bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Physaloptera maxillaris (Nematoda: Physalopteroidea) in skunk (Mephitis mephitis) and the role of paratenic and other hosts in its life cycle
Authors: Cawthorn Richard J. , Anderson Roy C.
Published: August 2008

The development of Physaloptera maxillaris in skunk (Mephitis mephitis) was examined. The third moult was first observed at 5 days after infection and the fourth at 10 days. The prepatent period was determined as 41–45 days in skunk maintained under summer conditions. Various stages occurring in skunk are briefly described. Development of worms from the third stage to adulthood was consistently asynchronous in skunk.The striped skunk appears to be the only suitable definitive host of P. maxillaris. Experimentally it was not possible to produce patent infection in dogs (Canisfamiliaris), cats (Felis catus), mink (Mustela vison), ferrets (Mustela furo), rats (Rattus norvegicus), or raccoons (Procyon lotor) fed on the same diet as skunk. P. maxillaris is redescribed briefly.Leopard frogs (Rana pipiens) and garter snakes (Thamnophis sirtalis) may be potential paratenic hosts of P. maxillaris. Third-stage larvae did not penetrate tissues but remained in the gut for several days after infection and retained their infectivity. However, frogs and snakes are apparently not important components of the diet of skunk in the Guelph area.
Persistent infection of Malacosoma disstria (Lepidoptera: Lasiocampidae) cell cultures with Nosema (Glugea) disstriae (Microsporida: Nosematidae)
Authors: Sohi S. S. , Wilson G. G.
Published: August 2008

Cell lines were developed from hemocytes and ovarian tissues of Malacosoma disstria larvae that were naturally infected with Nosema disstriae. The infection was carried over into the cell cultures. N. disstriae disappeared from the ovarian cultures after several passages in vitro involving a period of more than 2 years, but hemocyte cultures are still infected after 6 years (199 passages). The spores produced in cell cultures were infectious for M. disstria larvae.
Physiological maturation and reproductive behaviour of female doves (Streptopelia risoria) held under long and short photoperiods
Authors: Liley N. R.
Published: August 2008

Female doves were held under long (16 h per day), or short (8 h per day) photoperiod and exposed to actively courting males for 4.5 h per day for 15 days. The occurrence of egg laying and nest building was recorded daily. Behavioural observations were recorded for 15 min on alternate days.Seven out of eight long-photoperiod females laid eggs, whereas only one of nine short-photoperiod females began egg laying. Soliciting by the female and nest building involving male and female are the best indicators of a female's readiness to begin breeding. The occurrence of these activities is correlated with the growth of follicles and oviduct. Copulation and associated behaviours are not correlated with follicle and oviduct growth, and appear to be controlled by factors different from those governing courtship behaviour associated with the nest site.
Time course of uptake, elimination, and tissue levels of [14C]DDT in wood-frog tadpoles
Authors: Licht Lawrence E.
Published: August 2008

Rana sylvatica tadpoles were treated with 0.001 and 0.003 ppm [14C]DDT (1,1,1 -trichloro-2,2-bis(p-chlorophenyl)ethane) at 15 and 21 °C and the time course of uptake and residue levels in several tissues of contaminated tadpoles were studied. By 24 h post treatment, highest concentrations of DDT were found in whole animals and in isolated tadpole tissues. After 80 h, DDT tissue levels began to diminish and fall slowly throughout the duration of the experiment. Liver and fat were the main sites for pesticide deposition. Tadpoles treated at 15 °C retained higher tissue levels of DDT for longer periods, i.e., they lost DDT more slowly than tadpoles at 21 °C.
Philometroides huronensis n.sp. (Nematoda: Dracunculoidea) of the common white sucker (Catostomus commersoni) from Lake Huron, Ontario
Authors: Uhazy Leslie S.
Published: August 2008

A new species of nematode, Philometroides huronensis n.sp., is described from the fins and peritoneum around the swim bladder of the common white sucker (Catostomus commersoni). The gravid females and the males of this species are readily distinguishable from those of other members of the genus by the body size, cuticular ornamentation, caudal ventrolateral hypodermal extensions, size and shape of first-stage larva, length of spicules, size and shape of gubernaculum, and location in the host. Measurements of mature and subgravid females are presented.
Oxygen consumption during simulated vertical migration in Mysis relicta (Crustacea, Mysidacea)
Authors: Foulds J. B. , Roff J. C.
Published: August 2008

When Mysis relicta was induced to swim at speeds of 1.0 and 1.6 cm/s, which are similar to observed vertical migration rates in Lake Ontario, there was no significant (P <.05) increase in oxygen consumption over the 'routine' rate of 5.28 μg oxygen per animal per hour for a 5-mg animal (dry weight). At higher swimming speeds (2.1 to 3.6 cm/s) an increase in oxygen consumption to 1.2 times the 'routine' rate was demonstrated. Exopodite beat rate increased from 3.7 cycles per second under 'routine' conditions to 5.3 cycles per second al a swimming speed of 3.6 cm/s. Increased external salinity under 'routine' conditions resulted in decreased rates of oxygen consumption from 5.28 μg oxygen per animal per hour at 0‰, to 3.28 μg oxygen per animal per hour at 15‰ for a 5-mg animal. At 25‰ and 30‰, oxygen consumption remained about the same as at 15‰. The results add further support to earlier theories that postulate a negligible "cost" for vertical migration.
Growth of Colpidium campylum in monoxenic batch culture
Authors: Taylor William D. , Berger Jacques
Published: August 2008

