bluuebunny/crossref_metadata_2025 huggingface dataset:
Prey consumption in acarine predator-prey populations reared in the greenhouse
Authors: Burnett T.
Published: August 2008

Two factors, in addition to temperature, could affect the assessment of Amblyseius fallacis as a natural enemy of Tetranychus urticae infesting alfalfa. These are initial prey density and sampling of the predator–prey populations during daylight hours. The influence of these factors was determined by propagating predator–prey populations having different initial prey densities on alfalfa in the greenhouse, recording the subsequent variation in the numbers of the two species during daylight hours, and comparing estimates of the rates at which prey entered and were removed from the populations. A. fallacis was able to reduce prey density before webbing of the alfalfa plants occurred. Prey consumption by the predator populations was judged capable of inducing the observed decline in prey numbers.
Wing aberrations induced by precooling pharate adults of the fly Pseudosarcophaga affinis
Authors: Hegdekar B. M.
Published: August 2008

Storing pharate adults of the fly Pseudosarcophaga affinis for 2 to 4 weeks between 0 and 4 °C induced certain wing aberrations in the adults. These included a large number (about 20%) of up-curl wings and a few other minor variations (up-bent, down-bent, and out-spread). In all cases the costal vein was abnormally sclerotized.
Premature melanocyte differentiation in vitro in the skin of chick embryos
Authors: Pollock Robert , Abbott Ursula K.
Published: August 2008

Melanoblasts in chick embryo skin explants cultured on a semisolid complex medium at 37 °C produce visible melanin granules 24 to 36 h earlier than they do in vivo.
Geraldius n. gen., Macrolaiminae n. subfam., with a revision of the subfamilies and genera of Chambersiellidae (Nematoda)
Authors: Sanwal K. C.
Published: August 2008

Chambersiella bakeri is transferred to a new genus, Geraldius. Diagnoses of the genus Chambersiella and family Chambersiellidae are emended. Subfamily Chambersiellinae is reinstated to include the genera Chambersiella, Geraldius, Diastolaimus, and Santafea, and a new subfamily Macrolaiminae is established for the species of Macrolaimus. A key to the subfamilies and genera of Chambersiellidae, based on the presence or absence of cephalic cirri, shape and structure of stomatorhabdions, and the number of female gonads, is given.
Synchronization of life cycles of three mermithids (Nematoda) with their chironomid (Diptera) hosts and some observations on the pathology of the infections
Authors: Hominick William M. , Welch H. E.
Published: August 2008

The life cycles of three mermithid species were synchronized with those of the chironomid hosts. Hydromermis palustris overwintered as an advanced parasite in Cladotanytarsus sp., emerged in early May, and infected new hosts throughout the summer. Gastromermis deltensis overwintered as an early parasite, mainly in Harnischia sp., emerged in late May, and also infected new hosts throughout the summer. Hydromermis conopophaga probably overwintered as an egg, infected new hosts in spring, and emerged from Polypedilum simulans and Harnischia sp. in late June. It had only one generation per year. The chironomids overwintered as third instars. Cladotanytarsus sp. was the first to molt to the fourth instar in the spring, Harnischia sp. was second, and P. simulans last. Both Cladotanytarsus sp. and Harnischia sp. emerged throughout the summer; P. simulans had a limited period of emergence in the summer. The sex of the mermithids was correlated with their number per host. Intersexes in parasitized adult Harnischia sp. are described and illustrated.
Failure of ovarian development in the Douglas-fir bark beetle, Dendroctonus pseudotsugae; an analysis of gut proteases and female-specific proteins
Authors: Sahota T. S.
Published: August 2008

The failure of ovarian development in Douglas-fir bark beetles denied of their natural gallery environment and maintained on host bark chips was investigated. Such insects possessed a high activity of proteolytic enzymes in their guts but relatively small amounts of female-specific proteins both in haemolymph and the oocytes. Topical application of farnesyl methyl ether did not increase the activity of gut proteases but resulted in increased amounts of female-specific proteins in haemolymph and ovaries. Thus it appears that the Douglas-fir bark beetles maintained on bark chips do not suffer from an inability to break down the ingested proteins, but synthesize and transfer less than normal amounts of female-specific proteins to the developing oocytes.
Ecdysis of the snow crab, Chionoecetes opilio
Authors: Watson J.
Published: August 2008

Time to complete ecdysis in Chionoecetes opilio increased with size from 2 to 9 h. A passive phase, during which pericardial sacs began to swell and the old carapace lifted to expose the new thorax, was followed by an active phase, characterized by rhythmic thoracic contraction and expansion. During the active phase, exuviation accelerated and the pericardial sacs functioned to redistribute body fluids to newly emerging parts of the crab. In contrast to other accounts, the results showed that these sacs attained maximum swelling well into the active phase. To escape predation, C. opilio may carry out this prolonged ecdysis while partially or wholly buried in mud. In laboratory tanks, crabs hardened to a commercially acceptable condition 2 to 3 months after ecdysis.
Electrical coupling and growth in lobster muscle fibers
Authors: Jahromi S. S. , Atwood H. L.
Published: August 2008

Muscles of the walking legs of lobster (Homarus americanus) contain "fibers" or subunits which are coupled electrically by pathways of high electrical resistance. Histological examination has shown that the pathways are small sarcoplasmic bridges apparently resulting from incomplete separation of a large muscle fiber or unit into two or more subunits. Examination of muscles from large and small lobsters has shown that subdivision is more extensive, and subunits more numerous, in muscles of the larger, older animals. Probably the muscles gain additional units as some of the preexisting ones split apart during growth.
Eucotyle castanea n.sp. and other trematodes of the family Eucotylidae from birds in British Columbia
Authors: Jensen Doris N.
Published: August 2008

