bluuebunny/crossref_metadata_2025 huggingface dataset:
Fine structure of the abdominal neurosecretory organs of Rhodnius prolixus Stål.
Authors: Kuster J. E. , Davey K. G.
Published: April 2009

Abdominal segments II–V of female Rhodnius prolixus adults each contain a pair of abdominal neurosecretory organs (ANO). They are attached to the anterolateral borders of their respective tergites and sternites. The ANO consist of neurosecretory neurons containing granules approximately 120 nm in diameter, together with glial and connective tissue elements. Apparent neurohaemal areas are located dorsally.
Morphological and biochemical systematics of chubs, Nocomis biguttatus and N. micropogon (Pisces: Cyprinidae), in southern Ontario
Authors: Ferguson Moira M. , Noakes David L. G. , Danzmann Roy G.
Published: April 2009

Examination of 17 presumptive gene loci by starch-gel electrophoresis revealed differential mobilities only at acid phosphatase-1, alcohol dehydrogenase, esterase-1, and phosphoglucomutase between Nocomis biguttatus and N. micropogon. No intraspecific variation was observed for any loci. The genetic identity (I) and genetic distance (D) were 0.874 and 0.134, respectively. The correlation of electrophoretic mobilities and nuptial tubercle pattern in sexually dimorphic males supports the present taxonomic distinction of these species and provides a simple, unambiguous means of identifying any individuals.Stepwise discriminant function analysis of a series of mensural characters was used to compare fish identified as to species by electrophoresis. At best this correctly assigned fish to their respective species in 85.7% of cases, with a probability of misclassification of 0.1335.This study suggests these two are sibling species, based on a comparison of biochemical and morphological differentiation.
Helminths of a Vancouver Island marmot, Marmota vancouverensis Swarth, 1911, with a description of Diandrya vancouverensis sp.nov. (Cestoda: Anoplocephalidae)
Authors: Mace T. F. , Shepard C. D.
Published: April 2009

A female Vancouver Island marmot, Marmota vancouverensis Swarth, 1911, collected on Green Mountain, Vancouver Island, British Columbia, was infected with the nematode Baylisascaris laevis and anoplocephalid tapeworms of the genus Diandrya. These worms differed from D. composita, the only species of Diandrya previously recorded, and are described as Diandrya vancouverensis sp.nov. The dimensions of reproductive organs and the presence of a neck and unarmed cirrus are characters distinctive to D. vancouverensis.
Population structure and dispersal of Peromyscus leucopus on Muskeget Island
Authors: Nadeau Joseph H. , Lombardi Rosemarie T. , Tamarin Robert H.
Published: April 2009

A 6-year experimental study was used to examine the effects of resident, breeding males on recruitment and dispersal of juveniles on Muskeget Island, Massachusetts. Dispersal was studied by providing a vacant area into which mice could move. Residency and recruitment in males depended on weight but not breeding condition. Dispersing males were a random sample of the adjacent control population. Dispersing females weighed less than all other mice and were more likely than control females to have perforate vaginae and small lactation tissues. Although the patterns of density variation and breeding activity were similar to those of other P. leucopus populations in New England, our results are unlike those of most other studies of population regulation in Peromyscus spp. and suggest that males were not territorial and did not limit the recruitment of juveniles. A hypothesis is proposed to explain the anomalous effects of males on density limitation and is based on density-dependent strategies employed by males to acquire access to breeding females.
In vitro primary spreading and dissociation of zebrafish, Brachydanio rerio, blastoderm-derived embryonic epidermis
Authors: Laale Hans W.
Published: April 2009

Blastoderm isolates from Brachydanio rerio (Teleostei: Cyprinidae) blastulas were maintained in nutrient medium for up to 40 days. Of 120 blastoderm isolates cultured 75% showed initial attachment and underwent major changes in adhesive properties affecting aggregative and locomotory behaviour. Of the attached blastoderm isolates, 70% differentiated into embryos of varying degrees of organization and all exhibited subsequent primary membrane formation and spreading. The paper, covering the first 18 days of culture, focuses on the phenomenon of primary membrane spread formation, dissociation, and its associated cell types. A discussion of the relevant literature is provided.
In vitro secondary spreading from dissociating blastoderm-derived embryonic tissues of the zebrafish, Brachydanio rerio
Authors: Laale Hans W.
Published: April 2009

Brachydanio rerio (Teleostei: Cyprinidae) blastoderm-derived embryos, deprived of their epidermis in in vitro culture, dissociate and their tissues disperse radially upon the culture substrate. The phenomenon, referred to as secondary spreading, follows primary epidermal membrane formation and dissociation and spans a period from 18 days to 40 days of culture at 24 °C.Secondary spreads and associated cell types and cellular phenomena are described, and medium conditioning, substrate modification, degeneration, and necrosis are discussed.
Play by Peary caribou calves before, during, and after helicopter harassment
Authors: Miller Frank L. , Gunn Anne
Published: April 2009