The population growth rate, as measured by changes in cell number or biomass, of Colpidium campylum monoxenically cultured on Aerobacter aerogenes was found to vary significantly among batch cultures using the same medium and temperature. The lowest estimates of cell number growth rate were found in cultures where late exponential phase cells were used as inocula. Under these conditions, biomass growth rate exceeded growth in cell numbers. When stationary phase cells were used as inocula, the opposite was true. Variation in growth rate measurements could be reduced by transferring cultures every 24 h, so that early exponential phase cells were used as inocula. The growth dynamics of Colpidium are discussed in terms of an ecological strategy for dealing with environmental patchiness.
Comparative ultrastructure and systematics of the Colpodida. An ultrastructural description of Colpoda maupasi Enriquez, 1908
Authors: Lynn Denis H.
Published: August 2008

Structural variation at different levels of biological organization is considered important to the systematics of ciliated protozoa. Analysis of the ultrastructural literature on ciliates led to the structural-conservatism hypothesis, which has been formulated to account for the variation of ultrastructural components, primarily microtubular, in the cortex of diverse ciliate genera. The hypothesis proposes that the conservation of structure through time is inversely related lo the level of biological organization. This study presents a light microscopic and ultrastructural description of Colpoda maupasi Enriquez, 1908. Comparison of C. maupasi with other species of the Colpodida supports the structural-conservatism hypothesis. With this hypothesis, several relational inconsistencies are demonstrated in the present scheme of classification of the ciliates.
Lateral jaw muscles of Elachistodon westermanni Reinhardt (Reptilia: Serpentes)
Authors: Rosenberg Herbert I. , Gans Carl
Published: August 2008

Lateral jaw musculature of the very rare Elachistodon is described for the first time and compared with Dasypeltis. The enormous Harderian glands of both genera and their relationships with adjacent muscles are also described. Myological differences and similarities between Elachistodon, Dasypeltis, and some generalized colubrid snakes are tabulated. The primary myological differences are found in the adductor muscles of the lower jaw. Elachistodon and Dasypeltis have a single, major adductor muscle of the lower jaw, that attaches dorsally along the length of the quadrate and ventrally along the lower jaw. This muscle probably represents a fused medialis and profundus. Both species also have a small superficialis that may play a minor role in elevating the lower jaw. The reduction in size and shift of origin of the adductors is discussed in terms of functional demands associated with egg eating. Morphological similarities indicate that Elachistodon and Dasypeltis are probably related.
Seasonal population changes of Physaloptera maxillaris (Nematoda: Physalopteroidea) in striped skunk (Mephitis mephitis)
Authors: Cawthorn Richard J. , Anderson Roy C.
Published: August 2008

The stomachs of 162 (89%) of 183 striped skunk (Mephitis mephitis) collected in the area of Guelph, Ontario, between September 1973 and August 1974 were infected with Physaloptera maxillaris. Adult worms were most abundant in midsummer (June–July) and rare in winter (December–March). Third-stage larvae were most abundant in late fall and midwinter (October–January) and least abundant in midsummer (June–July). Fourth-stage larvae were most abundant in spring (April–May) and least abundant in early fall (August–September). It is suggested that adults appear mainly when skunk are feeding regularly in spring and midsummer. Third-stage larvae acquired in late summer and fall fail to develop (probably because of inadequate food consumption by skunk) and persist over the winter. In spring when skunk start to feed again, overwintering larvae grow into adults and initiate the annual cycle in skunk and intermediate hosts.
Habitat selection by two parapatric species of chipmunks (Eutamias)
Authors: Meredith Don H.
Published: August 2008

Eutamias minimus oreocetes and E. amoenus luteiventris are altitudinally parapatric in the southern Alberta Rocky Mountains; minimus occupies the alpine and amoenus occupies the forest. In the field, minimus was captured or observed in or near talus, while amoenus was captured or observed in or near forested areas. Field-experienced individuals of both species selected rock over trees during habitat-selection experiments in the laboratory. Laboratory-raised minimus selected rock over trees, while laboratory-raised amoenus had no significant preference. I conclude that minimus oreocetes has evolved an innate preference for the cover quality of talus because talus is the only cover with vertical depth that is available in the alpine. Amoenus luteiventris may learn to select talus because of its cover quality, but does not inherit such a preference because of the variety of cover types available in the forest. Based on the cues provided in the laboratory, habitat selection does not appear to restrict amoenus luteiventris to the forest, but may reinforce the restriction of minimus oreocetes to the alpine.
The morphology of the femur in marten and fisher
Authors: Leach Doug , Dagg Anne Innis
Published: August 2008

The morphological characteristics of the femora of 377 fisher and 142 marten were studied to determine those characteristics which could be used to distinguish between species and between sexes. Measurements and illustrations were used to supplement the descriptions of these bones. The femora of marten and fisher are similar in structure but it is possible to distinguish between these bones using morphometric data. Distinction can also be made between femora of male and female marten using bone measurements. The robustness of these femora was also examined. The femora of female marten were more robust than those of male marten, while those of male and female fisher were similar in robustness.
When Caenorhabditis elegans (Nematoda: Rhabditidae) bumps into a bead
Authors: Croll Neil A.
Published: August 2008

