The population metabolism and life history tactics of Neobisium muscorum (Leach) (Arachnida: Pseudoscorpiones)

Summary The population metabolism of N. muscorum at a beechwood site in southern England was determined for two separate year periods by two methods; a detailed computer analysis and a best estimate. These methods, which are based on data of biomass, population dynamics, field temperatures, and respiration rates of all life stages with temperature, are compared. The validity of extrapolating laboratory determined basal metabolic rates to field activity is discussed; and the population metabolism of N. muscorum is compared with that reported for other soil and litter invertebrate species, both predatory and non-predatory.The metabolic rates of the adults of a second species of pseudoscorpion found at the beechwood site (Chthonius orthodactylus (Leach)), were determined, and the life cycle and metabolism of this species is compared to N. muscorum. The influence of low environmental temperatures on poikilothermic predators, with reference to life cycle strategies, basal metabolism and geographic distribution, is discussed.     

Changes in microbial nutrient status during secondary succession and its modification by earthworms

Summary Microbial biomass, nutrient (N and P) status, and carbon and nutrient limitation of the microflora were investigated in soils from five different sites (field, 5-, 12-, and about 50-year-old fallow, beechwood), which represent different stages of a secondary succession from a wheat field to the climax ecosystem of a beechwood on limestone. In addition, the effect of faeces production by the substrate feeding earthworm species Octolasion lacteum (Örley) on the nutrient status of the soil microflora of these sites was studied. Humus had accumulated in the soil of the third fallow site, with an enhanced biomass of microflora. However, in the beechwood soil, which had the highest humus content, microbial biomass was lower than in the soil of the third fallow site and similar to that of the field and the two younger fallow sites. In general, soil microbial biomass was little affected by the passage of soil through the gut of O. lacteum. The soil microflora of the field, the 5-, 12-, and about 50-year-old fallow was limited by carbon, whereas in the beechwood soil phosphorus limited microbial growth. NItrogen availability to the soil microflora was low in the two younger fallow sites and high in the field and the third fallow. In the beechwood soil nitrogen supply did not affect microbial carbon utilization. Application of phosphorus stimulated glucose mineralization in the soil of the field, the third fallow, and the beechwood, but not in the two younger fallow sites. Therefor, the nutrient status of the soil microflora seems to have changed during secondary succession: presumably, during the first phase the availability of nitrogen decreased, whereas during the second phase microbial phosphorus supply became more important, which resulted in phosphorus limitation of the soil microflora in the climax ecosystem. The passage of soil through the gut of O. lacteum caused an alteration in the microbial nutrient status. Generally, microbial growth in earthworm casts was limited by carbon. The relative effect of the gut passage of the soils on microbial carbon utilization seems to increase during succession. Therefore, the effect of decomposer invertebrates on microbial nutrient supply seems to increase during secondary succession. In general, nitrogen did not limit microbial carbon utilization in earthworm casts. Phosphorus requirements of the soil microflora were lowered by the gut passage of the soil of the third fallow site and the beechwood, which indicates an increased phosphorus supply in earthworm casts. Howerver, this additional supply was not sufficient to enable optimal carbon utilization by the soil microflora. The results indicate that the effect of decomposer invertebrates on the soil microflora depends on the nutrient status of the ecosystem.     

Clonal organization of populations of Asarum europaeum and Maianthemum bifolium in contrasting woodland habitats

Populations of two rhizomatous species, Asarum europaeum (asarabacca) and Maianthemum bifolium (May lily), were examined in two, and four forest habitats respectively, in the Roztocze National Park (south-eastern Poland). May lily populations were studied in habitats: the Carpathian beechwood, upland mixed fir forest, subboreal moist mixed coniferous forest and bog-alder forest. Asarabacca was studied in two habitats: beechwood and Scots pine community (an 80-year-old plantation). In both the species studied intra- and inter-populational differences of the size of genets in terms of above- and below-ground parts of individuals as well as the biomass and area occupied were observed. In May lily populations the greatest mean number of shoots per genet was found in the fir forest (11.62±3.29), a value almost twice as great as that in the moist coniferous forest and nearly three times greater than in the bog-alder forest. Total rhizome length was also the greatest in the fir forest (351.9±98.7 cm) followed by moist coniferous forest, beechwood and alder forest habitats. In all populations of May lily a greater part of total dry weight biomass is in below-ground organs. The greatest biomass value of a genet was found in the fir forest (4.275 g), the smallest in the bog-alder forest (0.110 g). All populations differed significantly in terms of leaf area, leaf length (with the exception of fir forest and beechwood habitats where the values were the greatest), and leaf width (excluding moist coniferous and bog-alder forests which had the smallest values). In the case of asarabacca, both the mean number of ramets per genet (3.36±0.45 vs. 2.49±0.20) and total rhizome length (40.3±6.4 cm vs. 21.1±1.8 cm) were greater in the beechwood habitat than in the pine community. In the first population genets had 3–5 times greater the total biomass of those from the pine community. Only genets of the latter had proportionately more dry weight biomass in above-ground parts. It seems to be correlated with greater rhizome dieback and disintegration of genets into smaller units. Both populations were significantly different in terms of all examined parameters of leaves. Genets of both the species studied were found to have their own structure of developmental phases that often differed for shoots and rhizomes.     