We observed 93 bouts of play behaviour by Peary caribou (Rangifer tarandus pearyi) calves on northeastern Prince of Wales Island, Northwest Territories (N.W.T.), between 23 June and 16 August 1977. Play consisted of 58 contagious, 20 exploratory, 13 agonistic, and 2 sexual bouts. Calves engaged in 30 bouts of play during the undisturbed phase, 30 bouts during the harassed phase, and 33 bouts during the recovery phase of the observations. Play was proportionately most frequent during the harassed phase, least frequent during the undisturbed phase, and occurred slightly less than expected during the recovery phase (P < 0.005). We speculate that (1) Peary caribou calves were more excited than adult companions by helicopter; (2) this higher excitement led to a general readiness to be active; and (3) when adults did not overtly respond, the readiness of the calves to be active was released as play. Therefore, play by Peary caribou should not be used as an indication of a total lack of stress during or shortly after periods of harassment.
Phagocytose de cellules à cristaux intranucléaires dans l'épithélium de l'intestin moyen de la larve de Tenebrio molitor L.
Authors: Gouranton Jean , Thomas Daniel
Published: April 2009

In the midgut of the larvae of Tenebrio molitor degenerating cells are sometimes engulfed by neighbouring cells. Midgut embryonic cells as well as differentiated cells that contain intranuclear crystals are phagocytosed.Aggregation of chromatin near the nuclear envelope and cytoplasmic condensation are observed in the engulfed cells. Sometimes, the nuclear envelope breaks down; this would explain the nuclear fragmentation and the appearance of chromatin clumps without surrounding envelope in the cytoplasm. The chromatinous nature of these clumps was determined by autoradiography in animals previously injected with tritiated thymidine.In the phagocytosis of cells with intranuclear crystals described in the present paper, the presence of a crystal identifies some intracellular inclusions as ingested cells at a late stage of disintegration.
A simple method for analyzing oral and intravenous treatment effects on biomass redistribution of Hymenolepis diminuta (Cestoda) in the rat intestine
Authors: Podesta R. B. , Mettrick D. F.
Published: April 2009

A simple mathematical expression is proposed to allow determination between the important and nonessential factors involved in analyzing the migrational responses of the tapeworm Hymenolepis diminuta to a variety of oral, intravenous, and vagal stimulations. Analysis of previous data suggests that the parasite is not responding to any single luminal factor but is reacting to a complex of changes mediated through vagal–hormonal interactions.
Growth and its relationship to the initial annual cycle of the golden-mantled ground squirrel, Spermophilus lateralis
Authors: Phillips John A.
Published: April 2009

Thirty-eight litters of golden-mantled ground squirrels (Spermophilus lateralis), from two populations that experienced different lengths of active season, were born and raised in the laboratory. Growth and development in young were inversely related to litter size. Offspring from smaller litters were both able to attain their prehibernation peak of body mass sooner and hibernate after fewer days of homeothermy than squirrels from larger litters. Young that remained homeothermic throughout the initial overwintering period were always from large litters and among the slowest growing littermates. Fecundity was lower in females from the temporally compressed environment. There was no significant difference between populations in the nutrition provided by mothers to their litters. The results suggest that reproductive effort is more conservative in populations of ground squirrels that experience short seasons of activity, yet this conservatism allows the offspring of those populations to reach independence and attain the prehibernation state of preparedness at an earlier age than their counterparts from populations of more moderate climates.
Metabolic expenditure of waleye (Stizostedion vitreum vitreum) as determined by rate of oxgen consumption
Authors: Tarby Martin J.
Published: April 2009

Energy expended by walleye (Stizostedion vitreum vitreum) for metabolism was assessed by measuring oxygen consumption of different size fish in respirometers under various conditions of temperature, activity, and ration. Standard metabolism was estimated as rate of oxygen consumption of unfed resting fish, and relationships to weight and temperature were expressed by simple and multiple regression equations. Although slopes for simple regressions did not differ significantly from slopes for analogous equations determined previously for walleye in maintenance feeding trials, the intercept or level of metabolism for a fish of unit weight at 20 °C computed from feeding experiments was over three times greater than that computed by respirometry. Heat increment, which was quantified from the difference in oxygen consumption of resting walleye fed and deprived of food at 20 °C, ranged from about 9 to 11% of the energy ingested and appeared independent of ration and fish size. Metabolism for swimming determined as the difference between rate of oxygen consumption of unfed fish resting and swimming one body length per second was calculated to be approximately equal to the energy expended by walleye for standard metabolism.
Growth, fecundity, and reproductive biology in the pedunculate cirripede Pollicipes polymerus at San Juan Island, Washington
Authors: Lewis Cindy Arey , Chia Fu-Shiang
Published: April 2009

Four populations of Pollicipes polymerus were sampled monthly for 26 months at two localities and two intertidal levels at San Juan Island, Washington, to determine the breeding season near the northern limit of the distribution of the species and for the comparison of growth, breeding cycles, and fecundity between the four populations.Pollicipes polymerus may reach a rostral–carinal length of 17 mm and sexual maturity during its 1st year after settlement. Subsequently, growth rate is reduced to about 2 mm in rostral–carinal length per year. The mean adult size increases from high intertidal level, Edward's Reef to low intertidal level, Edward's Reef to high intertidal level, Eagle Point to low intertidal level, Eagle Point. Juvenile growth rates, the percentage of breeding adults in an average month, and the mean monthly egg production also followed the above trend. Pollicipes polymerus breeds from late April through early October with a peak in July. The breeding season of the population at Eagle Point is longer than that of Edward's Reef. Obvious environmental factors that may have some effects on fecundity, growth rate, and the breeding season include temperature, wave action, food supply, and salinity. Preferred conditions include heavy surf and oceanic salinity.
The "polygyny threshold" model: a reassessment
Authors: Garson Peter J. , Pleszczynska Wanda K. , Holm Celia H.
Published: April 2009

