Seasonal dynamics of Bythonomus lemani and Bothrioneurum vejdovskyanum (Oligochaeta, Annelida) in relation to environmental variables

The seasonal dynamics of Bythonomus lemani (Lumbriculidae) were studied for the first time and the knowledge of Bothrioneurum vejdovskyanum (Tubificidae) was extended based on four quantitative samples of oligochaetes taken monthly in the Rokytná River (Czech Republic) during a two-year study (April 1999–April 2001). The influence of water temperature, velocity, depth, discharge, pH, conductivity, dissolved oxygen amount and biochemical oxygen demand (BOD) on their life cycles was evaluated. Habitat preferences of the juvenile and adult stages were recorded. Time series analysis was used to determine the worm densities, seasonality and trends. For Byth. lemani one distinct reproduction cycle per year was found and this was regulated by temperature, while Both. vejdovskyanum showed a one-year cycle not significantly dependent on measured environmental variables. The overall trend was an increase in density for Byth. lemani and a decrease in density for Both. vejdovskyanum. Byth. lemani showed a significant negative correlation between the trend of its density and BOD concentration.     

Spermiogenesis in Bythonomus lemani and the phylogenetic position of the Lumbriculidae (Oligochaeta,Annelida)

Spermiohistogenesis and spermatozoal morphology of the lumbriculid Bythonomus lemani have been investigated by means of electron microscopy. Though spermiohistogenetic events follow the general microdrile pattern, some features are peculiar: chromatin is clumped in the first stages and its condensation is very irregular, as in Eisenia. Manchette geometry is similar to that of hirudineans, as the microtubules are helically arranged from the very early stages. A number of mitochondria are always present in the collar region.The mature sperm also departs from the microdrile model and is more similar to the megadrile one in (1) the strong withdrawal of the base of the acrosome vesicle into the acrosome tube; (2) the apparent development of rudimentary connectives. On the other hand, some features seem to be unique among oligochaetes, including the inclined longitudinal axis of the axial rod and tilted anterior end of the nucleus.Spermatologically, lumbriculids may be interpreted as advanced microdriles which may be descended from a stock which also gave rise to Haplotaxidae, Moniligastridae, and the true Opisthopores.     

Specific patterns of excavation in isolated ants

Summary The tunnels dug by isolated worker ants [Myrmica ruginodis Nylander,M. scabrinodis Nylander,Formica lemani Bondroit,F. fusca L. andLasius niger (L.)] have been studied photographically. Although there was much variation within species, certain interspecific differences in tunnel shape appeared. The tunnels ofL. niger are more spreading, longer and more convoluted than those of the other species, and often branch beneath the surface. The tunnels ofM. scabrinodis show the same features to a smaller degree. The tunnels ofF. fusca andF. lemani are straight, unbranched and vertical.

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Résumé Nous avons étudié par un moyen photographique les tunnels que creusent les ouvrières isolées deMyrmica ruginodis Nyl.,M. scabrinodis Nyl.,Formica fusca L.,F. lemani Bondroit etLasius niger (L.). Quoiqu'il y ait une variation intraspécifique très importante, nous avons constaté plusieurs différences entre ces espèces. Les tunnels deL. niger sont plus longs, plus ramifiés et moins rectilignes que chez les autres espèces. Les tunnels deM. scabrinodis montrent les mêmes caractéristiques, mais d'une façon moins prononcée. Les tunnels deFormica fusca etF. lemani sont plus on moins verticaux et rectilignes et ne se divisent pas.

     

The response of digging ants to gravity

Summary Workers ofFormica lemani, confined in a cavity surrounded above and below by sand, showed a significant tendency to dig upwards. This orientation persisted in darkness and disappeared if the dishes were rotated about a horizontal axis.When workers ofFormica lemani andMyrmica ruginodis were placed on a sand surface in apparatus which was rocked slowly –30° to each side of vertical in the dark, their tunnels showed changes in hourly alinement which regressed significantly on the angle of the apparatus to the vertical. The regression appeared to be more important inF. lemani than inM. ruginodis. Workers ofLasius niger failed to show a significant regression.The variance of the hourly inclination of tunnels in rocked experiments was significantly greater than that in control experiments (not rocked) inF. lemani andM. ruginodis, but not inL. niger. These differences dissappeared when the variance due to regression on rocking was eliminated.The total variance in hourly inclination was significantly greater inLasius niger than in the other two species and the within-ants variance was also significantly greater inF. lemani than inM. ruginodis.