Four species of trematodes of the family Eucotylidae were collected from birds in British Columbia. Eucotyle castanea n.sp. from Melanitta deglandi (Bonaparte) differs from other members of the genus mainly by the presence, throughout its parenchyma, of a reddish-brown pigment. E. cohni Skrjabin, 1924 was recovered from Podiceps grisegena holböllii Reinhardt, Clangula hyemalis (Linnaeus), Bucephala clanguia (Linneaus), and Padiceps aurittis (Linnaeus). E. warreni Schell, 1967 was collected from Bucephala islandica (Gmelin) and Tanaisia fedtschenkoi Skrjabin, 1924 from Charadrius vociferus Linnaeus. This is the first record of the occurrence of these parasite species in Canada.The structure of the cirrus sac in E. castanea and E. cohni and the excretory system of the latter species are described. The relationship between Eucotyle and Tanaisia is discussed and a key to the species of Eucotyle is included.
Sarcoplasmic resistivity of crayfish muscle fibers
Authors: Law P. K. , Atwood H. L.
Published: August 2008

The sarcoplasmic resistivity of long- and short-sarcomere muscle fibers in the walking leg extensor muscle of a crayfish (Orconectes virilis) was measured using a single intracellular microelectrode (the method of Dr. O. Schanne). For long-sarcomere fibers, the mean value was 143 ? cm; for short-sarcomere fibers, the mean value was 150 ? cm. There was no significant difference between the two values, but they differed from some given previously in the literature.
Émergence saisonnière de quelques éphéméroptères d'un ruisseau des Laurentides
Authors: Harper Françoise , Magnin Etienne
Published: August 2008

Six emergence traps set up in a stream have permitted the discovery of two types of seasonal emergence in Ephemeroptera: one very short and synchronized (type 1) and the other more gradual and dispersed (type 2). Unfavorable climatic conditions have some effect on an emergence of the second type but none on an emergence of the first type. The emergence pattern is usually similar at all stations and the males emerge before the females.
Factors affecting the onset and termination of respiration in the salamander, Amphiuma tridactylum
Authors: Toews Daniel P.
Published: August 2008

Respiratory control was studied in 22 intact, free-swimming Amphiuma tridactylum. Termination of inspiration was shown to be controlled by a volume-detection mechanism. Animals were shown to continue the breathing process if air was simultaneously removed from the lungs through a lung cannula. Injections of nitrogen into the lungs terminated inspiration for a short time but breathing occurred a short time after. Carbon dioxide injected into the lungs in doses 3-5 times the concentration normally present was removed from the lungs rapidly and did not result in the onset of breathing if the oxygen tensions were sufficiently high. Very high concentrations of carbon dioxide in the lungs resulted in a shortening of time between breaths. Increased levels of carbon dioxide in the dorsal aorta did not bring about the breathing response. Removal of oxygen from the lungs brought about a rapid breathing response. The presence of an oxygen chemoreceptor was postulated as a mechanism for controlling breathing in Amphiuma.
Three new itch mites from Canadian small mammals (Acarina: Psorergatidae)
Authors: Kok Nico J. J. , Lukoschus Fritz S. , Clulowi Frank V.
Published: August 2008

Three new Psorergates species parasitic in epithelium of the external ear of Sorex cinereus Kerr, Microtus pennsylvanicus (Ord), and Peromyscus maniculatus (Wagner) are described and figured in detail. Distinctive features of species of the "insectivora" and "dissimilis" groups of the genus Psorergates Tyrell are tabulated.
Postembryonic development of certain tetraphyllidean and trypanorhynchan cestodes with a possible alternative life cycle for the order Trypanorhyncha
Authors: Mudry Dwight R. , Dailey Murray D.
Published: August 2008

Development of metacestode stages obtained from experimental infection of copepods (Tigriopus californiens) with one species of tetraphyllidean (Acanthobothrium olseni) and two species of trypanorhynchs (Lacistorhynchus tenuis and Parachristianella monomegacantha) is described. Both A. olseni and L. tenuis produced procercoids lacking a cercomer. The procercoid of A. olseni had paired dorsal and ventral osmoregulatory canals which connected to the exterior both laterally and at the posterior end, while those of L. tenuis emptied only posteriorly. A procercoid was not produced by P. monomegacantha; instead development continued to an immature plerocercus stage with developing proboscides and bothridia.The contrasting metacestode stages of the trypanorhynchs L. tenuis and P. monomegacantha indicates the possibility of two different life cycles in this group. One, in which a procercoid develops, requires a teleost intermediate host as well as a crustacean intermediate host. The second life cycle would require only a microphagous crustacean intermediate host in which a plerocercus stage infective to elasmobranchs may develop.
The route of migration and pathogenesis of Skrjabingylus spp. (Nematoda: Metastrongyloidea) in mustelids
Authors: Lankester Murray W. , Anderson Roy C.
Published: August 2008

