bluuebunny/crossref_metadata_2025 huggingface dataset:
The response of the follicle cells of Rhodnius prolixus to juvenile hormone and antigonadotropin in vitro
Authors: Davey K. G. , Huebner E.
Published: August 2008

In a medium consisting of 40% Eagle's basal medium in Schneider's Drosophila medium, large spaces appear between the cells of the follicular epithelium over vitellogenic oocytes of Rhodnius prolixus when juvenile hormone is present. Such spaces are less prominent when juvenile hormone is absent. A method is described by which the size and number of spaces can be assigned a value, on a scale of 0–5, called the index of patency. The index of patency increases with increasing concentration of juvenile hormone from 10−15 μl/ml to 10−4 μl/ml. At higher concentrations, the index of patency decreases. When a source of antigonadotropin is present in the medium, together with juvenile hormone at its maximally effective concentration, the patency index is decreased.
The helminth parasites of the blue jay, Cyanocitta cristata bromia, from South Bass Island, Ohio
Authors: Cooper C. Lawrence , Crites John L.
Published: August 2008

Fifty blue jays, Cyanocitta cristata bromia, from South Bass Island, Ottawa County, Ohio, were examined for helminth parasites during the spring of 1969 and 1970. Twenty-five helminths were identified: 9 trematodes, 3 cestodes, 12 nematodes, and 1 acanthocephalan. Seventeen of these are new host records.
Paratylenchus robustus n. sp. (Paratylenchinae: Nematoda) from forest soil in Ontario
Authors: Wu Liang-Yu
Published: August 2008

Paratylenchus robustus n. sp. was found in soil around birch (Betula papyrifera Marsh.) in the forest near Aylen Lake, Ontario, Canada. It is distinguished from other species in that it has a robust body, a markedly reduced postvulval diameter, an ovary usually with double reflexure at the distal end, a spermagonium, and a spear 58 to 73 microns (μ) long.
Records of cestodes in varying lemmings and an arctic fox from Bathurst Island, Northwest Territories
Authors: Webster W. A.
Published: August 2008

Cysticerci of Taenia crassiceps Rudolphi, 1810 and adult Andrya arctica Rausch, 1952 from Dicrostonyx torquatus, and Taenia polyacantha Leukart, 1856 from Alopex lagopus, are reported for the first time from Bathurst Island, Northwest Territories.
Fine structure of the mucous cell in the sea pen, Ptilosarcus guerneyi, with special emphasis on the possible role of microfilaments in the control of mucus release
Authors: Crawford Bruce J. , Chia Fu-Shiang
Published: August 2008

One unique feature of the ectodermal mucous cell in the sea pen, Ptilosarcus guerneyi, is the possession of an apical sac, which is formed by the infolding of the apical cell membrane. The apical sac is guarded by several rows of microvilli at the rim of the opening and is surrounded intracellularly by arrays of microfilaments. The microfilaments, 50 Å in diameter, are interrupted by treatment with cytochalasin B (10–20 μg/ml) for 4 h. We provided morphological evidence to suggest that the apical sac is used for mucus storage and that contraction of the microfilaments would release the mucus from the sac.Other features of significance, such as the possible relationships between calcium transport and apical vesicles and between mucus release and bioluminescence are also reported.
Identification and description of hybrids of Fundulus heteroclitus and F. diaphanus (Pisces: Cyprinodontidae) from Porters Lake, Nova Scotia, with evidence for absence of backcrossing
Authors: Fritz E. S. , Garside E. T.
Published: August 2008

Phenotypic analysis of 2143 killifish (Cyprinodontidae) collected in Porters Lake. Halifax County, Nova Scotia, from May 1971 to September 1972, indicated that 1973 killifish were of two readily distinguishable species, either Fundulus heteroclitus or F. diaphanus, and 170 individuals were an apparent hybrid of the two which was intermediate for the eight morphometric, meristic, and molecular characters analyzed. Character index analysis and consistent electrophoretic patterns of muscle malate dehydrogenase and lactate dehydrogenase suggested that the hybrids, which comprised four age-classes, were invariably F1 hybrids. There was no indication of backcrossing. Reciprocal interspecific fertility and postlarval viability were confirmed in F1 laboratory crosses. These forms possessed structural measures, character indices, and electrophoretic patterns that were virtually identical with those of the natural hybrids.
Histopathological changes associated with the attachment of Ixodes (Ceratixodes) uriae White, 1852
Authors: Eveleigh Eldon S. , Threlfall William , Belbeck Larry W.
Published: August 2008

Forty-eight hours after the attachment of a nymphal Ixodes uriae to a domestic chicken, the mouthparts were fully embedded in the skin with a layer of cement, forming an irregular cone, surrounding them. An intense localized reaction was evident, over one-half of the tick being engulfed in host tissue. Areas of edema, necrosis, leucocyte infiltration, cavitation, and vasodilation were noted around the mouthparts. The extent of the host response is discussed in terms of the host being 'unnatural'.
Aerial pursuit flights in the shoveler
Authors: Seymour Norman R.
Published: August 2008

