Spectrophotometric study of green microalgae biomass color

It has been found visually and by spectrophotometric measurements that the infection of the algae culture of Sc. acuminatus used for biomass production has caused a changing of its color toward the large wavelengths of the spectrum. Experimental studies have proved that the color change was due to the reaction between the phytoplankton and the nitrous acid produced throughout the cultivation process. It has also been demonstrated that the coefficient of bathochromicy introduced in this study was efficient for quantitative estimation of algae biomass color, and could be used for control of algae culture color.     

Taxonomic significance of asymmetrical helmet and lance bristles in the genus Mallomonas (Synurophyceae) and their discovery in Eocene lake sediments

Complex bristle types formed by species in the genus Mallomonas include those with helmet or lance-shaped apices. The ornamentation on each side of the helmet has been thought to be equivalent or symmetrical, whereas on a lance-shaped bristle an expanded portion folds over one side of the shaft to form an asymmetrical structure. We describe, for the first time, helmet bristles with a distinctly asymmetrical design, also formed by the folding of a siliceous membrane over one side of the helmet. We postulate that the asymmetrical helmet represents a structure that combines the formation of a symmetrical helmet and a lance-shaped design on the same bristle. Further, we report structurally similar asymmetrical helmet bristles, lance-shaped bristles and scales that are unambiguously assigned to Mallomonas asmundiae in Middle Eocene sediments from a maar lake in northern Canada, supporting the hypothesis that scale and bristle morphology in the Synurophyceae has undergone extensive prolonged evolutionary stasis. Given differences in scale morphology and the presence of asymmetrical helmet bristles, we transfer the North American endemic Mallomonas acaroides var. muskokana to the rank of species. Further, we formally describe Mallomonas dispar and M. lancea, fossil species with asymmetrical helmet bristles and lance-shaped bristles, respectively. The taxonomic and biogeographic significance of asymmetrical and lance-bearing bristles is discussed.     

Karyotypic differences and evolutionary tendencies of some species from the subgenusObliquodesmus Mlad. of genusScenedesmus Meyen (Chlorophyta, Chlorococcales)

Karyotype structures ofScenedesmus acuminatus (Lagerch.) Chod. andScenedesmus pectinatus Meyen are compared. The karyotype ofS. acuminatus (n = 5) is described for the first time. It reveals four large metacentric and one large submetacentric chromosomes (4M + 1SM). The established karyotype differences have been helpful in clarifying the taxonomic position of these two species. The cytological analyses of other related clonal cultures suggest an evolutionary transition fromS. pectinatus towardsS. regularis throughS. pectinatus f.regularis, which correlates with the morphological data about their variability. These results are discussed from the cytogenetic, morphological and evolutionary point of view. On the basis of the karyotypic analysis, it was confirmed that from a taxonomic point of viewS. pectinatus, S. acuminatus andS. regularis are separate biological species.     

Occurrence of Conchophthirus acuminatus (Protista: Ciliophora) in Dreissena polymorpha (Mollusca: Bivalvia) along the River Shannon, Ireland

Samples of Dreissena polymorpha were collected at several sites along the River Shannon navigation in Ireland, to determine the occurrence and distribution of their obligate host-specific commensalistic ciliate, Conchophthirus acuminatus, in this newly invaded region. Mussels collected by various methods were fixed immediately in 75% ethanol, in which they were later dissected under a stereoscopic microscope, beginning with thorough flushing of the mantle cavity and removal of the gills. One ml of sediment flushed from the mantle cavity and dissection residue of each mussel was examined under a compound light microscope using brightfield, phase-contrast, and differential-interference-contrast optics. Of 180 mussels examined, 125 (69.44%) harbored C. acuminatus. The ciliates were invariably well fixed and easily identifiable in all preparations. Mean sampling intensity for infected mussels was 8.47 ciliates per ml of sediment. Both prevalence and sampling intensity varied between sites, but no pattern was discernible. The present results are consistent with other reports of C. acuminatus being the most widespread and abundant symbiont of D. polymorpha throughout Europe, often occurring where no other symbionts occur. Its occurrence in Ireland indicates introduction of the mussels as adults, since planktonic veliger larvae are not known to harbor ciliates. Following similar reasoning, it is possible that the earlier North American invasion by D. polymorpha included only veligers, since C. acuminatus has not been found on that continent. Using these simple and quick methods, the ciliates could be easily identified and counted to give general comparative data among sites regarding intensity and prevalence. Thus, this method has promise for future efforts to obtain basic information rapidly in newly invaded systems.     

