bluuebunny/crossref_metadata_2025 huggingface dataset:
Sibling species delimitation in the Aedes communis (Degeer) aggregate (Diptera: Culicidae)
Authors: Ellis R. A. , Brust R. A.
Published: August 2008

Aedes communis (Deg.) sens. str. from Canada and the United States, A. nevadensis Chapman and Barr n. status from the northwestern United States, and A. churchillensis sp. n. from western Canada are described. The distribution and keys to the larvae, female imagos, anti male genitalia of the three species are presented. The size and chorionic markings of the eggs of A. communis and A. churchillensis are described and illustrated. Variation in the anatomy and chaetotaxy of the fourth-instar larvae, the anatomy of the salivary glands, and the chaetotaxy of the thorax of female imagos, and the ungues of the imagos is described and illustrated. An autogeny survey revealed that the female imagos oi A. communis and A. nevadensis are normally obligatorily anautogenous or rarely facultatively autogenous whereas those of A. churchillensis are normally obligatorily autogenous. Differences in the size and general anatomy of the salivary glands of A. churchillensis and their possible association with autogeny are discussed. Mating success of caged imagos of A. communis and A. churchillensis, caged separately or together, was evaluated; imagos of the former species are eurygamous whereas those of the latter are stenogamous; some mating between caged imagos of the two species is possible. Observations of mating between imagos of A. communis in nature are discussed in relation to swarming. Hybridization in the laboratory revealed a low degree of genetic affinity between A. communis and A. churchillensis.
Sequential changes in regional distribution of blood in Eptesicus fuscus (big brown bat) daring arousal from hibernation
Authors: Rauch Josefine C.
Published: August 2008

Heart rates were studied in deeply hibernating and in arousing bats (Eptesicus fuscus). Values range from an average of 12 beats/min in deep hibernation to an average of 800 beats/min during peak arousal.Body temperatures were recorded. Arousing bats develop the "usual" anteroposterior temperature gradient.The distribution of blood was determined (Sapirstein method), and capillary organ blood-flow rates were approximated in deeply hibernating, in arousing, and in postarousal bats.The study indicates that, after the initiation of arousal, there is a redistribution of blood such that capillary blood-flow rates in organs of the anterior body rise more rapidly than do those in organs of the posterior body. A higher metabolic requirement for oxygen by brown adipose tissue as compared to other tissues, and the relatively high rate of heat production by brown fat, are thought to be largely responsible for this "shunting" of blood to anterior body regions during early arousal.
A study of specialized cells of the tracheal gills of Paragnetina media (Plecoptera)
Authors: Kapoor N. N. , Zachariah K.
Published: August 2008

Light and electron microscopic examination of the gills of the plecopteran nymph Paragnetina media revealed a highly tracheated epithelium with many specialized cells. These cells show several features characteristic of the osmoregulatory tissue of other animals. In the cell, numerous mitochondria are lodged in elongated folds of the plasma membrane in such a way that they are brought into a very close relationship to an area of the cell surface. It is assumed that this arrangement provides metabolically active surface for the exchange of materials, absorption, or excretion. It is most likely that the gills can absorb salt from the water, and thus compensate for the loss of salt through the urine. The distinctive cuticular plaque which forms the interface of each cell with the external environment is featured and discussed too.
A possible hybrid cottid (genus Myoxocephalus) from Newfoundland
Authors: Cowan Garry I. McT.
Published: August 2008

A sculpin collected from Portugal Cove, Conception Bay, Newfoundland, is found to represent a possible hybrid between Myoxocephalus scorpius and Myoxocephalus octodecemspinosus. Investigation of meristic, morphometric, and anatomical criteria suggests that the specimen has closer affinity to M. scorpius than to the other species but in most respects is intermediate.
The energy budget of the adult stage of the greater wax moth, Galleria mellonella (L.)
Authors: Carefoot Thomas H.
Published: August 2008

Energy budgets calculated for the nonfeeding adult stages of Galleria mellonella show that the animals die with a remaining energy content of 33–35% of the original caloric content of the newly eclosed adult, In the female, eggs account for 17% of the original energy content of the new adult and metabolism for about 50%. In the male, 65% of the original adult energy is accounted for by metabolism and an immeasurably small amount by production of sperm. The averaged energy budgets deviate from the balanced condition by +1% for the females and by 0% for the males, but with considerable variation between individuals (−15 to +24% for 10 females, and −17 to +19% for 10 males).
Hypophysectomy and pectoral fin regeneration in adult Fundulus heteroclitus (killifish)
Authors: Liversage Richard A.
Published: August 2008

Adult male and female Fundulus heteroclitus (killifish) between 7 and 9 g body weight were included in this work, which was designed to determine the effects of hypophysectomy upon pectoral fin regeneration.Consideration was given to a possible relationship between the pituitary gland and fin regeneration and whether or not the presence of the pituitary is essential for regeneration. Included in this investigation were 436 killifish which consisted of three hypophysectomy, two sham hypophysectomy, and one control regenerate series. In the experiments, hypophysectomy was (a) concomitant with fin amputation; (b) followed in 5 days by fin amputation; or (c) performed 5 days after fin amputation.The results show that after hypophysectomy long-term regeneration ensues and the resulting morphogenetic pattern is very similar to that found in regenerates of the sham hypophysectomized and control regenerate killifish.
DDE and reproductive success in some Alberta common terns
Authors: Switzer Bruce , Lewin Victor , Wolfe Fred H.
Published: August 2008