When C. elegans bumps into a bead, it stops moving, withdraws a short distance, and then resumes forward movement, often in a new direction. This series of events has been analysed in its constituent parts and the features making up the 'stimulus' have been compared numerically with those making up the 'response.' No significant correlations were found that support the interpretation that this is a simple stimulus–response phenomenon. It is argued that the data support an alternative view that when forward movement is interrupted, C. elegans is primed to undergo a short, rapid reversal and that this is not mediated through sensory mechanoreceptors.
Cellulose content of food and faeces of Diprion similis as an internal marker for determining food consumption and digestibility
Authors: Fogal W. H. , Webb D. P.
Published: August 2008

The consumption and digestibility of Scots pine (Pinus sylvestris L.) foliage by a diprionid sawfly (Diprion similis (Htg.)) can be determined indirectly by using the cellulose content of needles and faeces as an indigestible marker substance. No difference between figures obtained this way and those obtained by direct gravimetric determinations could be detected. This demonstration was preceded by exploratory studies to determine the feasibility of using lignin or cellulose content of the needles and faeces as the marker. Lignin was not employed because its methoxyl content decreases upon passage through the gut. By comparison with gas–liquid chromatography, the glucose oxidase (EC 1.1.3.4) method was shown to be satisfactory for the quantitative estimation of glucose in hydrolysates of cellulose isolated from needles and faeces.
Les caryotypes de trois planaires marines nord-américaines : contribution à la phylogénie et à la classification du groupe (Platyhelminthes, Turbellaria, Tricladida)
Authors: Ball Ian R.
Published: August 2008

The karyotypes of three species of marine planarians have been studied, this being the first time that karyometric data have been made available for this group. Procerodes littoralis has a diploid complement of 14 metacentric chromosomes. Uteriporus vulgaris and Foviella affinis both have diploid complements of 16 more-or-less metacentric chromosomes. The karyotypes of V. vulgaris and F. affinis are virtually identical and the data support a prior taxonomic decision to remove Foviella from the Procerodidae and to classify it within the Uteriporidae. So little is known of the karyotypes of the Maricola and the Proseriata, and the basic numbers are so varied, that it is impossible to use the karyotype as a prior phylogenetic character, even in the freshwater triclads, which have been so well studied.
Walrus ethology. II. Herd structure and activity budgets of summering males
Authors: Miller Edward H.
Published: August 2008

Male walruses, Odobenus rosmarus (L.), summering (outside the breeding season) at an Alaskan hauling ground, use all available kinds of beach habitat: cobble and boulder beaches, rock benches, and large boulders. Formation and dissolution of large herds on land can occur rapidly. Walruses are very gregarious and positively thigmotactic. In cool weather about 98% of walruses on land lie in passive body contact with other walruses. Dominant walruses (large, with long unbroken tusks) are most successful in entering herds on land, and in keeping positions in them. This results in overrepresentation of subordinates in the periphery of herds. Agonistic interactions occupy 5–10% of the time of walruses in large herds on land, and cause local disturbances that lead to agonistic involvement of up to 20 animals. Fewer kinds of social activity occur on land than in water. On land and in shallow water, small walruses are generally more active than large ones. Extensive body contact while they are hauled out is chiefly an adaptation for heat conservation and may also facilitate molting. The extreme gregariousness of walruses may have evolved because individuals joining large herds have a greater probability of achieving extensive body contact than have those joining small herds.
Nuclear changes preceding microgamete formation in Leucocytozoon simondi and Leucocytozoon tawaki
Authors: Desser S. S. , Fallis A. M. , Allison F. R.
Published: August 2008

After the removal of blood that contained gametocytes from a duck and a penguin that were infected with Leucocytozoon simondi and L. tawaki respectively, the nuclei of microgametocytes undergo rapid changes before exflagellation. The nuclear chromatin of the parasite assumes a reticulate appearance after its escape from the host cell and soon contracts into a central, compact mass, then flagella begin to emerge from the peripheral cytoplasm. The chromatin divides and becomes dispersed, and a small portion enters each of the eight forming microgametes. This process may be completed in less than 1 min.
Observations on the ultrastructure of papillae and associated sensilla on the scolex of Monoecocestus americanus (Stiles, 1895) (Cestoda: Anoplocephalidae)
Authors: Blair David G. , Burt M. D. B.
Published: August 2008

The structure of sense organs associated with papillae and elsewhere in the tegument, found on the scolex of Monoecocestus americanus (Cestoda: Cyclophyllidea), is described. These organs consist of a basal bulb containing one or two electron-dense collars, mitochondria, and an apical cilium.
Fine structure of granulated cells in the posterior cardinal and renal veins of Amia calva L.
Authors: Youson John H.
Published: August 2008