Analysis of 266 pursuit flights of wild birds provided a qualitative and quantitative description of aspects of this phenomenon. Flight behavior and frequency were analyzed for the general prelaying, laying, incubation, and renesting periods.Flight behavior of pursued males and females and that of the pursuing male varied little throughout the breeding season. No difference was detected on a daily basis.Flight frequency was greatest during the morning (0500 to 1000 h) period throughout the season. On a seasonal basis, frequency was greatest during territory establishment and declined after general incubation began. Another peak of activity occurred during the renesting period. Frequency during all periods reflected the number of non-territorial pairs interacting with territorial pairs.Attempted rape and associated flight was rare, with most flights apparently resulting from hostility associated with territorial defense. The pursuer was invariably a territorial male.The pursuit flight functioned in the establishment and maintenance of territories and was the major active mechanism in the spacing of breeding pairs.
Postmetamorphic growth rates in a natural population of Fowler's toad, Bufo woodhousei fowleri
Authors: Clarke Raymond D.
Published: August 2008

A population of Fowler's toad (Bufo woodhousei fowleri) living on a golf course in New Haven, Connecticut, was studied for 3 years by the capture–mark–recapture method. Individual growth rates were determined using tibia length, which is isometric with body length, as the measure of size. Growth was rapid, with an average 6.58-fold length increase during the 1st year after metamorphosis. Males began to show secondary sexual characteristics about 1 year after metamorphosis; at this age the cohort began to overlap in body size with the older males. Females grew faster than males, but also reached a larger size, and the body sizes of the maturing female cohort began to overlap with the older females 1 month later than the males. The growth curve for length was inflected, which is predicted by von Bertalanffy's growth model.
The effect of experience on the development of parental behavior in the blue gourami, Trichogaster trichopterus
Authors: Chang B. D. , Liley N. R.
Published: August 2008

Male blue gouramis normally perform parental behavior after spawning. Non-spawning, non-parental males can also be induced to perform parental behavior when presented with a large number of eggs. In the experiment reported here, non-spawning, non-parental males with and without reproductive experience were tested with successively larger stimuli of 500 to a maximum of 3000 eggs, or until a criterion for a strong parental responsiveness was reached. At least 10 days elapsed between successive tests of the same male. As stimulus size increased the number of males performing parental behavior increased. The experienced males showed parental behavior in response to smaller numbers of stimulus eggs than did inexperienced males. The experiential effect was long-term, since the experienced males had had their last reproductive experience at least 21 days before the start of testing.
Developmental changes in amounts of sulfhydryl-agent decolorant released by sea urchin embryos
Authors: Wolfson N.
Published: August 2008

Live embryos of the sea urchin, Paracentrotus lividus, release materials which decolor the yellow ion formed by the reagent DTNB (5,5′-dithiobis(2-nitrobenzoic acid)) in amounts titratable with dithiothreitol, and this decolorant activity increased to about the 32-cell stage, declining gradually thereafter. The embryos release decolorants into a saline medium only if it contains Tris buffer and little or no calcium and is adjusted to a pH below 8.
Haemocytology of the supraneural myeloid body in the sea lamprey during several phases of life cycle
Authors: George J. C. , Beamish F. W. H.
Published: August 2008

The supraneural myeloid body of the sea lamprey (Petromyzon marinus) was studied in the feeding adult, late spawning run adult, and metamorphosing ammocoete. The fatty nature of the tissue was established by histochemical staining and electron microscopy. The presence of the fat cells and the actively differentiating blood cells evinced its similarity to the bone marrow in higher animals, thereby suggesting a phylogenetic affinity. In the late spawning run lampreys, the tissue was found to be almost empty of blood cells, leaving empty spaces within the stromal skeleton. In the feeding adult tissue, the various blood cell types differentiated from precursor cells have been identified. Megakaryoblasts possibly representing early phases of the cell type were observed only in the transforming (macrophthalmia stage) and adult lampreys. A marked active development of the tissue in the ammocoete was seen only at the fourth stage of the metamorphosing ammocoete immediately before macrophthalmia. At the macrophthalmia stage, the haematopoietic activity in the tissue increased substantially.
The glochidia of certain Unionidae (Mollusca) in Nova Scotia and their fish hosts
Authors: Wiles Michael
Published: August 2008

Morphological and morphometric comparisons among adult and glochidial unionids from two Nova Scotian locations showed that Anodonta implicata, A. cataracta cataracta, A. c. fragilis, Elliptio complanatus, and Lampsilis radiata radiata were present. Gravidity studies suggested that fully developed glochidia occur from September to May in Anodonta marsupia, for only 5–6 weeks in June and July in E. complanatus, and perhaps at least from spring to early fall in L. r. radiata. Seven of 12 fish species sampled bore glochidia, which were identified in five host species by comparisons of their shapes and dimensions with those of glochidia from adult clams. Results were as follows: A. c. cataracta in Catostomus commersoni in June only, A. implicata or A. c. cataracta in Gasterosteus aculeatus in May and June, Anodonta sp. in Apeltes quadracus and Pungitius pungitius in June, and E. complanatus in Fundulus diaphanus in June and July. Thus, no relationships between gravidity periods of adult clams and infestation periods of their fish hosts by their glochidia were evident for species of Anodonta.
Seasonal changes in abomasal worms (Ostertagia spp.) in white-tailed deer (Odocoileus virginianus) at Long Point, Ontario
Authors: Baker Michael R. , Anderson Roy C.
Published: August 2008