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Zusammenfassung Arbeiterinnen vonFormica lemani Bondroit, in einer Hohle oben und unten von Sand beschrankt, graben vorzuglich aufwarts. Diese Steurung kommt im Dunkel noch vor; wenn man die Sandteller langsam um eine waagerechte Achse drehe, die Steurung verschwindet.Arbeiterinnen vonF. lemani undMyrmica longinodis Nylander auf Sandoberflache in einem langsam durch 60° hin und her schwingenden Apparat graben in wechselnden Richtungen, die vom Winkel zwischen Apparat und Senkrecht abhangen. Diese Regression scheint wichtiger beiF. lemani als beiM. ruginodis zu sein. Also besetzen grabende Arbeiterinnen dieser beiden Arten eine Schwerkraftorientierung. BeiLasius niger gibt es keine Regression und deswegen auch keine Schwerkraftorientierung.Die Varianz der Neigungen der Tunnels in Schwingversuchen ist grösser als die in ungeschwungenen Controlversuchen beiF. lemani undM. ruginodis; beiL. niger dementgegen, nicht. Diese Unterschiednissen verschwinden wenn man die Regressionvarianz ausnehme.Die Gesamtvarianz ist grösser beiL. niger als bei die anderen Arten.

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Résumé Les ouvrières de la fourmiFormica lemani Bondroit, confinées dans du sable placé aussi bien au-dessus qu'au-dessous, creusent toujours dans un sens ascensionnel. Cette orientation persiste en pleine obscurité, mais disparaît lorsqu'on fait tourner les boîtes de sable autour de leur axe horizontal.Des ouvrières deF. lemani et deMyrmica ruginodis Nylander, placées sur une surface de sable qui oscille de 60° à gauche et à droite, montrent des changements d'alignement des tunnels qui dépendent de l'angle entre l'appareil et la verticale. Cette régression est plus importante chezF. lemani queM. ruginodis. Les ouvrières qui creusent possèdent alors une orientation à la pesanteur. ChezLasius niger (L.), par contre, la régression (et par conséquent l'orientation) manque.La variance de l'inclinaison des tunnesl est réduite dans des expériences de contrôle non oscillées, par comparaison aux expériences oscillées, chezF. lemani etM. ruginodis. Ces différences disparaissent quand on élimine la variance due à la régression. ChezL. niger, les deux expéreinces ne diffèrent pas.La variance totale de l'inclinaison est plus grande chezL. niger que chez les deux autres espèces. Ceci confirme ce qui a été constaté dans les travaux précédents.

     

Temporal and spatial patterns of foraging in two syntopic ant species,Manica yessensis and Formica lemani,on Mount Fuji,Japan

Spatiotemporal characteristics of terrestrial foraging were studied in two ant species, Manica yessensis and Formica lemani, in a volcanic desert on the southeast slope of Mount Fuji, Gotenba, Japan. Both ants are common in this habitat, and they construct underground nests in this dry area with sparse vegetation. Nests of M. yessensis have multiple nest-openings on the surface, whereas nests of F. lemani have very few openings, but their nesting and foraging areas overlap completely. A “mark-and-observe” method applied to M. yessensis demonstrated that worker ants of this species move between openings more than 3 m away. A study plot (6 m × 12 m quadrat) was set up, in which all nest-openings of both species were mapped. Day-long observations on numbers of foragers in this plot revealed that foraging M. yessensis are active in morning and evening, while F. lemani continues foraging all day, but both species cease activity at night. Associations between locations of foragers and nest-openings differed significantly between the two species, that is, surface foraging of M. yessensis workers was largely confined to the vicinity of their nest-openings, whereas foragers of F. lemani travelled far from their nest-openings. The function of multiple nest-openings in M. yessensis is discussed.     

Nuclear reassembly in vitro is independent of nucleosome/chromatin assembly

It was show11 that nuclear reassembly was induced by small pieces of DNA fragments in cell-free extracts ofXenopus. In an attempt to learn the relationship between the nuclear reassembly and nucleosome/chromatin assembly, limited amounts of CM-Cellulose are used to eliminate the capacity of the egg extract S-150 to assemble chromatin. while the forming of nucleosomes is checked with DNA supercoiling by plasmid DNA pBR322 incubated in the extract, and further analysed by micrococcal nuclease digestion. This depleted extract is then used to induce nuclear reassembly around demembraned sperms with membrane vesicles. It is found that CM-Cellulose depletes histones H2A and H2B efficiently and blocks the assembly of nucleosomes, the demembraned sperms are yet reconstituted into nuclei in the treated S-150, although the chromatin in reassembled nuclei does not produce protected DNA fragments when digested with micrococcal nuclease. It suggests that in the cell-free system ofXenopus, DNA can be formed into nuclei without assembly of nucleosomes or chromatin. Projrrt supported by the National Natural Science Foundation of China (Grant No. 39730240)     