Granulated cells located in the walls of the posterior cardinal and renal veins in the holostean fish Amia calva resemble cells of the adrenal medulla of higher vertebrates. The cells all contain similar electron-dense secretory granules, apparently originating from the Golgi apparatus, and are innervated by nerve terminals. These features suggest that the cells are involved in the production and release of catecholamines. The relationship of the cells to the endothelium of the large veins also suggests that the secretory products of the cells reach the circulation by traversing a complex subendothelial space and passing through the fenestrae of the endothelium. This appears to be an efficient means for the immediate release and distribution of catecholamines in this species of fish.
Accuracy of the tritium water dilution method for determining water flux in reindeer (Rangifer tarandus)
Authors: Cameron R. D. , White R. G. , Luick J. R.
Published: August 2008

The accuracy of the tritium water dilution method in estimating water flux was evaluated in reindeer under various conditions of temperature and diet. Two non-pregnant female reindeer were restrained in metabolism stalls, within controlled-environment chambers, at temperatures of + 10, −5, and −20 °C; varying amounts of a commercial pelleted ration (crude protein, 13%) or mixed lichens (crude protein, 3%) were offered, and water was provided ad libitum either as snow or in liquid form. Total body water volume and water turnover were estimated using tritiated water, and the daily outputs of feces and urine were measured for each of 12 different combinations of diet and temperature. Statistical analysis of the data showed that the tritium water dilution technique gives accurate determinations of total body water flux over a wide range of environmental and nutritional conditions.
Resource overlap between co-occurring copepods: effects of predation and environmental fluctuation
Authors: Maly Edward J.
Published: August 2008

Two high-altitude copepods, Diaptomus shoshone and D. coloradensis, exhibit temporal differences in development and abundance, and they are of different size. Studies of adult sizes attained and of diets reveal that competition for resources between the two species is slight; however, laboratory experiments demonstrate that D. shoshone, the larger of the two species, preys extensively upon D. coloradensis. The population characteristics of the two species can be attributed both to avoidance of predation by the smaller species and to high variation in season length. Results are discussed in relation to theory, indicating that competition is a primary determinant of degree of resource overlap between congeneric species.
Plasma bradykininogen and reproductive cycles: studies during the oestrous cycle and pregnancy in the rat, and in the human menstrual cycle
Authors: McDonald M. , Perks A. M.
Published: August 2008

Plasma bradykininogen levels have been shown to rise about threefold late in pregnancy in the rat. However, they declined sharply 1–2 days before delivery.Plasma bradykininogen levels remained relatively unchanged through most the oestrous and menstrual cycles (rat, man). However, they showed a fall at two similar periods, in both cycles. A smaller decline occurred in metoestrus in the rat, and (probably) in the late luteal phase in the human. The largest fall took place around the time of ovulation in both the oestrous and the menstrual cycles. The decline was about 59% in the rat and 42% in the human. Bradykininogen showed no similar changes in the blood of male human controls. The suggestion that bradykinin could be involved in ovulation is discussed.
A comparison between woodland and tundra forms of the common shrew (Sorex cinereus)
Authors: Zyll de Jong C. G. van
Published: August 2008

Cranial measurements, dentition, tail length, and color pattern of woodland and tundra forms of Sorex cinereus were compared to elucidate their systematic relationship. The structure of the glans penis was compared in a small number of specimens that represented the two forms. The tundra forms, including S. c. ugyunak from the North American mainland and S. pribilofensis and S. jacksoni from islands in the Bering Sea, are closely related forms within the cinereus group; they are distinct from the woodland forms in cranial as well as external characters. Skulls from neighboring populations of S. c. ugyunak and S. c. cinereus from the Mackenzie Delta could be separated using four characters. The probability of incorrectly identifying a skull using these characters was low (P = 0.0025). The prairie form S. c. haydeni also differed from the woodland forms and resembled the tundra forms in a number of characters. S. c. hollisteri resembled the woodland forms. Further study is needed to settle the taxonomic status of the forms compared.
Haemopoiesis in Lepidoptera. I. The multiplication of circulating haemocytes
Authors: Arnold J. W. , Hinks C. F.
Published: August 2008

Haemopoiesis in Lepidoptera is doubtless accomplished to a large extent by mitosis of the circulating haemocytes. but there are some anomalies with regard to certain classes. Granular haemocytes and spherule cells are the only classes that divide frequently enough to account alone for their continued increase in numbers. Prohaemocytes divide frequently, but their numbers do not increase markedly. There is little doubt that they differentiate exclusively to plasmatocytes, which rarely divide themselves but continue to increase in numbers during larval life. An increase in plasmatocyte size and numbers after the fourth instar, when the mitotic index of prohaemocytes is declining, suggests an alternative source as well. Oenocytoids never divide, and undoubtedly derive from a separate source.
Attachments of phasic and tonic abdominal extensor muscles in crayfish
Authors: Jahromi S. S. , Atwood H. L.
Published: August 2008

