bluuebunny/crossref_metadata_2025 huggingface dataset:
Haemopoiesis in Lepidoptera. II. The role of the haemopoietic organs
Authors: Hinks C. F. , Arnold J. W.
Published: August 2008

Haemopoietic organs were found in association with the wing discs in 15 species of Lepidoptera examined. The organs were shown to contain small stem cells organized into islets which generate either oenocytoids or prohaemocytes–plasmatocytes. The great majority of islets comprised the latter, and there was evidence that prohaemocytes transformed into plasmatocytes. A decline in the size of the haemopoietic organs during the fifth instar indicated a major release of cells, and correlated with changes in the complement of circulating haemocytes.Total haemocyte counts were reduced in the posterior section of larvae ligatured in the middle, but differential counts showed a more marked decline in prohaemocytes and plasmatocytes than in other classes of haemocytes. Larvae with two or more ligatures usually showed higher prohaemocyte and plasmatocyte counts in the parts of the body that included the haemopoietic organs. Inclusion of the head and prothorax in such sections resulted in still higher counts of prohaemocytes and plasmatocytes as well as higher mitotic indices.The concept that there is a dual origin of haemocytes, from division of cells in circulation (granular and spherule cells) and from the haemopoietic organs (prohaemocytes, plasmatocytes, and oenocytoids) is presented.
A preliminary study of insulin participation in the growth regulation of coho salmon (Oncorhynchus kisutch)
Authors: Ludwig Bryan , Higgs David A. , Fagerlund Ulf H. M. , McBride Jack R.
Published: August 2008

As part of an ongoing survey to identify hormones capable of stimulating growth in Pacific salmon, groups of underyearling coho salmon were injected with bovine (Ultralente) insulin (0.32, 1.0, 3.2, or 10 IU/kg body weight) into the peritoneal cavity either once or twice weekly for 70 days.All doses of insulin, when injected twice weekly, increased the values for specific growth rates and decreased those for food–gain ratios relative to solvent-injected controls, but the differences were not statistically significant. All doses of insulin caused a marked increase in the granulation of the pancreatic B cells. Plasma glucose concentrations in starved coho injected with 10 IU insulin/kg body weight were significantly lower than in solvent-injected controls 4 h after injection.It is concluded that proper evaluation of the effectiveness of insulin as a growth promoter for salmon requires further studies preferably using insulin preparations specific to teleosts.
Brood size manipulations in herring gulls
Authors: Haymes Gerard T. , Morris Ralph D.
Published: August 2008

Herring gull broods were artificially increased to four and five chicks while others were reduced to one chick. The growth rates of chicks and chick weights at fledging were similar among all control and experimental broods. The experimentally increased brood sizes had a slightly higher fledging success than control broods, and the fledging success of one-chick experimental broods was higher than that of one-chick control broods. Thus, chick survival was not reduced in larger brood sizes and the number of young fledged per pair of adults increased with brood size. Further. chicks in large broods were at no weight (or viability) disadvantage despite the presence of a larger number of brood mates. We conclude that food was not limiting either the growth rate or fledging success of chicks from broods larger than the modal clutch size, and suggest that parents used local, abundant, artificial food sources in addition to their natural food supply.
Cytochemistry of the very early stages of in situ coagulation in Calpodes ethlius (Lepidoptera)
Authors: Neuwirth M. , Lai-Fook J.
Published: August 2008

Coagulation and phagocytosis are defence reactions which insects use in response to the introduction of foreign particles into their hemocoel. Coagulation occurs within 10 s of injection of latex beads and ink particles into a midfifth larval instar of Calpodes ethlius. A stringy, flocculent coagulum forms, trapping the particles and hemocytes. The hemocytes then go on to phagocytize the particles.The coagulum stains with alcian blue and lanthanum and dialyzed iron. The surface coat of granular hemocytes stains differently after coagulation has taken place with the same stains and with ruthenium red. There is no corresponding change in staining of the surface coat of plasmatocytes.
Primary molt of blue grouse (Dendragapus obscurus) and its relation to reproductive activity and migration
Authors: Zwickel Fred C. , Dake Jane A.
Published: August 2008