The "polygyny threshold" model, first outlined by G. H. Orians in 1969, can be viewed as a functional explanation for the maintenance of polygyny in a population by natural selection. This model has been particularly associated with resource defence polygyny in passerine birds. Thus it is used here to generate some quantitative predictions concerning how the females in such a passerine population should distribute themselves for breeding over a series of territories defended by males, some of whom become polygynous as a result. Some of the assumptions underlying the model are examined and the predictions are tested using both new field data and some taken from the literature.
Use of saponin in the preparation of brush border from a parasitic flatworm
Authors: Rahman M. S. , Mettrick D. F. , Podesta R. B.
Published: April 2009

Saponin treatment in hypotonic or hypertonic fluids, followed by vibration, was used to isolate the brush border membrane from the surface epithelial syncytium of Hymenolepis diminuta. Electron microscopy of the membrane pellets and the parasites indicated that the area of the syncytium sheered by vibration of the parasites was correlated with the areas of the syncytium in which there occurred the greatest amount of osmotically induced swelling: below and adjacent to the brush border in hypotonic incubation, and the infoldings of the basal plasma membrane of the syncytium in hypertonic incubations. Vesiculation of the microvilli occurred in incubations made hypertonic with mannitol.
Properties of a Mg2+-dependent, and Ca2+-inhibited ATPase localized in the brush border of the surface epithelial syncytium of a parasitic flatworm
Authors: Rahman M. Saidur , Mettrick D. F. , Podesta R. B.
Published: April 2009

The brush border membrane of the surface epithelial syncytium of the parasitic flatworm, Hymenolepis diminuta, was isolated by saponin treatment, and the ATPase activity was determined. The ATPase activity was insensitive to ouabain, SCN−, HCO3−, ethanol, and, although slightly inhibited by high oligomycin concentrations, was inhibited by ethacrynic acid. Reaction mixtures made increasingly hypertonic with mannitol resulted in vesicular changes in the microvilli and decreased ATPase activity. Although treatment of the brush border fraction with deoxycholate increased ATPase activity, the dependence of activity on the osmotic pressure of the reaction mixture persisted in the solubilized membrane preparations. ATPase activity was dependent upon Mg2+ and Na+ + K+ concentration. It is suggested that the ATPase in the flatworm surface membrane is involved in volume regulation in hypotonic media.
Geography of larval dormancy in the tree-hole mosquito, Aedes triseriatus (Say)
Authors: Holzapfel Christina M. , Bradshaw William E.
Published: April 2009

Among Aedes triseriatus from 30–40° N latitude, photoperiod and temperature mediate the onset and maintenance of larval diapause. Photoperiod has a significant effect not only on the initiation and maintenance of diapause but also on the rate of postdiapause development, both directly and by modifying response to temperature. The critical photoperiod for larval diapause is shorter than that for controlling rate of development. Over most of the range considered, both the critical photoperiod for the induction and maintenance of larval diapause and that for rate of development are shorter than the critical photoperiod governing embryonic diapause. Based on relative photoperiodic response and censuses of overwintering populations, we conclude that larval diapause in A. triseriatus is mainly a backup or fail-safe system for embryonic diapause and that the major adaptive significance of larval diapause relates to the modulation of late winter and spring development rather than to overwintering, per se.
Seasonal changes in morphology of the thyroid gland of a hibernator, Spermophilus richardsoni
Authors: Winston Brent W. , Henderson Nancy E.
Published: April 2009

Seasonal changes in morphology of the thyroid gland were studied in Richardson's ground squirrels, Spermophilus richardsoni. Animals were sampled at six times during the annual cycle, and thyroid tissue was examined at the light and electron microscope levels. Synthesis and resorption of thyroglobulin were assessed on the bases of numbers of apical vesicles, colloid droplets, dense granules, and dense bodies, development of the Golgi apparatus and RER, and number and appearance of microvilli and mitochondria.Synthetic and resorptive activities of the throid-hormone-producing cells are high during the early prehibernation or preparative phase and decrease to moderate levels before entry into hibernation. Onset of hibernation is accompanied by further reductions in thyroid cell activities which reach minimal levels by midhibernation. Synthetic and resorptive functions increase slightly toward the end of hibernation. The reproductive phase following emergence is marked by a return to high levels of activities. Colloid storage in the follicles increases between early prehibernation and midhibernation and then decreases. The morphological observations suggest that triiodo-L-thyronine (T3) and L-thyroxine (T4) production and secretion are markedly reduced in hibernating ground squirrels. However, measurements of the circulating levels of the hormones have shown that the titres of both T3 and T4 are elevated in hibernating animals. The apparent contradiction between morphological and physiological data is discussed.
Reproduction in yearling female Columbian ground squirrels (Spermophilus columbianus)
Authors: Festa-Bianchet M.
Published: April 2009

In 1980, 4 of 13 yearling female Columbian ground squirrels in a colony in southwestern Alberta raised litters. Mean litter size was not significantly smaller than that of adult females. Breeding and nonbreeding yearling females had similar growth rates as juveniles in 1979, but the former had a lower weight gain in 1980 before their young were weaned. Breeding yearling females were more aggressive and played less than nonbreeders. A combination of apparently good habitat quality in the study area and favourable weather conditions during summer of 1979 and in May of 1980 may have produced early sexual development of these females.
Distribution in Manitoba of Mustela frenata longicauda Bonaparte, the long-tailed weasel, and the interrelation of distribution and habitat selection in Manitoba, Saskatchewan, and Alberta
Authors: Gamble R. Lloyd
Published: April 2009