In skunk (Mephitis mephitis), third-stage larvae of S. chitwoodorum penetrate the wall of the stomach and intestine where they rapidly complete 2 molts, 1 to 2 and 3 to 4 days later. Four to 5 days after infection, fifth-stage worms migrate from the gut wall into the peritoneal cavity. They then move into muscles of the abdominal wall. Moving beneath the perineurium of nerves, worms enter the vertebral canal, and move into the spinal subarachnoid space. They move anteriorly to the front of the brain and eventually along olfactory nerves which pass through the cribriform plate of the ethmoid bone. They arrive in the nasal sinuses as early as 6 days after infection. S. nasicola follows a similar route to the frontal sinuses of mink (Mustela vison).Most migrating worms associated with the central nervous system do not enter the neural parenchyma but are confined to the subarachnoid space where they provoke leptomeningitis and some haemorrhage. However, the worms sometimes enter the ventricles of the brain and cause trauma. Also the migration of worms is sometimes impeded by intense inflammation in the piarachnoid. Severe neurologic signs were observed in some skunk given S. chitwoodorum.Chez la mouffette Mephitis mephitis, les larves du troisième stade de S. chitwoodorum pénètrent dans la paroi de l'estomac et de l'intestin où ils subissent rapidement deux mues, 1 à 2 jours après, et 3 à 4 jours après. Quatre à cinq jours après l'infestation, les vers du cinquième stade passent de la paroi intestinale dans la cavité péritonéale. Ils pénètrent ensuite dans les muscles de la paroi abdominale. Ils suivent le périneurium des nerfs, entrent dans le canal vertébral et se déplacent dans l'espace spinal subarachnoïde. Ils gagnent ainsi la partie antérieure du cerveau et peuvent éventuellement suivre les nerfs olfactifs qui passent à travers la lame criblée de l'ethmoïde. Ils arrivent ainsi rapidement dans les sinus nasaux, six jours après l'infestation. S. nasicola suit une route semblable jusque dans les sinus frontaux du vison (Mustela vison).La plupart des vers dont les déplacements sont associés avec le système nerveux central n'entrent pas dans le parenchyme neural; ils restent confinés à l'espace subarachnoïde où ils provoquent des lepto-méningites et des hémorragies. Quelques fois, cependant, les vers pénètrent dans les ventricules du cerveau et provoquent un trauma. La migration des vers peut être entravée par une forte inflammation dans le piarachnoïde. De graves signes neurologiques ont été observés chez des mouffettes infestées par S. chitwoodorum.
Effects of continuous competition in two species of cellular slime mold: Dictyostelium discoideum and Polysphondylium pallidum
Authors: McQueen Donald J.
Published: August 2008

Competitively induced population changes were studied in the laboratory. The experimental organisms chosen for the work were two cellular slime mold species: Dictyostelium discoideum and Polysphondylium pallidum. Culturing these organisms on a temperature gradient of 15 °C to 30 °C induces long-term continuous competition for food and space. The organisms respond by changing their rates of resource exploitation and their susceptibility to interference.Before competition, D. discoideum interfered with P. pallidum fruiting, body formation. This effect was not observed after competition. Specifically, when grown alone before competition, P. pallidum fruited from 18° to 37 °C and D. discoideum from 9° to 27 °C. In mixed cultures, before competition. P. pallidum fruited from about 24° to 37 °C and D. discoideum from about 9° to 27 °C. In mixed cultures, after continued competition, P. pallidum fruited from about 20° to 37 °C and D. discoideum from about 9° to 24 °C. There is evidence to suggest that the change is genetic and related to parasexuality in P. pallidum.Rates of resource exploitation (which depend upon spore germination times and amoeba colony expansion rates) also changed. Germination times were unaltered but amoeba colony expansion rates increased.Apparently continued competition resulted in convergence and divergence with respect to resource use. Because P. pallidum gained the ability to fruit in the presence of D. discoideum it converged with respect to resource use. At the same time the two species diverged by increasing rates of resource use over different segments of the temperature range.
Observations on parasite–host relationships of Echinococcus multilocularis Leuckart, 1863, in North Dakota
Authors: Rausch R. L. , Richards S. H.
Published: August 2008

Red foxes, Vulpes vulpes (Linnaeus), and small mammals were collected and examined during 1965–69, to investigate parasite–host relationships of Echinococcus multilocularis Leuckart, 1863, in North Dakota. Comparative studies of this cestode were carried on concurrently through experimental infection of carnivores and rodents. In winter, red foxes in North Dakota exhibited high rates of infection of comparatively low intensity. Deer mice, Peromyscus maniculatus (Wagner), and voles, Microtus pennsylvanicus (Ord), were important intermediate hosts, but the larvae in deer mice produced fewer protoscolices. The strains of E. multilocularis from North Dakota and from St. Lawrence Island, Alaska, differ biologically, as indicated by findings in experimentally infected rodents, but they could not be distinguished morphologically at the infraspecific level. Helminths recorded from red foxes in North Dakota are listed, and some ecological data are presented and discussed.
The systematic status of the African molossid bats Tadarida bemmeleni and Tadarida cistura
Authors: Peterson R. L.
Published: August 2008

Twenty-four specimens of Tadarida bemmeleni, collected in Cameroun in 1970, appear to be the first taken since the holotype was collected in 1875 from Liberia. Morphological comparisons with T. cistura from East Africa indicate that the two taxa are subspecies of the same species. Systematic relations, age, and sexual variation, as well as ecological notes, are provided. The facial features, caudal glands, palatal ridges, and cranial details are illustrated for the first time.
Aggressive behavior of Apis mellifera L. workers towards introduced queens. III. Relationship between the attractiveness of the queen and worker aggression
Authors: Yadava R. P. S. , Smith M. V.
Published: August 2008