A study of the relationship of DDE to reproductive success of an inland breeding population of common terns. Sterna hirundo, had been carried out in 1969 and 1970 at Chip Lake, Alberta. Although a continuing decrease of DDE residues in eggs bad occurred, eggshell thickness remained unchanged. In addition, reproductive success markedly increased in 1970; however, the percentage of eggs suffering breakage did not change between years. Low correlations between DDE and eggshell thickness or weight in both years suggest that DDE is unrelated to these eggshell parameters, which in turn are not related to reproductive success in this population.
Helminths of wolves, Canis lupus L., in the Yukon and Northwest Territories
Authors: Choquette L. P. E. , Gibson G. G. , Kuyt E. , Pearson A. M.
Published: August 2008

Wolves from the Yukon and Northwest Territories harbored the following gastrointestinal helminths: Alaria americana (10 of 171), A. arisaemoides (2/171), Diphyllobothrium sp, (1/171). Mesocestoidcs kirbyi (3/171), Taenia hydatigena (54/111), T. krabbei (63/111), T. pisiformis (2/111), T. serialis (41/111), Echinococcus granulosus (24/171), Toxascaris leonina (83/171). Uncinaria stenocephala (11/171), Spirocerca arctica (1/171), and S. lupi (1/171). Larval Trichinella spiralis occurred in 72 of 153 diaphragms. A. arisaemoides, M. kirbyi, and S. arctica were found for the first time in Canis lupus, while S. lupi, S. arctica, and the prevalence of T. spiralis in wolves are reported for the first time in Canada.
Seasonal changes in the accessory sex glands and gonaducts of male mink
Authors: Basrur P. K. , Ramos A. S.
Published: August 2008

The anatomic and developmental changes in the reproductive ducts and accessory sex glands of male mink have been examined at regular intervals during the year. The accessory sex glands noted in mink included a well-developed prostate gland and distinct ampullae while seminal vesicles and bulbourethral glands were absent. The cyclical changes noted in the gross morphology and histology of the duel system, the ampullae, and prostate gland of mink appeared 10 parallel the seasonal changes noted in the testes. It is postulated that the functional anatomy of the gonaducts and accessory sex glands of the adult mink may be causally related to the seasonal changes in the endocrine activity of the interstitial cells of the testis.
Social learning and the significance of mixed-species flocks of chickadees (Parus spp.)
Authors: Krebs John R.
Published: August 2008

The experiments described in this paper show that two species of chickadees learn from one another about the location and nature of potential feeding places when they are foraging together in mixed flocks in large aviaries. In the first experiment, I show that when an individual of one species finds a single food item, members of the other species modify their foraging behavior over the next few seconds so that they put more effort into searching near the site of the find. This applies to both species. Further, members of both species modify their foraging behavior when a bird of the other species searches in a place unsuccessfully. This response to an unsuccessful search is similar to, but weaker than, the response to a food find. The second experiment shows that when the two species are trained to forage in different positions in the experimental trees, they converge in their foraging behavior when they are put in mixed flocks, This is a result of copying. The third experiment shows that individuals of both species are more likely to discover a completely new foraging place if they are in the presence of an experienced bird of the other species.I discuss these results in relation to theories on the adaptive significance of flocking, and conclude that learning about potential feeding places from other species is an important function of mixed flocks, at least for some species. This does not exclude the possibility of other functions of mixed flocks.
The morphology of associations between a trematode (Megalodiscus temperatus) and bacteria
Authors: Morris Gerald P.
Published: August 2008

Rod-shaped bacteria are associated with the tegument surface and cecum of Megalodiscus temperatus (Stafford, 1905). Some bacteria appear to be attached to the tegument by a finely filamentous material while others are partially embedded in the tegument. The depressions occupied by the bacteria can be seen in micrographs taken with both transmission and scanning electron microscopes. The association between the bacteria and the cecal epithelium is not so intimate, although occasional depressions in the surface of the epithelium appear to result from the presence of bacteria.
Mode of action of clomiphene citrate in inducing ovulation of goldfish
Authors: Pandey S. , Stacey N. , Hoar W. S.
Published: August 2008

Hypophysectomized and sham-operated gravid goldfish were injected with clomiphene citrate. Only the sham-operated fish ovulated. This indicates that clomiphene citrate acts through the hypophyseal axis.
A sense organ in the ventral anterior body wall of the nematode Capillaria hepatica (Bancroft, 1893)
Authors: Wright K. A. , Chan J.
Published: August 2008

A sense organ, located just posterior to the nerve ring in the ventral line of the body wall of Capillaria hepatica, is described. It consists of a pore opening through the cuticle to a cuticle-lined chamber into which four dendritic processes extend. The structure of the organ suggests that it may be chemoreceptive.
Quelques aspects du peuplement thécamoebien des sols de la province de Québec (Canada)
Authors: Bonnet Louis
Published: August 2008

