bluuebunny/crossref_metadata_2025 huggingface dataset:
Territoriality, density, and prey of the lion in Ngorongoro Crater, Tanzania
Authors: Elliott John P. , Cowan I. McTaggart
Published: August 2008

The population size, area of occupation, and prey consumption of the resident prides of lions at Ngorongoro Crater, Tanzania, were studied from 1970 to 1972. Each pride of lions maintained a territory, yet this sometimes differed for the two sexes. The mean pride territory was 87.5 km2 corresponding to 5 km2 per lion.Net food consumption of an adult female was 2413 kg per year, of which about one-quarter was scavenged from prey killed by hyaenas. In contrast about one-quarter of the hyaena's food was scavenged from the lions' kills (a proportion involving forcing the lions to depart).The social organization of the lions in Ngorongoro Crater appears finely tuned to the extent that with a relatively stable food supply the population of lions remained stable with low input of young, no starvation losses of young during their period with the pride, but losses to the young age-classes resulting from aggression by adults. Aggressive interaction between prides primarily involved the males and seems not to be food related.
Competition, coexistence, and survival: a computer simulation study of ostracods living in a temporary puddle
Authors: McLay C. L.
Published: August 2008

A modelling study of the population biologies of two species of ostracod (Herpetocypris reptans Baird, 1835 and Cyprinotus carolinensis Fergusson, 1958) in a temporary puddle shows that competition is mediated via density-dependent mortality and maturation rates. Herpetocypris is the superior competitor, despite its longer maturation time, because it is better able to withstand crowding and the stress of food shortage. In addition, the structure of the habitat and periodic freezing are shown to play important roles in maintaining spatial separation of the species. The simulation model shows that Herpetocypris is dominant over Cyprinotus by a factor of 7:1 and this reduces the possibility of environmental instability favouring coexistence. Competitive exclusion of Cyprinotus by Herpetocypris is prevented by periodic freezing of part of the puddle which destroys all the ostracods, but harms population growth of Herpetocypris more than that of Cyprinotus.
Autumnal migration routes of the eastern population of the monarch butterfly (Danaus p. plexippus L.; Danaidae; Lepidoptera) in North America to the overwintering site in the Neovolcanic Plateau of Mexico
Authors: Urquhart F. A. , Urquhart N. R.
Published: August 2008

Based upon numerous recaptures of alar-tagged migrating monarch butterflies, together with extensive field expeditions through various parts of North and Central America, the migrating routes of monarchs have been plotted with considerable accuracy.Five overwintering areas have been defined representing 13 loci of concentrations, in the Neovolcanic Plateau of Mexico.It appears that migrants from the breeding areas of the Great Plains region overwinter in the western mountains of Mexico and those from breeding areas east of the Great Plains region overwinter in the eastern mountains. The greatest concentration occurs in the central mountains and represents migrations from parts of the Great Plains regions and parts of the eastern regions.
Responses of dauerlarvae of Caenorhabditis elegans (Nematoda: Rhabditidae) to thermal stress and oxygen deprivation
Authors: Anderson Gary L.
Published: August 2008

Larval forms of the free-living nematode Caenorhabditis elegans possess the ability to enter a developmental stage which is thought to be specialized for survival in harsh environmental conditions, i.e. the dauerlarval stage. In this study the responses of dauerlarvae to thermal stress and oxygen deprivation are investigated. Oxygen consumption of dauerlarvae is less sensitive to temperature change that that of adults, with Q10 values of 1.7 and 2.6 respectively. The upper thermal tolerance limit of dauerlarvae is also different from that of adults; dauerlarvae survive approximately three times longer than adults when exposed to 37 °C. In addition to differences in thermal tolerance, dauerlarvae survive longer under anaerobic conditions than adults, 7 days and 2 days respectively. On recovery from anaerobic stress dauerlarvae exhibit behavior changes which are suggestive of emergence from the dauerlarval stage. The responses of dauerlarvae to thermal stress and oxygen deprivation appear to be important aspects of the specialization for survival in this facultative developmental stage.
The effects of constant and variable temperatures on the size, growth, and reproduction of the freshwater amphipod Hyalella azteca (Saussure)
Authors: March B. G. E. de
Published: August 2008

In a study done on one laboratory population of Hyalella azteca, the size at maturity of both males and females was determined to be dependent on temperatures during development. Temperatures of 10 and 15 °C produced relatively large animals and also delayed reproductive development. Temperatures of 20–23 °C produced relatively small animals, while 18 °C produced animals of intermediate size. The temperatures to which the ovum and embryo were exposed were most strongly related to maturation sizes.The time to reach maturity and the embryonic development time were inversely correlated with temperature in animals reared at constant temperatures. The maturation times were longer than expected if early development occurred at lower temperatures, and shorter if early development occurred at higher temperatures.These laboratory results are discussed with respect to the natural size variation and its adaptive advantage in H. azteca and other related taxa.
The nymphal development of Paraleptophlebia adoptiva (McDunnough) and Paraleptophlebia mollis (Eaton) (Ephemeroptera: Leptophlebiidae) and the possible influence of temperature
Authors: Corkum Lynda D.
Published: August 2008