The attractiveness of virgin queens of five age groups was determined using a new bioassay technique; queen attractiveness increased with age. By introducing queens of these age groups to small cages of worker bees, a direct relationship was found between queen attractiveness and worker aggression. The significance of these results is discussed.
Speciation, transmission, and schizogony of Leucocytozoon in corvid birds
Authors: Khan R. A. , Fallis A. M.
Published: August 2008

Leucocytozoon sakharoffi, L. berestneffi, L. laverani, and L. zuccarelli have been described from corvids although their gametocytes are indistinguishable. Experimental evidence suggests that the raven, Corvus corax, and crow, C. brachyrhynvhos harbor a species which is distinct from that in the blue jay, Cyanocitta cristata. The minimum prepatent period (92 h) in the jay is about a day shorter than that in the crow and raven. Hepatic, renal, and splenic schizonts occur in the jay and are probably initiated by sporozoites. Only hepatic and renal stages have been seen in a crow and raven but the relationship to each other is unknown. Hepatic schizonts are probably derived from sporozoites but the enormous number of the former at autopsy of two birds is suggestive of more than one hepatic generation. Our material exhibited neither megaloschizonls (as reported for L. sakharoffi) nor small hepatic schizonts (known from L. berestneffi). Additional studies of life cycles of Leucocytozoon in other corvids are necessary for the satisfactory elucidation of the specific status of these parasites.
The postembryonic development of the indirect flight muscles in Oncopeltus fasciatus (Dallas) (Hemiptera: Lygaeidae)
Authors: Scudder G. G. E. , Hewson R. J.
Published: August 2008

The postembryonic development of the indirect flight musculature is described from light microscope observations. In the mesothorax, a pronounced metamorphosis of the indirect flight muscles is reported. The initial dorsolongitudinal muscle fibers of the first instar disappear in the early second instar. In the late second instar, an aggregation of myoblasts is found, and this in subsequent instars, enlarges and gives the muscle of the adult. In the metathorax, the dorsolongitudinal muscle grows by enlargement and fiber cleavage, while in the prothorax the fibers in the comparable muscle simply enlarge, but do not cleave. The developmental events in Oncopeltus fasciatus are compared with similar ontogenetic situations in other animals. Muscle histolysis in the mature adult of O. fasciatus was not observed.
The occurrence of Paruterina candelabraria (Goeze, 1782) and Cladotaenia globifera (Batsch, 1786) in Manitoba
Authors: Baron R.W.
Published: August 2008

Paruterina candelabraria was found in 4 out of 40 rodents collected in gravel pits near St. Lupicin, Mulvihill, Wasagaming, and Lockport, Manitoba. The hosts were Microtus pennsylvanicus and Peromyscus maniculatus. Cladotaenia globifera was found in 1 out of 15 M. pennsylvanicus collected near Bissett, Manitoba.
Effect of host dietary constituents on intestinal pH and the migrational behavior of the rat tapeworm Hymenolepis diminuta
Authors: Mettrick D. F.
Published: August 2008

Changes in intestinal pH and in the position of Hymenolepis diminuta within the rat small intestine, have been followed for up to 7 h after feeding a 2.5-ml meal containing either 1 g or 3 g glucose, 2 g dextrin, 2 g galactose, 2 ml olive oil or an amino acid mixture containing 2.5 μmoles of 18 different amino acids.Both the quantity and quality of the dietary constituents have statistically significant effects (P < 0.001) on the pH gradients in the small intestine at any time up to 7 h after feeding. This implies that the buffering system of the rat is unable to maintain a very efficient homeostatic control of the hydrogen ion concentration in the intestine. The changes in intestinal pH are neither the cause of, nor are directly caused by, the migrational movements of the worms.The migrational response of the worms, which involved both scolex attachment sites and worm biomass (dry weight), varied depending on the quantity and quality of the meal.While the pattern of the migrational response was very similar following the feeding of 1 g and 3 g glucose, there was a 3-h delay after feeding 3 g glucose before the worms attained the maximum anteriad migrational position. Although there was an anteriad migration of worm biomass following the feeding of all the carbohydrates tested, the most marked anteriad movement was in response to feeding olive oil. Glucose does not appear to be the direct stimulus controlling the migrational behavior of H. diminuta.
Mechanical responses of the body wall muscle of the earthworm, Lumbricus terrestris, to segmental nerve stimulation
Authors: Drewes Charles D. , Pax Ralph A.
Published: August 2008

Suitable nerve–muscle preparations are described for recording the electrical and mechanical responses of the longitudinal and circular muscle to segmental nerve stimulation in the earthworm, Lumbricus terrestris. The longitudinal muscle response to prolonged repetitive stimulation consists of a smooth increase in tension to form a peak in less than 10 s followed by a slow decline in tension to about one-half peak tension in 45 s. The circular muscle response to prolonged repetitive stimulation consists of two distinct phases of tension development: an initial, rapidly developing peak resembling that in longitudinal muscle and a slow, irregularly developing second phase. The circular and longitudinal muscle responses are obtained at frequencies above f or 2/s, with the amplitude of each response being a function of the stimulus strength within a range of 0.4–1.4 V (2 ms) and the stimulus frequency within a range of 5–50/s. In addition there is a threshold-dependent inhibition of the second phase of the circular muscle response.Circular and longitudinal responses to single stimuli are obtained with stimulus strengths approximately 10 times greater than those of the responses to repetitive stimulation and the amplitude of these responses appears to be a function of the strength of stimulation. The single stimulus response appears to be a result of repetitive firing in the same motor fibers which mediate the response to repetitive stimulation.
Mate selection in two species of sunfish (Lepomis gibbosus and L. megalotis peltastes)
Authors: Steele Robert G. , Keenleyside Miles H. A.
Published: August 2008