A census of Thecamoebae in 295 soil samples, mostly from the Province of Quebec (Canada), has yielded a total of 143 species and varieties. As a whole, these Thecamoebae populations differ little from those found in comparable biotopes throughout the world. A new family, Distomatopyxidae, and a new genus, Puytoracia (Euglyphidae), have been studied.Biogeographic, biocenotic, and ecological aspects are discussed. Mathematical analysis (factor analysis of affinities) has led to the definition of 16 associations of species for the various biotopes.
Cone-top morphology of the white females and cysts of the genus Heterodera (subgenus Heterodera), a cyst-forming nematode
Authors: Mulvey Roland H.
Published: August 2008

Comparative studies with the scanning electron and interference contrast microscopes of white females and cysts provided new information for identification of species of the genus Heterodera (subgenus Heterodera). Most significant was the differences found in the development of the underbridge and bullae of several economically important species. Differences in vulval cone and fenestral structures of the white female provided additional information for the separation of species.
Behavior of adult Simuliidae (Diptera). I. Response to color and shape
Authors: Bradbury Wayne C. , Bennett Gordon F.
Published: August 2008

Collections of mammalophilic Simuliidae on variously colored and shaped two-dimensional silhouettes indicated that the species oriented to and landed on certain 'preferred' colors. The Prosimulium mixtum/fuscum complex and Cnephia (Stegopterna) mutata were consistently attracted to black targets, the Simulium venustum complex was consistently more attracted to blue silhouettes, and Simulium vittatum oriented and landed on all colored silhouettes except yellow. Black, blue, and red were the most attractive for all species. Colors reflecting the least amount of incident light were the most attractive, a matte surface was more attractive than a glossy one. The response of the flies to simple geometric shapes indicated that all shapes were equally attractive, with the flies aggregating at the points of convergence of the silhouette outline.
Juvenile denticles of the swell shark Cephaloscyllium ventriosum: function in hatching
Authors: Grover Charles A.
Published: August 2008

The swell shark Cephaloscyllium ventriosum is an oviparous scyliorhinid. The young possess two longitudinal, dorsolateral rows of denticles, designated juvenile denticles, which are larger and different in form from the surrounding ones. Observations of the hatchings of five sharks and analysis of films taken of one indicate that these specialized denticles interact with the edge of the egg-case opening in the manner of a pawl and ratchet during the shark's emergence, thus serving as a mechanical aid which increases the efficiency of the shark's movements in hatching. These specialized denticles are found on the young of a variety of oviparous sharks and chimaeroids, and disappear from the young soon after hatching.
Observations on the life history and burrow construction of the crayfish Cambarus fodiens (Cottle) in a temporary stream in southern Ontario
Authors: Williams D. Dudley , Williams N. E. , Hynes H. B. N.
Published: August 2008

Cambarus fodiens, usually considered an inhabitant of ponds and drainage ditches, is shown to be able to complete its life cycle in a temporary running-water habitat. Details of its life history are given. Sampling methods for burrowing crayfishes are briefly reviewed and a new method is described. The typical burrow construction of this species is shown to be modified at two stages in the life cycle, once in the ovigerous females, and again in the newly released juveniles. It is possible that other inhabitants of temporary streams use these crayfish burrows as refuges when the groundwater table rereats.
Search for elaphostrongyline parasites in cervids from Alberta
Authors: Samuel W. M. , Holmes J. C.
Published: August 2008

No elaphostrongyline parasites were found in the cranial cavities of 140 while-tailed deer, 20 mule deer, and 37 moose from Alberta. No larvae with dorsal caudal spines were found in white-tailed deer feces from eastern Alberta, but spined larvae indistinguishable from those of Parelaphostrongylus spp. were found in mule-deer feces from western Alberta. These results suggest that P. tenuis is not found in Alberta and that the larvae from mule deer may represent a metastrongyloid, probably a species of Parelaphostrongylus, that is not found in the cranial cavity as an adult.
Seasonal breeding of the narwhal (Monodon monoceros L.)
Authors: Best Robin C. , Fisher H. D.
Published: August 2008

The narwhal (Monodon monoceros) has been shown to be a seasonal breeder, like the closely related beluga (Delphinapterus leucas). The gestation period is estimated to be about 14 months, while the reproductive cycle is 2 or 3 years. Narwhals appear similar to other odontocetes in those reproductive aspects for which there is information.
Selective elevation of the upper lethal temperature of the mummichog Fundulus heteroclitus (L.) (Cyprinodontidae), with a statement of its application in fish culture
Authors: Jean Ronald , Garside E. T.
Published: August 2008

The highest median lethal temperature (LT50) reported for mummichog Fundulus heteroclitus in a. 10 000-min bioassay is 36.31 (+0.19, −0.18 SD) in isosomotic medium (14‰ salinity (S)) after acclimation to 25C and 14‰ S. Results of a subsequent confirming bioassay on large samples are in accord with that value. Survivors of the confirming test were acclimated again to 25C and 14‰ S and the LT50 was determined again in the same conditions. There was a significant increase in the upper lethal temperature of 1.22C, to 37.53C ± 0.05 SD. The application of this simple selective procedure for more thermally tolerant genotypes in fish culture is discussed.
Fine structure of an unusual spermatozoon of a brooding sea cucumber, Cucumaria lubrica
Authors: Atwood David G. , Chia Fu-Shiang
Published: August 2008