Nymphal development of Paraleptophlebia adoptiva (McDunnough) and Paraleptophlebia mollis (Eaton) was studied in the West and East branches of the Credit River, Peel County, Ontario. Nymphs of P. adoptiva were found only in the cooler water of the West branch; they continued to grow during winter months and had a short emergence period in mid-May. Paraleptophlebia mollis nymphs occurred in both branches, nymphs in the West branch being significantly smaller than those of the East. No growth was observed for P. mollis nymphs in winter and a protracted emergence period for this species throughout June was evident. Both mayfly species are univoltine.
Observations on helminth parasites of the spectacled eider, Somateria fischeri (Brandt), in Alaska
Authors: Dau Christian P.
Published: August 2008

Data concerning the occurrence and species diversity of helminth parasites in a sample of 11 spectacled eiders from the Yukon–Kuskokwim Delta, Alaska, are presented. Differences in helminth species diversity and intensity of infections were encountered between adult males and females. Adult males and young of the year were host to the greatest variety of species and in most cases total helminths. Helminth parasitism in the spectacled eider may be a compounding factor in the mortality of young birds after departure from the nesting grounds.
A systematic review of the fish genus Lycodapus (Zoarcidae) with descriptions of two new species
Authors: Peden Alex E. , Anderson M. Eric
Published: August 2008

Six of 11 nominal species of Lycodapus, L. australis Norman, L. derjugini Andriashev, L. dermatinus Gilbert, L. fierasfer Gilbert, L. mandibularis Gilbert, and L. parviceps Gilbert, are recognized. Original descriptions and the disintegrated type do not permit adequate diagnosis of L. extensus Gilbert, which we treat as a nomen dubium. The holotype of L. microchir Schmidt must be reexamined before the status of this nominal species can be assessed. We describe L. endemoscotus n.sp. and L. pachysoma n.sp. off the west coast of North America and another population of L. pachysoma from the Antarctic. The species of Lycodapus form two natural groupings. Long gill rakers and a tendency toward fewer preoperculomandibular head pores characterize L. australis, L. derjugini, L. dermatinus, and L. fierasfer. Short gill rakers, single interorbital pore, and more preoperculomandibular pores typify the remaining species of which L. endemoscotus, L. mandibularis, L. pachysoma, and another undescribed species from the Antarctic possess broad, stout rakers. Very reduced rakers indicate L. parviceps as the most differentiated of the short-rakered species. Descriptions, spot distribution maps, synonymies, and illustrations are provided for all named valid species.
Scanning electron microscopy: a direct method of identifying pollen grains on moths (Noctuidae: Lepidoptera)
Authors: Turnock W. J. , Chong J. , Luit B.
Published: August 2008

A simple method of using scanning electron microscopy to observe pollen grains in situ on feral moths (Noctuidae) is described. This method does not require freeze drying, critical point drying, or any chemical fixation procedures to prepare the specimens for scanning. Pollen grains were found mainly on the proboscises of the moths and can be identified directly from the scanning electron micrographs, thus expediting the study of moth–plant relations.
Avian Haemoproteidae. 9. Description of Haemoproteus stellaris n.sp. and a review of the haemoproteids of the swallow family Hirundinidae
Authors: White Ellen M. , Bennett Gordon F.
Published: August 2008

The haemoproteids of the family Hirundinidae are reviewed. Haemoproteus stellaris n.sp., a haemoproteid with extremely large pigment granules arranged in a distinctive pattern, is described. Haemoproteus prognei Coatney and Roudabush, 1937 is redescribed. The statuses of Haemoproteus hirundinis (Sergent and Sergent, 1905) emend. Levine and Campbell, 1971 and Haemoproteus chelidonis Franchini, 1922 are reviewed; H. hirundinis is considered a valid species but H. chelidonis is considered to be a species inquirenda.
Dauerlarvae of Pelodera strongyloides (Schneider, 1860) (Nematoda: Rhabditidae) in the conjunctival sacs of lemmings
Authors: Cliff G. M. , Anderson R. C. , Mallory F. F.
Published: August 2008

Dauerlarvae of Pelodera strongyloides (Schneider, 1860) Schneider, 1866 were found for the first time in the conjunctival sacs of Dicrostonyx groenlandicus (Traill) and Lemmus trimucronatus (Richardson). Prevalence of dauerlarvae was significantly higher in D. groenlandicus than in L. trimucronatus. The larvae were cultured and populations of P. strongyloides were obtained. Dauerlarvae obtained from the cultures were transmitted to various rodents in the laboratory. Larvae remained in the conjunctival sac for a maximum of 5 days. They had no apparent effect on rodents and were not morphologically different from those reared on agar.
Effects of experimental vitamin E deprivation in the harp seal, Phoca groenlandica
Authors: Engelhardt F. R. , Geraci J. R.
Published: August 2008

Captive harp seals, Phoca groenlandica, were fed a diet of herring with no vitamin E supplement for 18 months and were examined for abnormalities which might be attributable to a lack of the vitamin. Vitamin deficiency was based on clinical, physiological, and biochemical parameters. All of the deprived seals showed decreased plasma vitamin E concentrations, as well as evidence of electrolyte imbalance characterized by low plasma sodium levels. Vitamin E deprivation also led to abnormal molting patterns, characterized by incomplete and irregular cycles.
Field studies of the sensory basis of homing and orientation to the home site in Ulvaria subbifurcata (Pisces: Stichaeidae)
Authors: Goff Gregory P. , Green John M.
Published: August 2008

