The early work in India relating to genome manipulation consisted of synthesis of B. juncea by crossing B. campestris with B. nigra, experimental resynthesis of Brassica species and non-homologous pairing and genetic exchange at the interspecific level. The alloploid species B. napus and B. carinata have not been successful in India due to agrometereological limitations. However, synthetic forms of B. napus have been produced which have a desirable maturity period with good yield potential. Also, through non-homologous pairing, pod shatter resistant B. napus has been obtained, B. napus ordinarily suffers from pod shattering. Similarly, synthetic forms of B. carinata have been derived from reciprocal crosses between morphotypes of B. oleracea and B. nigra and also through protoplast fusion of B. nigra with B. oleracea. Molecular analysis has revealed that one of the somatic hybrids had a novel cytoplasmic combination which carried B. nigra mitochondrial and B. oleracea chloroplast genomes. A range of wild and weedy species related to crop Brassicas possess extensive genetic variability. Work for utilizing this variability included hybridization between wild and crop species, analysis of chromosome pairing and induction of alloploidy. Among Brassicas of interest to India, protoplast culture and regeneration has been successful in the case of B. oleracea, B. juncea, B. nigra and B. carinata (cultivated species) and Eruca sativa and Diplotaxis muralis (related wild species). Polyethylene glycol mediated protoplast fusion has been the most commonly used method in India for producing somatic hybrids involving Brassicas. The eight somatic hybrids produced and studied showed that in the majority of cases the fusions led to symmetric hybrids combining the complete genomes of the donor species. For developing suitable male sterile lines, B. juncea, B. campestris and B. napus nuclei have been combined with the cytoplasm of six wild species and stable male steriles have been developed. Protoplast fusion methodology has been used extensively for improving these CMS by manipulating cytoplasmic organelles, including production of new combinations of cp and mt.     

Bothriocephalus gadellus n. sp. (Cestoda: Bothriocephalidae) from the beardless codling Gadella imberbis (Vaillant) (Moridae) in the southwestern Gulf of Mexico,with a review of species of Bothriocephalus Rudolphi, 1808 reported from gadiform fishes

Bothriocephalus gadellus n. sp. is described from the intestine of the beardless codling Gadella imberbis (Gadiformes: Moridae) from the southwestern Gulf of Mexico. It resembles B. scorpii, the type-species of Bothriocephalus, and B. manubriformis, the only species of the genus reported from the Gulf of Mexico. B. gadellus n. sp. differs from both species in having four excretory canals on each side of the proglottid (three per side in B. scorpii; two per side anastomosing to form an extensive plexus throughout the medulla in B. manubriformis ), 24-33 testes per proglottid (30-60 in B. scorpii; 60-100 in B. manubriformis), a total length of 31-47 mm (32-950 mm in B. scorpii; 130-1,000 mm in B. manubriformis), and a seminal receptacle and wing-like expansions on each proglottid (absent in B. scorpii and B. manubriformis), as well as lacking two sets of reproductive organs per proglottid (present in B. scorpii) and a vagina with a bulbous sphincter near the opening (present in B. manubriformis). An amendment to the generic diagnosis of Bothriocephalus might be warranted if other species of this genus are found to possess a seminal receptacle. B. gadellus n. sp. appears to be like those species of Bothriocephalus that can utilise two intermediate hosts (copepod and fish). B. ellipticus and B. neglectus are designated as species inquirendae. This is the first report of a cestode from a morid fish in the Gulf of Mexico, and the first report of a parasite from a species of Gadellus.     

Bacteroides gingivalis,Bacteroides asaccharolyticus,andBacteroides melaninogenicus subspecies: Cell surface morphology and adherence to erythrocytes and human buccal epithelial cells