Three species of nematodes were recovered from the abomasa of white-tailed deer (Odocoileus virginianus) collected at Long Point, Ontario, from September 1972 to August 1973. Ostertagia odocoilei was recovered from 45 deer (96%), O. mossi from 31 (66%), and O. dikmansi from 30 (64%). Abundance of adult stages of all three species was greatest in summer and least in winter. O. odocoilei was the most abundant species, especially during winter. Females were more abundant than males at all times of the year, particularly during winter.Numerous inhibited early fourth-stage larvae were recovered during winter and early spring, while few were found in July and August. The decrease in numbers of inhibited larvae in spring was coincident with a corresponding increase in abundance of adult worms. This is the first indication of the existence of inhibition (previously reported in domesticated animals) in species of Ostertagia parasitizing deer. Inhibition was not related to host age, indicating that the phenomenon is probably not due to development of immunity by the host over the grazing season.
The blackflies (Diptera: Simuliidae) of insular Newfoundland. III. Factors affecting the distribution and migration of larval simuliids in small streams on the Avalon Peninsula
Authors: Lewis David J. , Bennett Gordon F.
Published: August 2008

Factors affecting the population dynamics, distribution, and migration of nine species of simuliid larvae in a complex of small streams on the Avalon Peninsula, Newfoundland, were studied. The most significant factors affecting the distribution and migration of simuliid larvae were current velocity, substrate type, and water depth; temperature, light, chemical composition of the water, and parasites were found to be of little or no significance.
Insect prothoracic glands: function and ultrastructure in diapause and non-diapause larvae of Diatraea grandiosella
Authors: Yin C.-M. , Chippendale G. M.
Published: August 2008

The function and fine structure of the larval prothoracic glands (PG's) of the southwestern corn borer, Diatraea grandiosella Dyar, were examined. A novel vacuum-ligation technique was developed to isolate whole PG's from the hemocoel of last-stage non-diapause larvae. This treatment prevented larvae from pupating unless they received an injection of β-ecdysone and thereby confirmed the need for a hormonal secretion from the PG to initiate molting.The structure of PG's from mature non-diapause and diapause larvae was compared. Each gland consists of about 33 large secretory cells, and receives efferent neurones, some of which are neurosecretory, from the central nervous system. Each PG cell of a non-diapause larva is bounded by a thin tunica propria and consists of a large nucleus and a dense cytoplasm containing evenly dispersed mitochondria, ribosomes, and glycogen particles. In contrast, each inactive PG cell of a diapause larva is bounded by a thick tunica propria and contains a shrunken convoluted nucleus and an inner cytoplasmic zone of glycogen particles.
Synopsis of the Brachypterinae, (Insecta: Plecoptera: Taeniopterygidae)
Authors: Ricker W. E. , Ross H. H.
Published: August 2008

In the subfamily Brachypterinae 13 genera are recognized. The most primitive genus is Kohnoperla, from Japan. One new North American genus is described, Bolotoperla, and four from Eurasia, Kohnoperla, Mesyatsia, Okamotoperla, and Zhiltzovia. Species newly described by the authors are Taenionema atlanticum, Strophopteryx appalachia, S. arkansae, S. inaya, and S. ostra, while Kohnoperla yugawae is described by M. Kohno. Taenionema frigidum (Navás) is synonymized with T. japonicum (Okamoto), and there are several changes in generic assignment.
Ultraviolet-induced histological and histochemical changes in the integument of newly molted American cockroaches, Periplaneta americana (Dictyoptera: Blattaria: Blattidae)
Authors: Gingrich John B.
Published: August 2008

Hypodermal cells of newly molted cockroaches irradiated with UV (254 nm) are progressively destroyed, with first evidence of structural damage occurring 2 h after initiation of irradiation. Before that, melanin formation begins to fall and irradiated animals become progressively more deficient in melanins or their precursors. Proteins of the exocuticle fail to tan in irradiated cuticle, as indicated by continued uptake of protein stain at a time when unexposed cuticle becomes refractive to staining. Hypodermal cells are irreversibly damaged by UV irradiation, as evidenced by lack of endocuticle production. Similarly, tonofibrillae are progressively destroyed in tergal attachments of tergostemal muscles exposed to UV. Muscles become detached, possibly in the legs as well, resulting in sluggish behavior. With tanning incomplete and hypodermal cells destroyed, the integument ceases to become an effective barrier to dehydration, and molting failure or death, due to desiccation, may result.
Role of the caeca in Japanese quail energetics
Authors: Thompson D. C. , Boag D. A.
Published: August 2008

We investigated the caecal contribution to the energy budget of Japanese quail (Coturnix coturnix) through feeding and metabolic studies of intact and caecectomized birds. The feeding trials indicated that, under the conditions described, the caeca contributed 5.7% of the mean daily energy requirements of the quail. Comparisons of metabolic rates of intact and caecectomized birds under cold stress failed to show any significant differences, suggesting that the thermogenic contribution of the caeca to the energy budget is negligible.
K reproductive strategy and larval behavior of the pitcher plant sarcophagid fly, Blaesoxipha fletcheri
Authors: Forsyth Adrian B. , Robertson Raleigh J.
Published: August 2008