A total of 906 blue grouse (Dendragapus obscurus fuliginosus) were examined for primary molt from 1969 to 1976 on east-central Vancouver Island. First birds to molt were yearling males, followed by adult males, lone (broodless) females, and brood females, in that order. General reproductive activity of the different sex–age classes followed the same rank order (least to greatest). No brood hens molted until after their chicks were hatched, with adult females molting earliest, in relation to yearling females. The rates of molt of yearling males, adult males, and lone females were all linear but brood females, which began their molt latest, had an accelerated, curvilinear rate of molt. Our data most closely fit the hypothesis that molt is inhibited by reproductive activities. The close relationship between initiation of molt and reproductive activity agrees with data for most other species of north-temperate birds.There was no separation of molt and summer–autumn migration. The most likely explanation for an accelerated rate of molt in late starters is a preparation for winter.
A new species of Axiopsis (Axiopsis) (Thalassinidea, Axiidae) from the Pacific coast of Colombia
Authors: Squires H. J.
Published: August 2008

Axiopsis (Axiopsis) baronai is a new species of Thalassinidea (family Axiidae) from the Pacific coast of Colombia in depths of 5–9 m with soft mud substrate. A male holotype and three female paratypes are deposited in the Smithsonian Institution, Washington. D.C. Compared with other species of the genus it is large, reaching 94 mm total length (35 mm cl (measurement from the orbit to the posterior edge of the carapace in the midline dorsally)) in six specimens examined. It resembles A. (A.) consabrina but major differences include the similarity in size of first chelae. more spines on carinae of gastric region and only two or three spines laterally on the telson.
Size relations and yolk utilization in embryonated ova and alevins of Atlantic salmon Salmo salar L. in various combinations of temperature and dissolved oxygen
Authors: Hamor T. , Garside E. T.
Published: August 2008

Relations among weight (W), surface (S), and volume (V) for freshly fertilized water-hardened Atlantic salmon ova from 5 to 7 mm in diameter are: S = log V2/3, S = 1.21 log W, and V = W/1.2.Fresh weights remained relatively constant from fertilization to the establishment of blood vessels in the yolk sac. Subsequently, there was a rapid increase to 110%, followed by a gradual decline to 105% shortly before hatching. Large blastodiscs weighed 1.2 mg and embryonal weight increased very gradually until late prehatching stages, when growth was accelerated rapidly. Embryos, at hatching, after continuous incubation at 5 and 10°C and three levels of dissolved oxygen, varied from 22.1 mg (5 °C, 100% air saturation) to 11.9 mg (5 °C. 30%) and From 14.5 mg (10 °C. 100%) to 10.0 mg (10 °C, 30%).Cumulative and mean daily yolk depletion declined with lowered oxygen supply, but they were considerably greater at 10 °C than at 5 °C. Gross conversion ratios (including uptake of exogenous materials) indicate that yolk is used more efficiently at 5 °C, and 100% air saturation. Alevins, kept in their original environments, became more efficient than they were in their encapsulated state, and, at 10 °C. 100% air saturation, they overtook those at 5 °C before the completion of yolk absorption. Those in lower oxygen supplies continued to lag, at both temperatures.
Destruction of eggs by the long-billed marsh wren (Telmatodytes palustris palustris)
Authors: Picman Jaroslav
Published: August 2008

The frequency of nest destruction by the long-billed marsh wren (Telmatodytes palustris palustris) and the stimuli eliciting it were examined by experimentally offering marsh wrens different nests with eggs or nestlings. Marsh wrens of both sexes, as well as juveniles, attacked any type of eggs in any type of nest, including those of conspecifics; they attacked them regardless of where the nests were placed. Nestlings of redwing blackbirds and marsh wrens were also attacked.It is suggested that nest destruction by marsh wrens has evolved as an interference mechanism to reduce possible interspecific competition. Through this behaviour marsh wrens most likely exclude redwing blackbirds and possibly some other marsh nesting species from certain parts of marsh nesting areas.
'Handedness' in the Pacific tree frog (Hyla regilla)
Authors: Dill Lawrence M.
Published: August 2008