An autoradiographic study of RNA synthesis during maturation and germination of pollen grains ofHyoscyamus niger

Summary The pattern of RNA synthesis during maturation and germination of pollen grains ofHyoscyamus niger was studied using³H-uridine autoradiography. Incorporation of label during pollen maturation was periodic with peak RNA synthesis occurring in the uninucleate, nonvacuolate pollen grains and in the vegetative cell of the bicellular pollen grains. During the early stages of germination, isotope incorporation occurred predominantly in the nucleus of the vegetative cell with little or no incorporation in the generative cell. With the appearance of the pollen tube, incorporation of³H-uridine in the vegetative cell nucleus decreased and completely disappeared at later stages of germination. No incorporation of isotope was observed in the sperms formed in the pollen tube by the division of the generative cell. From a comparison of the results of this study with those of previous works on RNA synthesis during pollen embryogenesis in cultured anthers ofH. niger, it is concluded that in contrast to embryogenic development, there is no requirement for sustained RNA synthesis by the generative cell nucleus for normal gametophytic development.     

Larval development of two species of barracuda,Sphyraena guachancho andS. tome (Teleostei: Sphyraenidae), from southeastern Brazil

Morphological development of barracudas (Sphyraena guachancho andS. tome) is described, based on larval and juvenile specimens collected in the southeast Brazilian Bight. Preflexion larvae of the two species are similar, butS. tome larvae can be distinguished from those ofS. guachancho by having small melanophores on the midbrain and a row of melanophores along the ventral midline of the lower jaw and isthmus. Flexion and postflexion larvae ofS. tome are more slender than those ofS. guachancho. Morphology and pigment patterns ofS. tome are similar to those ofS. borealis from the north Atlantic. whereasS. guachancho larvae are similar toS. barracuda in having a fusiform body, advanced position of the pelvic fins and a heavily pigmented tail region, but differ in having a fleshy tip on the lower jaw in postflexion and juvenile stages.     

Egg Recognition and Social Parasitism in Formica Ants

Nests of social insects are an attractive resource in terms of nutrition and shelter and therefore targeted by a variety of pathogens and parasites that harness the resources of a host colony in their own reproductive interests. Colonies of the ants Formica fusca and F. lemani serve as hosts for mound‐building Formica species, the queens of which use host colonies during colony founding. Here, we investigate whether workers of the host species can mitigate the costs imposed on them by invading parasite queens by recognizing and selectively removing eggs laid by these queens. We used behavioural assays, allowing host workers to choose between con‐colonial eggs and eggs laid by the parasite species F. truncorum. We show that workers of both host species discriminate between the two types of eggs in favour of con‐colonial eggs. Moreover, workers of F. fusca rejected more con‐colonial eggs than F. lemani. This higher rate of error in F. fusca may reflect a greater selectivity or a greater difficulty in discriminating between the two egg types. Nevertheless, both host species removed parasite eggs at a similar rate, when these were artificially introduced into the colonies, although some eggs remained after 10 d. In addition, upon receiving parasite eggs, host workers started to lay unfertilized male‐destined eggs within 6 d, thus employing an alternative pathway to gain direct fitness when the resident queen is no longer present and the colony is parasitized.     

Chemical examinations of some non-vascular Paleozoic plants

The organic chemical constituents of compression fossils ofNematothallus,Spongiophyton, Orestovia andEohostimella are identified and compared with those isolated from living and fossil forms ofBotryococcus (a green alga) andTaeniocrada (a vascular plant fossil). The range and maxima in the carbon numbers observed in the normal, saturated acids isolated fromNematothallus, Orestovia, andSpongiophyton are similar to those of fossilBotryococcus, while those acids contained within compression fossils ofEohostimella are similar to the hydrocarbon composition ofTaeniocrada. Isoprenoid, branched hydrocarbons and steroids identified fromNematothallus, Orestovia, andSpongiophyton suggest these genera have algal affinities, while the presence of thick cuticles and in some cases cutin-like compounds appear to show adaptation to a terrestrial environment. Phenolic compounds retained within rock matrices associated withEohostimella are similar to those isolated fromTaeniocrada suggesting chemical, as well as morphological parallels with the land plant habit. These data are interpreted as indicating an early polyphyletic exploitation of the terrestrial habitat during the Paleozoic.     