The distribution of Mustela frenata longicauda was ascertained for Manitoba, Saskatchewan, and Alberta by examination of 91 labelled museum specimens and 186 carcasses provided by trappers from Manitoba. Collection records on site selection and distribution reaffirm the author's contention that M. frenata prefers late seral stages or ecotones in close proximity to free standing water. The transition between aspen parkland and the boreal forest or taiga is the northernmost distribution of this species in the Canadian prairies.
Body growth and carcass composition of lean reindeer (Rangifer tarandus tarandus L.) from birth to sexual maturity
Authors: Ringberg Tata M. , White Robert G. , Holleman Dan F. , Luick Jack R.
Published: April 2009

Body growth and carcass composition were measured in lean reindeer during the juvenile growth period between birth and 3 years of age. Mean carcass weight in these lean reindeer was 56 ± 4% of body weight and the deposition of body muscle and bone mass was linearly correlated with body weight after the 1st month of age. The weight of the brain relative to body weight and carcass weight declined, while the relative changes in heart, liver, kidneys, parotid glands, and tissues of the gastrointestinal tract were small after the neonatal period. The extractable fat content in carcasses increased from 4.4 to 11.4% of wet weight or approximately 100 g fat at birth and 3.5 kg fat in adult reindeer. Fat-free dry matter represented a constant percentage (18–20%) of wet carcass weight independent of body weight after the neonatal period, while a significant inverse relationship between carcass fat and body water was found.
Seasonal variations in thyroxine and testosterone levels in relation to the moult in the adult male mink (Mustela vison Peale and Beauvois)
Authors: Boissin-Agasse L. , Maurel D. , Boissin J.
Published: April 2009

Plasma thyroxine (T4) and testosterone concentrations were measured in adult male mink maintained outdoors under natural light and fed ad libitum the whole year round. Plasma T4 concentrations presented a biphasic seasonal change, the highest values occurring in the spring and autumn months and the lowest values in the winter months. The plasma testosterone cycle showed an annual maximum in January–February. The possibility of testis–thyroid interactions is discussed. The changes observed are correlated with environmental temperature, photoperiod, and molting cycle.
Mechanics of ostraciiform propulsion
Authors: Blake R. W.
Published: April 2009

Two hydromechanical models are employed to analyse the motions of the caudal fin of a small specimen of Ostracion lentiginosum (Ostraciidae). Values of the drag coefficient of the body of the fish are inferred by equating the impulse of the thrust force produced over the tail beat cycle with the impulse of the drag force acting on the body over the same period of time. On average, the inferred values for the drag coefficient are within 15% of experimentally determined values. Drag coefficients for ostraciiform fish are an order of magnitude greater than those for streamlined fish. The hydromechanical efficiency of the caudal fin propeller of O. lentiginosum is calculated to be of the order of 0.5. This result is predicted by the hydromechanical theory.
Prey capture in the chain pickerel, Esox niger: correlations between feeding and locomotor behavior
Authors: Rand David M. , Lauder George V.
Published: April 2009

The predatory behavior of the chain pickerel Esox niger was studied by high-speed cinematography to correlate patterns of jaw bone movement with locomotor patterns. Pattern B strikes were initiated at significantly shorter distances from the prey, had higher acceleration rates, and the velocity of mouth opening and suspensorial abduction was greater than for pattern A strikes. No difference was found in the excursion amplitudes of jaw movements between pattern A and pattern B strikes. Significant differences were found between midwater and corner strikes in the amplitude of mouth opening and hyoid depression: both were smaller in corner attacks and suction velocity was higher. Both velocity and amplitude of each mechanical unit in the head can be varied depending on the locomotor pattern and the position of the prey.
Copepodids of Bradyidius similis (Sars, 1902) (Crustacea: Copepoda) in the Saguenay fjord and the St. Lawrence estuary
Authors: Shih Chang-Tai , Rainville Luc , Maclellan Delphine C.
Published: April 2009

All copepodite stages of Bradyidius similis were taken in plankton samples from the deep water of the Saguenay fjord and the adjacent St. Lawrence estuary during the months of May to October in 1974. They are described and illustrated. The spinules on the posterior surface of the second to fourth pairs of legs, which were reported absent in this species, appear on copepodite IV onwards.
Initiation of breeding by northern Peromyscus in relation to temperature
Authors: Millar John S. , Gyug Les W.
Published: April 2009

Initiation of breeding by Peromyscus leucopus noveboracensis (Fischer) near London, Ontario, P. maniculatus maniculatus (Wagner) near Pinawa, Manitoba, and P. m. borealis (Mearns) near Hay River, N.W.T. was examined in relation to seasonal changes in daily minimum temperatures. Spring breeding commenced in all three populations before minimum temperatures reached 0 °C. A comparison of mean breeding temperatures between populations indicated that first litters of P. m. borealis were conceived at significantly higher temperatures (−1.7 °C) than those of P. m. maniculatus (−5.8 °C). During the first 15 days of the nesting period, minimum ambient temperatures and the percentage of nights below freezing were higher and lower, respectively, for P. m. borealis (6.0 °C; 4%) than for P. m. maniculatus (3.2 °C; 30%) or P. leucopus (4.3 °C; 22%). We suggest that P. m. maniculatus and P. leucopus breed early in order to maximize the number of descendants during the summer. Earlier breeding by P. m. borealis would not enhance the number of descendants per season.
Observations of the echolocation, feeding behaviour, and habitat use of Euderma maculatum (Chiroptera: Vespertilionidae) in southcentral British Columbia
Authors: Woodsworth G. C. , Bell G. P. , Fenton M. B.
Published: April 2009