The jumping directions of 24 individual Pacific tree frogs (Hyla regilla), in response to repeated presentations of a model predator, were recorded. The mean jump angle was 70° from the frog's initial bearing regardless of whether the jump was to the left or the right. There was a slight bias within the sample towards left jumps, and most frogs had longer right than left hindlimbs. Some individual frogs jumped preferentially to the left, indicating the existence of 'handedness' in this species.
Sodium pentobarbital induced alterations in regional distribution of blood in Peromyscus maniculatus (deer mouse) and Eptesicus fuscus (big brown bat)
Authors: Rauch Josefine C. , Beatty David D.
Published: August 2008

This study demonstrates the effect of sodium pentobarbital anaesthesia on heart rate (HR) and blood distribution (Sapirstein method) in the deer mouse, Peromyscus maniculatus, and in the big brown bat, Eptesicus fuscus.Resting HR's average 400 beats/min and 334 beats/min in deer mice and bats, respectively. Administration of 40 mg/kg sodium pentobarbital results in marked tachycardia in deer mice but not in bats. A dose of 60 mg/kg causes a slight increase of HR above resting values in the mice and a significant decrease in the bats. The comparatively low HR's in bats are considered to be due to their lowering of body temperature to near environmental levels.The general pattern of blood distribution is comparable between the two species investigated. Sodium pentobarbital administration results in a pronounced redistribution of blood which includes an increase in the fractional delivery of cardiac output to viscera of the abdomen primarily at the expense of skeletal muscle.
Demography, behavior, and genetics of a colonizing population of blue grouse
Authors: Zwickel Fred C. , Redfield James A. , Kristensen John
Published: August 2008

The demography, behavior, and genetics of a population of blue grouse (Dendragapus obscurus) that colonized an area from which most grouse were removed were compared with those of grouse on a nearby control area. Population density increased on the removal area from 1971 to 1974 but remained essentially stable on the control area. Although there were some differences in survival and reproductive rates among years and between areas, none appeared related to the experimental removal and subsequent replacement by new founders.No consistent differences in potentially aggressive behavior were observed between birds in the two populations. Behavioral differences that occurred were likely related to differences in age structures of the two populations or to the synchronous settling of a cohort of mostly young birds on the experimental area.There was no excess of Ng (Birdsall, α., J. A. Redfield, and D. G. Cameron. White bands on starch gels stained for esterase activity; a new polymorphism. Biochem. Genet. 4: 655–658 (1970)) homozygotes among recruits to the experimental area, in contrast with Redfield's (Demography and genetics in colonizing populations of blue grouse (Dendragapus obscurus). Evolution, 27(4): 576–592 (1974)) report of such an excess among birds colonizing new habitat.The increase in the population on the experimental area compared with the control area must have resulted from an increased recruitment of yearlings. No clear evidence was found that this increase was related to qualitative differences between stocks on the two areas.
Influence of capturing a prey on subsequent search in the ovenbird (Aves: Parulidae)
Authors: Zach Reto , Falls J. Bruce
Published: August 2008

Ovenbirds responded to capture of a prey with area-restricted searching regardless of the prey distribution they experienced previously. However, in clustered distributions area-restricted searching occurred immediately, while in even distributions it was delayed. These responses were more pronounced when birds could learn patch or prey locations. Area-restricted searching also occurred before finding prey if birds had learned a patch location previously. Area-restricted searching was due to a decrease in move length and an increase in absolute magnitude of turn rather than a change in the pattern of directions of turns. Speed of search also decreased in synchrony with these changes in search path. Since birds foraged differently in clustered than in even distributions, without having an opportunity to learn specific patch or prey locations, they may have learned patchiness and evenness of prey distributions.
The use of nutrient reserves by breeding male lesser snow geese Chen caerulescens caerulescens
Authors: Ankney C. Davison
Published: August 2008