The reactions of 20 male and 20 female pumpkinseed (Lepomis gibbosus) and longear sunfish (L. megalotis peltastes) to conspecifics and heterospecifics of the opposite sex were studied. Female pumpkinseeds showed a preference for conspecific males in the absence of visual cues; female longears showed a preference for conspecific males when both types of male could be seen. Males of both species did not discriminate between the two kinds of females in either the presence or absence of visual cues. Female choice of a conspecific spawning partner may be an important ethological isolating mechanism between these two species. A mechanism for hybridization between them is proposed.
Scanning electron microscopical studies of some cephalopod radulae
Authors: Aldrich Margueritte M. , Barber Vernon C. , Emerson Carolyn J.
Published: August 2008

In an attempt to evaluate the possible uses of scanning electron microscopical (SEM) studies of cephalopod radulae, we examined the radulae of 58 specimens (representing 22 species of nine genera), the majority being from the genera Loligo, Rossia, and Illex. Octopod and decapod radulae have considerable differences and were easily distinguished, as were decapod radulae down to the family level. However, considerable differences in radular tooth form between individuals of a species, not related to size or sex of the animals, were found. Also, similarities between species in a genus, and genera in a family were noted. The advantages of the scanning electron microscopical method of examining radulae are discussed.
Hibernation in the blackfly Prosimulium mysticum: quiescence or oligopause?
Authors: Mansingh A. , Steele R. W. , Helson B. V.
Published: August 2008

Composition of an overwintered larval population of the blackflies Prosimulium mysticum Peterson, their rates of development, and feeding activity at different temperatures were studied. On the basis of the hibernating characteristics of the species, the dormancy appears to be a case of oligopause, a physiological category of dormancy intermediate between quiescence and diapause.
Tardigrades from New Brunswick, Canada. 2.
Authors: Argue C. W.
Published: August 2008

Seven kinds of tardigrades, not before reported for Canada, are identified from sites in south central New Brunswick. They are Echiniscus (Echiniscus) spiniger, E. (E.) spinuloides, Macrobiotus ambiguus, M. furciger, M. hibernicus, Hypsibius (Diphascon) nodulosus, and H. (D.) pinguis brunsvicensis which is proposed as a new variety. A summary of species and varieties of tardigrades so far known for Canada is given. Markings on the pharyngeal tube of species of Diphascon are discussed.
Sex ratio in pigeons segregating at the dilute locus
Authors: Sittmann K.
Published: August 2008

Published data from Norway (Christie and Wriedt 1930) and the United States (Cole and Kelley 1919) were reanalyzed to compare viabilities of males and females and of intense (D) and dilute (d) pigmentation types. Of the four sex–color phenotypes intense males hatched best except in the last brood of the year when dilute females were in excess in at least one population. Evidence from both series suggested that hatchability was affected not only by genotype (D, d) and environment (sex, season) but also by interactions between these factors.The seasonal trend in pigeons resembled the reduced hatchability of the more heavily pigmented embryos in some sex-linked crosses of chickens.
Simultaneous apnoea and bradycardia in the lobster Homarus americanus
Authors: McMahon Brian R. , Wilkens Jerrel L.
Published: August 2008

Periods of simultaneous apnoea and bradycardia lasting for up to 20 min have been recorded from specimens of Homarus americanus isolated under experimental conditions but otherwise exposed to no direct stress. The onset of the response and the resumption of normal activity occurred abruptly and simultaneously in both respiratory and circulatory parameters. A study of the response leads the authors to propose a central control area which can inhibit both branchial and cardiac pumps simultaneously. Blood oxygen tensions were monitored during the response and possible mediating effects of oxygen are discussed.
Experimental thiamine deficiency in captive harp seals, Phoca groenlandica, induced by eating herring, Clupea harengus, and smelts, Osmerus mordax
Authors: Geraci J. R.
Published: August 2008

Freshwater smelts, and Atlantic herring, both shown to contain thiaminase, were fed to harp seals under a variety of experimental conditions. When thiamine was not administered, the seals developed thiamine deficiency which, in some cases, was fatal. Red blood cell transketolase was effective in demonstrating deficiency.In a controlled experiment, three seals ingesting smelts died within 80 days; two showed terminal signs of central nervous system disturbances and concomitant plasma electrolyte imbalance. Seals fed a diet of thiamine-free herring survived despite biochemical evidence of deficiency. This is attributed to the high fat content of herring.Thiamine administered either intramuscularly or orally, during the course of deficiency, effected prompt recovery. Thereafter, seals maintained on herring required 25–33 mg thiamine/kg of ingesta, if the vitamin was consumed in the diet; if administered 2 h before feeding, 35 mg/day was sufficient for normal maintenance.
The biology of Jaera spp. (Crustacea, Isopoda) in the northwestern Atlantic. 1. Jaera ischiosetosa
Authors: Steele D. H. , Steele V. J.
Published: August 2008