Ecological investigations of the pitcher plant sarcophagid fly (Blaesoxipha fletcheri) indicate that larvae of this species are highly aggressive. The ecological basis of the larval behavior and spacing system is examined in terms of resource utilization. The unusual reproductive biology of the fly is analyzed within the context of r and K selection. The number of pitcher plant (Sarracenia purpurea) leaves ultimately limits the density of B. fletcheri larvae. Intraspecific competition for the leaf microhabitat and for food produces high density-dependent mortality and a spacing system of one B. fletcheri larva per pitcher leaf. The reproductive strategy of B. fletcheri reflects this density dependence in that comparatively few, but very large, competitive larvae are produced. It is suggested that B. fletcheri is a K strategist relative to many other sarcophagid species. The reproductive resource allocation method is potentially not sufficient for recognition of K strategy in B. fletcheri or other species.
An interpretative study of the organization of the visual cells and tapetum lucidum of Stizostedion
Authors: Zyznar E. S. , Ali M. A.
Published: August 2008

The tapeta lucida and the organization of the visual cells of the walleye and the sauger are studied. The reflecting material of the tapeta is demonstrated to be a reduced pteridine, 7, 8-dihydroxanthopterin, which occurs in the epithelial processes as densely packed anisometric granules about 0.5 μm long.The organization of the visual cells and the unusual structure of the cones are suggestive of the manner in which incoming light is distributed in the retina. In dark-adapted eyes, the cods are in groups optically isolated from each other by the tapetal processes. Light can be reflected back and forth between the tapetal processes with additional absorption by the rods after each reflection. The cones do not move in response to changes of light intensity, remaining always at the external limiting membrane, and the light reaching the rods must first pass through the cones. The cone ellipsoids which contain lipid inclusions function as light funnels and increase the angle of acceptance of the rod groups. The melanosomes are stationary and concentrated at the tips of the pigment epithelial processes at the level of the cone ellipsoids. The disposition of the dark pigment indicates that it delimits the angle of acceptance of the cones.
The effects of capture, "stress," and storage of whole blood on the red blood cells, plasma proteins, glucose, and electrolytes of the winter flounder (Pseudopleuronectes americanus)
Authors: Fletcher G. L.
Published: August 2008

When the blood from flounder caught in the field was compared with the blood of laboratory-maintained flounder, a number of differences were observed. Hematocrits, mean red blood cell volumes, blood hemoglobin, plasma osmolality, and plasma Na+ and Cl− were significantly higher in the field flounder, while the mean cell hemoglobin concentrations and plasma K+ were significantly lower.Experiments conducted on the effects of "stress" suggested that differences in plasma osmolality, protein, Na+, Cl−, red blood cells, hemoglobin, and mean cell hemoglobin between field and laboratory flounder could have been due to the effects of capture on the field fish.The high hematocrits and mean cell volumes, and the low mean cell hemoglobin concentrations observed in the field samples may have been caused by the combined effects of capture and the 1.5- to 3-h storage of the red blood cells when they were transported back to the laboratory.The low K+ concentrations observed in the plasma of the field blood samples appeared to be due to the storage of the blood samples.
A second diapause in Wyeomyia smithii: seasonal incidence and maintenance by photoperiod
Authors: Lounibos L. P. , Bradshaw W. E.
Published: August 2008

Wyeomyia smithii ordinarily diapauses in the third larval instar, but a second, photoperiodically maintained developmental arrest may occur in the fourth instar. Two years of sampling from a Massachusetts bog revealed that the fourth-instar diapause phenotype is most abundant in the spring after the termination of third-instar diapause, and in the fall when a new overwintering generation of third instars accumulates in the pitcher-plant habitat. Fourth-instar larvae from this population cannot, however, survive the winter. This mortality during winter is apparently balanced by advantages that a second diapause confers upon the mosquito population in the spring.Fourth-instar diapause may be induced from diapausing third-instar larvae in the laboratory by a brief exposure to long days followed by short days, or by a long-term exposure to short days at 25 °C. Continuous exposure to long days readily terminates fourth-instar diapause. The critical photoperiod and number of long days required for the termination of diapause is similar for larvae which diapause in either the third or fourth instar.
Age and sex determination of striped skunks (Mephitis mephitis) from Ontario, Manitoba, and Quebec
Authors: Casey G. A. , Webster W. A.
Published: August 2008

The determination of age by the number of annular layers in the tooth cementum and the determination of sex by examination of the hippocampal neurons for sex chromatin are described. A total of 750 skunks, consisting of 351 females and 399 males, were examined. Of these, 376 were less than 1 year of age. The oldest animals were between 5 and 6 years of age.
Fine structure of sunken thick-walled pegs (sensilla ampullacea and coeloconica) on the antennae of mosquitoes
Authors: Boo K. S. , McIver S. B.
Published: August 2008

Sensilla ampullacea (pegs in tubes), a type of sensillum heretofore unknown from mosquitoes, occur on the antennae of female Anopheles stephensi Liston and Aedes aegypti (L.). Sensilla coeloconica (pegs in pits) with thick-walled pegs, previously reported from A. aegypti and Culex pipiens L. also occur on the antennae of An. stephensi.The fine structure of the sensilla ampullacea and coeloconica is similar. Each sensillum consists of a non-perforated, thick-walled peg located in either a deep tube or a pit, and is innervated by three neurons. The unbranched dendrites of two neurons extend into the lumen of the peg. The dendrite of the third neuron, which is distally folded into lamellae in all of the sensilla ampullacea and some of the sensilla coeloconica, terminates beneath the peg. Three sheath cells are associated with each sensillum.Sensilla coeloconica on the antennae of female Aedes aegypti are thermoreceptors. On the basis of similarity in fine structure, sensilla coeloconica and ampullacea of An. stephensi probably also play a role in thermoreception.
The radiotracer labelling of the phospholipids of the brain of Nereis virens (Polychaeta) in very young and older animals
Authors: Marsden J. R. , Jost J.
Published: August 2008