Comparative study of musculature in goldon monkey (Rhinopithecus)

Some differences between the muscular system of three species of golden monkeys were shown. The major features of the myology in these animals, besides that ofCercopithecoidea, are similar to the anthropoid apes and humans. Although most of the features between taxa of golden monkeys are largely homologous, there are also some differences. Our results differ slightly from thosePatterson (1942) obtained inR. roxellanae. Some conclusions reported by Patterson were obviously incorrect, since the specimen he used did not have a head. Many mylogical characters are similar to other species ofCercopithecoidea while some resemble those of apes. Many are similar to those of the leaf monkey, though some of them show much more development. The golden monkey is more advanced than any other species ofCercopithecoidea. We hypothesize that in terms of the myological characters the golden monkeys seem to occupy a position between the leaf monkeys and the apes.     

The cytochromec oxidase from the yeastCandida parapsilosis

In the yeastCandida parapsilosis, the proteins encoded by mitochondrial DNA are different in number and size from those ofSaccharomyces cerevisiae. Nevertheless, the purified cytochromec oxidase fromCandida parapsilosis shows kinetic properties similar to those ofSaccharomyces cerevisiae.     

Morphological and ultrastructural aspects of Branchiobdella pentodonta Whit. (Annelida,oligochaeta) suckers

The muscular system in the posterior sucker of Branchiobdella pentodonta Whit. has circular, longitudinal and radial fibers. In the anterior sucker, which has circular and longitudinal fibers, the muscle system is scarce. Concentric fibers are found around the mouth. In both suckers the glandular elements form voluminous complexes secreting mucus for attachment to the substrate. Suckers show neuromuscular junctions and three distinct types of neuroglandular junctions: one with typical neurosecretory granules, one with larger neurosecretory granules produced by cells located at the origin of the segmental nerves, and one with presynaptic vesicles. The second type is peculiar to the posterior sucker. A comparison is made between suckers of Branchiobdella and those of leeches.     

Indopithecus giganteus distinct fromSivapithecus indicus

The very large Eurasian Miocene apeIndopithecus giganteus is distinct from contemporaniousSivapithecus (non-Dryopithecus)indicus. The probabilities that length and width for the only specimen ofI. giganteus could be sampled from populations similar or identical to those ofS. indicus are less than six chances in 100,000 for both parameters.     

CELL WALL CHEMISTRY AND ULTRASTRUCTURE OF CHLOROCOCCUM OLEOFACIENS (CHLOROPHYCEAE)1,2

Cell walls of Chlorococcum oleofadens Trainor & Bold were examined ultrastructurally and chemically. The wall of zoospores has a uniform 30 nm width and a regular lamellar pattern. Zoospores and young vegetative cell walk exhibit periodicities, consisting of 20 nm ridges on the outer layer. Vegetative cell walls have a variable thickness of Up to 800 nm and are composed of multiple layers of electron dense material. Further, vegetative walk contain a microfibrillar material composed predominantly of glucose and presumed to be cellulose. Except for this cellulose, vegetative cell wall chemistry is very similar to that of Chlamydomemas being composed of glycoprotein rich in hydroxyproline. The hydroxyproline in Chlorococcum walls is linked glycosidically to a mixture of hetrooligosaccharides composed of arabinose and galactose, and in one instance, an unknown 6-deoxyhexose. Altogether, the glycoprotein complex accounts for at least 52% of the wall. The amino acid composition of the walls is stikingly similar to those of widely different plant species. Indirect evidence indicates zoospore cell walls are also chemically similar to those of Chlamydomonas, and like them, are cellulose free. Thus a major chemical difference between zoospore and vegetative cell walk of Chlorococcum is the presence of cellulose in the latter. The contribution of this microfibrillar cellulose to the physical properties of the vegetative wall is discussed.     

Laboratory culture and taxonomy of two species ofPedobesia (Bryopsidales,Chlorophyceae) in Japan

The morphology ofPedobesia lamourouxii andDerbesia ryukyuensis, both collected in Shimoda and the adjacent areas in central Japan, was studied from field specimens and laboratory cultures. Specimens which had the same morphology as EuropeanP. lamourouxii produced stephanokont zoospores which developed into either prostrate filaments or expanded discoidal thalli similar to those described by Feldmann and Codomier (1974) and Feldmannet al. (1975). Erect filament identical with the thallus found in nature developed directly from prostrate filaments. The specimens which had morphology similar to that ofDerbesia ryukyuensis described by Yamada and Tanaka (1938) also produced stephanokont zoospores which developed similarly to those ofP. lamourouxii. This species is, therefore, a member ofPedobesia, and it is made a new combinationP. ryukyuensis (Yamada et Tanaka) Kobara et Chihara, comb. nov.     