The sperm of Cucumaria lubrica consists of an elongated head, 1.5 microns (n) in diameter and 5.2 μ in length; a mitochondrial midpiece of 1.9 μ in length; and a tail of 65 μ. The acrosome contains an irregularly circular granule which is located in an anterior nuclear depression. The granule is surrounded by a complete limiting membrane in most of the sperm examined. Occasional sperm contain granules surrounded by incomplete membranes. The acrosomal granule consists of a homogeneous material except for an electron-dense sphere displaced anteriorly. A subacrosomal layer consisting of a homogeneous reticular material encircles the granule. This layer contains several vesicular structures and a fibrous component immediately posterior to the granule.The nucleus measures 6.8 μ in length and 1.4 μ at its greatest diameter, but tapers to a diameter of 0.5 μ at the posterior end. A single mitochondrial mass surrounds the posterior 1.6 μ of the nucleus. The proximal and distal centrioles, lying perpendicular to each other, are found posterior to the nucleus. Microtubules are observed in close association with the satellite of the distal centriole.The adaptive significance of this unusual sperm is discussed.
Splendidofilaria fallisensis (Nematoda) in the common loon, Gavia immer (Brünnich)
Authors: Anderson Roy C. , Forrester Donald J.
Published: August 2008

Splendidofilaria fallisensis (Anderson 1954) is reported from two loons spending the winter in Florida. It is suggested that Simulium euryadminiculum may be the vector of the parasite between ducks and loons.
Responses of cercariae of Trichobilharzia ocellata to white light, monochromatic light, and irradiance reduction
Authors: Wright D. G. S.
Published: August 2008

Cercariae of Trichobilharzia ocellata exhibited a significant directed response to white light starting at an illuminance level of 0.35 lx. When exposed to an equal energy spectrum of monochromatic light (irradiance = 0.22 μW/cm2), the most significant directed response occurred at 500 nm. Swimming in response to illuminance reduction varies inversely as the preadaptation irradiance levels.
Growth of secondary Echinococcus multilocularis in experimentally infected hosts
Authors: Baron R. W. , Rau M. E. , Tanner C. E.
Published: August 2008

The growth of larval Echinococcus multilocularis in cotton rats, jirds, and A/J mice was measured. Single, thin-walled, acephalic cysts from cotton rat donors were inoculated intraperitoneally into the experimental hosts, and cyst weights were taken at several intervals after infection. It is shown that larval growth can be quantitatively described since it follows a sigmoid curve. Protoscoleces were produced within the cysts in all three hosts, although the time of appearance differed in each case.
Hormonal control of protein sequestration in the fat body of Calpodes ethlius Stoll
Authors: Collins Janet V.
Published: August 2008

The hemolymph of larvae and pupae of Calpodes ethlius contains proteins which have been characterized by immunodiffusion as belonging to three antigen groups. Extracts of fat body from non-pupating larvae contain antigens 1 and 2. The third antigen was detected in the fat body during the last 24 h of the larval stage. This timing coincides with the initiation of pupal development, and the formation of granules of stored protein in the fat body. Ligation to remove the influence of the prothoracic glands prevents molting, the formation of storage granules, and the appearance of antigen 3 in the fat body. Ligation has no effect on either the presence of antigens 1 and 2 in the fat body, or of all three antigens in the blood. It is concluded that the uptake of antigen 3 by fat body cells requires the presence of ecdysone.
Two cases of human Sarcophaga (Diptera: Sarcophagidae) myiasis in Quebec, with descriptions of the larvae
Authors: Ali-Khan F. E. A. , Ali-Khan Z.
Published: August 2008

Two cases of Sarcophaga myiasis are reported from Montreal, Quebec. In the first case, larvae were passed in a bloody stool of a 5-year-old child and in the second, larvae were removed from a sore on the toe of a middle-aged man. The external morphology, cephalo-pharyngeal sclerites, prothoracic respiratory organs, and the posterior spiracular pit of the larvae ate described. Case I larvae agree with descriptions of S. haemorrhoidalis Fallén. Those from case II are probably S. crassipalpis Macquart. Both species are known to occur in Quebec. Probable modes of infection are discussed.
Production of surface casts by the earthworm Eisenia rosea
Authors: Thomson A. J. , Davies D. M.
Published: August 2008

Eisenia rosea was shown to produce surface casts for the first time. The number increased with soil bulk density, organic matter, and fine silt particles. Soil moisture had little effect.
Procedure for mass collection of mermithid postparasites (Nematoda: Mermithidae) from larval blackflies (Diptera: Simuliidae)
Authors: Bailey C. H. , Gordon R. , Mokry J.
Published: August 2008

Larval blackflies, Prosimulium mixtum/fuscum Syme and Davies and Simulium venustum Say, were collected from natural populations and maintained in the laboratory for emergence of their mermithid parasites, Neomesomermis flumenalis (Welch, 1962) Nickle, 1972. Between April and July 1973, 4378 postparasitic N. flumenalis were obtained from about 250 000 blackflies for laboratory culture experiments.
Mucopolysaccharide histochemistry of the mink uterus during gestation
Authors: Murphy Bruce D. , James Derek A.
Published: August 2008