Colonization,Species Composition,and Conidial Production of Aquatic Hyphomycetes on Chirpine Needle Litter in a Freshwater Kumaun Himalayan Stream

Aquatic hyphomycetes colonizing the submerged chirpine (pinus roxburghii SARG .) needle litter in a high altitude, Kumaun Himalayan stream were studied. 15 species belonging to different genera of aquatic Hyphomycetes have been recognized as the colonizers of chirpine needle litter. Clavariopsis aquatica, Heliscus lugdunensis, Lunulospora cymbiformis, Triscelophorus acuminatus and T. monosporus were found with a high frequency of occurrence. The conidial production was highest in Flagellospora penicillioides, however, Campylospora chaetocladia, L. cymbiformis and T. acuminatus had less number of conidia per unit area of pine needles. The chirpine needle litter decomposition in the freshwater habitat is also discussed.     

A Quantified Ethogram for Oviposition in Triturus Newts: Description and Comparison of T. helveticus and T. vulgaris

Female newts of the genus Triturus deposit and wrap their eggs individually in the submerged leaves of aquatic macrophytes. Although this behaviour has previously been described, the different elements of the oviposition process have not been fully characterized nor any attempt made to quantify the behavioural elements. The study examined the oviposition behaviour of the two similarly sized species, Triturus helveticus and T. vulgaris on a standardized substrate macrophyte, Rorippa nasturtium–aquaticum. Continuous focal sampling was used to develop a baseline of discrete behavioural elements enabling quantification and comparison of oviposition behaviour between the two species. The results showed that the same pattern of elements was followed for each egg laid and the same key elements of the process were present in each newt species. Although these are broadly similar in size, there were striking differences in certain aspects of the oviposition sequence between the two species. Key findings were that leaf sniffing and leaf flexing and a measure of the duration of ovipositing were all significantly greater in females of T. helveticus and females of T. vulgaris laid significantly more eggs than those of T. helveticus in a standard observation period. The work presented here defines a baseline ethogram and shows how it can be used to reveal quantifiable differences in closely related species. This demonstrates its value in furthering our understanding of oviposition – a key aspect of female behaviour currently understudied in Triturus behavioural ecology, despite its intrinsic interest and value in understanding recruitment and maintenance of populations.     

Doxycycline-Dependent Inducible and Reversible RNA Interference Mediated by a Single Lentivirus Vector

Most fermented milk prepared by strains of Lactobacillus helveticus showed significant antihypertensive effect in spontaneously hypertensive rats (SHR) by oral administration. However, milk fermented by other species of lactic acid bacteria did not show significant antihypertensive effects. Most of the whey fractions of the milk fermented by L. helveticus or Lactobacillus delbrueckii subsp. bulgaricus showed higher angiotensin I-converting enzyme (ACE) inhibitory activity than the activity of milk fermented by other species. Proteolytic activity in cell wall and peptide content of the fermented milk were higher in L. helveticus strains than other species.     

Zur Taxonomie,Verbreitung und Ökologie des Filzigen Schmierlings Chroogomphus helveticus (Sing.) Moser

Chroogomphus helveticus is an european, dealtomontanous species with a south-hercynian-alpian-carpathian and illyrian-macedonian distribution. It grows in association with various conifers. Picea abies, Pinus cembra, Pinus peuce, Pinus strobus and Abies alba probably are partners of the mycorrhiza. The area is similar to that of Abies alba, Hygrophorus marzuolus and various dealpine plants. Distribution centres are districts, where 5-needled pines (Pinus cembra, Pinus peuce) are to be found naturally. Chroogomphus helveticus is to be found in an altitude from 300 to over 2000 m NN. The species is acidophilous, but not strongly bound to acid soils. A subdivion of the species into subspecific taxa is not possible. The closest relative of Chroogomphus helveticus occurs in Asia and Northern America. An other related european species is only known from England.     