Ant predation ofEriocrania miners in a polluted area

We tested the hypothesis that air pollution may affect population densities of birch-feeding leafminers via changes in ant predation. Foraging activity of three ant species (Formica rufa, F. fusca andF. lemani), predation rates and population densities of both solitary and gregariousEriocrania (Lepidoptera: Eriocraniidae) miners were investigated at 13 sites around the Harjavalta copper-nickel smelter, SW Finland. Ant species differed in their distribution patterns relative to pollution. However, the total percentage of birch trees foraged by ants (all species combined) showed no correlation with the distance from the factory complex. As a result, no clear trends in predation rates were apparent in relation to the distance from the pollution source for either solitary or gregariousEriocrania species. Densities of the solitaryEriocrania species tended to increase with the distance from the pollution source whereas densities of the gregariousE. haworthi peaked close to the factory complex. No corresponding differences in predation rates between solitary and gregarious miners were found. Ant predation, thus, did not explain density patterns ofEriocrania miners in the polluted area.     

Distribution of similar self-incompatibility (<Emphasis Type="Italic">S</Emphasis>) haplotypes in different genera,<Emphasis Type="Italic"> Raphanus</Emphasis> and<Emphasis Type="Italic"> Brassica</Emphasis>

The nucleotide sequences of ten SP11 and nine SRK alleles in Raphanus sativus were determined, and deduced amino acid sequences were compared with those of Brassica SP11 and SRK. The amino acid sequence identity of class-I SP11s in R. sativus was about 30% on average, the highest being 52.2%, while that of the S domain of class-I SRK was 77.0% on average and ranged from 70.8% to 83.9%. These values were comparable to those of SP11 and SRK in Brassica oleracea and B. rapa. SP11 of R. sativus S-21 was found to be highly similar to SP11 of B. rapa S-9 (89.5% amino acid identity), and SRK of R. sativus S-21 was similar to SRK of B. rapa S-9 (91.0%). SP11 and SRK of R. sativus S-19 were also similar to SP11 and SRK of B. oleracea S-20, respectively. These similarities of both SP11 and SRK alleles between R. sativus and Brassica suggest that these S haplotype pairs originated from the same ancestral S haplotypes.     

Size variation in the postcranium ofAustralopithecus afarensis and extant species of hominoidea

The postcranial sample ofA. afarensis can be divided into two size groups. Among the best preserved elements which are represented by both morphs are the distal femur, proximal ulna, and capitate. The difference between the large and small fossil femora is similar to the difference between average male and femaleG. gorilla andP. pygmaeus. The distal femora ofH. sapiens are less sexually dimorphic while those ofP. paniscus, P. troglodytes, andH. lar are not significantly dimorphic at all. Large and small capitates and proximal ulnae ofA. afarensis differ slightly more than the highly dimorphic species of extant Hominoidea. In my sample of Amerindians, the capitate and proximal ulna are also strongly dimorphic. The two species ofPan have insignificant sexual dimorphism in these traits. There results imply that strong sexual dimorphism in body size is the primitive condition for the large bodied hominoids.     

Observations on gymnoascaceae. IX. A new species of pseudoarachniotus from soil-burial beds

Summary A new species ofPseudoarachniotus P. marginosporus, is described and illustrated. The developmental morphology of this new ascomycete is discussed. On a standard medium such as YpSs,P. marginosporus can be distinguished from other species of the genus by colonial coloration which varies from ochre-rust to very pale yellow at different stages of maturation. The colony ofP. roseus is red, red-orange or orange-yellow;P. citrinus is lemon yellow to brownish yellow in age;P. reticulatus is red orange andP. hyalinosporus is yellowish and usually with a great deal of green pigmentation in the mycelium and in the medium. Furthermore ascospores ofP. marginosporus are oblate, small and thin-walled, measuring 2.2–3.0×4.0–4.4 µ, with a minute elevated rim around the long axis, while ascospores ofP. reticulatus are globose and reticulate, and those ofP. roseus andP. citrinus are large and thick-walled, measuring about 4.4×7.7 µ. Ascospores ofP. hyalinosporus are similar in size and shape to those ofP. marginosporus, but lack a rim or other markings.