The roles of olfaction and vision in the homing behaviour and orientation to a home site in Ulvaria subbifurcata were investigated. These were examined by studying the home-site fidelity and the homing performance of normal, blind, and anosmic fish and the orientation to the home site of normal and sensory-impaired fish. The orientation and homing experiments indicated that olfactory contact with the home site is involved in the steering mechanism in homing. The home-site fidelity of anosmic fish, and the fact that some anosmic fish homed, indicated that vision may also be involved in the recognition of a restricted area around the home site.
A pulsed-removal experiment on the vole Microtus townsendii
Authors: Krebs Charles J. , Redfield James A. , Taitt Mary J.
Published: August 2008

A grassland population of Microtus townsendii was subjected to an alternating sequence of 1 month total removal and 2 months mark and release for 2 years. The demographic performance and aggressive behaviour of voles from this pulsed-removal area were compared with those of voles from an adjacent control population. The population on the pulsed-removal area increased rapidly from immigration at all times of the year, regardless of whether the control population was increasing or declining. Voles that colonized the pulsed-removal area were able to breed and survive as well as, or better than, voles from the control population. Males and females from the pulsed-removal area showed more submissive behaviour when fought in a neutral arena against resident control animals. The subordinate behaviour pattern of pulsed-removal colonists was detectable in voles tested 6–8 weeks after colonization. Thus we have satisfied two necessary conditions to show that spacing behaviour limits the breeding population of this vole: surplus, nonbreeding voles exist in large numbers at all times and can reproduce successfully when the dominant animals are removed.
Characterization in vitro of H+ secretion and H+:Na+ exchange by an organism normally inhabiting a CO2-rich environment: Hymenolepis diminuta (Cestoda) in the rat intestine
Authors: Podesta R. B.
Published: August 2008

H+ and Na+ transport by the intestinal parasite Hymenolepis diminuta were studied in vitro. The flatworms acidified the ambient fluid by secreting H+ and the acidification could not be correlated with organic acid excretion. Ambient CO2-independent H+ secretion was attributed to protons of metabolic origin: dephosphorylation reactions and ionization of organic acids within the tissues. Ambient CO2-dependent H+ secretion was attributed to protons produced as a result of the hydration of CO2 within the tissue and to the stimulation of anaerobic metabolic pathways by CO2 acting as a cosubstrate in energy metabolism. Studies in which Na+ uptake was stimulated by CO2 or glucose and inhibited by ouabain, amiloride, or Na+ replacement suggested a partial direct coupling of Na+ absorption and H+ secretion but the different activation energies and the effect of buffer anions other than HCO3− suggested an indirect interaction. Various interactions were considered, including the effect of CO2 and intracellular ion concentrations on metabolic reactions leading to the supply of protons for H+ secretion and energy for ion transport.
Ration digestion and retention times of digesta in domestic cattle (Bos taurus), American bison (Bison bison), and Tibetan yak (Bos grunniens)
Authors: Schaefer A. L. , Young B. A. , Chimwano A. M.
Published: August 2008

Digestive functions, digesta retention times, and plasma thyroid hormone concentrations were measured in three species of Bovidae: domestic cattle (Bos taurus; three breeds), American bison (Bison bison), and Tibetan yak (Bos grunniens), fed a pelleted ration (nitrogen, 2.62%) at a near maintenance level. Apparent digestibilities of dry matter, energy, and nitrogen components of the ration were not significantly different among animal groups except for one breed of cattle (Holstein–Friesian) which had higher dry matter and energy digestibilities than all the other animal groups and a higher nitrogen digestibility than the other breeds of cattle. Nitrogen disappearance from the gastrointestinal tract (apparent absorption) per 100 g of dry matter digested was greater in the bison and yak than in the cattle, and mean retention time of digesta in the gastrointestinal tract was 65–69 h in the cattle, compared with 79 and 78 h in the bison and yak, respectively. The longer total retention time of digesta in the bison and yak may account in part for their apparent improved nitrogen economy and greater ability to digest fibrous feed material.
Effects of ergocryptine, prolactin, and growth hormone on survival and ion regulation in rainbow trout, Salmo gairdneri
Authors: Brewer K. J. , McKeown B. A.
Published: August 2008

Ergocryptine, an ergot alkaloid that suppresses prolactin (PRL) secretion and also affects growth hormone (GH) levels in mammals, was injected into juvenile rainbow trout, Salmo gairdneri, averaging 8 to 31 g. In fresh water the drug caused few fatalities but lowered plasma Na+, plasma Ca2+, muscle K+, muscle Mg2+, and haematocrit values. The simultaneous injection of low doses of PRL or GH did not significantly modify the results obtained with the drug alone except for an increase in muscle Mg2+ levels. This suggests a possible peripheral action of the drug.Ergocryptine caused the death of S. gairdneri in dilute sea water, while in certain circumstances PRL and GH prevented mortalities. In this medium the drug caused elevated levels of plasma Ca2+ and muscle K+. The simultaneous injection of ergocryptine plus PRL in hyperosmotic media produced an elevated plasma Na+ concentration but a decrease in intracellular Na+ content and concentration.The results suggest that PRL is not critical for the survival of S. gairdneri in fresh water but may still be necessary to maintain body ion concentrations. In hyperosmotic media, however, PRL and GH may be essential for survival and may act on general metabolic processes rather than specific osmoregulatory organs.
Observations on behavior and ecology in an Australian turtle, Chelodina expansa (Testudines: Chelidae)
Authors: Legler John M.
Published: August 2008