The subgenus Scaptodrosophila (Diptera: Drosophilidae)

Four major subgenera, Drosophila, Sophophora, Hirtodrosophila and Scaptodrosophila, and several minor subgenera, have been recognized in the genus Drosophila. The hitherto little studied subgenus Scaptodrosophila, possessing a complicated synonymy, contains 144 named species, or about 11% of the total described in the genus; it is likely that many more Scaptodrosophila species await discovery. Scaptodrosophila probably originated in tropical Asia, and the greatest Scaptodrosophila faunas occur in Asia, south-east Asia, New Guinea, Australia and Africa, with very few species in north and south America and Europe. Scaptodrosophila species usually possess a pair of prescutellar bristles, a propleural bristle, and three large subequal sternopleural bristles; other morphological features are more variable. Ecological information concerning the majority of Scaprodrosophila species is scanty or absent, but known feeding or breeding sites include tree sap, fungi, fruit, flowers and 1eaf litter; larvae of at least one species are gall forming in plant tissues. The establishment of species groups is complicated by lack of detailed knowledge of many species, but six groups containing four or more species are recognized.     

Facial bristle feather histology and morphology in New Zealand birds: Implications for function

Knowledge of structure in biology may help inform hypotheses about function. Little is known about the histological structure or the function of avian facial bristle feathers. Here we provide information on morphology and histology, with inferences for function, of bristles in five predominantly insectivorous birds from New Zealand. We chose species with differing ecologies, including: brown kiwi (Apteryx mantelli), morepork (Ninox novaezealandae), hihi (Notiomystis cincta), New Zealand robin (Petroica australis), and New Zealand fantail (Rhipidura fuliginosa). Average bristle length corrected for body size was similar across species. Bristles occurred in distinct groups on different parts of the head and upper rictal bristles were generally longest. The lower rictal bristles of the fantail were the longest possessed by that species and were long compared to bristles of other species. Kiwi were the only species with forehead bristles, similar in length to the upper rictal bristles of other species, and the lower rictal bristles of fantails. Herbst corpuscles (vibration and pressure sensitive mechanoreceptors) were found in association with bristle follicles in all species. Nocturnal and hole‐nesting birds had more heavily encapsulated corpuscles than diurnal open‐nesting species. Our results suggest that avian facial bristles generally have a tactile function in both nocturnal and diurnal species, perhaps playing a role in prey handling, gathering information during flight, navigating in nest cavities and on the ground at night and possibly in prey‐detection. These differing roles may help explain the observed differences in capsule thickness of the corpuscles. J. Morphol., 2011. © 2010 Wiley‐Liss, Inc.     

Mouthparts of larvae of Opifex fuscus and Aedes australis (Diptera: Gulicidae); a scanning electron microscope study

Abstract

Larvae of the New Zealand culicid species Opifex fuscus and Aedes australis have previously been reported to show dimorphism in the structure of their labral brushes, some larvae having pectinate bristles and others only simple hairs. In the scanning electron microscope all larvae showed some degree of pectination of hairs in these brushes. There is also a gradation in the pectination. Some bristles are only sparsely pectinate; because the dimensions of their teeth are close to the limit of resolution by the compound microscope, the pectination had previously gone undetected. The mouthparts of both species are intermediate in character between those typical of filter-feeding larvae and those typical of browsing larvae. The SEM appearance of maxillary sensoria and bristles on the ventral surfaces of the mandibular brushes is described; the latter bristles comb food particles out of the labral brushes and towards the mouth. Features of the mouthparts are illustrated with scanning electron micrographs.     

A new species of Tunga perforating the osteoderms of its armadillo host in Argentina and redescription of the male of Tunga terasma

A new species of Tunga (Siphonaptera: Tungidae) collected from armadillos in Argentina is described. The new species is characterized by large and pigmented eyes, the presence of two bristles on antennal segment II, two bristles at the base of the maxilla, and a discoid neosome compressed anteroposteriorly. The gravid female is located in the carapace of the host, perforating the osteoderms. The new species resembles Tunga penetrans and Tunga terasma in general appearance. However, it differs by the greater anteroposterior compression of the neosome, a more angular head, and a manubrium with a pointed proximal end and convex ventral margin (the proximal end of the manubrium is rounded or slightly pointed in T. terasma, and the ventral margin is straight in both T. penetrans and T. terasma). In addition, specimens of T. penetrans have more bristles in antennal segments II and III, and lack bristles in the posterior tibia. This is the first report of a species of Tunga perforating the osteoderms of its host and thereby showing a high degree of specialization. Tunga terasma is recorded for the first time in Argentina; the male is described again and the characteristics of the species amended. This information may be useful in epidemiological studies of diseases caused by species of Tunga.     