All study strains ofBacteroides gingivalis, B. asaccharolyticus, andB. melaninogenicus subspecies possessed numerous pilus-like fibers and capsule-like outer surface structures. The capsular morphology varied between the different species and subspecies.B. gingivalis strongly agglutinated 16 erythrocyte species studied.B. asaccharolyticus showed variable and weak agglutination of only a few erythrocyte species.B. melaninogenicus subsp.intermedius strains strongly agglutinated rabbit erythrocytes and exhibited variable, often weak agglutination of 8 other erythrocyte species. Preparations of capsular polysaccharide or lipopolysaccharide fromB. gingivalis failed to agglutinate human erythrocytes, while pili preparations from the same organisms possessed marked hemagglutinating activity.B. gingivalis cells adhered in high numbers to human buccal epithelial cells, whereas strains ofB. asaccharolyticus failed to show measurable adherence. Oral strains ofB. melaninogenicus subsp.intermedius feebly adhered to the buccal epithelial cells. Pretreatment ofB. gingivalis cells with serum or saliva prevented the adherence to epithelial cells. Our findings suggest that cell surfaces with distinct properties exist on the various black-pigmentedBacteroides species and subspecies and this may accout for markedly differing ability of these organisms to attach to mammalian cells.     

Call Variation in the Bufo microscaphus Complex: Implications for Species Boundaries and the Evolution of Mate Recognition

Since the Modern Synthesis, many species concepts have considered characters mediating mate recognition essential to both the identification and definition of species. To explore divergence in mate recognition systems, calls were recorded and toads measured from all three species of the monophyletic Bufo microscaphus species complex including five populations of Bufo californicus, three populations of B. microscaphus, and one population of B. mexicanus. Call duration, dominant frequency, and pulse rate were significantly related to temperature, but not snout-vent length. When adjusted for temperature, calls of B. californicus had a significantly longer call duration, higher dominant frequency, and slower pulse rate than B. mexicanus and B. microscaphus, which did not differ from one another. However, the magnitude of variation among populations of B. californicus was similar to that between species. Discriminant analysis using call variables provided some separation of B. californicus and B. mexicanus from B. microscaphus, and cross-validation analysis correctly classified approximately 75% of B. californicus and B. mexicanus. Given only slight divergence in mate recognition systems between B. californicus and the other two taxa, the biological significance of this difference remains ambiguous. Comparisons among B. americanus group members indicate that hybridizing taxa may or may not exhibit divergence in advertisement calls. Maintenance of independently evolving lineages may be driven by other evolutionary mechanisms. These results support the notion that species recognition is best viewed as an effect of mate recognition.     

Botrytis sinoallii: a new species of the grey mould pathogen on Allium crops in China

A study was conducted to identify Botrytis spp. isolated from bulb onion, green onions, garlic, and garlic chives grown in Hubei Province of China. Based on colony morphology and conidial characteristics, 367 strains of Botrytis spp. were identified as five distinct species, namely, B. cinerea, B. squamosa, B. porri, B. byssoidea, and an undescribed Botrytis species (Botrytis sp.), which accounted for 64.3, 29.9, 3.3, 0.3, and 2.2%, respectively. The previously undescribed species is herein described as a new species, B. sinoallii sp. nov., which is characterized by production of numerous small sclerotia on potato dextrose agar. Phylogenetic analysis using partial sequences of three nuclear genes (G3PDH, HSP60, and RPB2) showed that B. sinoallii forms a unique lineage, which is closely related to B. squamosa, a well-known species on Allium crops, but distantly related to the other species of Botrytis on Allium crops, including B. cinerea, B. porri, B. aclada, B. allii, B. byssoidea, B. globosa, and B. sphaerosperma. Results of inoculation tests showed that B. sinoallii is a newly identified agent that can cause leaf blight of green onion, garlic, and garlic chives. Potential impact of B. sinoallii on production of Allium crops in China is discussed.     

Comparative electrophoretic studies of proteins and enzymes of some Brassica species

Summary A considerable amount of variation with respect to soluble proteins and esterase isoenzyme pattern was observed between different species of Brassica. Naturally occurring amphidiploids had comparable proteins and isoenzyme patterns to either one or both of the parental species. The species relationship based on percentage homology of protein and esterase bands revealed that B. nigra and B. campestris are the parental species of B. carinata and not B. nigra and B. oleracea, as suggested on the basis of cytological studies. Elimination of a pair of chromosomes might have resulted into 2n=34 in the case of B. carinata. Further studies are needed to confirm this view. The peroxidase and catalase isoenzyme patterns did not show much variation in different species and amphidiploids.     