The uptake of 32P from H332PO4 has been measured in the phospholipids of the supraoesophageal ganglion of the polychaete Nereis virens. In vivo injections at 3 and 6 h before dissection show a more extensive incorporation of tracer into phosphatidylinositol than into any other phospholipid. In young sexually undifferentiated animals the radioactivity in phosphatidylinositol at 6 h is about 13 times that in mature animals. Turnover of phosphatidic acid is also high. This and other aspects of phosphatidylinositol metabolism in Nereis brain are shown to be very like that characteristic of stimulated secretory tissue in birds and mammals. It is suggested that these phenomena may be related to hormone secretion by the brain of N. virens.
Mode of action of royal jelly in honeybee development. X. Some aspects of lipid nutrition
Authors: Kinoshita G. , Shuel R. W.
Published: August 2008

Two components of the lipid fraction of royal jelly, 10-hydroxy-trans-2-decenoic acid and a sterol(s) are important for growth and development of the immature stages of the honeybee. Removal of the lipids by extraction with ether has been known for several years to have an accelerating effect on growth of laboratory-reared larvae; the readdition of 10-hydroxydecenoic acid to the diet before larvae are 72 h of age has now been found to prevent this effect. The slow growth and development of laboratory-reared larvae compared with larvae reared in the honeybee colony may be due to a higher than optimal level of the fatty acid in the diet of older larvae. A dietary level of at least 100 ppm of sterol was essential for larval growth and development. This was extremely low compared with the actual sterol content (about 3000 ppm) of whole royal jelly. The dietary sterol requirement for normal success in pupation was more than 400 ppm. The addition of 10-hydroxydecenoic acid to a diet containing not more than 100 ppm of sterol enabled normal pupal development and the emergence of adults to take place. The possible role of 10-hydroxydecenoic acid in honeybee growth and development is discussed.
Breathing movements in the frog Rana pipiens. II. The power output and efficiency of breathing
Authors: West N. H. , Jones D. R.
Published: August 2008

The work done by the buccal cavity during buccal and lung ventilation cycles has been estimated from measurement of the area enclosed by pressure–volume loops for each cycle. The loops cycled in an anticlockwise direction with respect to time during buccal cycles. On the other hand, pressure–volume loops from the lungs cycled clockwise, showing that work was being done on the lungs by the buccal pump. Inflation and deflation of the buccal cavity from a syringe, in curarized frogs, gave a clockwise loop enclosing about 5.5–6.5% of the area enclosed by a naturally generated loop of the same pressure and volume. However, inflation and deflation of the lungs gave a loop which enclosed an area virtually identical with that obtained from a normally generated sequence of lung inflation and deflation. The power output of the buccal pump was directly proportional to body weight, the major determinant of the former being the larger buccal volume rather than pressure change as body weight increased. The mechanical efficiency of the buccal pump varied from 0.4% to 16.2%, efficiency increasing with increased power output over most of the physiological range. Mean efficiency of all buccal movements was calculated to be 8% and, at this value of efficiency, oxygen consumption of the respiratory muscles was 0.89 ml O2 100 g−1 min−1. In Rana pipiens at rest the oxygen cost of breathing appears to be about 5% of the total resting metabolism.
Morphology of the perineal pattern of the root-knot nematodes Meloidogyne hapla and M. incognita
Authors: Mulvey R. H. , Johnson P. W. , Townshend J. L. , Potter J. W.
Published: August 2008

Scanning electron microscope studies of Meloidogyne hapla and M. incognita revealed features of the female perineal pattern previously obscure under light microscopy. M. hapla is characterized by a deep invagination of the cuticle between the anal and vulval areas and a strong demarcation of dorsal and ventral striae. M. incognita lacks the infolding of the cuticle and is characterized by forked striae.
Some notes on shoaling behavior and growth of Mysis gaspensis (Mysidacea) in a small Newfoundland estuary
Authors: Dadswell M. J.
Published: August 2008

Mysis gaspensis habitually concentrated in a zone of medium current (12–40 cm/s) and low salinity (1.0–4.0‰) along one bank of a small estuary during low tide. Population size for the estuary was estimated at 38 000 animals (0.1 mysid/m2). Growth of M. gaspensis was about 3 mm during July, and this species apparently has a 2-year life cycle.
Development of Physaloptera maxillaris (Nematoda) in the common field cricket (Gryllus pennsylvanicus)
Authors: Lincoln Robert C. , Anderson Roy C.
Published: August 2008

Physaloptera maxillaris (Molin) from the stomach of striped skunk (Mephitis mephitis Schreber) developed to the infective stage in the common field cricket (Gryllus pennsylvanicus Burmeister). Development took place in host capsules on the ileum. The first molt occurred 4 days and the second 8 days after infection in crickets kept at 30C and a relative humidity of 68–80%. The larval stages are described in detail and it is suggested that the field cricket may be a most important intermediate host of P. maxillaris in the Guelph area.
Feeding ecology of the ancient and marbled murrelets near Langara Island, British Columbia
Authors: Sealy Spencer G.
Published: August 2008