Histochemical localization of polysaccharide and protein-polysaccharide complexes (mucopolysaccharides or MPS) was studied in the uteri of female mink in three phases of gestation. These phases were the period of delay which precedes nidation, days 2 to 7 postimplantation, and days 13 to 16 postimplantation. Glycogen was found in uterine epithelial cells during delay, but appears to be depleted at nidation. This depletion may reflect the postnidation increases in progesterone observed in mink plasma. There is a general increase in MPS concentration in postimplantation uteri when compared with delay uteri. In addition, sulfated MPS are found in the uterine glands of postimplantation specimens, but not in the glands of delay specimens. The observed increase and shift in site of MPS production may reflect a perinidational increase in uterine protein.An acidic MPS layer is present between fetal and maternal placental components during postimplantation pregnancy. This coat appears to be synthesized by the trophoblast and may represent an immunoisolatory mechanism.
An artificial substrate for the quantitative comparison of the densities of larval simuliid (Diptera) populations
Authors: Lewis David J. , Bennett Gordon F.
Published: August 2008

The use of a 10 × 10 cm, unglazed, ceramic, fireplace tile for the quantitative comparison of the population densities of immature simuliids in a variety of stream conditions throughout the year is described. Comparisons with other techniques described in the literature are given. In view of the numerous techniques reported, it is recommended that researchers in this field use a standard methodology for obtaining population numbers of immature simuliids; it is suggested that this technique could be such a standard.
Gyrodactylus alexanderi: reproduction, mortality, and effect on its host Gasterosteus aculeatus
Authors: Lester R. J. G. , Adams J. R.
Published: August 2008

Individual flukes of the monogenetic trematode Gyrodactylus alexanderi, maintained at 15 °C on isolated fish (Gasterosteus aculeatus leiurus), gave birth to only two daughters, the first after an average of 1.6 days, and the second after 6.9 days. For at least 20 generations, the first daughter was produced every 1.6 days without cross-fertilization occurring. Maximum longevity at 15 °C was 28 days, but reached 71 days at 7 °C.The mean life expectancy of flukes away from fish was 1.8 days at 15 °C. This was shortened in the presence of young sticklebacks which preyed on the Gyrodactylus. One to 13% of flukes survived slow changes in salinity.Fish heavily infested with G. alexanderi died. Of 67 fish, 25–35 mm in length and carrying over 150 flukes. 54 died, compared with only 33 of 174 fish carrying fewer flukes. Deaths were not associated with infections of protozoa, fungi, or bacteria.
Development of nematode behavior: sex attraction among different strains of the free-living Panagrellus redivivus
Authors: Balakanich S. , Samoiloff M. R.
Published: August 2008

The behavioral response of three genetically different stocks of the dioecious free-living nematode species complex Panagrellus redivivus – Panagrellus silusiae to mating attractant was examined. The male response to mating attractant showed strain differences, as did the nature of attractant produced by the females. The response of males is dose-dependent and showed optima at specific concentrations of females. These differences are under genetic control. Mating attraction increases inbreeding at low population densities and promotes outbreeding at high population densities. Several distinct attractants were isolated, at least one of which was protein, and none were ether-soluble. Most attractants were of low molecular weight, with only one high molecular-weight component.
Dactylogyrus buddi n. sp. (Monogenoidea: Dactylogyridae) from the gills of the sculpins of Lake Huron
Authors: Dechtiar Alex O.
Published: August 2008

A new species of monogenean, Dactylogyrus buddi from the gills of the sculpins Cottus bairdi Girard (type host) and C. cognatus Richardson (other host) is described. This is the first report of a monogenean of the genus Dactylogyrus from North American cottid fishes and the second from the world.
The histochemical demonstration of myofibrillar adenosine triphosphatase activity in fish muscle
Authors: Johnston I. A. , Patterson S. , Ward P. , Goldspink G.
Published: August 2008

A technique for the demonstration of myofibrillar adenosine triphosphatase activity (ATPase) used for mammalian muscle has been modified to suit fish muscle. The mammalian method involves selectively inhibiting fiber types by preincubation at either alkaline (pH 10.4) or acid (pH 4.3) pH before incubation for myofibrillar (ATPase) activity. Fish muscle fibers were found to be generally inactivated under these conditions. Preincubation at an acid pH was found to be unsuitable for fish muscle because of the indiscriminate inactivation of the fibers. The effects of preincubating at pH 10.4 and incubating tissue sections for different time periods and at different pH's and temperatures have been investigated. A differential staining of fiber types correlated with biochemical data on myofibrillar ATPase for red and white muscles was obtained by preincubating sections for short periods (1–2 min) at pH 10.4. Under these conditions the intermediately positioned pink fibers were found to stain similarly to the white fibers of high myofibrillar ATPase activity. An investigation has been made of the qualitative distribution of fiber types in the myotomal muscle of live teleost species: coalfish (Gadus virens), grey mullet (Mugil cephalus), crucian carp (Carassius carassius), black mollie (Mollienesia sp), and glassfish (Chanda ranga). The pink fibers were found to be abundant in all the species examined with the exception of the glassfish.
Calyculism in Musculium securis (Pelecypoda: Sphaeriidae) and its significance
Authors: Mackie G. L. , Qadri S. U.
Published: August 2008