Observations of natural populations and captives over a period of 6 years provide preliminary information on the ecology of a poorly known and secretive species. Included are observations on habitat partitioning in small pools where two other chelid species occur and notes on the carnivorous diet and manner of feeding. Head bobbing and self-grooming behavior are described.
Bothriocephalus cuspidatus Cooper, 1917 (Cestoda: Bothriocephalidae) in Dorosoma cepedianum from two Illinois lakes
Authors: Jilek Reid , Price Robert
Published: August 2008

Adult pseudophyllidean tapeworms, Bothriocephalus cuspidatus, were recovered from the intestines of three gizzard shad, Dorosoma cepedianum, collected from two Illinois lakes, Crab Orchard and Carlyle. This represents a new host record.
On some freshwater ostracod type specimens from Indonesia
Authors: Victor Reginald , Fernando C. H.
Published: August 2008

The type specimens of Indonesian freshwater ostracods Cypris weberi, Cypris odiosa, Cyprinotus pyxidatus, and Cypris sarsi (Meniez, 1892) are reexamined. The first three species are reassigned as Strandesia weberi, Strandesia odiosa, and Hemicypris pyxidata. Lectotypes and paralectotypes are designated for these species. The type specimen lot of Cypris sarsi was found to contain two species: Cypretta globosa (Brady) 1886 and Cypretta cf. globula (Sars) 1889. The taxonomic problems are considered in detail. Additional descriptions, illustrations, and notes on distribution are provided.
Some aspects of reproduction in the vole Microtus townsendii
Authors: Anderson Judith L. , Boonstra Rudy
Published: August 2008

Changes in various reproductive parameters have pronounced effects on microtine population fluctuations. This study presents a detailed account of reproduction in Microtus townsendii. Populations in two areas were studied. On Westham Island, litter size, estimated by autopsy, was correlated positively with weight. There was no significant difference in litter size between primiparous and multiparous females. Females pregnant in spring had more embryos than those pregnant in summer or fall. Breeding was concentrated in spring and summer, with most females continuously pregnant.In the University of British Columbia Research Forest, litter size at recruitment was found to be unrelated to parity, size, or LAP genotype of the mother. While the size of consecutive litters (determined by autopsy) was significantly repeatable within an individual mother, recruitment litter size was not. Autopsy litter size, as at Westham Island, was largest in spring, but recruitment litter size was largest in autumn. Entire litters were lost most often during winter and summer. Overnight trapping may be responsible for loss of some litters at or just before parturition. Litters born in traps were usually unsuccessful, but otherwise mothers of totally unsuccessful litters seemed to avoid traps. Neither parity nor LAP genotype was related to the loss of entire litters.
Seasonal patterns of body temperature and activity in free-ranging muskrats (Ondatra zibethicus)
Authors: MacArthur Robert A.
Published: August 2008

Radiotelemetry techniques were employed to study the relationship between activity and abdominal temperature (Tb) changes in free-ranging muskrats (Ondatra zibethicus). Body cooling accompanied foraging activity by adults in winter and juveniles in summer and was retarded by periodic withdrawal from water. Net Tb decline during winter foraging rarely exceeded 2 °C and was relatively independent of foraging time for excursions exceeding 40 min duration. In addition to periodic rewarming within feeding shelters, muskrats appeared to avoid hypothermia during under-ice excursions by elevating Tb prior to entering water. This elevation was maximal (mean increase = 1.2 °C) for excursions exceeding 40 min duration. Comparable increases were not observed in summer.
Seasonal population changes in Rhabdias ranae Walton, 1929 (Nematoda: Rhabdiasidae) in Rana sylvatica of Ontario
Authors: Baker M. R.
Published: August 2008

Rana sylvatica collected monthly from April to October of 1976 and 1977 in a marsh near Guelph, Ontario, were examined for the presence of Rhabdias ranae. Prevalence and intensity of infections were lowest in summer and highest in spring and early fall of both years. Many nematodes collected in late summer and early fall were subadults found in the body cavity of frogs and, therefore, this period was important for transmission. No nematodes were recovered from the body cavity of frogs in spring and few were recovered from this location in late fall. Seasonal fluctuations in size of worms indicates there was a single annual cycle of growth of worms and that there was only one or possibly two generations in frogs each year. The data indicate transmission began later in the spring of 1976 than 1977 and ceased later in the fall of 1976 than 1977. Young-of-the-year frogs acquired infections in the same summer they transformed from tadpoles. Survival of the species in Ontario is dependent on adult nematodes overwintering in frogs.
Development and ultrastructure of sex-pheromone gland cells in females of the cabbage looper moth, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae)
Authors: Percy Jean
Published: August 2008

The sex-pheromone-producing gland in female Trichoplusia ni (Hübner) is a modified intersegmental membrane and the gland cells are ductless. Lipid spheres are located throughout gland cells and vary both in number and size relative to the age of the female. Most of the lipid is surrounded by oval to elongate distensions of smooth tubular endoplasmic reticulum which contain the enzyme catalase and are thus microperoxisomes. Lipid spheres evert the apical plasma membrane between microvilli, move away from the gland cells, and are stored in the cuticle as discrete lipid deposits. These deposits, in turn, move to the surface of the gland by tubular structures that differ from epicuticular filaments.
Eimeria contorta Haberkorn, 1971: a valid species of rodent coccidium?
Authors: Stockdale P. H. G. , Tiffin G. B. , Kozub G. , Chobotar B.
Published: August 2008