Two field seasons (1970 and 1971) were spent studying the feeding ecology of the ancient murrelet (Synthliboramphus antiquus) and the marbled murrelet (Brachyramphus marmoratus) near Langara Island, Queen Charlotte Islands, British Columbia. The relatively offshore-feeding ancient murrelet nests in colonies, lays two-egg clutches, and has truly precocial young. The inshore-feeding marbled murrelet is apparently a solitary nester, has one-egg clutches, and semiprecocial young. The ancient murrelet feeds predominantly on two species of euphausiid crustaceans, Euphausia pacifica and Thysanöessa spinifera, during the early portion of the terrestrial phase of its breeding cycle (early April to late May), but takes a fish, Ammodytes hexapterus, toward the end of the cycle. It is believed that this change in diet as the season progresses reflects a change in prey availability. The apparent patchy distribution of the prey of the ancient murrelet, which requires more time to locate the food source, has probably promoted the evolution of the 72-h incubation shifts found in this species.During the terrestrial phase of the marbled murrelet's breeding cycle (early May to late August), the fish Ammodytes hexapterus and Cymatogaster aggregata are predominantly taken. During the very early part of its breeding season, Thysanöessa spinifera constitutes a considerable part of its diet.
Regulation of crop contraction in the blowfly Phormia regina Meigen
Authors: Thomson A. J.
Published: August 2008

The rate of crop contraction in the blowfly Phormia regina reaches a maximum at a crop volume of 6 μl. At this crop volume, the contraction rate is determined by the nature of the physiological medium, glucose decreasing the contraction rate and trehalose increasing the contraction rate. The regulation of the crop-emptying rate by glucose is discussed in relation to the results of Gelperin (1966).
Movement and burrowing of Helisoma trivolvis (Say) (Gastropoda, Planorbidae) in a small pond
Authors: Buerger Hans
Published: August 2008

The movement of 120 marked Helisoma trivolvis (Say) (Gastropoda, Planorbidae) was followed for up to 26 days in a shallow, 0.75-ha pond in southern Ontario during the autumn of 1970. At water temperatures of 7–15 °C, the mean and maximum rates of dispersal were 1.4 and 19.2 cm/h, respectively. One snail moved 18.3 m in 26 days. The snails burrowed 1–2 cm into the bottom of the pond and remained burrowed for up to 45 h. The percentage of the snails which burrowed into the mud seemed to increase as the water became colder. No evidence could be found of either an autumn migration to deeper water or the occurrence of a homing behavior. The snails moved freely throughout the pond at all times of the year except when movement was curtailed by cold temperature. The rate of dispersal of lentic snails seems not to differ from that of lotic snails.
A light and electron microscopic study of the respiratory epithelium of the adult aquatic newt, Notophthalmus viridescens
Authors: Hightower J. A. , Burke J. D. , Haar J. L.
Published: August 2008

Light microscopy reveals that the non-partite lung of the fully aquatic adult newt, Notophthalmus viridescens, possesses four distinct types of epithelium: (1) pseudostratified columnar ciliated epithelium with goblet cells, (2) simple squamous epithelium, (3) simple cuboidal to columnar epithelium, and (4) vascularized epithelium with columnar-shaped cells.The pseudostratified columnar ciliated epithelium is distributed as a narrow band of tissue which extends nearly the entire length of the elongated lung on the dorsal or ventral aspects in close association with large pulmonary blood vessels. At the margins of this tissue, simple columnar, cuboidal, or squamous epithelium can occasionally be observed. Vascularized epithelium with columnar-shaped cells is the most prevalent of the four epithelia and lines the rest of the lung surface. Structures of particular importance present in these columnar cells are lamellated, osmiophilic, perinuclear bodies resembling cytosomes. Electron microscopy demonstrates that attenuated cytoplasmic projections extend laterally from the apical surfaces of adjacent columnar cells and are attached to one another by desmosomes. Thus, the columnar-shaped cells of the vascularized epithelium in the adult newt appear to be functioning not only as type I cells of mammals in that they form a continuous epithelial lining at the surface of the lung, but also as mammalian type II cells since they possess cytosomes.
Fate maps and gastrulation in Amphibia — a critique of current views
Authors: Løvtrup Søren
Published: August 2008

In the urodele blastula the ectomesoderm consists of a layer of cells bound to the hyaline membrane and of an aggregate of free cells lying inside the marginal zone. In the fate maps published by Vogt (1929) the chordamesoderm is located exactly above this annular aggregate, and Vogt himself realized that the mesoderm, in part at least, is derived from these inner cells.The results of several of the experiments recorded by Vogt, however, are impossible to account for on the assumption that any mesoderm is derived from the superficial membrane-bound cells, and it is therefore suggested that the mesoderm in toto is represented by the inner, free cells. Various lines of evidence support this contention, above all the fact that none of the ruptures between the germ layers implied by Vogt's fate maps has ever been observed.If the suggested origin of the mesoderm is accepted, the pre-Vogtian views on the mechanism of gastrulation are largely correct, having the consequence, among others, that the notochord can be considered to be derived from the ectoderm, and not from the mesoderm.
Soluble acid phosphatases of the hemolymph and fat body of Calpodes ethlius (Stoll) and the control of protein storage by fat body
Authors: Collins Janet V.
Published: August 2008