A record of the spotted bat, Euderma maculatum, from Oliver, British Columbia, is the first for Canada, extending its known range approximately 900 km. The specimen was obtained from a well-established breeding population in this area and does not represent an accidental or stray record. Observations of the foraging bahaviour of E. maculatum suggest that it may change its strategy from a rapid traplining approach in the spring, to spending more time per feeding site later in the summer, always foraging in ponderosa pine montane woodland. In the study area, E. maculatum appeared to roost in areas with high steep cliffs. The echolocation calls of this species are of low frequency (fundamental from 15 to 8 kHz) and moderate intensity (80–90 dB). Our observations and the theoretical implications of its echolocation call structure suggest that E. maculatum is a fast-flying, high-level forager that may include a high proportion of tympanate moths in its diet.
La croissance de la capsule céphalique et du siphon respiratoire des formes larvaires d'Aedes (Ochlerotatus) atropalpus (Coquillett) (Diptera : Culicidae)
Authors: Bourassa Jean-P.
Published: April 2009

Morphometric analysis of the cephalic capsule and the respiratory siphon of larval forms of Aedes atropalpus shows a deviation from the exponential function of Dyar's growth rule. The larval growth of the species followed a linear function more closely, which would result from the rapid drying of the colonized pools and the uncertain availability of food.
Onchocleidus ferox (Mueller, 1934) and O. similis Mueller, 1936 (Monogenea: Ancyrocephalinae) from Lepomis gibbosus L. (Pisces: Centrarchidae) in Ontario, Canada: anatomy, systematic position, and possible evolution
Authors: Beverley-Burton M. , Suriano D. M.
Published: April 2009

Onchocleidus ferox (Mueller, 1934) Mueller, 1936 and O. similis Mueller, 1936 (Monogenea: Ancyrocephalinae) from the gills of Lepomis gibbosus L. (pumpkinseed) in Ontario, Canada, are redescribed with details of their internal anatomy as well as the sclerotized components of the haptor and copulatory complex. A revised generic diagnosis incorporating features of the reproductive systems is presented. The North American freshwater ancyrocephalines which have a penis of similar type to that of O. ferox appear to be confined to genera of the Centrarchidae, Percichthyidae, and Etheostomatini. A similar penis occurs in ancyrocephalines parasitizing marine percoid fishes. Possible evolutionary pathways for this group of monogenes, based on an awareness of the probable origins of their piscine hosts, are discussed.
A simple method for perfusion fixation of avian liver for electron microscopy
Authors: Bhatnagar M. K. , David L. L. , Vrablic Olga , Therien A. , Blouin Andre
Published: April 2009

A simple method and apparatus are described for perfusion fixation of avian liver for electron microscopy. A constant perfusion pressure is maintained at or below a fixed value with the use of a compressed air cylinder and without the use of automatic devices. A hyperosmotic (580–600 mosm) fixative solution containing 4% glutaraldehyde, 0.0005 M CaCl2, and 0.0005 M MgCl2 in 0.05 M phosphate buffer (pH 7.4, buffer osmolality 122 mosm) produced consistent fixation without swelling or undue shrinkage. The cytoplasmic organelles were well preserved; notably, the mitochondria had electron-dense matrices and well-defined cristae. A pressure of 60 mmHg (1 mmHg = 133.322 Pa) maintained by compressed air permits a minimum to maximum flow rate of 14–19 mL∙min−1∙kg body weight−1, and optimum preservations of the architecture of sinusoids.
A preliminary investigation on the effects of parasitism of domestic ducklings by Theromyzon rude (Hirudinoidea: Glossiphoniidae)
Authors: Davies Ronald W. , Wilkialis Josef
Published: April 2009

Domestic ducklings (499–580 g) were parasitized experimentally with the temporary ectoparasitic blood sucking leech Theromyzon rude (Baird, 1869) (Glossiphoniidae). Compared with the unparasitized control group of ducklings, the parasitized ducklings showed significant differences in live body weight, and the mean weights of the thymi, spleen, and liver. Histopathologically the only evidence of the parasitism was congestion of the vessels of the lamina propria and erythrocytes in the lumen; microscopically no ulceration or inflammation of the mucosa of the nares was visible. An antigenic reaction against T. rude was also detected.
Fat and protein reserves of wintering and prebreeding rock ptarmigan from south Hudson Bay
Authors: Thomas Vernon G. , Popko Richard
Published: April 2009

The proximate body composition and muscle and organ composition of rock ptarmigan (Lagopus mutus rupestris) were measured in birds collected during late winter at Winisk, Ontario, and just prior to breeding after their migration to southern Baffin Island. The neutral fat reserve was less than 4% of the body weight in male and female ptarmigan from both locations. This small lipid-energy reserve, coupled with the catabolism of labile protein, would not maintain the existence-energy requirements of rock ptarmigan for longer than 2 days during fasting winter conditions.The ovary weight and liver weight were not correlated with the neutral fat load of prebreeding females, but hypertrophy of the liver was apparent. In the absence of food the small amount of neutral fat and labile protein could help form only a fraction of the normal clutch size, but the possible role of these reserves in buffering short-term dietary shortages during egg formation is outlined. The small size of the energy reserves emphasizes the importance of persistent feeding during winter, to maintain homeothermy, and during egg formation, when the quantity and quality of food could be a proximate limiting factor in reproduction.
Pelage polymorphism in Pacific harbor seals
Authors: Kelly Brendan P.
Published: April 2009