Decomposition of roots and twigs: Effects of wood type (beech and ash), diameter,site of exposure and macrofauna exclusion

Carbon loss and nitrogen dynamics in beech roots (Fagus sylvatica L.), beech twigs and ash roots (Fraxinus excelsior L.) of 0–3, 3–10 and 10–40 mm diameter were investigated during 36 months of exposure in litter bags of 1 and 4 mm mesh. Four experiments were set up: (1) Beech and ash roots (three size classes) were placed in a soil depth of ca 5 cm in a beechwood on limestone; (2) beech twigs (three size classes) were placed on the soil surface of the beechwood; (3) beech roots (3–10 mm) were placed on the soil surface of the beechwood: (4) beech twigs (3–10 mm) were placed on the soil surface of four sites representing different stages of secondary succession (wheat field, 13 year old fallow, ca 50 year old fallow, beechwood). Ash roots generally lost more C than beech roots. Loss in C of ash roots was similar for each of the size classes, whereas in beech roots and beech twigs C loss was in the order large roots > medium roots > small roots. Beech roots (3–10 mm) placed on the soil surface lost considerably less C than beech twigs (3–10 mm). Decomposition of beech twigs varied among ecosystems but generally did not follow clear patterns with successional stages. The fit of linear vs exponential models of decay is compared and in most materials exponential models fitted the data better. In each of the wood materials an accumulation of N occurred. Irrespective of wood type, root and twig diameter, mineralization of N of wood materials placed in the beechwood started uniformly after 12 months. Multiple regression analysis indicated a negative relationship between initial N content and C loss in beech roots and twigs but not in ash roots. The analysis also indicated a significant influence of the degree of white rot and of the amount of mineral soil deposited in the litter bags on C loss of certain wood materials. Generally, mesh size affected C loss and N dynamics only slightly, which is attributed to the comparatively short exposure time.     

Stenosoma stephenseni sp. n. (Isopoda, Idoteidae), from the southwestern Mediterranean, with a note on the nomenclatural status of Synisoma Collinge, 1917

Recent collections of isopods in Alboran Island and Algeria included several specimens of the species Stenosoma stephensenisp. n. This is the fourteenth species described in the genus Stenosoma Leach, 1814. Examination of two specimens collected during the Danish oceanographic cruises of the Thor (1908-10) close to the Galite Islands, and identified as Stenosoma acuminatum Leach, 1814, revealed that both belong to Stenosoma stephensenisp. n. In light of these findings, the Mediterranean records of Stenosoma acuminatum are revised, and it is proposed that Stenosoma acuminatum is a strictly Atlantic species. An updated diagnosis for the genus Stenosoma is given, together with a key for the identification of its species. The nomenclatural status of the name Synisoma Collinge, 1917 is addressed, and although it is in prevailing usage, it is shown that Stenosoma Leach, 1814 is the valid name of the genus.     