Hemolymph proteins of fifth-instar larvae of Calpodes ethlius were separated by precipitation with ammonium sulfate, followed by column chromatography on DEAE-cellulose. The three main proteins (antigens) of the larval hemolymph were present in varying amounts in all fractions precipitated by ammonium sulfate. Two of these antigens (1 and 2) were isolated by column chromatography. Acid phosphatase activity of hemolymph and fat body proteins was assayed by electrophoresis and colorimetry. Enzyme activity varied with stage of development in the fifth instar. In the hemolymph, activity declined along with protein concentration towards the end of larval growth. In the fat body, enzyme activity was highest during the main synthetic phase, and declined just before the start of protein uptake and storage. The activity rose again during the period of massive uptake of blood proteins. This increase may reflect storage of hemolymph phosphatases, and may also be correlated with the phase of heterophagy and autophagy which immediately precedes pupal ecdysis.
Echinocephalus sinensis n.sp. (Nematoda: Gnathostomatidae) from the ray (Aetabatus flagellum) in Hong Kong, Southern China
Authors: Ko Ronald C.
Published: August 2008

Mature and young adults of Echinocephalus sinensis n.sp. are described from the intestine of eagle rays (Aetabatus flagellum Bloch and Schneider) caught in Deep Bay, Hong Kong. This new species is readily distinguished from the other members of the genus by the number of rows of cephalic spines, presence of cuticularized preoesophageal serrations, length of spicules, presence of a gubernaculum, and the number and distribution of caudal papillae. Oysters (Crassostrea gigas Thunberg) probably are the intermediate host of this parasite. Second- and third-stage echinocephalid larvae found in these molluscs are described. The taxonomic status of Echinocephalus is briefly discussed and the generic diagnosis is emended.
Accommodative lens movement in holosteans (Amia calva and Lepisosteus osseus oxyurus) and in the sea lamprey (Petromyzon marinus)
Authors: Sivak J. G. , Woo G. C. S.
Published: August 2008

Accommodative lens movements were induced with drugs in Amia calva and Lepisosteus osseus oxyurus. The resulting refractive state changes, measured with a retinoscope and photographically, indicate that holosteans accommodate in the manner already described for teleosts. In both species the principal direction of lens movement was found along the pupil axis.Attempts were made to induce accommodative changes in Petromyzon marinus. These efforts included monitoring of the refractive state retinoscopically before and after (a) anaesthesia with MS 222, and (b) electrical stimulation of various periorbital locations. Only when electrical stimulation was of sufficient magnitude to produce contraction of the muscles of the head was a refractive change observed. This consisted of a shift from higher to lower levels of hyperopia. Further study of accommodation in lampreys is indicated.
Relative response to colored substrates by ovipositing blackflies (Diptera: Simuliidae). I. Oviposition by Simulium (Simulium) verecundum Stone and Jamnback
Authors: Golini Victor I. , Davies Douglas M.
Published: August 2008

Gravid females of Simulium verecundum made up 84% of eight simuliid species trapped on test strips floating on a stream in Algonquin Park, Ontario. When six colored strips with almost equal reflectances were exposed over a midbrown stream background, these females oviposited more on green and yellow than on purple, blue, orange, and red strips. Females oviposited also more on a white than on a black and two grey strips. After the stream background was changed to black, differences were less pronounced, and the preference shifted toward purple and blue among colored strips, and toward light grey among neutral strips, although green, yellow, and white strips still remained the most attractive. With a white stream background few eggs were laid on the strips. Gravid females trapped on sticky strips discriminated little among black and grey strips, but selected preferentially white, and retained a preference for green and yellow. Attractance of the colored strips varied inversely with the reflectance ratio of 450–500 nm/500–550 nm. Attractance of the neutral strips varied directly with their luminous reflectance. Thus both the hue and intensity of light reflected from the strips influenced ovipositing simuliids, but reflectance of the stream-bed background modified the primary effect.
Egg production by Trichobilharzia ocellata (Trematoda: Schistosomatidae) after initial and challenge infection in ducks
Authors: Rau M. E. , Bourns T. K. R. , Ellis J. C.
Published: August 2008

Evaluation of reproductive success by Trichobilharzia ocellata was based upon numbers of miracidia hatching in sidearm flasks. Hatchable eggs appeared in feces 13–14 days after the duck's foot was exposed to cercariae, rose to peak numbers by about day 19, then declined to zero, usually by day 45. Patent infections also resulted from implantations of 10–100 unsexed adults and in some but not all birds exposed to 10–25 cercariae on 51 consecutive days. Most birds challenged by massed cercariae failed to support egg-laying second populations regardless of whether the initial infection followed cercarial invasion or implantation of adults.
Sex-specific aging in the nematode Panagrellus redivivus
Authors: Abdulrahman M. , Samoiloff M. R.
Published: August 2008

Females of the free-living nematode Panagrellus redivivus have a greater mean life span than do males. Unmated animals live longer than mated individuals. Decreased nutritional levels or increased temperature decrease life span. The sex differences in life expectancy are also shown by behavioral activity and osmotic fragility. Behavioral activity decreases in older animals.
Ambient temperature effects on physiological traits of white-tailed deer
Authors: Holter J. B. , Urban Jr. W. E. , Hayes H. H. , Silver H. , Skutt H. R.
Published: August 2008