A culture of Eimeria contorta, a rodent species of coccidium reported to infect mice and rats was passaged through rats and mice. The oocysts subsequently recovered from these rats gave protection against E. nieschulzi. Similarly, the oocysts recovered from the mice provided protection against E. falciformis. We conclude that the original culture was a mixture of E. nieschulzi and E. falciformis though labelled E. contorka, and from these results and those of other workers we infer that E. contorta is probably not a valid species of coccidium.
Review of the genus Romanomermis (Nematoda: Mermithidae) with a description of R. communensis sp.n. from Canada
Authors: Galloway T. D. , Brust R. A.
Published: August 2008

A taxonomic review of the Romanomermis spp. parasitizing mosquitoes is presented, with a description of Romanomermis communensis sp.n. from Aedes communis (Degeer) larvae collected at Goose Creek, Manitoba. The type locality for R. communensis is identical with that of Hydromermis churchillensis Welch, 1960; however, the latter species was not found in 1974, 1975, or 1976. Consideration is given to the status of H. churchillensis.
Étude immunochimique des protéines hémolymphatiques et ovocytaires de Rhodnius prolixus (Stål.)
Authors: Chalaye D.
Published: August 2008

Haemolymph and egg proteins of Rhodnius prolixus have been investigated by immunological and electrophoretic methods. Vitellogenin, which was immunologically identical with the yolk protein, was found in egg-maturing females but also in haemolymph of fed males. Continuous gradient gel electrophoresis of egg yolk revealed two predominant proteins (proteins A and B) stained with Sudan black find periodic acid – Schiff's reagent, and the molecular weights were estimated to be 260 000 ± 20 000 (protein A) and 430 000 ± 30 000 (protein B). These two lipo-glycoproteins were also found in both male and female haemolymph. Other glycoproteins or lipoproteins were found in larvae and adult haemolymph. No vitellogenin has been identified by immunological methods in fifth-instar larvae haemolymph 5 days after feeding. However two-dimensional immunoelectrophoresis showed that the onset of synthesis of this protein in a small amount began approximately 15 days after the blood meal.
Intraerythrocytic 'gametocytes' of Babesia microti and their maturation in ticks
Authors: Rudzinska Maria A. , Spielman Andrew , Riek Russel F. , Lewengrub Sondra J. , Plesman Joseph
Published: August 2008

The electron microscopic study of several strains of Babesia microti provided evidence that this parasite has two types of organisms in the intraerythrocytic stage. In one, the trophozoites undergo differentiation and reproduce by formation of merozoites. In the other no differentiation or reproduction occurs and the parasites acquire an unusual shape. A hypothesis was put forward that the latter organisms might be gametocytes. This term has been used tentatively throughout this paper. An examination of ticks fed on hamsters' blood infected with B. microti has shown that parasites emerging from hemolyzed erythrocytes closely resemble the intraerythrocytic gametocytes in their shape. A reorganization and differentiation of the cytoplasm expressed in the appearance of new structures occurs. Among them the most striking is a complex organelle that looks like an arrowhead. Several arrowheads are found in a single gametocyte, each marking an incipient gamete. Most gametes are equipped with an arrowhead organelle, a tail, microtubules, and a cytostome. Occasionally a close apposition of two gametes and cytoplasmic fusion between the two organisms was found but it is not excluded that this might represent division. The use of the terms 'gametocyte' and 'gamete' is not yet fully justified. More evidence is needed.
Action du glutathion sur l'induction de pseudopodes et l'activité locomotrice d'Amoeba proteus
Authors: Marsot Pierre , Couillard Pierre
Published: August 2008

Amoeba proteus was exposed to physiological concentrations of glutathione (0.5 and 1 mM). We found that this molecule has an activating effect on pseudopod initiation of Amoeba immobilized at low temperature and on its locomotor activity.
Interactions between the pompilid wasp Anoplius relativus (Fox) and the burrowing wolf spider Geolycosa domifex (Hancock)
Authors: McQueen Donald J.
Published: August 2008

The interactions between populations of Geolycosa domifex (Hancock) and Anoplius relativus (Fox) were studied in southern Ontario from 1974 through 1977. The spiders required 3 years before reaching maturity and the wasp population preyed upon 2- and 3-year olds. In each year the wasps emerged near the end of June and disappeared at the end of July. During this time the wasps were able to paralyze more than 99% of the adult female spiders, but not until their eggs had hatched. Juvenile spiders minimized the effect of wasp predation by closing their burrows during the time when the wasps were present. High-speed 16-mm films (300 frames per second) were used to analyze wasp attack behaviour and spider defence. Normal-speed (18 frames per second) 8-mm film was used to analyze wasp nest-building behaviour. It is hypothesized that G. domifex and A. relativus have coevolved tactics which allow A. relativus to reproduce each year without destroying the G. domifex population.
The responses of miracidia and cercariae of Bunodera mediovitellata (Trematoda: Allocreadiidae) to light and to gravity
Authors: Kennedy Murray James
Published: August 2008