Secondary succession, soil formation and development of a diverse community of oribatids and saprophagous soil macro-invertebrates

Investigations into different stages of secondary succession (from a wheat field to a beechwood on Threstone; Northern Germany) demonstrated the formation of a carbon rich top soil in later successional stages. Parallel to changes in plant species and soil formation, there were also changes in species composition and diversity of saprophagous macro-invertebrates (Lumbricidae, Diplopoda, Isopoda) and oribatid mites (Acari: Oribatida). Diversity of diplopod and isopod species increased after cessation of cultivation, but in a late successional stage (ca 50 y-old fallow, ash-dominated wood) species number of diplopods and isopods declined strongly. In comparison with the other soil invertebrate groups, species composition of earthworms among the sites was more similar. Accumulation of soil C was assumed to be related to wood formation and occurrence of woody debris and recalcitrant leaf litter of beech trees. Incorporation of recalcitrant litter materials by earthworm species living in the upper mineral soil presumably contributed significantly to accumulation of soil C. Accumulation of soil C was accompanied by the development of an oribatid mite community rich in species. In early successional stages oribatids predominantly colonized the litter layer, while most oribatid mites of the beechwood inhabited the upper mineral soil. Maximum diversity of oribatid mites in the beechwood is assumed to be related to instability of the mineral soil caused by earthworm activity. Changes in species composition and diversity are discussed considering succession theory. Even soil invertebrates of similar trophic groups appear to respond very differently to successional changes. It is concluded that conservation strategies to maintain high diversity of soil invertebrates are most likely to be successful if a wide range of habitats of different successional stages is included.     

Species distribution modeling of storm-petrels (Oceanodroma furcata and O. leucorhoa) in the North Pacific and the role of dimethyl sulfide

Storm-petrels have been shown to use dimethyl sulfide (DMS) as a foraging cue, suggesting that this compound may be used to predict their distribution. We describe a new distribution model that employs machine learning software and geographic information systems to model storm-petrel distribution. We used environmental predictor variables that included newly available climatologies of sea surface DMS concentrations to construct distribution maps of fork-tailed storm-petrel (Oceanodroma furcata) and Leach’s storm-petrel (O. leucorhoa) in the North Pacific and Bering Sea. Model accuracy was assessed by (1) using the area under the receiver operating characteristic curve (AUC) values and (2) comparing predicted distributions to presence and non-detection data from two opportunistic pelagic surveys performed in summer 2008. Models using all predictor variables gave AUC values of 0.89 and 0.75, sensitivity values of 0.73 and 0.61, and specificity values of 0.83 and 0.73 for fork-tailed and Leach’s storm-petrel, respectively. Models using all predictor variables except DMS gave AUC values of 0.87 and 0.74, sensitivity values of 0.81 and 0.60, and specificity values of 0.77 for fork-tailed and Leach’s storm-petrel, respectively. The large-scale link between DMS and how storm-petrels use it to locate foraging areas was reinforced by the partial dependence of DMS on the relative index of occurrence (RIO) of storm-petrels, and by a decrease in AUC values when removing DMS as a predictor. This work is a preliminary step toward linking seabird distribution to globally important infochemicals and should be a basis for further study.     

Preliminary observations on the induction of maturity and spawning in the female Penaeus kerathurus (Leach)

The removal of two eyestalks from Penaeus kerathurus (Leach) in the middle of the intermoult period was followed by very poor survival. Unilateral ablation was found to be sufficient for the induction of full maturation of the ovaries.     

Annotated checklist of the Hydraenidae (Coleoptera: Staphylinoidea) recorded from Iran

According to our analysis of literature sources on the family Hydraenidae (Coleoptera: Staphylinoidea) of Iran, it is represented by 67 species and three genera: Hydraena Kugelann, 1794 (21 species), Limnebius Leach, 1815 (six species) and Ochthebius Leach, 1815 (40 species). Twenty-two species are supposed to be endemic to Iran. Here, for the first time, we summarize species distribution data in Iranian provinces and present them in a checklist of Iranian Hydraenidae. We also present two additional species lists: one with incorrect records (one species and one subspecies) and the other with unidentified species.     

Individuals lacking the Gerbich blood-group antigen have alterations in the human erythrocyte membrane sialoglycoproteins beta and gamma.