Oogonia of female Jaera ischiosetosa begin to enlarge in April and the first hatched young appear in June. Reproduction continues until August. From September to March the females lack oostegites and are in a resting stage. Females do not produce continuous broods during the season, but lose their oostegites after every brood. Individuals survive for 1 year at the most. In August the population consists almost entirely of young of the year, some of which may breed in the same year. Egg size is small and the fecundity relatively high.
Stimulation of bioluminescence in lanternfishes (Myctophidae). II.
Authors: Anctil Michel
Published: August 2008

Injections and applications of hydrogen peroxide, peroxidase, and other chemicals evoked luminescence with variable success in three Atlantic lanternfishes of the family Myctophidae: Benthosema glaciale, Myctophum punctatum, and Notoscopelus kroeyeri. Electrical stimulation of the spinal cord and of isolated photophores resulted in only a few brief light responses in the first two species. Epinephrine injections evoked luminescence in the gonostomatid Maurolicus muelleri while injection and external application of hydrogen peroxide failed to produce a response in this species and in the stomiatid Stomias boa ferox. These and earlier data are discussed in terms of methodology and physiological states of the fish, biochemical systems involved, and luminescence control.
Optimal niche space of the redwinged blackbird (Agelaius phoeniceus). I. Nesting success in marsh and upland habitat
Authors: Robertson Raleigh J.
Published: August 2008

Survival value of different parts of the fundamental niche of the redwinged blackbird was determined by comparing nesting success in marsh and upland habitats. Marsh nesting populations had greater success than those in uplands because of a smaller proportion of nests destroyed by predators. Predation pressure in marshes was negatively correlated with the depth of water beneath the nest, and the synchrony and density of nesting in marshes in some cases has a swamping effect on local predator populations. The structure and phenology of marsh compared with upland vegetation is an important factor in determining nesting density and synchrony.Growth rates of nestlings and weight at fledging are similar between habitats. Genetic separation between marsh and upland populations is unlikely. Territoriality probably results in a limitation to breeding density in both habitats.The results support the hypothesis that where sympatric, redwings are excluded from their optimal niche space by yellow-headed blackbirds.
Eudromoxyura elonbyrdi n. g., n. sp. (Nematoda: Oxyuroidea) from crested tinamou (Eudromia elegans)
Authors: Anderson Roy C. , Prestwood Annie K.
Published: August 2008

Eudromoxyura elonbyrdi n. g., n. sp. from the caecum of Eudromia e. elegans and E. e. albida of Argentina is distinguished from all other genera of the Oxyurinae by the presence of an intestinal caecum. Its affinities lie with Syphaciella also from birds.
Intranuclear, paracrystalline inclusions in various cells of Quinqueserialis quinqueserialis and Notocotylus urbanensis (Trematoda: Notocotylidae)
Authors: Beverley-Burton Mary , Sweeny Phillip R.
Published: August 2008

Intranuclear, paracrystalline inclusions measuring up to 3.9 μ in diameter were observed in tegumental, parenchymal, and muscle cells of Quinqueserialis quinqueserialis (Barker and Laughlin, 1911) Harwood, 1939, and Notocotylus urbanensis (Cort, 1914) Harrah, 1922. Ultrastructural observations show that the inclusions are closely associated with the nucleolus and that the center-to-center spacing of the electron-dense parallel line pattern is about 200 Å. In some inclusions a lattice pattern was seen. Both structural and preliminary histochemical findings suggest that the inclusions may be proteinaceous. It is considered possible that the inclusions may be associated with a virus infection or they may represent storage sites.
Blood parasites of some birds from Labrador
Authors: Bennett Gordon F.
Published: August 2008

Four hundred and fifty-four birds of 38 species were collected from various parts of Labrador and examined for hematozoa. One hundred and seventy-one birds (37.6%) of 20 species harbored one or more blood parasites. Species of Leucocytozoon were the most commonly encountered parasites, with a relatively low incidence of Parahaemoproteus recorded. Trypanosoma avium and microfilaria were also noted.
Validation of a new species and a new variety of Coelomomyces (Blastocladiales, Coelomomycetaceae) described from Marion Lake, British Columbia
Authors: Weiser Jaroslav , McCauley Victor J. E.
Published: August 2008

A Latin diagnosis is given for Coelomomyces beirnei and Coelomomyces chironomi var. canadense thereby validating this new species and new variety erected in 1971.
Observations on aspects of the life history of the crayfish, Orconectes virilis (Hagen), in northwestern Ontario
Authors: Weagle Kenneth V. , Ozburn George W.
Published: August 2008

A 1-year study was conducted to expand upon the life history of Orconectes virilis (Hagen). In the course of the study 852 adults and 692 young were examined.The eggs were laid during the last week of May. The number of eggs laid per female was proportional to carapace length and averaged 214. The eggs hatched during the 2nd week of July. During the first summer the young underwent five molts; the first occurred while they were still attached to the mother.Year I males underwent three or four molts and year I females underwent three molts. Fifty percent of the males and 65% of the females reached maturity during their first year.Year II and year III males underwent two molts; the first was from form I to form II (mid-June) and the second was from form II to form I (early August). Year II and year III females underwent only one molt which occurred after the young had abandoned the mothers in July.The mating season was August through September.Growth increments and carapace length ranges for the four age groups were found to be similar to those for O. virilis in Michigan and Alberta.
The occurrence, life cycle, and pathogenicity of Echinuria uncinata (Rudolphi, 1819) Soloviev, 1912 (Spirurida, Nematoda) in waterfowl at Delta, Manitoba
Authors: Austin F. G. , Welch H. E.
Published: August 2008