Chiloplectus masleni sp. nov. and variability in populations of Plectus acuminatus Bastian 1865 (Nematoda: Plectidae) from the nunatak Basen,Vestfjella, Dronning Maud Land,East Antarctica

 A new species, Chiloplectus masleni sp. nov., and 12 populations of Plectus acuminatus are described from the nunatak Basen, Vestfjella, Dronning Maud Land, East Antarctica. C. masleni sp. nov. is distinguished from the closely related C. loricatus by a broader lip region, longer stoma, the more posterior position of amphids, a pear-shaped basal bulb, more narrow annuli, anterior annuli that are evenly rounded and a larger number of tail setae. New information is provided on internal and external morphology of specimens of P. acuminatus from Basen. Received: 20 December 1995/Accepted: 17 March 1996     

POPULATION PERSISTENCE AND REPRODUCTIVE ECOLOGY OF A FOREST HERB: ASTER ACUMINATUS

Aster acuminatus Michaux, a patchily distributed herb of eastern forests, is commonly represented in all stages of forest succession. To determine its mechanisms of persistence, we carefully examined the distribution patterns of this species as affected by its reproductive ecology and demography. Using A. acuminatus as a model, we hypothesized that 1) availability of propagules and location of adequate recruitment sites impose first-order control over plant distributions in stands of all ages by determining where plants might be found and 2) light and other resources exert a second-order control over herb distributions by determining where established plants cannot persist. Results from our study at the Hubbard Brook Experimental Forest in New Hampshire demonstrated this species' ability to exploit resource-rich disturbances through immediate and profuse ramet and seed production. This ensured rapid colonization of new sites and provided genetic exchange for longer-term survival. Relict colonies which survived the disturbance served as the sole propagule-producing loci for the first year of colonization. After several years, resources became more limiting and the aster shifted to a more conservative asexual reproduction strategy which provided population stability until the next disturbance. The clumped distribution of A. acuminatus in mature forests is explained by strict adherence to asexual ramet replacement in which there is no year-to-year change in aster importance. Location of persistent colonies probably is dictated by location of suitable seedbeds during the first few years of recovery after disturbance. Whereas numerous sites may be colonized initially, timing of colonization and quality of site impose constraints on which colonies persist.     

A new genus and a new species of tachinids (Diptera,Tachinidae) from the south of middle Asia

Ventoplagia gen. n. is described, with the type species Ventoplagia brevirostris sp. n. The frontal bristles extending only to the base of the pedicel, 2+3 dorsocentral bristles, 0+2 intraalar bristles, the absence of prealar bristle, the short and fine anepimeral (pteropleural) bristle, the scutellum without lateral bristles, and the welldeveloped posteroventral bristle of the hind tibia indicate that the new genus belongs to tribe Minthoini. Ventoplagia gen. n. is closely related to the genus Palmonia Kugler. The characters distinguishing these genera are given.     

What remains from a 454 run: estimation of success rates of microsatellite loci development in selected newt species (Calotriton asper,Lissotriton helveticus,and Triturus cristatus) and comparison with Illumina‐based approaches

The development of microsatellite loci has become more efficient using next‐generation sequencing (NGS) approaches, and many studies imply that the amount of applicable loci is large. However, few studies have sought to quantify the number of loci that are retained for use out of the thousands of sequence reads initially obtained. We analyzed the success rate of microsatellite loci development for three amphibian species using a 454 NGS approach on tetra‐nucleotide motif‐enriched species‐specific libraries. The number of sequence reads obtained differed strongly between species and ranged from 19,562 for Triturus cristatus to 55,626 for Lissotriton helveticus, with 52,075 reads obtained for Calotriton asper. PHOBOS was used to identify sequences with tetra‐nucleotide repeat motifs with a minimum repeat number of ten and high quality primer binding sites. Of 107 sequences for T. cristatus, 316 for C. asper and 319 for L. helveticus, we tested the amplification success, polymorphism, and degree of heterozygosity for 41 primer combinations each for C. asper and T. cristatus, and 22 for L. helveticus. We found 11 polymorphic loci for T. cristatus, 20 loci for C. asper, and 15 loci for L. helveticus. Extrapolated, the number of potentially amplifiable loci (PALs) resulted in estimated species‐specific success rates of 0.15% (T. cristatus), 0.30% (C. asper), and 0.39% (L. helveticus). Compared with representative Illumina NGS approaches, our applied 454‐sequencing approach on specifically enriched sublibraries proved to be quite competitive in terms of success rates and number of finally applicable loci.     