Studies on calyculate and uncalyculate forms of Musculium securis (Prime) indicate that calyculism is a predictable feature, and that the so-called "caps" of Sphaerium species are probably "pseudocalyculae." True calyculae are separated from adult valves by a sulcus, but pseudocalyculae are separated by an annulus. The nature of development of a sulcus and an annulus appear to be different. The calyculate character is of significance in identifying different generations in Musculium populations.
Range extensions of some northeastern Pacific nudibranch molluscs
Authors: Robilliard Gordon A.
Published: August 2008

The range of the nudibranch molluscs Archidoris odhneri, Cadlina luteomarginaia, and Dendronotus rufus has been extended northward to Auke Bay, Alaska, from Vancouver Island, British Columbia. The range of Archidoris montereyensis has been extended to Port Valdez, Alaska, from Sitka, Alaska, while that of Dirana aurantia and Coryphella fusca has been extended to Port Valdez from Vancouver Island. The range of Archidoris odhneri has also been extended southward to San Diego, California, from Point Conception, California. Large gaps in the geographic distribution of Triopha carpenteri and Dendronotus dalli were partially filled by observation of animals in southeastern Alaska. Finally, the distribution of Tochuina tetraquetra along the Pacific Coast is discussed.
Endocrinological and other factors influencing testis development in Rhodnius prolixus
Authors: Dumser J. B. , Davey K. G.
Published: August 2008

In Rhodnius, as in many insects, the testis undergoes a tremendous increase in size during late larval development. An histological study of this growth shows three clearly separable phenomena: production of spermatogonial cysts through synchronous division to a size of 27 cells per cyst; massive accumulation of spermatocytes (28 cells per cyst) during the late fourth and early fifth instar; production of spermatids and maturation of spermatozoa in the period from the fifth-larval blood meal to the adult. All of these processes continue in the adult.Germ-cell differentiation appears to be a sequential process, the spermatocyte stage being reached at 28 cells per cyst. Accumulation occurs as a result of the lengthy period of meiotic prophase maturation, but no specific inhibition of meiosis is evident. Spermiation during the diapause before the fifth-instar blood meal is prevented by specific autolysis of spermatid cysts. The application of a juvenile hormone analogue (FME) produces a dose-linked depression of spermatocyte meiosis, evidenced by a decline in the number of spermatid cysts. The spermatocyte-compartment level remains constant, indicating an equivalent depression of spermatogonial mitosis. Acceleration of division activity can be correlated with times of known ecdysone presence.
Use of artificial subice air pockets by wild ringed seals (Phoca hispida)
Authors: Milne Allen R.
Published: August 2008

Ringed seals were observed to inhale exhaust air expelled by SCUBA divers who were diving under 1.9-m thick, 1-year-old fast ice in Lancaster Sound during mid-April, 1973, The underside of the sea ice was imperfectly flat so that some of the bubbles of exhaust air coalesced into large lenticular bubbles 1 to 3 cm in depth, and these, on occasions, were partially inhaled by seals. Between dives, separated in time by as little as 3 h, all the under-ice air bubbles, large and small, vanished. It is assumed that the buoyant air migrated upward into the sea ice by the progressive displacement of brine in drainage channels. Although the exhaust air was readily used by ringed seals, it is unlikely that naturally occurring air pockets can persist beneath 1 -year-old sea ice to enable seals to extend their under-ice travels.
Marking aphids with rubidium
Authors: Frazer B. D. , Raworth D. A.
Published: August 2008

Pea aphids (Acyrthosiphon pisum (Harris)) were marked with rubidium by rearing them on broad bean plants (Vicia faba L.) maintained in nutrient solutions that contained rubidium chloride. Rb+ was readily detected by atomic absorption spectrophotometry in groups of aphids, and it varied in concentration with the concentration in the plant. A technique was developed for the preparation and analysis of single aphids marked with Rb+. More than 77% of the Rb+ in marked adult aphids was lost within 2 days of leaving the source plant, but detectable quantities remained for 4 days.
Heat transfer and body temperatures in non-thermoregulatory teleosts
Authors: Stevens E. D. , Fry F. E. J.
Published: August 2008

Coefficients of temperature change in relation to body size are given for three species of fish native in Lake Huron, subjected to a sudden drop in ambient temperature of about 5C. These observations together with published data provide cooling coefficients for fish and aquatic reptiles over a weight range of 1–5000 g. The slope of the regression-log cooling coefficient on log body weight is about −0.6. The hypothesis offered is that the magnitude of the slope in question results from the temperature measured being close to the center of a body of constant thermal conductivity, retaining essentially the same proportions throughout growth.In addition, various observations of excess deep-body temperatures were collected in relation to weight for poikilothermal fish and aquatic reptiles, all presumed to be in thermal equilibrium with their environment. A double logarithmic plot of deep body temperature on weight in this case has a slope of about 0.4. The relation between these two slopes appears to be satisfactorily explained by the general observation that the slope of a double logarithmic plot of metabolic rate per unit weight on body weight has a slope of about −0.2.
Life cycles and larval behavior of two species of Hydrachna (Acari, Hydrachnidae), parasitic upon Corixidae (Hemiptera–Heteroptera)
Authors: Harris D. A. , Harrison A. D.
Published: August 2008