Vertical glass tubes, with various portions blackened, were illuminated by a horizontal beam of white light to determine the photoresponse and georesponse of miracidia and cercariae.Four-arm test chambers were used to determine the lowest light intensity at which miracidia and cercariae showed a phototactic response. This intensity (.0.35 lx) was the same for miracidia and cercariae even though miracidia, whose next host is a bottom-dwelling clam (Pisidium casertanum), are photonegative, and cercariae, with a bottom-dwelling caddisfly larva (Limnephilus sp.) as next host, are photopositive.Two-arm test chambers, illuminated with monochromatic light, were used to determine the wavelengths to which the larval stages were responding. Cercariae showed a single response peak at 550 nm while miracidia showed two peaks, one at 550 nm and the other at 650 nm. The second peak may be a result of a screening effect by the pigment which surrounds the photoreceptor.Miracidia showed a positive georesponse when tested in vertical test tubes. However, the negative photoresponse determined their distribution in a conflicting situation. No conclusive results were obtained when the georesponse of cercariae was tested. These larvae remained on the bottom of test chambers under all conditions.
Subcutaneous injection of small fish: radionuclide release from the injection site
Authors: Busacker Greg P. , Chavin Walter
Published: August 2008

A technique is described for the subcutaneous injection of small fish using the goldfish (Carassius auratus L.) as a model. Using radioactive tracers, (109Cd, 125I), maximum levels occur in the plasma at 4 and 16 min, with statistical plateaus evident by 2 and 4 min, respectively. The plateau level of injected material occurring in the plasma shortly after the injection exposes the tissues to a constant dose of the injected material for the duration of the plateau. In the case of 109Cd, this period is in excess of 4 h. Subcutaneous injection by this method provides low variability in delivery, rapid plasma – delivery site equilibration of the injected material, and a constant plasma level of the injected material for a significant time interval.
Breeding by Peromyscus in seasonal environments
Authors: Millar John S. , Wille F. B. , Iverson Stuart L.
Published: August 2008

Reproductive characteristics of Peromyscus maniculatus in Manitoba and Peromyscus leucopus in Ontario were compared in order to determine the extent to which breeding compensates for relatively short breeding seasons. Peromyscus maniculatus had a shorter breeding season than P. leucopus, but frequency of litters, litter size, and age of females at sexual maturity were the same for both species. A comparison of breeding characteristics among Peromyscus from different geographic areas indicated that basic reproductive characteristics do not vary in relation to length of the breeding season.In general, we have no evidence that the basic reproductive characteristics of Peromyscus vary in relation to length of the breeding season. Peromyscus with short breeding seasons, on average, must have a lower annual reproductive rate than Peromyscus with long breeding seasons.
The life history and distribution of Neomysis americana (Smith) (Crustacea, Mysidacea) in Passamaquoddy Bay
Authors: Pezzack D. S. , Corey S.
Published: August 2008

Neomysis americana in Passamaquoddy Bay produces two generations per year. Breeding occurs during the spring, summer, and early fall. Each female is capable of producing two or three broods; average brood sizes for spring and summer females were 45 and 32, respectively. Development time of eggs varied directly with temperature. The intermolt period of juveniles remained constant up to the time of the development of secondary sexual characteristics, between the eighth and ninth molts, and then increased. The life history of N. americana in Passamaquoddy Bay is compared with that in other areas.
The effects of exogenous juvenile hormone treatment on embryogenesis in Schistocerca gregaria
Authors: Injeyan H. S. , Tobe S. S. , Rapport E.
Published: August 2008

Exogenous juvenile hormone (JH) application to Schistocerca gregaria eggs interfered with normal embryogenesis in a dose- and age-dependent manner. Embryos treated between 3 to 9 days postoviposition were inhibited at (1) blastokinesis; (2) postblastokinesis; (3) as vermiform larvae; or (4) as first-instar hoppers unable to shed their provisional entitle completely. The development of 3- to 5-day-old embryos was inhibited at blastokinesis when the embryos were treated with 1 μg JH but not with 0.1 μg JH. However, sensitivity increased with age, so that 8-to 9-day-old embryos were unable to shed the provisional cuticle when treated with as low as 0.01 μg JH. Treatment of embryos later than 10 days after oviposition did not disrupt embryogenesis and did not result in postembryonic aberrations at any stage in the life cycle. Furthermore, exogenous JH treatment of developing embryos did not enhance solitarization of S. gregaria.Disruption of embryogenesis was accompanied by an increase in brown coloration of the embryos. Microscopic examination revealed an interference with the normal development of the provisional cuticle.
Intra- and inter-specific agonistic behavior among terrestrial slugs (Pulmonata: Stylommatophora)
Authors: Rollo C. David , Wellington W. G.
Published: August 2008

Intra- and inter-specific aggression among slugs varied greatly with the species. Among pugnacious species only the mature animals displayed such behavior. Aggressiveness varied seasonally, with the most fighting occurring during summer when hot, dry weather reduced the number of shelters and availability of food. No fighting occurred in winter, when formerly aggressive conspecifics frequently aggregated. Large aggressors caused smaller conspecifics as well as other species to avoid shelters they occupied. Since slugs selected shelters closest to food, agonistic behavior improved the chances of acquiring shelter and food simultaneously.
Territory regulation, tenure, and migration in rufous hummingbirds
Authors: Gass Clifton Lee
Published: August 2008