Breeding male lesser snow geese were collected at the McConnell River, Northwest Territories, and the size of their nutrient reserves (fat and protein) were indexed. The males use these reserves during nesting but protein use is less than that reported for females. It is argued that males use food available on the territory and thus remain in better condition than females. This allows them to protect the female and to become guardian of the family after hatch.
Paratylenchus labiosus n.sp. (Nematoda: Paratylenchidae) from Canada
Authors: Anderson R. V. , Kimpinski J.
Published: August 2008

Paratylenchus labiosus n.sp., a bisexual plant parasitic nematode from Prince Edward Island, is described and illustrated. Females have short stylets 15 to 17 μm long and concave–conoid heads with large, rounded submedian dorsal and ventral lips which readily separate this species from most paratylenchids. The spermatheca is well developed and usually filled with sperm. Males were present in a ratio of 1:2 females. They lacked a stylet and their distinctively conoid heads and delineated lips are the main diagnostic characters that identify the males of this species. A bisexual species from Saskatchewan and Alberta is compared and judged to be identical with P. labiosus n.sp.
Intraspecific nest destruction in the long-billed marsh wren, Telmatodytes palustris palustris
Authors: Picman Jaroslav
Published: August 2008

Long-billed marsh wrens of both sexes attacked other marsh wren nests and destroyed the eggs. Female marsh wrens reduce this type of nesting failure by placing a soft inner lining in their nests and by aggressively excluding other marsh wrens from the vicinity of their nests. Intraspecific nest destruction may have evolved either as a consequence of interspecific nest destruction or more likely as a mechanism of reducing intraspecific competition.
Etude du parasitisme des simulies (Diptera : Simuliidae) par des Mermithidae (Nematoda) en Afrique de l'ouest. IV : Description de Isomermis lairdi, n.sp., parasite de Simulium damnosum
Authors: Mondet B. , Poinar Jr. G. O. , Bernadou J.
Published: August 2008

The present communication describes a new species of mermithid nematode, Isomermis lairdi, found parasitizing blackflies in the Ivory Coast, West Africa. This nematode is the most common mermithid parasite of Simulium damnosum Theobald and occurs in the larval, pupal, and adult stages of this blackfly in streams of various sizes. The diagnostic characters of the adults of I. lairdi are (1) terminal mouth. (2) strongly S-shaped vagina, (3) ratio of spicule length to anal body width (1.7–2.8), and (4) circular amphids and amphidial openings.The postparasitic juveniles of I. lairdi differ from those of I. tansaniensis Rubtsov, 1972, in having three or four rows of cells in the lateral cords and a longer tail appendage in the male.This is the third species of mermithid nematode described from blackflies (including Simulium damnosum) in West Africa, and the first of the genus.
Effects de la réserpine sur le développement et la croissance de Schistocerca gregaria Forsk. au cours des quatrième et cinquième stades larvaires
Authors: Paré F. , Huot L.
Published: August 2008

Various doses of reserpine were injected in the body cavity of fourth-instar nymphal Schistocerca gregaria. Treatment within 48 h from the beginning of the instar significantly increased its duration, whereas treatment at 72 or 96 h did not affect the duration of the fourth stage. However the length of the fifth stage was markedly increased irrespective of the time of treatment in the preceding stage. Fresh body weight of treated larvae increased almost as fast as in the controls. Thus food intake was affected little or not at all by the treatment. In contrast with isolation, reserpine treatment did not affect body pigmentation. Reserpine treatment, destruction of the pars intercerebralis, and isolation were compared with regard to their effects on the molting process
Visual orientation of Pissodes strobi Peck (Coleoptera: Curculionidae) in relation to host selection behaviour
Authors: Vandersar T. J. D. , Borden J. H.
Published: August 2008