The seasonal population fluctuations, population distributions, and pattern of attachment of the larvae of two species of Hydrachna parasitic upon Sigara solensis Abbott and Sigara modesta Hungerford were investigated in a permanent pond in Waterloo County, Ontario, throughout 1969. Seasonal fluctuations of parasitism occurred as a result of the fluctuations in the numbers of the free-living larvae and of the corixid hosts. Analysis of the intensity distribution of the larvae on their hosts fitted the data to a Poisson distribution. The parasitic larvae of the two mite species were evenly distributed over most of the potential attachment sites on their hosts. Absence, or reduced numbers, of larvae at any site has been explained in terms of nonavailability of the site to parasitism as a result of host behavior or physical unsuitability.
Two instances of precocious development in the eggs of the pinworm Leidynema appendiculata (Nematoda: Thelastomatidae)
Authors: Hominick W. M. , Davey K. G.
Published: August 2008

Two adult females of P. americana were found to harbor females of the pinworm L. appendiculata with eggs at the infective stage of development. It is suggested that this may be a consequence of a slowing of the rate of oviposition of the nematodes. The potential significance of the observations is discussed.
The digestion of carbohydrates in the chinchilla (Chinchilla lanigera)
Authors: Krishnamurti C. R. , Kitts W. D. , Smith Diana C.
Published: August 2008

The activity of maltase, sucrase, and lactase in the alimentary tract of adult chinchilla (Chinchilla lanigera) was found to be maximal in the middle third of the small intestine and absent in the stomach and large intestine. Intestinal sucrase and maltase and pancreatic amylase were low at birth but increased to adult levels after 12 weeks. Lactase reached a peak activity at 2 weeks of age and dropped sharply at 3 weeks to the low levels found in the adult.Using chromic oxide as the marker, it was found that the rate at which pelleted feed passes through the digestive tract of the chinchilla was about 35 h. The extent of cellulose degradation and dry matter digestibility in chinchilla fed pellets was 47.5 and 68.4%, while in those fed hay and pellets it was 48.9 and 57.9% respectively. Cellulose was digested mostly in the large intestine with the production of volatile fatty acids at a concentration of 0.492–0.547 meq/g of dry contents. The molar percent composition of acetic, propionic, and butyric acids in the cecal contents was 72.2, 11.3, and 14.1% respectively.
Determining dry weight and percentage dry matter of chironomid larvae
Authors: Dermott R. M. , Paterson C. G.
Published: August 2008

Reproducible live wet weights may be obtained for medium to large larvae of Metriocnemus knabi and Chironomus attenuatus after blotting them on filter paper for 1 min. To obtain reliable measures of wet weight for smaller larvae the blotting time must be reduced in proportion to the surface area/volume ratio of the larvae. Dry weights are easily obtained by oven drying at 60 °C for 24 h but drying for several days does not affect the results. A temperature of 100 °C decreases die percentage dry matter in C. attenuatus. Both species display an increase in percentage dry matter with increasing size. The extent to which the gut is filled with food has no effect on the percentage dry matter. Attempts to determine dry weight directly from preserved larvae were unsuccessful.
Seasonal prevalence of avian hematozoa in passeriform birds of Atlantic Canada
Authors: Bennett Gordon F. , Cameron Marilyn
Published: August 2008

The seasonal prevalence of avian hematozoa in two populations of passeriform birds from Newfoundland and New Brunswick in Atlantic Canada was correlated with the seasonal activity of appropriate vectors. Prevalence of Leucocytozoon in Newfoundland was considerably higher than in New Brunswick, and transmission occurred throughout the summer; ornithophilic simuliids were relatively abundant throughout the same period. In New Brunswick, transmission of Leucocytozoon was restricted to May and June, the period during which simuliid vectors were demonstrated to be present in the area. Seasonal prevalence of Haemoproteus was similar in both populations, and transmission occurred at a time when ceratopogonid vectors were available. Transmission of Plasmodium in New Brunswick was coincident with the appearance of adult Culiseta morsitans and Mansonia perturbans as major elements of the mosquito population.
Length–weight allometric relationships in four crustaceans from Alberta lakes and ponds
Authors: Daborn Graham R.
Published: August 2008

The relationship between length and dry weight was studied in Branchinecta gigas Lynch, Branchinecta mackini Dexter, Eubranchipus bundyi (Forbes) (Anostraca), and Diaptomus nevadensis Light (Copepoda) from shallow lakes in Alberta. Two distinct allometric equations were required to accommodate changes in length–weight relationships during the life cycles of Branchinecta and were also found applicable to Diaptomus. All of these species batch as first nauplii. Their life cycles may therefore be described as consisting of two growth phases: a larval phase terminating upon attainment of the definitive adult number of segments and characterized by predominantly anamorphic growth in length, with exponents of 1.45 (B. gigas), 1.51 (B. mackini), and 1.74 (D. nevadensis); and a postlarval phase of more rapid increase in dry weight. During the latter phase, growth exponents were 3.24 in B. gigas, 2.36 and 2.57 respectively in male and female B. mackini, and 3.39 and 3.61 in D. nevadensis males and females. In contrast, a single equation with an exponent of 2.46 was found to be adequate for Eubranchipus bundyi, which passes through the first metanauplial stages enclosed within the blastoderm cuticle.
An electron microscopic study of the formation and structure of the periostracum in Astarte (Bivalvia)
Authors: Saleuddin A. S. M.
Published: August 2008