The fine structure of attachments of phasic and tonic crayfish abdominal extensor muscles to the exoskeleton was studied by means of electron microscopy. Tonic muscles contract more slowly and exert more tension per unit area of cross section than phasic muscles. The muscle attachment regions show differences in structure which are correlated with the different contractile properties. In both muscles, microtubule-filled tendinous cells intervene between the end of the muscle and the exoskeleton; but in phasic muscles the tendinous cells are joined to the muscle by rather long extracellular microfibrils which in general run obliquely to the longitudinal axis of the muscle, whereas in tonic muscle, the tendinous cells and the muscle are joined together more directly by shorter microfibrils running parallel to the muscle's longitudinal axis, and also by desmosome-like structures. In addition, the extracellular materials in tonic muscles appear to be firmly attached to the Z lines of the muscle sarcomeres; such an association was not observed in phasic muscle.
A comparative study of scent-gland location and related behaviour in some northwestern nearctic ground squirrel species (Sciuridae): an evolutionary approach
Authors: Kivett V. Keith , Murie Jan O. , Steiner André L.
Published: August 2008

Location and hisiology of integumentary glands were investigated in six species of ground squirrels of the genus Spermophilus found in northwestern North America; S. columbianus, S. undulatus, S. richardsonii, S. tridecemlineatus, S. lateralis, and S. franklinii. Among these species, glands in oral, dorsal, and anal regions were structurally similar. Locations of oral and anal glands were identical but location of individual glands in dorsal-gland fields varied considerably. Gland development was greater in S. columbianus and S. undulatus and least in S. franklinii. Active scent marking was most frequent and extensive in S. columbianus and S. undulatus, less frequent in S. lateralis and S. tridecemlineatus, and absent in S. franklinii. In most instances, greeting behavior (which is focused on the mouth-corner oral-gland area) and the degree of sociality paralleled levels of scent marking. A hypothetical scheme of development or scent marking in relation to habitat and social organization is presented. This scheme fits, in general, classical interpretations of phylogeny.
Morphogenetic sequences during tadpole tail regeneration
Authors: Atkinson Kristine H. , Atkinson Burr G. , Merrifield Peter A.
Published: August 2008

The appearance of differentiated tissue types after amputation of Rana catesbeiana tadpole tail follows a precise chronological order. Migrating epithelial cells invest the wound within 3 days. Blastemal cells accumulate under the distal epithelium in the early stages when tissue debris is cleared away, then by day 11 notochordal outgrowth and nerve axon replacement predominate in the highly vascularized blastema.Fusion of the myoblasts to form the first detectable myotubes occurs in the proximal region of the regenerate by day 14. Myogenesis proceeds distally with myotubes present under the epithelium of the distal tip of the regenerate at day 19. After day 22 further increase in tail musculature is probably due to the growth of fibers already formed. At day 22 the new muscle fibers begin to anastomose with the healed ends of the old fibers. From 35 to 48 days the major remaining difference from control tissues is the size and extent of the regenerated muscle fibers; capillaries, axons, epidermis and dermis, and neuromuscular junctions are morphologically indistinguishable from unregenerated tissues.
The mechanics of lung ventilation and the effects of hypercapnia on respiration in Bufo marinus
Authors: Macintyre D. H. , Toews D. P.
Published: August 2008

Respiratory and circulatory changes associated with exposure to elevated ambient carbon dioxide (CO2) levels were studied in free-moving Bufo marinus. The buccal cavity, lungs, and systemic arch were cannulated singly or in various combinations. Simultaneous recordings from the lungs and buccal cavity permitted analysis of respiratory rate and pattern, while systemic cannulae provided constant blood-pressure measurements. All experiments were conducted at 22 °C.Normal breathing patterns consisted of continuous buccal 'oscillations' with irregularly occurring lung 'ventilations' and occasional high pressure 'inflations.' On exposure to increased ambient CO2 levels, oscillations decreased, ventilations increased, and inflations predominated, resulting in an overall increase in lung minute-volume. Systemic pressure decreased as ambient CO2 approached 3%, but returned to normal, with an associated increase in heart rate, at the 5% level. It is postulated that the ventilatory and concomitant circulatory responses are mediated by receptors functioning in both the chemoreceptive and baroreceptive modes.
Wing polymorphism in the insect species Agonum retractum Leconte (Coleoptera: Carabidae)
Authors: Carter Alan
Published: August 2008

Reproduction and flight ability in a wing polymorphic carabid. Agonum retractum Leconte, from an aspen woodland ecosystem in the Kananaskis Valley of Alberta were studied. Females were short and long winged and males were mainly short winged with the occasional long-winged individual. Females of both morphs gave rise to mixed progeny. Dimorphism of females may have been maintained by selective advantage of the heterozygote. Heterozygous long-winged females may have been more efficient colonizers because they produced mixed progeny that played different roles in migration and colonization.No adults were flight trapped. Long-winged females had flight ability until between coition and egg development, after which flight musculature atrophied. The ratio of short- to long-winged individuals may remain low where migration from populations is minimal or non-existent, such as in the Kananaskis Valley population.
Cardiovascular responses of winter flounder, Pseudopleuronectes americanus (Walbaum), to acute temperature increase
Authors: Cech Jr. Joseph J. , Bridges David W. , Rowell David M. , Balzer Paul J.
Published: August 2008