Membranes from erythrocytes with a new Gerbich (Ge)-negative phenotype (Leach phenotype), as well as those from two other Ge-negative phenotypes, were examined. Whereas cells of the Leach phenotype apparently lack three minor sialoglycoproteins (beta, beta 1 and gamma), the membranes of Ge- Yus- and Ge- Yus+ erythrocytes apparently lack beta- and gamma-sialoglycoproteins but contain additional diffusely migrating components of apparent Mr 30 500-34 500 and 32 500-36 500 respectively. Immunoprecipitation experiments showed that the abnormal components of both Ge- Yus- and Ge- Yus+ erythrocytes reacted with two monoclonal antibodies, BRIC 4 and BRIC 10. These antibodies have been shown to react with sialoglycoproteins beta and beta 1 in normal erythrocytes. Cytoskeletal preparations from Ge- Yus- and Ge- Yus+ erythrocyte membranes contained the abnormal components. In contrast with cells of the Leach phenotype, which are elliptocytic, Ge- Yus- and Ge- Yus+ were of normal shape, despite their apparent lack of beta- and gamma-sialoglycoproteins. It seems likely that the abnormal components in these cells contribute to their normal shape. Ovalocytic erythrocytes were shown to incorporate more radioactivity in the sialoglycoprotein-beta 1 region than normal erythrocytes after labelling by the periodate/NaB3H4 technique. It is suggested that abnormal components in Ge- Yus- and Ge- Yus+ erythrocytes result from chromosomal misalignment with unequal crossing-over at meiosis between the genes giving rise to beta-, beta 1- and gamma-sialoglycoproteins.     

Electrophoretic analysis of proteins from Mycoplasma capricolum and related serotypes using extracts from intact cells and from minicells containing cloned mycoplasma DNA

The acidic proteins of six different mycoplasma serotypes causing bovine or caprine pleuropneumonia were compared by two-dimensional gel electrophoresis of extracts of 35S-labelled cells. The organisms investigated were Mycoplasma mycoides subsp. mycoides (PG1), M. mycoides subsp. mycoides (Y-goat), M. mycoides subsp. capri (PG3), M. capricolum (California kid), the unclassified bovine serogroup 7 of Leach (PG50) and the F38-like group (F38). The results suggested a close relationship between M. capricolum and F38 and a similarly close relationship between the different M. mycoides subspecies, whereas the two M. mycoides subspecies appeared to be quite distant from M. capricolum and F38. The representative strain of the bovine serogroup 7 of Leach was equally distant from F38, M. capricolum and the three strains of M. mycoides. Strikingly, all six mycoplasma strains apparently shared six proteins in the two-dimensional gels. In Escherichia coli minicells, DNA from strain PG50 cloned in the vector pBR325 gave rise to incorporation of radioactive label into proteins which were identified as mycoplasma proteins by two-dimensional electrophoresis and immunoprecipitation.     

A mathematical model on sampling diplopods using pitfall traps

Summary Trapping of three species of diplopods, viz. Cylindroiulus punctatus (Leach), Tachypodoiulus niger (Leach) and Polydesmus angustus Latzel with pitfall traps in areas with known densities follows a definite mathematical relationship. The number of each species trapped is density dependent upto a lavel: beyond that the increased density levels are not proportionately reflected in the catches. Ecological and mathematical implications of the observations are discussed.     

Salinity and temperature tolerance by Nymphon gracile (Leach) and Achelia echinata (Hodge) (Pycnogonida)

The tolerance of two species of pycnogonid, Achelia echinata (Hodge) and Nymphon gracile (Leach) to a range of salinities, temperatures and relative humidities has been examined. In most instances N. gracile is more resistant than A. echinata and indeed is found higher in the littoral zone during the warmer months and thus likely to be subjected to greater environmental fluctuation.     

Alien shrimps in evidence: new records of the genus Athanas Leach, 1814 on the coast of S?o Paulo, southern Brazil (Caridea: Alpheidae)

The occurrence of two alien alpheid shrimps of the genus Athanas Leach, 1814 [in Leach 1813–1814], the Indo-West Pacific A. dimorphus Ortmann, 1894 and the Eastern Atlantic A. nitescens (Leach, 1813 [in Leach 1813–1814]), on the coast of the state of S?o Paulo, Brazil, is reported. The presence of A. dimorphus extends the range of this species in the western Atlantic farther to the south in Brazil, whereas A. nitescens is reported for the first time in the western Atlantic, representing the second alien alpheid species on this side of the Atlantic and the twenty-first decapod crustacean introduced in Brazil. We provide morphological accounts of the material examined and illustrate the most important diagnostic characters of both species. An overview of the possible mechanisms of their introduction on the coast of S?o Paulo is also provided.     

The ecology of the larger fungi; an investigation into the influence of rainfall and temperature on the seasonal production of fungi in a beechwood and a pinewood

The present paper deals in a somewhat generalized way with the influence of environmental factors, particularly rainfall and temperature, on the seasonal production of fungus sporophores in a beechwood and pinewood, both situated near Newbury (Berks.), during a selected part of the seasons 1933-6, and is intended to be complementary to the previous papers in the same series.     