An electron microscopic study of the outer and middle folds of the mantle edge of Astarte castanea reveals the fine-structural details of the cells which are involved in the formation of the periostracum. There are four types of cells in the outer fold whereas there is only one type in the middle fold. The role of different cell types in the formation of the periostracum has been discussed. The periostracum originates in the intercellular space between the basal cell of the outer fold and the first cell of the middle fold. Even at the point of origin it consists of two outer membranous layers and the inner dark homogeneous layer. The fibrous translucent layer, which is the third layer of the fully mature periostracum, does not appear until the young periostracum has moved down the periostracal groove at the level of the third cell. As the periostracum matures, the two membranous layers remain remarkably constant in width, whereas the two inner layers, dark homogeneous and fibrous translucent, increase in thickness. Scanning electron microscopy and thin sectioning reveal that the fully mature periostraca of A. castanea and A. elliptica appear uniformly pitted, but the nature of the pits between the two species is different. The fibrils of the fibrous layer show either uniform or random arrangements, depending on the region. It is the innermost part of the fibrous layer of the periostracum that provides the nuclei for calcification.
Radio tracking of small mammals using a grid of overhead wire antennas
Authors: Chute F. S. , Fuller W. A. , Harding P. R. J. , Herman T. B.
Published: August 2008

A radiotelemetry system is described that can be used to monitor three activity states of, and distance travelled by, mammals as small as Clethrionomys gapperi, having a winter weight of 16 g. Precision with which animals are located is constant and error does not exceed 75 cm. Preliminary biological results show marked seasonal changes in activity patterns. Advantages and disadvantages of the grid of fixed antennas vis à vis triangulation systems are discussed and other potential uses of the system are suggested.
The New World Aesalinae, with notes on the North American lucanid subfamilies (Coleoptera, Lucanidae)
Authors: Howden H. F. , Lawrence J. F.
Published: August 2008

The North American Lucanidae are divided into four subfamilies: Aesalinae, Syndesinae, Nicaginae, and Lucaninae, and a key is presented to the subfamilies, tribes, and genera. Subfamily characters are briefly described with a more detailed account of the Aesalinae, including Aesalus Fabricius and Lucanobium squamosum n. gen., n. sp., from Venezuela.
The tapetum lucidum of gars (Lepisosteidae) and its role as a reflector
Authors: Wang Richard T. , Nicol J. A. Colin
Published: August 2008

Eyes of four species of gars were studied, namely, alligator (Lepisosteus spatula Lacépède), spotted (L. oculatus (Winchell)), shortnose (L. platostomus Rafinesque), and longnqse (L. osseus (L.)). The retina is duplex, a yellow tapetum lucidum is present, rods and retinal pigment move, and the tapetum is uncovered in dim light. The visual pigment is a porphyropsin, λmax 523, and the optical density of the pigment in the retina is 0.22. Transmission through the retina is low at short wavelengths and rises steeply above 460 nm. Reflectance from the tapetum is diminished in the blue, and rises progressively at longer wavelengths to reach a maximum (70%) at about 650 nm. Underwater illumination was measured in waters where gars occur. In lake waters maximal transmissivity occurred at 375 nm and the transmission per meter ranged from 76 to 62%. In rivers and bays, transmission was maximal at long wavelengths, ≥600 nm, and the transmission per meter ranged from 37% to 0.001%; these waters sometimes were stained, and were fairly turbid to very muddy. The yellow tapetum is an efficient reflector of underwater light, the greater part of the energy of which occurs at long wavelengths. It is calculated that the tapetum increases light absorption in the retina by 30%. In muddy rivers inhabited by gars, scotopic vision involving the tapetum probably operates during the daytime at depths of 2 m or less.
Histogenesis of the islets of Langerhans in Malathion-treated chick embryos
Authors: Arsenault A. L. , Gibson M. A.
Published: August 2008

Chick embryos were exposed to a teratogenic dose of Malathion at the 5-day incubation stage and the effect of this treatment on the histogenesis of the islets of Langerhans was studied during the 11- to 19-day incubation stages. The Malathion caused a significant increase in the amount of alpha tissue on incubation days 13 and 15, and a significant increase in the amount of beta tissue on incubation days 13, 15, and 17.
Environmental factors and the incidence of neoteny in Ambystoma gracile (Baird) (Amphibia: Caudata)
Authors: Sprules W. Gary
Published: August 2008

Laboratory experiments were conducted to evaluate the effects of temperature, water evaporation rate, and food availability on the incidence of neoteny in Ambystoma gracile and to assess the nature of its genetic control. Larvae hatched from six clutches of eggs from ponds in British Columbia were reared until they were about to metamorphose. Six experiments were then initiated, each involving larvae from a single distinct clutch. Results indicated that at 12 °C larvae metamorphosed later and the incidence of neoteny was higher than at 19 °C; similarly, larvae fed once per week transformed more slowly and were more frequently neotenic than larvae fed three times per week. The rate at which water evaporated, and associated changes in salinity and depth appeared to have no effect. With one exception, under standard conditions there were no differences in the timing of metamorphosis of larvae from different clutches and different populations. It appears that populations of A. gracile are highly polymorphic, comprising some individuals which always metamorphose, some which never do, and others which may or may not transform, depending on the nature of the habitat.