Regional variation in the percentages of harbor seals, Phoca vitulina, in light- and dark-phase pelages has been reported recently. Distributions of color phases among sex classes and age-classes and within family groups were examined during two pupping seasons on Tugidak Island and one season on Otter Island, Alaska. The ratio of light phase to dark phase in 880 pups with light mothers showed a good fit with expected values predicted by the hypothesis that the pelage dimorphism is controlled by a pair of autosomal alleles with light phase dominant over dark. A sample of 229 pups with dark mothers did not fit the hypothesis well. Color phase ratios did not differ between sexes or size classes but varied consistently with age-class. Differential selection against seals with light-phase pelage seems to be highest in the youngest age-classes at both localities.
A world review of the convallis species group in the genus Typhlodromus Scheuten (Acarina: Phytoseiidae)
Authors: Chant D. A. , Shaul E. Yoshida
Published: April 2009

A newly conceived convallis species group in the genus Typhlodromus Scheuten is proposed. Characters for the group are described and descriptions of the adult females of each species are given. Keys to the liliaceus and convallis species groups as well as keys to the seven species in the latter group are also given.
A revision of Cycloplectanum Oliver, 1968 (Monogenea: Diplectanidae) and descriptions of C. hongkongensis n.sp. and C. lantauensis n.sp. from Epinephelus spp. (Serranidae) in the South China Sea
Authors: Beverley-Burton Mary , Suriano Delia Mabel
Published: April 2009

An emended generic diagnosis for Cycloplectanum Oliver, 1968 (Monogenea: Diplectanidae) is provided which emphasizes the importance of the terminal genitalia (penis and vagina) in generic separation. Cycloplectanum americanum (Price, 1937) Oliver, 1968 is recognized as type species of Cycloplectanum. Cycloplectanum epinepheli (Yamaguti, 1938) n.comb., C. serrani (Yamaguti, 1953) n.comb., C. amplidiscatum (Bravo-Hollis, 1955) n.comb., C. latesi (Tripathi, 1955) n.comb., C. melanesiensis (Laird, 1958) n.comb., C. querni (Yamaguti, 1968) n.comb., C. cupatum (Young, 1969) n.comb., C. summanae (Young, 1969) n.comb., C. vagampullum (Young, 1969) n.comb., together with C. hongkongensis n.sp., C. lantauensis n.sp., and C. yamagutii nom.nov., are included in the genus. Cycloplectanum yamagutii nom.nov. is proposed for Pseudorhabdosynochus epinepheli which was named a synonym of C. americanum by G. Oliver in 1968.Based on material from Epinephelus spp. (Serranidae) taken in the South China Sea, redescriptions are presented for C. cupatum and C. vagampullum. In addition, C. hongkongensis n.sp. from E. brunneus and E. awoara and C. lantauensis n.sp. from E. brunneus and E. fario are proposed. The findings of C. cupatum and C. vagampullum on E. fario represent new host and geographic records.
New species of Lumbricillus (Oligochaeta, Enchytraeidae) from littoral habitats of British Columbia
Authors: Coates Kathryn
Published: April 2009

Three new marine, intertidal species of Lumbricillus are described from oligochaete collections taken in British Columbia. Lumbricillus tsimpseanis sp.nov., which was collected in upper intertidal habitats near Prince Rupert, is similar in morphology and habitat to L. helgolandicus Michaelsen emend. Nielsen and Christensen and L. kamtschatkanus Michaelsen, but is characterized by gland cells both around the spermathecal orifice and along its ectal duct. Specimens of Lumbricillus curtus sp.nov., a small species, were collected from three well-separated silty upper intertidal habitats. It is characterized by enlarged posterior lobes of the pharyngeal (=septal) glands of 6/7 and by spermathecae which unite with the oesophagus at one-half V. Lumbricillus rupertensis sp.nov., from intertidal silty sediments with much wood debris near Prince Rupert, is similar to L. lineatus with which it was found, but is characterized by a globular ampullar expansion lateral to the connection of the spermatheca with the oesophagus.
Hapalorhynchus rugatus sp.nov. (Digenea: Spirorchiidae) from a Malaysian freshwater turtle
Authors: Brooks Daniel R. , Sullivan James J.
Published: April 2009

A new species of Hapalorhynchus collected from a Malaysian soft-shelled turtle, Trionyx cartilagineus, most closely resembles H. lyssimus from an Indian soft-shelled turtle by having vitelline follicles restricted to the hindbody and by having lateral muscular papillae on the body, traits no other species of Hapalorhynchus possesses. The new species differs from H. lyssimus by lacking an expanded hindbody and possessing a relatively smaller cirrus sac, lobate rather than smooth testes, and body papillae restricted to the hindbody rather than extending into the forebody and which are fewer in number than those present on H. lyssimus. Coeuritrema macrotesticularis is transferred to Hapalorhynchus and a key to members of Hapalorhynchus is provided.
Observation et analyse de la prédation des œufs d'Ambystoma maculatum (Shaw) (Amphibia, Urodela) par des larves de Diptères chironomidés, dans la région de Trois-Rivières (Québec)
Authors: Leclair Jr. Raymond , Bourassa Jean-Pierre
Published: April 2009