Postbreeding migrant rufous hummingbirds (Selasphorus rufus) establish feeding territories in alpine meadows. An inverse hyperbolic relationship between territory size and flower density indicates that territory size is regulated to maintain food supply: individual hummingbirds make daily adjustments in their territories. These adjustments maintain food supplies from day lo day and improve them over what they would be if no adjustments were made. The ability of individuals to maintain territory quality, however, and the length of time they remain in the meadows, is affected by their age and sex and by the level of competition for food by conspecifics. Territoriality, therefore, must be considered in relation to factors operating beyond the local food environment, both in terms of effects on and effects of the short-term dynamics of energy regulation. This has important implications for hummingbird migration.
The ultrastructure of mink (Mustela vison) spermatozoa
Authors: Kim J. W. , Kitts W. D. , Ahmad M. S. , Krishnamurti C. R.
Published: August 2008

The subcellular structure of epididymal spermatozoa obtained from standard dark mink was studied. Conventionally prepared thin sections were observed under a transmission electron microscope. The mink spermatozoan head showed six swellings on the dorsoventral aspects: two connected hump-like swellings at the anterior border of the equatorial segment of the acrosome, and one at the post acrosomal sheath on each side. These swellings are a species-specific structural feature which might be necessary for recognition of the ovum or attachment to it in fertilization. The neck appeared to show a dorsoventrally continuous but laterally separated capitulum which was followed by two major and five minor columns, forming at first a striated ring and then joining with the dense fibers of the axial fiber bundle. The dense fibers numbered 9, 1,5, and 6 were larger than the rest. In the axonemal complex, subfiber A was larger than the central fiber, while subfiber B was the smallest. The middle piece was of medium length when compared with other mammalian spermatozoa. The shape of the annulus was triangular in longitudinal sections. The occurrence of swellings anterior and posterior to the equatorial segment of the head and the arrangement of the connecting piece, the modified capitulum, and the grouping of the striated columns are some of the important features of mink spermatozoa.
Serpinema spp. (Nematoda: Camallanidae) from turtles of North America and Europe
Authors: Baker M. R.
Published: August 2008

Cephalic and male caudal morphology of Serpinema microcephalus (Dujardin, 1845) Yeh, 1960 and S. trispinosus (Leidy, 1852) Yeh, 1960 have been compared and S. trispinosus is confirmed us a valid species, Camallanus pipientis Walton, 1935 is designated a synonym of S. trispinosus. Serpinema trispinosus is characterized by relatively slender, long ridges in the buccal valves which are separated into dorsal and ventral groups by a number of short spike-like medial ridges, whereas in S. microcephalus the long dorsal and ventral ridges are relatively thick and separated by a number of inconspicuous knob-like medial ridges, The caudal end in males of both species is similar; there are 15 pairs of papillae, conspicuous caudal alae, and unequal spicules.
Life history patterns of some species of Hydropsyche (Trichoptera: Hydropsychidae) in southern Ontario
Authors: Mackay Rosemary J.
Published: August 2008

Life history patterns are described for five species of Hydropsyche in the Credit and Humber rivers. Larvae of univoltine species matured in May or June. Bivoltine species had a fast-growing summer generation of larvae maturing in July or August and a slow-growing winter generation of larvae maturing in April or May. Hydropsyche betteni, H. dicantha, H. slossonae, and H. sparna were bivoltine at some sampling stations, univoltine at others. Hydropsyche scalaris was exclusively univoltine. Most species were represented by many instars concurrently during summer. Overwintering occurred in a smaller number of instars. Species that overwintered in the final or penultimate larval instar were more likely to mature early and to be bivoltine than species overwintering in younger instars. High summer water temperatures and (or) food quality increased growth rates and the probability that a summer generation could mature before fall. Smaller species were more likely to be multivoltine than larger species.Differences among the life cycles of the five species did not suggest effective ecological segregation in summer in terms of larval size. Different overwintering stages among the species may prove to be important factors controlling the number of generations per year.
The Brindley's glands of Rhodnius prolixus. I. Structure of the mature gland
Authors: Barrett F. M. , Millen B. F. , Lai-Fook J.
Published: August 2008

A detailed light and electron microscopic study of the Brindley's glands of adult Rhodnius prolixus has confirmed the presence of type B glandular units similar to those described for the dermal glands of Rhodnius and has identified the second type A glandular unit, also composed of secretory apparatus, saccule, and duct, but outnumbered approximately 18:1 by the type B units. Similarities and differences between type A and type B glandular units are described and the possible functional significance of the two types of unit is discussed.
Digital reduction in Sitana (Reptilia: Agamidae) and the dual roles of the fifth metatarsal in lizards
Authors: Russell Anthony P. , Rewcastle Stephen C.
Published: August 2008

The agamid lizard Sitana ponticeriana shows complete loss of the fifth digit of the pes. This is unusual in a normal-limbed lizard and especially so as the region of the fifth digit serves as the focal point of the crural muscles operating to extend the foot. The pattern of digit reduction does not resemble that seen in lizards showing serpentiform tendencies. Sitana is bipedal at high speeds and has well developed, greatly elongated hind limbs. It thus provides an ideal natural experiment for testing recently advanced hypotheses concerning the functional role of the hooked fifth metatarsal and fifth digit of the pes in normal-limbed lizards. While the phalanges of the fifth digit and the shaft of the fifth metatarsal are absent, the proximal end of the fifth metatarsal remains, with a similar shape and topographic relationship to that seen in other lizards. The functional morphology of the remainder of the pes is only very slightly affected by the loss of the fifth digit indicating that it is functionally independent of the rest of the pes. The role of the proximal part of the fifth metatarsal as a 'heel bone' is strongly supported by the available evidence.
The walk of large quadrupedal mammals
Authors: Dagg Anne Innis
Published: August 2008