Measurements of oxygen consumption rate, heart rate, total hemoglobin concentration, and arterial–venous blood pH, pressure, and oxygen tension and content were made on about 15 seasonally acclimatized winter flounder in flow-through respirometers at the seasonal mean temperatures of 5, 10, and 15 °C. These data along with calculated values of cardiac output and stroke volume were compared with similar measurements in winter flounder exposed to a 5 °C temperature increase over a 2-h period. To meet the significantly enhanced oxygen demand after the temperature increase, the primary cardiovascular adjustments changed from an increased arteriovenous (AV) O2 content difference with no change in cardiac output at winter temperatures to an increased cardiac output and relatively unchanged AV O2 difference at summer temperatures. Significantly increased heart rates also characterized the 5 °C increase at each of the seasonal regimes. Seasonal fluctuations in blood oxygen capacity may be influencing the observed changes in cardiovascular adjustment patterns to temperature increase.
Some infaunal fishes associated with the scleractinian coral Madracis mirabilis
Authors: Luckhurst B. E. , Luckhurst K.
Published: August 2008

Fifteen clumps of the coral Madracis mirabilis were collected and examined for infaunal fishes. A total of 19 specimens of fishes representing five families was obtained. Most of the specimens were members of the families Gobiidae and Grammistidae.
Platynosomum andersoni n.sp. (Trematoda: Dicrocoeliidae) from bile ducts of Rattus huang (Bonhote)
Authors: Ko Ronald C.
Published: August 2008

Platynosomum andersoni n.sp. is described from the bile ducts of Rattus huang (Bonhote) trapped in the New Territories, Hong Kong. This new species is readily distinguished from the other members of the genus mainly by the commencement of the vitellaria at the pharyngeal region and by having a smaller number of uterine loops.
Zschokkella embiotocidis sp.n. (Protozoa, Myxosporida) from California pile perch, Damalichthys vacca, and striped perch, Embiotoca lateralis
Authors: Moser Mike , Haldorson Lewis
Published: August 2008

Zschokkella embiotocidis sp.n. was found in the gallbladders of Damalichthys vacca and Embiotoca lateralis from Diablo Cove off central California.
The role of estrogen and progesterone in the regulation of reproductive behaviour in female ring doves (Streptopelia risoria) under long vs. short photoperiods
Authors: Liley N. R.
Published: August 2008

Female ring doves held under long (16 h per day) or short (8 h per day) photoperiods were treated daily for 15 days with saline, estrogen, or progesterone, alone or in combination. Seven days after the start of hormone therapy females were placed with reproductively active males for 4 h per day for 9 days. There was no difference in egg-laying, courtship, and nest-building by control birds under the two photoregimes.Ovarian follicles remained small in all birds receiving hormone treatment. Oviducts of birds receiving progesterone alone remained small in the short-photoperiod group, but at long photoperiods oviducts became enlarged. Estrogen stimulated oviduct growth at both photoperiods. The combined hormone treatment resulted in considerably greater oviduct development than estrogen alone, and in this case the oviducts of birds under long photoperiod were significantly heavier than those of short-photoperiod birds.Female soliciting and nest-building activity remained low in progesterone-treated females under short photoperiod, but increased rapidly under long photoperiod. Birds treated with estrogen and estrogen and progesterone performed considerable soliciting and nest-building. There was a marked tendency for birds under long-photoperiod conditions to be more active in nest-oriented behaviour. Copulatory behaviour by the female (begging and sexual crouch) occurred infrequently in all hormone-treated birds.
A light and electron microscopic study of the structure of the nucleus preopticus and nucleus lateral tuberis of the goldfish, Carassius auratus
Authors: Peter R. E. , Nagahama Y.
Published: August 2008

On the basis of fine structure only one cell type could be identified in the nucleus preopticus. The nucleus lateral tuberis (NLT) contains three distinct cell types. Cell type 1, primarily in the NLT pars lateralis, is a large cell with many dense-core granules (DCG) 97.3 nm average diameter. Cell type II, primarily in the NLT pars anterioris, is smaller and contains few DCG, averaging 70.9 nm. Cell type III, found in the NLT pars posterioris, pars inferioris and posteriorly in the pars anterioris, is a small cell with DCG similar to type II cells. Cell type III additionally has large irregular granular bodies (dimensions up to 2 μm) that stain with aldehyde fuchsin and are visible with the light microscope. The possible role of the various cell types in controlling pituitary function is discussed.The juxta-ventricular border of the ependyma in the NPO and NLT regions is lined with cilia and microvilli, each with a regionalized distribution. In addition, there are cells with bleblike cytoplasmic extensions into the third ventricle in the ependyma layer in the NLT pars anterioris and pars posterions regions.
Growth of the opisthonephric kidney during larval life in the anadromous sea lamprey, Petromyzon marinus L.
Authors: Ooi E. C. , Youson J. H.
Published: August 2008

Light microscopy, autoradiography, and gross anatomical measurements are used to study the growth of the larval opisthonephric kidneys of anadromous sea lamprey, Petromyzon marinus. Linear regression analysis of kidney lengths of the ammocoetes, ranging in length from 13 mm to 151 mm, reveals six natural groups of ammocoetes, year classes 0 to V, with each group demonstrating a definite growth pattern of the kidneys.Within the year classes 0 to III, the nephron rudiments at the posterior tip of the kidney differentiate periodically into functional nephrons as the larval opisthonephros lengthens in an anterior lo posterior direction. Labelling of cells with [3H]thymidine occurs in the differentiating nephrons and in the adjoining nephrogenic tissue. In contrast, the growth of the opisthonephric kidney in the year classes IV and V appears to result from the elongation of existing nephrons by cell proliferation.The length of the kidneys appears to be a valuable asset to our present means of age classification of the ammocoetes of anadromous P. marinus. The ammocoetes provide a unique opportunity to study growth and differentiation of a vertebrate kidney over a long period of time.
Alkaline phosphatase isozyme patterns and histochemistry in adult and differentiating skate spiral valve
Authors: Evans Robert E. , Ford Peter
Published: August 2008