Observations during spring 1980 in two temporary pools near Trois-Rivières, Quebec, and in the laboratory show that Dipterian chironomid larvae can go through the gelatinous envelopes of egg masses of the salamander Ambystoma maculatum and consume developing eggs and embryos. In the clear water pool, egg spawns are heavily infested by the chironomid Parachironomus cf. forceps and embryonic mortality reaches 70 to 100%. In the dark water pool, infestation by an unidentified chironomid is low and embryonic mortality reaches 8%. In both cases, chironomid larvae leave the egg masses some 9 days before hatching of the salamanders. Fortuitous exploitation of a readily available resource is hypothesized; the frequency and precision of the observed phenological coincidence, due to the presence of other syntopic amphibian spring breeders, will be examined further.
Gyrinicola batrachiensis (Walton, 1929) n.comb. (Oxyuroidea; Nematoda) from tadpoles in eastern and central Canada
Authors: Adamson Martin L.
Published: April 2009

Gyrinicola batrachiensis (Walton, 1929) n.comb. (=Pharyngodon batrachiensis Walton, 1929) was found in seven species of anurans belonging to the Ranidae, Hylidae, and Bufonidae in New Brunswick, Quebec, and Ontario, Canada. Transformed anurans were not infected. The species is redescribed from material collected near Guelph, Ontario. Pharyngodon armatus Walton, 1933 is considered a synonym of G. batrachiensis. Gyrinicola Yamaguti, 1938 is redefined and transferred to the Oxyuroidea from the Cosmocercoidea. The genus is distinguished by the presence of two egg types in females. Thick-shelled eggs with embryos in an early stage of cleavage were present in one horn of the reproductive tract, whereas thin-shelled larvated eggs were present in the other horn. Three species of Gyrinicola are recognized, namely, G. batrachiensis in North America, G. tba (Dinnik, 1930) n.comb. in Europe, and G. japonica Yamaguti, 1938 in Japan.
Development and transmission of Gyrinicola batrachiensis (Walton, 1929) Adamson, 1981 (Pharyngodonidae: Oxyuroidea)
Authors: Adamson Martin L.
Published: April 2009

Individual female Gyrinicola batrachiensis from tadpoles produce thin-shelled larvated eggs and thick-shelled eggs containing embryos in an early stage of cleavage. Larvae in thin-shelled eggs hatched soon after deposition and survived for less than 1 h in aged tap water, pond water, or diluted buffer. Results presented herein show that thin-shelled eggs are autoinfective whereas thick-shelled eggs are transmission agents. Thick-shelled eggs isolated from natural infections in Rana clamitans, Rana pipiens, and Bufo americanus were infective to tadpoles of R. clamitans, R. sylvatica, Pseudacris triseriata, and B. americanus but not to transformed anurans. All worms recovered from tadpoles experimentally infected with eggs from natural infections in B. americanus were females and only 15% of worms examined from tadpoles experimentally infected with eggs from natural infections in R. clamitans were males. Development of G. batrachiensis was studied in experimentally infected R. clamitans held at 20 and 25 °C. Development was more rapid at 25 °C and males developed more rapidly than females at both temperatures. Adult males were first observed after 9 days (25 °C) and 16 days (20 °C) and adult females were first observed after 12 days (25 °C) and 19 days (20 °C).
Seasonal changes in populations of Gyrinicola batrachiensis (Walton, 1929) in wild tadpoles
Authors: Adamson Martin L.
Published: April 2009

Five hundred and thirty-five tadpoles of Rana clamitans, collected from a permanent pond throughout spring, summer and fall, 1976 to 1978, and 85 tadpoles of Bufo americanus, collected from a seasonal marsh in summer, 1978 were examined for the presence of Gyrinicola batrachiensis. Rana clamitans laid eggs in June or July, passed one winter in the tadpole stage, and metamorphosed the following June or July. Gyrinicola batrachiensis occurred only in tadpoles and was lost from metamorphosing tadpoles prior to the eruption of the forelimbs. Individual female worms produce thick-shelled eggs involved in transmission as well as thin-shelled, autoinfective eggs. The number of each egg type in female worms collected from August 1977 to June 1978 was determined. Young-of-the-year tadpoles apparently were infected by ingesting thick-shelled eggs. In late fall almost all tadpoles contained adult worms and thin-shelled eggs predominated in female worms at this time. There was no transmission or autoinfection in winter; female worms which had wintered in tadpoles deposited autoinfective thin-shelled eggs in April resulting in a sharp increase in intensity. Females of the autoinfective generation matured in May and June, and contained almost exclusively thick-shelled eggs. Thus, young-of-the-year tadpoles enter an environment recently contaminated with thick-shelled eggs of G. batrachiensis. Bufo americanus hatches and metamorphoses in a single season. In this host, G. batrachiensis underwent a single generation. Males were not found and females contained only thick-shelled eggs. The absence of autoinfective eggs in worms from this host is understandable because of the brief period toads spent as tadpoles.
Experimental studies on acarine predator–prey interactions: effects of predator age and feeding history on prey consumption and the functional response (Acarina: Phytoseiidae)
Authors: Eveleigh Eldon S. , Chant D. A.
Published: April 2009