Six adult white-tailed deer (Odocoileus virginianus borealis) were exposed to 165 periods of 12 consecutive hours of controlled constant ambient temperature in an indirect respiration calorimeter. Temperatures among periods varied from 38 to 0 (summer) or to −20C (fall, winter, spring). Traits measured were energy expenditure (metabolic rate), proportion of time spent standing, heart rate, and body temperature, the latter two using telemetry. The deer used body posture extensively as a means of maintaining body energy equilibrium. Energy expenditure was increased at low ambient temperature to combat cold and to maintain relatively constant body temperature. Changes in heart rate paralleled changes in energy expenditure. In a limited number of comparisons, slight wind chill was combatted through behavioral means with no effect on energy expenditure. The reaction of deer to varying ambient temperatures was not the same in all seasons of the year.
Effect of thyroxine on the ultrastructure of the hypophyseal proximal pars distalis in Tilapia zillii
Authors: Leatherland John F. , Hyder Mohamed
Published: August 2008

The effects of exogenous L-thyroxine on the fine structure of the proximal pars distalis cells were examined in Tilapia zillii. In thyroxine-treated animals the thyrotrophic cells appeared marginally smaller and less active whereas the somatotrophs appeared markedly more active, with increased endoplasmic reticulum, larger mitochondria, and more granule release when compared with the same cell types in control animals. The gonadotrophs were similar in appearance in both thyroxine-treated and control groups.The possible interrelated activity of the somatotrophs and the TSH–thyroid axis is discussed.
Morphometric and flow indicator studies of the teleost heart
Authors: Cameron James N.
Published: August 2008

The structure of the heart of four species of Alaskan fishes (Thymallus arcticus, Esox lucius, Lota lota, and Catostomus catostomus) was examined in varying detail. The ventricle constitutes 0.07 to 0.09% of the body weight, 26 to 35% of which consists of an outer, cortical layer, and the balance a spongy, trabeculated inner layer. Blood supply to the cortex comes exclusively from the coronary artery, whereas the inner layer is supplied by venous (deoxygenated) blood from the ventricular lumen. Flow indicator studies implied that the cortical layer receives about half as much blood per unit weight as the inner layer, but probably receives about the same amount of oxygen, since arterial blood contains roughly twice as much oxygen as does venous blood. Calculations of the probable limits for oxygen uptake of the ventricle are made on the basis of data in this study and in the literature.
Differentiation of the Canada lynx, Felis (Lynx) canadensis subsolana, in Newfoundland
Authors: Jong C. G. van Zyll de
Published: August 2008

Cranial measurements, standard measurements, weights, and pelage color of the lynx from Newfoundland (Felis canadensis subsolana) and the North American mainland (F. c. canadensis) were compared to assess the difference between the two forms. Of the nine bivariate cranial relationships investigated, five (zygomatic width, mastoid width, interorbital width, postorbital width, and width between the postorbital processes) were found to be significantly greater relative to condylobasal length in F. c. subsolana. Overlap in variation between the two forms is considerable, however, Standard measurements and weights do not differ significantly. In addition, F. c. subsolana has a somewhat darker pelage than the mainland form. The isolation of the insular form may be of relatively recent date, as it has diverged only slightly from mainland populations and its recognition as a separate subspecies is questionable.
The unanswered question of high anaerobic capabilities of carp white muscle
Authors: Driedzic Wm. R. , Hochachka P. W.
Published: August 2008

Carp white muscle is considered to have a very high anaerobic capability; however, the accumulation of lactate is often not proportional to the amount of energy which must be generated. On the basis of whole-animal studies it is known that some fish produce NH4+ and CO2 anaerobically. This is interesting in light of the concept that many invertebrate facultative anaerobes simultaneously utilize carbohydrates and amino acids with the production of a variety of end products. We tested the hypothesis that in carp white muscle (a) lactate was not the sole end product of anaerobic metabolism and (b) amino acids were utilized as an anaerobic energy source. After an anaerobic work period induced by hypoxia we could detect none of the end products known to build up in invertebrate tissues and no mobilization of the free amino acid pool. Thus, carp white muscle appears to depend solely on glycogenolysis. The low level of lactate in carp white muscle even after severe hypoxic stress may be due to the transfer of this compound out of the tissue despite poor vascularization.
Antibody localization studies of the M-line in striated muscle
Authors: Palmer Esther G.
Published: August 2008

An investigation of species and organ specificity of M-protein was conducted with antibodies produced to M-protein extracted from porcine skeletal muscle with solutions containing 0.25 M sucrose. Light microscopic observations with fluorescein isothiocyanate (FITC) labeled antibody and electron microscopic observations with unlabeled antibody revealed that anti-M bound only to the M-line of both fresh and glycerinated porcine skeletal and cardiac muscle. Antibody binding was eliminated by extraction of KCl-washed myofibrils with sucrose solutions. Fluorescent staining with FITC-anti-M was eliminated by prior treatment with unlabeled anti-M serum but was not prevented by prior treatment with nonimmune rabbit serum. M-line-staining antibodies were removed from antiserum by absorption with M-protein but not by absorption with actin, tropomyosin, or α-actinin. Double diffusion of anti-M against M-protein resulted in a strong precipitin reaction, which did not occur with myosin, tropomyosin, α-actinin, actin, or phosphorylase. Antibody induced by porcine M-protein bound strongly to the M-line of mouse, rabbit, and human skeletal muscle and weakly to the M-line of frog skeletal muscle.