Classification of Lactobacillus helveticus Strains by Immunological Differences in Extracellular Proteinases

Polyclonal antibodies against an extracellular proteinase of Lactobacillus helveticus CP53 were raised. The antibodies reacted with a 170-kDa enzyme with activity and a 53-kDa protein that seemed to be a degradation product of the 170-kDa proteinase from results of immunoblotting. The antibodies reacted also with a 45-kDa extracellular proteinase of L. helveticus CP790. However, monoclonal antibodies to the CP790 proteinase did not react with the proteinase of L. helveticus CP53. Seventeen strains of L. helveticus were tested for immunological reactivity with the two kinds of antibodies. The strains all had the same reactivity as either strain CP53 or strain CP790. Eleven strains with the 45-kDa proteinase were identified as L. helveticus biovar jugurti because they did not ferment maltose, four other strains with the 170- and 53-kDa proteins were identified as L. helveticus biovar helveticus because they fermented maltose. The remaining two strains dit not fit this pattern; they had both the 170- and 53-kDa proteins, but classification by their sugar utilization showed them to be L. helveticus biovar jugurti.     

Pollen‐feeding in hover‐flies (Diptera: Syrphidae)

Analyses of the pollen contents of the crop and intestine of 11 species of New Zealand Syrphidae . showed that small, sparsely haired hover‐flies with unbranched hairs, short, simple bristles, and a short proboscis had ingested at least 99% anemophilous pollens, and that larger, more hairy hover‐flies with pollen‐collecting hairs, long, spirally grooved bristles, and elongate mouthparts had ingested pollens almost exclusively from nectar‐bearing flowers. Pollen‐feeding behaviour was studied in one hairy species, the drone‐fly Eristalis tenax, and in one sparsely‐haired species, Melanostoma fasciatum. Using granulated charcoal as a substitute for pollen, it was found that in E. tenax particles trapped among the body hairs are combed off by the front and hind tibiae and transferred to pollen‐retaining bristles on the front and hind tarsi respectively. Particles retained among the front tarsal bristles are ingested directly from the bristles. Those retained by the hind tarsi are transferred in flight by leg‐scraping movements to the front tarsi, from which they are subsequently eaten. E. tenax also eats pollen directly from anthers. In M. fasciatum apparently all the pollen ingested is taken directly from anther lobes or stigmas. The few pollen grains that adhere to the body of this species are combed off by the front and hind tibiae and transferred to the front and hind tarsi, but are not retained there because the bristles are short and simple. The mouthparts, hairs, and bristles of E. tenax and M. fasciatum are illustrated. Drawings of leg movements associated with pollen collection and ingestion, and photographs showing leg scraping in E. tenax are included. Morphological similarities between drone‐flies and honey‐bees, previously regarded as the result of mimicry, can be explained by convergent evolution in response to similar food‐gathering behaviour. Probably the majority of Syrphidae, and also the related Acroceridae, collect pollen by means of branched or curly‐tipped hairs.     

Some observations on the skin ofOxychilus spp. (Fitzinger), with particular reference toO. helveticus (Blum)(Mollusca,Pulmonata, Zonitidae)

Summary A sub-epithelial collagenous layer and pits in the skin have been described inOxychilus spp. The collagen is especially developed beneath the skin on the right side of the body inO. helveticus. It seems to arise from pore cells which previous authors have described in other molluscs. The pits inO. helveticus are lined by cells which together exhibit a gradation of electron densities. This probably represents an accumulation of secretory material and a macroapocrine secretory process has been observed.

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Zusammenfassung Bei denOxychilus-Arten wurden eine sub-epitheliale Kollagenschicht und Vertiefungen in der Haut beschrieben. Das Kollagen ist besonders ausgebildet unter der HautoberflÄche der rechten Körperseite inO. helveticus. Dies scheint aus den pore cells hervorzugehen, was auch von früheren Autoren in anderen Mollusken beobachtet wurde. Die Vertiefungen inO. helveticus sind umgeben von Zellen, die zusammen eine Abstufung von Elektronendichte zeigen. Wahrscheinlich representiert dies eine Ansammlung von Sekret-Material; ein macroapokriner Sekretionsvorgang wurde beobachtet.