Laboratory experiments were performed to determine the functional response to prey density of various instars of two species of predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, and to examine the effects of predator age and nutritional history on their responses. The experiments showed that the nutritional requirements of the predators, the time that they are exposed to prey in relation to their life-span, increasing age, and differences in nutritional history, can have important effects on predatory behaviour and the functional response. Prolonged exposure to one density of prey can cause lags in predation rates when the prey density is changed. The results indicated that functional responses are probably multiform in certain predators and the above factors may provide an explanation of the variety of responses previously reported for species of phytoseiid mites. Phytoseiulus persimilis appeared to be more sensitive to some of these factors than A. degenerans and was shown to be different in many aspects of its predatory behaviour.
Microsporidia (Microspora: Microsporida) from Newfoundland blackflies (Diptera: Simuliidae)
Authors: Vávra Jiri , Undeen Albert H.
Published: April 2009

Examination of several hundred microsporidia-infected blackfly larvae collected in Newfoundland, Canada, revealed the presence of seven clearly distinguishable microsporidian species: Caudospora simulii, Caudospora polymorpha, Amblyospora bracteata, Thelohania varians, Thelohania fibrata, Tuzetia debaisieuxi, and Pleistophora multispora. The classification of the last five species is reviewed. Microsporidium sp. was found in the fat body of larvae of Simulium longistylatum. Another Microsporidium sp. was found in the nerve chord of Prosimulium mixtum.
Octopine dehydrogenase and phosphoarginine kinase in squid mantle: cooperation of two enzymes at the arginine branchpoint in cephalopod muscle
Authors: Vollmer Maria , Hochachka Peter W. , Mommsen Thomas P.
Published: April 2009

Octopine dehydrogenase (ODH, EC 1.5.1.11) and phosphoarginine kinase (PAK, EC 2.5.3.3) from squid mantle (Loligo opalescens) were purified and obtained uncontaminated by each other and free of lactic dehydrogenase and malic dehydrogenase. Kinetic data were analyzed for substrates and cosubstrates for forward and reverse reactions.Octopine, NAD+, ATP, and ADP are inhibitors of the ODH forward reaction (octopine forming); arginine and NADH inhibit the reverse reaction. ATP and ADP inhibition disappears upon addition of Mg2+ to the assay medium. Arginine phosphate inhibits the PAK forward reaction (phosphoarginine forming), whereas arginine and NADH inhibit the reverse reaction.We suggest that PAK and ODH function is two-phased and cooperative, with PAK being active before ODH, PAK working in the reverse reaction, and ODH in the forward reaction, during burst muscle work, and PAK being active before ODH during recovery. ODH activity is probably regulated by pyruvate and NADH availability in the forward direction and by arginine deinhibition in the reverse direction.Evidence is presented for the suggestion that present concepts of the relationship between phosphagen and octopine should be revised to assume that resting concentrations of free arginine in cephalopod muscle are kept at a minimum.
The biology and parasites of deepwater sculpin, Myoxocephalus quadricornis thompsonii (Girard), in Burchell Lake, Ontario
Authors: Black Geoff A. , Lankester Murray W.
Published: April 2009

Ninety-five deepwater sculpin, Myoxocephalus quadricornis thompsonii (Girard), sampled from Burchell Lake, Ontario, 12 October 1980, were up to 92 mm long. Ninety-eight percent of the specimens were less than 4 years old. Some 2-year-old males had enlarged testes; all older males and females had enlarged testes and eggs (mean diameter, 1.43 mm), respectively. Spawning probably occurs during late fall or winter.Parasites found included Diplostomulum sp. (metacercariae), Bothriocephalus sp. (immature), Cyathocephalus truncatus (nongravid), Cystidicola cristivomeri (third-stage larvae), and third-stage larvae of a spirurine nematode.
The seal louse, Echinophthirius horridus: an intermediate host of the seal heartworm, Dipetalonema spirocauda (Nematoda)
Authors: Geraci J. R. , Fortin J. F. , Aubin D. J. St. , Hicks B. D.
Published: April 2009

Heartworms, Dipetalonema spirocauda, are common in harbour seals, Phoca vitulina, that strand along the New England coast. Lice, Echinophthirius horridus, taken from a stranded harbour seal infected with seal heartworm carried three developmental stages of D. spirocauda. This is the first report of an intermediate host of the seal heartworm.
A tide simulator and examples of its use
Authors: Carefoot Thomas H.
Published: April 2009

The design and operation of a tide simulator, suitable for teaching or research use, is presented. Two examples of its application to the teaching of marine ecology are included, one examining the influence of higher temperature on the vertical distributions of four species of intertidal snails, the other comparing the distributions of two species of limpets in response to a predatory sea star.
Corella species in the American Pacific Northwest: distinction of C. inflata Huntsman, 1912 from C. willmeriana Herdman, 1898 (Ascidiacea, Phlebobranchia)
Authors: Lambert Gretchen , Lambert Charles C. , Abbott Donald P.
Published: April 2009

The solitary phlebobranch ascidian Corella inflata, originally described by Huntsman in 1912 but later synonymized with C. willmeriana Herdman, 1898, is now reinstated as a separate species based on comparative morphology of adults, sperm, and tadpoles. Corella inflata is probably largely or completely self-fertilizing, broods its eggs and embryos until well after hatching of the tadpole larvae, and is confined in its distribution to shallow-water (0.1–18 m depth) areas of northwestern Washington and British Columbia. Corella willmeriana appears to be both self- and cross-fertilizing, does not brood its eggs, and is more widespread in distribution, occurring from southern Alaska to southern California and at least as deep as 50 m; it is rarely encountered at the sea surface. The two Corella species differ morphologically from the European Corella parallelogramma and the Japanese C. japonica and C. japonica asamushi. Differential spawning latencies are discussed and the possibility that C. inflata evolved through stasipatric speciation is proposed.