This project was undertaken to study the histochemical alkaline phosphatase (AP; EC 3.1.3.1) localizations in the spiral valve of adult and developing skates (Raja binoculata). Secondly, it was decided to determine if spiral valve AP isozymes, separated by disc electrophoresis, are altered during spiral valve differentiation.The histochemical localization of AP in the adult spiral valve is similar to that observed in the intestines of other vertebrates. Enzyme activity was found in brush borders and the Golgi zone of the epithelial cells, as well as in the lamina propria. The developing spiral valves showed an accumulation of enzyme in some areas and a depletion at other sites with advancing differentiation.Spiral valve AP banding patterns do change during morphological differentiation of the organ. It appears that one electrophoretic zone, present alone in early stages, loses activity upon completion of spiral valve morphological differentiation with the formation of the villi. Each isozyme becomes demonstrable at different developmental stages.
Macroinfauna of northern New England marine sand. III. The ecology of Psammonyx nobilis (Stimpson), 1853 (Crustacea: Amphipoda)
Authors: Scott K. J. , Croker R. A.
Published: August 2008

The boreal lysianassid Psammonyx nobilis is associated with very well sorted, fine sand of low intertidal and shallow subtidal habitats. It is a winter to early spring breeder, with recruitment from June to August in New England. Females produce up to 50 eggs and have one brood per breeding period. Generation time is 2 years. Larger adults occur only during colder months at more exposed intertidal habitats, while all life stages occur at sheltered intertidal habitats throughout the year. Females are larger than males and are more abundant at the landward periphery of intertidal populations. Subtidal populations show smaller adults and juveniles present most of the year. The species is a scavenger–omnivore exhibiting an aggregated pattern of distribution. Swimming activity is highest in the dark during falling tides. Respiration increases significantly at salinities < 20‰. The length of pereopod 7 was the sole sexually dimorphic character observed. The heretofore enigmatic, elongate gnathopod 2 is not used in precopula, but for removing organic debris from the thoracic cavity.
The genus Ceratomyxa (Protozoa: Myxosporida) in macrourid fishes
Authors: Moser Mike , Noble Elmer R.
Published: August 2008

Eight species of Ceratomyxa, two new, were found in seven genera and 12 species of macrourids. The constancy in spore size and shape seen in some geographically dispersed species was outstanding.
Diaphus hudsoni (Pisces: Myctophidae), a new lanternfish from the South Atlantic Ocean
Authors: Zurbrigg R. E. , Scott W. B.
Published: August 2008

A new myctophid species, Diaphus hudsoni, was captured in the South Atlantic Ocean, and is described. It is similar to Diaphus subtilis Nafpaktitis, which occurs in the North Atlantic Ocean, but is definitely distinct with its slender, more numerous gill rakers (total 23–25), and non-continuous AOp–Prc series. The AO series numbers 5 + 5–6. The holotype is deposited in the Royal Ontario Museum, ROM 27569.
Structure, innervation, and distribution of sensilla on the wings of a grasshopper
Authors: Albert P. J. , Zacharuk R. Y. , Wong L.
Published: August 2008

The upper surfaces of the wings of the adult grasshopper Melanoplus sanguinipes bear long, medium, short, and minute innervated trichoid hairs, and campaniform sensilla. There are 2.2 times more of these sensilla, and their density is 5.8 limes greater on the fore wings than on the hind wings. They are concentrated along the primary longitudinal veins, and at the tips of both wings, and at the base and along the leading edge of the hind wing. These sensilla could possibly provide a feedback mechanism towards a coordinating role in flight, and a proprioceptor role in wing folding and unfolding.Possible chordotonal organs, multipolar neurons of type II, and an unidentified sensillum were noted also, but their number, distribution, and functional roles were not studied.
Serologic characterization and identification of four lepidopteran cell lines
Authors: Krywienczyk J. , Sohi S. S.
Published: August 2008

The identity of four cell lines (Cf124, Md63, Md108, and Md109) was investigated using the technique of double diffusion. The absorbed antiserum of Cf124 cells formed strong precipitin lines with Choristoneura fumiferana antigen, and the absorbed antisera of Md63, Md108, and Md109 cells gave a strong reaction with the Malacosoma disstria antigen, thus substantiating their species identity. Although the M. disstria cell lines did not show any tissue specificity, they differed from each other in at least one antigen. The antigens from whole larvae of C. fumiferana and M. disstria were more suitable than their hemolymph for serological reactions with the antisera of tissue cultures by double diffusion.
Morphology of the neuroendocrine systems of two larval blackflies, Prosimulium mixtum/fuscum and Simulium venustum
Authors: Condon William J. , Gordon Roger , Bailey Charles H.
Published: August 2008