In the Delta Marsh, third-stage Echinuria uncinata juveniles were found in Daphnia magna, D. pulex, Simocephalus vetulus, and Gammarus lacustris. Daphnia magna, the major host, were found infected from late May to early November with a peak of 108 parasites per 100 Daphnia in early August. Experimentally, D. magna, D. pulex, Ceriodaphnia reticulata, C. acanthina, S. vetulus, Moina macrocopa, Eurycercus lamellatus, G. lacustris, Hyallela azteca, Chirocephalopsis bundyi, and Lynceus brachyurus became infected when exposed to E. uncinata eggs. Parasites developed to the infective stage in D. magna and D. pulex in 30 days at 15 °C and in 10 days at 20–24 °C.In mallard ducks, E. uncinata completed the fourth molt 20 days after infection; male worms were sexually mature after 30 days and females oviposited 40 days after infection. Parasites grew faster in 1-week-old Delta mallards than in 2- and 3-month-old birds. Adult nematodes were located beneath the mucosal layer at the junction of the proventriculus and gizzard where granulomas formed after 30 days. The number of granulomas was correlated with the number of parasites. Mallards, pintails, gadwalls, lesser scaup, common eiders, and domestic geese were more susceptible to Echinuria infection than were shovellers, blue-winged teal, redheads, ruddy ducks, and American coots. Parasite eggs died when frozen but 50% survived 85 days when dried on filter paper. Echinuria uncinata can survive winter in resident mallards.
The effect of odors on the behavior of adult Aedes aegypti and some factors limiting responsiveness
Authors: Wensler Rita J. D.
Published: August 2008

Caged adult Aedes aegypti aggregated at the source of ethyl ether soluble honey odors in relatively still air. Arrival at the source of odor was not random. The volatile substances stimulated locomotory activity in mosquitoes settled in the cage. The majority of these active individuals arrived at the odor source and did so within a mean period of 1.5 min. At the same time, arrivals at a visually similar, comparably situated control were rare. Insects probed at the odor source and remained in the area of highest odor concentration by turning at the boundary to a lower concentration. Habituation occurred within about 12 min of exposure to the odor and the aggregation was then dispersed.Male and female mosquitoes responded to honey odors equally well. Responsiveness increased with time of food deprivation and feeding raised the threshold of response.Mechanisms of orientation to the odor are discussed.
Color preferences in the lesser snow goose and their possible role in mate selection
Authors: Cooke F. , Mirsky P. J. , Seiger M. B.
Published: August 2008

Assortative mating in the dimorphic lesser snow goose could be explained if birds choose mates according to the color of their parents. Young birds were tested to determine if they would show color preferences at an early age. Blue and white phase lesser snow geese, as well as white phase geese dyed pink, were reared in families with either a blue, white, or pink foster parent. All birds were then combined in a large flock in an attempt to simulate natural conditions as closely as possible. Birds tested in a choice situation were found to show a significant preference for birds of the same color as their foster parents. The fact that the young were raised in families and later in a flock suggested that color preferences were a natural and not a laboratory phenomenon.Two lines of evidence suggest that where the color of the foster parent is altered, the preference for the color of the original foster parent is lost. This suggests that prolonged association of gosling and parent is important if parental color is to have an influence on mate selection.
Marine fish haematozoa from Newfoundland waters
Authors: So Bernard K. F.
Published: August 2008

Of 797 fish of 28 species, 159 of 12 species yielded blood protozoa. Trypanosoma rajae is recorded from Raja radiata. Undetermined trypanosomes are reported from Glyptocephalus cynoglossus and Gadus morhua, respectively. Haemogregarina myoxocephali is listed from the type host, Myoxocephalus octodecemspinosus. The occurrence of haemogregarine sporozoites (perhaps of this species) in the gut of a piscicolid leech (Malmiana nuda) from Myoxocephalus scorpius represents the first discovery of a potential vector of any fish haemogregarine. New hosts are listed for Haemogregarina delagei and H. platessae. A babesioid Haemohormidium terraenovae n. sp. is described from six hosts: Ammodytes americanus, Urophycis tenuis, Melanogrammus aeglefinus, Limanda ferruginea, Glyptocephalus cynoglossus, and Hippoglossoides platessoides; and another, Haemohormidium beckeri n. s p., from Myoxocephalus octodecemspinosus.
The fossil occurrence of Helophorus arcticus Brown (Coleoptera: Hydrophilidae) in Pleistocene deposits of the Scarborough Bluffs, Ontario
Authors: Morgan Anne
Published: August 2008

Fossils of Helophorus arcticus Brown are described from Pleistocene deposits believed to be about 70 000 years old. This is the first record of the species as a fossil in North America. At present H. arcticus is known only from damp tundra regions of the subarctic in Canada, and it is suggested that such conditions probably prevailed in the Toronto region during the deposition of the Scarborough Formation 70 000 years ago. This discovery also points out the vast changes in insect distribution which have taken place during and since the last glaciation.
Studies on the helminth fauna of Alaska. LI. Observations on eggshell formation in some diphyllobothriid cestodes
Authors: Hilliard Douglas K.
Published: August 2008