Visual orientation plays an important role in short-range host selection by Pissodes strobi. Results of laboratory orientation experiments suggest both sexes of P. strobi are predisposed to attack vertical or near-vertical Sitka spruce leaders that are about 3 cm in silhouette width and above-average in length. In addition, these data suggest that female weevils may possess greater visual discrimination than males. Field data confirm that both sexes of P. strobi select only the longer, larger diameter host leaders from among the population of leaders available. For brood hosts reattacked the 2nd year, stepwise discriminant analysis was performed to select that combination of host characteristics which best distinguished weevilled from unattacked lateral branches in host crowns. The most efficient host property in this regard was lateral branch length. Of decreasing importance were angular deviation from the vertical and lateral branch diameter measured at the midpoint. The data support the hypothesis that reattack of brood hosts is accomplished by resident weevil populations which fail to disperse after overwintering.
Comparison of three geographical isolates of Trichinella
Authors: Sukhdeo Michael V. K. , Meerovitch Eugene
Published: August 2008

Isolates of Trichinella from Alaska. Canada, and Kenya were compared in laboratory hosts using three criteria: infectivity, interbreeding, and morphology. It was found that the Canadian (north temperate) isolate had the highest infectivity in the four species of hosts used. The Alaskan (arctic) isolate was less infective to white rats and A/J mice than the Kenyan (tropical) isolate, but the infectivity of the arctic isolate to cotton rats and guinea pigs was similar to that of the tropical isolate. Interbreeding experiments, using single pairs of infective larvae in all isolate combinations in A/J mice, have demonstrated a complete reproductive isolation between the arctic and the other two isolates, and it partial reproductive isolation between the north temperate and tropical isolates, such that the tropical females could not be fertilized by north temperate males nor by north temperate – tropical hydrid males. North temperate adults were found to be longer than those of the other isolates, and so were the uteri of north temperate females. Since the numbers of larvae produced could be dependent on the length of the uterus, infectivity could be a function of uterus size. In fact, a direct correlation was established between the uterus lengths of the three isolates and their respective infectivities in A/J mice. It is concluded that the north temperate, tropical, and arctic isolates most probably correspond to the three species of Trichinella, T. spiralis, T. nelsoni, and T. nativa respectively (Britov.V. A. and S. N. Boev. Vest, Akad. Nauk Kaz. SSR, 28: 27–32 (1972)).
Precocial testicular maturation in the mourning dove, Zenaida macroura
Authors: Armstrong E. R. , Noakes D. L. G.
Published: August 2008

Testicular maturation, with mature spermatozoa, was found in a hatching-year male mourning dove in southern Ontario. This is the first report from the northern part of the range for this species. Successful reproduction by such individuals in the hatching year is unlikely in Ontario.
Shell structure in freshwater Sphaeriaceæ (Bivalvia: Heterodonta)
Authors: Mackie G. L.
Published: August 2008

Scanning electron microscope studies of shell fragments of 23 species of freshwater Sphaeriacea reveal the occurrence of two basic structural types, complex crossed lamellae and pallial myostracum, throughout the group. X-ray diffraction analyses show that the calcified layers consist of orthorhombic aragonite. Shell structure and crystal type show little or no variation with different environmental conditions and are presumably under genetic control.
Experimental alteration of sex ratios in populations of Microtus townsendii, a field vole
Authors: Redfield J. A. , Taitt M. J. , Krebs C. J.
Published: August 2008

Sex ratios in two populations of Microtus townsendii were experimentally manipulated toward 80% males and 20% males over a 2-year period. The demography of these manipulated populations was changed very little in comparison with a control population with 50% males. Neither survival, breeding, nor growth were related to the density of voles of the same sex. All populations had restricted immigration and the recruitment of females was more tightly regulated than recruitment of males. The number of young voles recruited per pregnancy is inversely related to female density on all areas, and not related to male density. The survival rate of juveniles was influenced more by the females than by the males.Microtus townsendii seems to fit the model of a species in which spacing behavior is sex specific, so that the partial removal of one sex has virtually no effect on the other sex. We need to determine the factors that restrict the entrance of recruits into a vole population. These experiments suggest that the role of females in the restriction on juvenile survival and female recruitment could be critical for vole population regulation.
The developmental stages of a species of Corycaeus (Copepoda: Cyclopoida) from Saanich Inlet, British Columbia
Authors: Gibson Victoria R. , Grice George D.
Published: August 2008