Photo‐inactivation of Bacillus endospores: inter‐specific variability of inactivation efficiency

The aims of this work were to (a) evaluate the susceptibility of endospores of Bacillus cereus, B. licheniformis, B. sphaericus and B. subtilis to photodynamic inactivation using a tricationic porphyrin as photosensitizer, (b) assess the efficiency of adsorption of the photosensitizer in endospore material as a determinant of the susceptibility of endospores of different Bacillus species to photo‐inactivation, (c) determine the value of B. cereus as a model organism for studies of antimicrobial photodynamic inactivation of bacterial endospores. The results of irradiation experiments with endospores of four species of Bacillus showed that B. cereus was the only species for which efficient endospore photo‐inactivation (> 3 log reduction) could be achieved. Endospores of B. licheniformis, B. sphaericus and B. subtilis were virtually resistant to photo‐inactivation with tricationic porphyrin. The amount of porphyrin bound to endospore material was not significantly different between species, regardless of the presence of an exosporium or exosporium‐like outer layer. The sensitivity of endospores to photodynamic inactivation with a tricationic porphyrin is highly variable among different species of the genus Bacillus. The presence of an exosporium in endospores of B. cereus and B. sphaericus, or an exosporium‐like glycoprotein layer in endospores of B. subtilis, did not affect the amount of bound photosensitizer and did not explain the inter‐species variability in susceptibility to photodynamic inactivation. The results imply that the use of B. cereus as a more amenable surrogate of the exosporium‐producing B. anthracis must be carefully considered when testing new photosensitizers for their antimicrobial photo‐inactivation properties.     

Morphological Stasis of Two Species Belonging to the L-morphotype in the <Emphasis Type="Italic">Brachionus plicatilis</Emphasis> Species Complex

Detection and characterization of sibling species complexes in zooplankton are critical to understanding their ecological responses and patterns of evolution. The taxon Brachionus plicatilis is a complex of at least 14 species with three major, deeply diverged clades, which are morphologically distinct. We studied morphometric differences between two species – B. plicatilis sensu stricto and B. ‘Manjavacas’– which belong to the L-(large) morphotype and often co-occur in ponds or lakes. B. plicatilis s.s. was on average 6% longer than B. ‘Manjavacas’. They differed significantly in the measurements related to lorica spines. A significant discriminant function relating spine measurements was found, however, individuals from each species showed extensive overlap. Our morphometric data provide additional evidence for the species status of B. plicatilis s.s. and B. ‘Manjavacas’. Since these are ancient species, our results support that a morphological stasis occurs in these taxa. We identified COI restriction sites for PvuII and KpnI which are diagnostic for B. ‘Manjavacas’ and B. plicatilis s.s., respectively. We conclude that morphometry is not useful in classifying the two species. At present, this can only be done reliably using molecular methods.     

Species limits in the genus Bleda Bonaparte, 1857 (Aves,Pycnonotidae)

African forest bulbuls of the genus Bleda are usually placed into three separate species: B. syndactyla and B. eximia distributed both in Upper and Lower Guinea forest blocks, and B. canicapilla restricted to the Upper Guinean one. Acoustic data lead to question traditional morphologically-based species limits in this genus. Colouration patterns and measurements, particularly bill shape and length, wing and tail lengths, are reconsidered for all taxa. Multivariate (discriminant functions) analyses lead to separate nominate B. eximia as an Upper Guinean species distinct from Lower Guinean B. notata. Furthermore B. eximia appears closer to B. syndactyla than to the other two species. Acoustically, by the physical traits of their calls and songs as well as the behaviour associated with their production, B. eximia and B. syndactyla are very close and quite different from B. canicapilla and B. notata which constitute another pair of very close species. Obviously, in the frame of the biological species concept, the four taxa branched in two groups from a common ancestor, B. eximia and B. syndactyla represent a species-pair whereas B. notata and B. canicapilla are allospecies of a single superspecies. Allopatric speciation patterns based on alternate fragmentations and unitings of forests can be drawn from present knowledge of African forest history in relation to Pleistocene-Holocene events. However, a brief review of recent data on interspecific genetic differentiation in birds suggests an important discrepancy between biogeographical and molecular time calibrations. The development of molecular studies appears as a priority for the understanding of the evolution of African tropical forests birds.