Formation and structure of the eggshell were studied with light and electron microscopy in 13 species of diphyllobothriid cestodes. In those having marine intermediate and final hosts, the shell of the fully developed egg is deeply pitted; the eggs as they first appear in the uterus are up to four times the size of mature eggs, and are asymmetrical, thin-shelled, cohesive, and plastic. As they move down the uterus, they become smaller, the shell thickens, the pits enlarge and deepen penetrating the shell to the lipoprotein layer, and the opercular suture develops. The pits may be formed by coalescence of proteins before quinone tanning. Hatching of eggs from such cestodes depends upon salinity rather than light; the pits may provide the means by which salt ions are conveyed to the mechanism that controls hatching. In cestodes having the aquatic phase of their life cycle in freshwater, the eggshells are only superficially pitted, and hatching usually is mediated by light. Origin of the pits in relation to eggshell formation is discussed, as is their possible phylogenetic and taxonomic significance.
The role of the nasal glands in the survival of ducks (Anas platyrhynchos) exposed to hypertonic saline drinking water
Authors: Bradley E. L. , Holmes W. N.
Published: August 2008

The supraorbital nasal glands were removed from the duck (Anas platyrhynchos) 1 week before experimentation. When sham-operated birds were given hypertonic saline drinking water (282 mM NaCl, 6 mM KCl) for 70 h they maintained their body weights and remained in positive water balance. When the ducks lacking nasal glands were similarly treated they became severely dehydrated, lost body weight at the rate of 5.59 ± 1.1 g/h and showed significant increases in the plasma concentrations of Na+, Cl−, K+, and total osmotically active material. When the glandless birds were given hypertonic saline drinking water, the disparity between the measured plasma osmolality and the osmolality calculated on the basis of the Na+, Cl−, and K+ concentrations in plasma increased two-fold. No such change in disparity between the measured and calculated osmolalities of plasma in the sham-operated birds was observed. Forty-eight hours after their return to a diet containing fresh drinking water, the birds without nasal glands regained some of the body weight they had lost and the plasma electrolyte concentrations were restored towards normal. It is concluded that in the absence of nasal glands, the kidney alone is incapable of maintaining positive water balance in ducks fed hypertonic saline as their only source of drinking water.
Radiothyroxine metabolism in several freshwater teleost fishes
Authors: Eales J. G.
Published: August 2008

The metabolism of intraperitoneally injected radiothyroxine labeled with 125I in 3′ and 5′ positions (*T4) was followed in several starved freshwater teleosts acclimated at 12–13 °C.Biological half-lives for initial loss of plasma PB125I (*T4) were 7.9 h (goldfish), 8.7 h (rainbow trout), 12.2–28.5 h (channel catfish), 19.2 h (sucker), 24.0–37.6 h (burbot), and 56.6–138.0 h (brown bullhead). Frequently, a single exponential decrease in plasma PB125I did not occur, and the usually large *T4 distribution spaces suggested that injected *T4 might not rapidly enter the circulation from the injection site. Plasma radioactive derivatives included 3,5,3′ triiodo-L-thyronine.Biliary *T4 excretion varied considerably between species and could relate to feeding habits.
Helminths from the digestive tracts of mallards and pintails in the Delta Marsh, Manitoba
Authors: Crichton V. F. J. , Welch H. E.
Published: August 2008

At least five species of cestodes, seven of trematodes, seven of nematodes, and two of acanthocephalans were found in Anas platyrhynchos platyrhynchos (L.) and Anas acuta (L.). Male and female adult and juvenile mallards harbored greater numbers of worms than did pintails. Adult females of both species had greater numbers of helminths per bird than did males. In addition, juvenile birds harbored greater numbers of parasites than did adults. The parasitic faunas of the two surface-feeding ducks, mallard and pintail, differed quantitatively despite their common habits. These differences were not a reflection of different diets but the suspicion is that mallards are more susceptible to parasitism than pintails. No serious cases of helminthiasis were found in the 101 mallards and 101 pintails examined in 1967 and 1968.
The anatomy, histology, and physiology of the reproductive systems of Lytta nuttalli Say (Coleoptera: Meloidae). II. The abdomen and external genitalia
Authors: Gerber G. H. , Church N. S. , Rempel J. G.
Published: August 2008

The abdomen of adult Lytta nuttalli is composed of 10 segments, the first 8 of which are well developed, except for the first two sterna. The last two segments are concealed within the eighth. The ninth segment of the male is represented by a pair of hemitergites dorsolateral to the genital chamber and a ventral sternum, which supports the aedeagus. The aedeagus is typical of the vaginate type of male coleopteran genitalia. Seven pairs of muscles and an unpaired muscle associated with the aedeagus and ninth sternum are involved in copulation. The female ninth segment is made up of a pair of hemitergites dorsolateral to the genital chamber and a pair of ventrolateral hemisternites bearing styli. These structures are characteristic of the compact type of female beetle genitalia. Bristles on the styli probably have a tactile function in copulation and possibly in oviposition. The 10th segment of both sexes consists of a pair of heavily sclerotized hemitergites dorsolateral and a lightly sclerotized sternum ventral lo the anus. The form and functions of the external genitalia of L. nuttalli are compared with those of other Meloidae and other Coleoptera.
Timing of breeding of pikas in southwestern Alberta
Authors: Millar John S.
Published: August 2008

Conception dates of pikas were determined from the age of embryos in 125 collected females. First litters were conceived as early as would allow nursing under favorable feeding conditions. Mean birth date of first litters (June 8) coincided with the mean date of initiation of growth of vegetation (June 9). Second litters were conceived immediately after birth of first litters. Although pikas in southwestern Alberta matured later and conceived fewer litters per year than some other species of pikas, they matured earlier and conceived more litters per year than other subalpine and alpine mammals of similar size. This breeding pattern may, in part, be responsible for the success of pikas at high elevations.