The postembryonic development of a species of the cyclopoid copepod genus Corycaeus from Saanich Inlet, British Columbia, is described and illustrated. Specimens were obtained from a large (40 000/m3) population of Corycaeus which developed in the control (unperturbated) enclosure of a Controlled Ecosystem Pollution Experiment studying the effects of copper on marine ecosystems. Population dynamics of the species in the 1700-m3 enclosed water columns are discussed.
Comparison of the effect of salmon gonadotropin administered by pellet implantation or injection on sexual development of juvenile male pink salmon (Oncorhynchus gorbuscha)
Authors: MacKinnon Colin N. , Donaldson Edward M.
Published: August 2008

In juvenile male pink salmon complete maturity was induced by September in the year of hatching by both pellet implantation (once per 3 weeks) and injection (thrice weekly) of 1.0μg of chinook salmon (Oncorhynchus tshawytscha) gonadotropin per gram body weight. Time of onset of mitotic division of spermatogonia and rate of spermatogenesis were accelerated in the precociously mature testes. Similar doses of salmon gonadotropin injected at longer time intervals (once per week and once per 2 weeks) resulted in slower maturation.
Intraspecific variation of adult Leucochloridium sp. (Digenea) from natural and experimental infections
Authors: Bakke Tor A.
Published: August 2008

The variability of adult Leucochloridium sp. from Norway (63°35′ N,9°45′ E) recovered from natural infections in Larus canus L. and experimental infections in L. canus and Taeniopygia guttata (Vieillot) was studied by light microscopy. The results are compared with five species (Nearctic and Palaearctic) having an experimentally known sporocyst stage (brown-banded brood sacs), and with eight other species with unknown intermediate stage, but placed in the genus Leacochloridium s.str. The five adult species (Leucochloridium variae McIntosh, 1932; Leucochloridium fuscostriatum Robinson, 1947; Leucochloridium perturbatum Pojmanska, 1969; Leucochloridium subtilis Pojmanska, 1969; Leucochloridium fuscum Rietschel, 1970) together with the Norwegian material are regarded as belonging to one species, the Nearctic Leucochloridium variae. The variability and validity of the characters used are discussed.
The potential for lactate utilization by red and white muscle of the eel Anguilla rostrata L.
Authors: Hulbert W. C. , Moon T. W.
Published: August 2008

The activities of lactate dehydrogenase (LDH) (L-lactate: NAD+ oxidoreductase, EC 1.1.1.27) can be divided into a lactate oxidase (lactate to pyruvate) and pyruvate reductase (pyruvate to lactate) component. These activities were examined in red and white muscle excised from the American eel Anguilla rostrata as an estimate of tissue lactate utilization, and compared with the kidney, gill, heart, and liver patterns. Phosphoenol pyruvate carboxykinase (PEP CK) activities in red and white muscle and liver were estimated as a marker for tissue gluconeogenic potential. Consistent with the possibility of lactate utilization for gluconeogenesis, both red muscle and liver possessed an active PEP CK and a bifunctional LDH, where oxidase activities were of the same magnitude as reductase activities. Kidney, which in mammals possesses gluconeogenic capabilities, together with heart and gill, also demonstrated LDH profiles consistent with the liver and red muscle enzymes. White muscle LDH was found to be essentially a pyruvate reductase and no PEP CK activity could be detected. These results suggest that eel red muscle has the potential to utilize lactate and has at least some of the enzymes required for gluconeogenesis. Therefore, the capacity of red muscle to perform a metabolic recycling function in addition to contraction cannot be excluded.
Nocturnal observations of coral reef fishes along depth gradients
Authors: Luckhurst Brian E. , Luckhurst Kirsten
Published: August 2008