The anatomical relations of the neuroendocrine systems of simuliid larvae Prosimulium mixtum/fuscum and Simulium venustum were examined histologically. The neuroendocrine system in the brain showed morphological similarities to culicids (viz., three pairs of cerebral neurosecretory cell clusters, one pair of nervi corporis cardiaci entering the corpus cardiacum glandular system). The retrocerebral glandular portion of the neuroendocrine system was comprised of a corpus allatum, corpora cardiaca, and surrounding peritracheal gland. The morphology of the blackfly neuroendocrine system is discussed in relation to those of other families of Nematocera and higher Diptera.
Hormonal regulation of reproduction and the antler cycle in the male Columbian black-tailed deer (Odocoileus hemionus columbianus). Part I. Seasonal changes in the histology of the reproductive organs, serum testosterone, sperm production, and the antler cycle
Authors: West Nels O. , Nordan H. C.
Published: August 2008

The hormonal regulation of reproduction and the antler cycle was investigated by measuring serum testosterone, testis volume, sperm production, and the antler growth cycle of wild and captive deer. The functional relationships of the testes and accessory sex glands to reproduction and antler growth were also studied by examining these organs histologically.Reproductive activity was maximal in November when the mean serum testosterone level of the adult males was 10 ng/ml, testis volume averaged 30 cm3, and the concentration of sperm in the semen was 100 × 106 to 700 × 106/ml. In winter, the activity of the reproductive organs declined, until a minimum was reached in February or March. The antlers were cast several weeks after the serum testosterone dropped below 1 ng/ml. In spring, a significant increase in spermatogenetic activity occurred, coincident with the initiation of antler growth. The serum testosterone level, however, remained low until velvet shedding, in late summer.These findings support the hypothesis that the maturation of antlers, shedding of the velvet, and the maintenance of antlers in the hard, functional condition are dependent on testosterone. The possible significance of increased spermatogenetic activity in the spring and its relationship to antler growth are also discussed.
Laboratory studies on the larval biology of Simulium venustum Say (Diptera: Simuliidae)
Authors: Mokry Joseph E.
Published: August 2008

Larvae reared from field-collected eggs of Simulium venustum were found to pass through six larval instars. Temperature strongly affected both the growth rate of larvae and their survival. At 5, 10, and 12 °C all S. venustum larvae died before reaching the sixth instar. At 15 °C, larvae were found to be able to complete development to the sixth instar, although only 10.5% survived to this stage. Increases in temperature led to increases in survival and rate of growth, with the best survival (20.4%) at 22 °C; most larvae required 22 days to reach this stage. Above 22 °C, survival decreased (5.7%), although the growth rate continued to increase. A growth model for blackfly larvae simulating natural conditions was constructed using temperature–growth curves obtained in laboratory trials and comparing these data with stream temperature profiles.
Variation in the diet of Myotis lucifugus (Chiroptera: Vespertilionidae)
Authors: Belwood J. J. , Fenton M. B.
Published: August 2008

By analysis of feces collected from bats in the field, we determined that aquatic insects, particularly chironomid Diptera, made up the major portion of the diet of Myotis lucifugus at sites in southern Ontario, northern New York, and Nova Scotia. The diets of adult males reflected the available insect prey as sampled by a malaise trap, while those of lactating females included proportionally more caddis flies and moths than were present in the malaise trap samples. The diets of subadults of both sexes showed greater variation than those of adults, although chironomids and caddis flies were important components. While we observed the aforementioned pattern at sites in Nova Scotia, northern New York, and southern Ontario, the diets of adult M. lucifugus in northern Ontario were as variable as those of subadults from more southerly areas. We suggest that M. lucifugus is opportunistic in its feeding habits, and that the adults efficiently harvest s warms of aquatic insects, a trait not fully acquired by the young we sampled at the end of August.
Phenetic affinities of the wood thrush, Hylocichla mustelina (Aves: Turdinae)
Authors: Gibson A. Ralph , Gates Michael A. , Zach Reto
Published: August 2008

A multivariate assessment of phenetic affinities among 11 North American and 2 European thrushes was carried out to characterize further the controversial systematic relationships of the wood thrush, Hylocichla mustelina. Principal components analysis based on 49 skeletal characters revealed that the wood thrush, which formed one of four distinct groups, was intermediate in a linear allometric series ranging from North American Catharus to European Turdus. These results, most similar to the pattern of relationships envisaged by Dorst, are discussed in terms of the findings and methodologies of previous studies. It is noted that the usual practice of interpreting principal components in terms of independent variation in size and shape is often an oversimplification.
Population dynamics of lice (Mallophaga) on auks (Alcidae) from Newfoundland
Authors: Eveleigh Eldon S. , Threlfall William
Published: August 2008

Two hundred and seventy alcids representing six species from Newfoundland, Canada, were examined for Mallophaga. A total of 12 species belonging to three genera (Saemundssonia, Cummingsiella, Austromenopon) were recovered. Each host species and the parasites recovered from it are discussed separately. Details of prevalence and intensity of parasitism are given, as are seasonal and annual data. Differences between the burdens of adults and chicks are recorded and the prevalence and intensity of infestation is related to the ecology of the hosts.