The walk patterns of 27 species of large mammals and of five of their young are presented, based on analyses of between 8 and 273 strides per species. These patterns, which reflect varying degrees of stability, are a function largely of diet, phylogeny, and environment, with importance of the last two factors depending on the taxon and its evolution. The camelids, unlike the equids, have walk patterns relatively immune to environmental influences. The walk patterns of large mammals are a function to a lesser extent of speed, morphology, and age.
Reduced spore production Nosema fumiferanae (Microsporida) in spruce budworm (Choristoneura fumiferana) reared at elevated temperature
Authors: Wilson G. G.
Published: August 2008

Rearing of naturally infected spruce budworm, Choristoneura fumiferana, at 23 °C resulted in an increase of 0.4 × 105 to 315.3 × 105Nosema fumiferanae spores in a 7- to 21-day period. At 30 °C, no increase in the number of spores was found in the same period. Removal of the host insect to the lower temperature resulted in reestablishment of spore production.
On Pelagiana trichodesmiae n.gen., n.sp., family Pandeidae, (Anthomedusae/Athecatae, Cnidaria), a new hydrozoan associated with the planktonic cyanophyte Trichodesmium thiebautii
Authors: Borstad Gary A. , Brinckmann-Voss Anita
Published: August 2008

A new athecate hydroid and its young medusa are described, the hydranths of which are commonly found embedded in colonies of the planktonic blue-green alga Trichodesmium thiebautii Gomont in the tropical and subtropical Atlantic. The hydroid and its medusa, named Pelagiana trichodesmiae n.gen., n.sp., are placed tentatively in the family Pandeidae (order Anthomedusae/Athecatae) because of the structure of the medusa and the one circle of filiform tentacles on the hydroid. The medusa is known only from one specimen which was 0.3 mm wide and 0.4 mm high immediately after release. It is deep bell shaped with a stomach one-third of the subumbrella and two marginal tentacles with large triangular marginal bulbs.
New records of helminths from the brown bear, Ursus arctos L., in the Soviet Far East
Authors: Rausch R. L. , Krechmar A. V. , Rausch V. R.
Published: August 2008

Helminths of six species are reported from the brown bear, Ursus arctos L., from the Taigonos Peninsula, northeastern Siberia. Trematodes of four species represent new host records: Microphallus pirum (Afanas'ev, 1941); Maritrema afanassjewi Belopol'skaia, 1952; Phocitrema fusiforme Goto and Ozaki, 1930; and Cryptocotyle lingua (Creplin, 1825). Nematodes of two species, Molineus patens (Dujardin, 1845) and Uncinaria yukonensis (Wolfgang, 1956), constitute respectively a new host record and a new record for Eurasia. The parasite–host relationships of these helminths are reviewed.
Effects of osmotic changes and neurosecretory extracts on kidney ultrastructure in the freshwater pulmonate Helisoma
Authors: Khan Hamidur R. , Saleuddin A. S. M.
Published: August 2008

The ultrastructure of the heart and kidney, and the effects of media of different osmotic concentrations and of nervous tissue extracts, have been investigated in Helisoma duryi and H. trivolvis. The auricle and ventricle walls do not appear to be possible sites for urine formation. In the kidney sac, ferritin and carbon particles are retained by the basement membrane of the epithelium, whereas horseradish peroxidase passes through the basement membrane into the intercellular spaces 10 min after injection. Epithelial cells have deep basal membrane infoldings. Intercellular spaces and spaces in the infoldings are wide in snails kept in distilled water but narrow in snails kept in isosmotic saline. When kidney sacs from saline-acclimated snails were treated in vitro with visceral ganglion extract from snails kept in distilled water these spaces rapidly expanded. Visceral ganglion extract from snails kept in saline, or extracts of other ganglia, had no effect. It is suggested that urine formation occurs in the kidney sac, and that a factor (probably neurosecretory) from the visceral ganglion may act on kidney sac epithelium to alter the rate of filtration and fluid (prourine) transport.
Transformation of the interlamellar epithelium of the gills of the anadromous sea lamprey, Petromyzon marinus L., during metamorphosis
Authors: Peek W. D. , Youson J. H.
Published: August 2008

The interlamellar areas of the gills of the anadromous sea lamprey, Petromyzon marinus, undergo structural modification during the process of metamorphosis of larvae to young adults. The initial changes involve a degeneration of presumed ion-absorptive superficial cells of the larvae and this is followed by a differentiation of adult-type chloride cells presumably from intermediate cells. Adult-type chloride cells are characterized primarily by the presence of an extensive tubular reticulum, which is continuous with lateral and basal plasma membranes. The tubules first appear in peripheral regions of intermediate cells and subsequent development involves a proliferation of the tubules toward the interior of the cell. Autoradiography with [3H]thymidine indicates that extensive DNA synthesis occurs synchronously in the interlamellar basal cells throughout the gill filaments. This DNA synthesis and division of both basal and intermediate cells is most common immediately preceding the first appearance of immature chloride cells. This suggests that cells are produced in apparent anticipation of a requirement for adult-type chloride cells and that they subsequently differentiate. The timing of differentiation of chloride cells is well correlated with developmental changes in other organs during metamorphosis.