A CLADISTIC ANALYSIS OF ANGOPHORA CAV. (MYRTACEAE)

Abstract— A cladistie analysis of Angophora Cav. used a data set dominated by quantitative morphological characters. These were coded into multistates using Generalized Gap-Coding, and treated as ordered sequences of stales. The reasons for choosing an ordered over an unordered sequence are discussed. A branch and bound method yielded one minimal-length, unrooted tree. Because of uncertainty in the position of the root, five cladograms were derived from the unrooted tree. The consensus cladogram comprises four main clades. The consensus cladogram was used for a biogeographic study using component analysis, which generated a single statement of relationships for five areas of eastern Australia. An infra-generic classification of Angophora comprising four series corresponding to the four main clades, and two subseries, is presented. The following new names are published: Angophora series i>Floribundinae , series Subvelutininae , series Bakerinae . subseries Costntitac. Angophora leiocarpa : L. Johnson ex G. Leach) K. R. Thiele and P. Y. Ladiges and A.paludosa (G. Leach) K. R. Thiele and P. Y. Ladiges are published as new combinations.     

Immunomodulatory activity of acidic xylans in relation to their structural and molecular properties

The structure/function relationship of two acidic heteroxylan types, the arabino-(glucurono)xylan from corn cobs (AGX) and 4-O-methylglucuronoxylans (GXs) from beechwood and three medicinal herbs (Rudbeckia, Altheae, and Mahonia), has been studied. The effect of the molecular mass of AGX, as well as the content and distribution of the 4-O-methylglucuronic acid side chains in GXs on the immunological activity of these xylans was characterized by their biological response in the mitogenic and comitogenic thymocyte in vitro tests. Depolymerization of AGX by ultrasonication resulted in unequivocal decrease of the immunomodulatory activity, whereas already a short treatment by endo-beta-1,4-xylanase brought about a significant increase in its activity when applied in the highest dose. In the case of the GX samples, neither the uronic acid content nor the distribution pattern of the uronic acid side chains was found to be determinant for the expression of their immunomodulatory activity.     

The larvae of Gnaptorina felicitana and Agnaptoria amdoensis of the tribe Blaptini from China(Coleoptera:Tenebrionidae)

This paper describes the morphological data of the larvae of two species from the tribe Blaptini Leach,1815.The two species are Gnaptorina felicitana Reitter and Agnaptoria amdoensis G.Medvedev,whose larvae have not been reported up to now.In this paper,morphological characters,informations of specimen,and character figures of the two species' larvae are provided.A key to the two genera and the reported species is listed here.The larvae specimens are deposited in the Museum of Hebei University.     

Correct diagnosis of early zoeal stages of Athanas nitescens (Leach, 1814) (Decapoda, Caridea, Alpheidae) using laboratory-raised larvae

The morphology of the first two larval stages of Athanas nitescens(Leach, 1814), reared under laboratory conditions, is redescribed.The present data are compared with previous works, since a clarificationof the morphological characters of the first two larval stagesof A. nitescens is needed, in order to avoid misidentificationof these stages in the future.     

Uptake of phosphorus and potassium in relation to root growth and root density

Summary This paper provides some quantitative data on the relationship between the rate of uptake of phosphorus and potassium from soil and the amount of root, root density and rate of root growth. Three experiments were conducted with winter wheat, all grown in the same soil. Root growth and density were manipulated in three ways: (1) by root pruning; (2) by a split-root technique; (3) by growing plants in different soil volumes. Root lengths as well as weights were determined.Potassium uptake per unit amount of root was generally lower the higher the root density, suggesting that roots were competing with each other for potassium even at the lowest density. In contrast, phosphorus uptake showed a good correlation with root growth irrespective of root density or plant age. Phosphorus uptake during a period was more closely and consistently correlated with root growth during that period than with the total amount of root on the plant. The results can be explained in terms of ion supply to the root surface, taking into account the diffusion coefficients of the ions and the approximate distances between neighbouring roots.Now Mrs. Watkins; address 39 Leach Heath Lane, Rubery, Birmingham.Now Mrs. Watkins; address 39 Leach Heath Lane, Rubery, Birmingham.