The foraging heights, at night, of some apogonid and holocentrid fishes are given. The noctural density of two species of planktivore (Chromis multilineatus and Clepticus parrai) along three depth (10–40 m) transects is figured. In the former species, density rapidly declined with depth. The use of the same shelter sites, at night, by individuals of the latter species is illustrated. The noctural abundance of three apogonid species is shown to be markedly higher than that observed during the day. The consistent use of two sponges for shelter is demonstrated.
Distribution and ecology of crayfish in the Kawartha Lakes region of southern Ontario
Authors: Berrill Michael
Published: August 2008

The distribution, relative abundance, and breeding cycles of seven species of crayfish were examined in the Kawartha Lakes region of southern Ontario. Of the five Orconectes species, whose breeding cycles are remarkably synchronous, the recently introduced O. rusticus has become particularly successful and now occurs commonly in the widest range of habitats where it may be replacing both O. propinquus and O. virilis. Orconectes obscurus, also recently introduced and as yet of very limited distribution, may become similarly successful. Orconectes immunis is found commonly only in the most eutrophic of the lakes, and is therefore not involved in the competition occurring amongst the other four Orconectes species. The two Cambarus species in the region, C. bartoni and C. robustus, are restricted to some of the swifter rapids and falls and to the rocky shores of some of the Shield lakes and, at least in part because their breeding cycles are organized differently, also appear uninvolved in direct competition with the Orconectes species. The success of O. rusticus is likely to be due to a complex combination of behavioral and physiological characteristics.
Ultrastructure and function of scolopophorous sensilla in the mandible of an elaterid larva (Coleoptera)
Authors: Zacharuk R. Y. , Albert P. J.
Published: August 2008

The mandibles of larvae of Ctenicera destructor (Brown) have a large primary tooth with five, and a small medial tooth with one, scolopophorous sensilla of an amphinematic type. Each sensillum is innervated by two bipolar neurons, one with a large and the other a small distal dendrite. Both distal dendrites are held together by a tight junction within a dendritic canal that extends to near the surface of the cuticular wall of the teeth. This canal is enclosed by a dendritic and a cuticular sheath, is closed apically by a cuticular plug, and extends through the mandibular cuticle within a larger sensillar canal. The distal dendritic plasma membranes are attached to the dendritic sheath, and bundles of microtubules in the inner sheath cell interconnect the latter to the proximal dendrites and their ciliary rootlets through desmosomal junctions. An outer sheath cell envelops the inner sheath cell, and a neurilemma cell envelops the basal parts of the nerve cell bodies and the axons individually. These sensilla did not respond to chemical stimulation. Both nerve cells were stimulated by bending the mandibular tooth outward. One produced impulses with a higher amplitude and at a higher rate than the other. These sensilla are proprioceptive mechanoreceptors.
Seasonal dynamics of Cu2+, Zn2+, Ca2+, and Mg2+ in gonads and liver of winter flounder (Pseudopleuronectes americanus): evidence for summer storage of Zn2+ for winter gonad development in females
Authors: Fletcher G. L. , King M. J.
Published: August 2008

The concentrations and total amounts of Zn2+, Cu2+, Mg2+, and Ca2+ were measured in the gonads and livers of sexually mature winter flounder caught at approximately monthly intervals in Chapel's Cove, Newfoundland.The winter flounder fed from April through to October each year. Male and female gonads initiated development in August and spawned in June. The maximum testes weight was observed in October corresponding to the end of the feeding period. The maximum ovary weight was not observed until February, indicating that considerable ovarian growth occurred after feeding had stopped.All four metals in the gonads and livers exhibited seasonal changes. The ovaries accumulated four to six times more Zn2+, Cu2+, and Ca2+ than did the testes. The testes accumulated more Mg2+ than did the ovaries during annual development. The ovaries continued to incorporate all four metals after the fish had stopped eating. Some of the ovaries postfeeding requirements for Zn2+ and Cu2+ could have been met by utilizing liver stores. However, most of the ovaries requirements for Zn2+ must have been obtained from other storage areas in the fish. The ovaries postfeeding requirements for Cu2+, Ca2+, and Mg2+ could have been obtained by the flounder absorbing these metals from the seawater.
The in vitro effects of mammalian and piscine gonadotropin and pituitary preparations on final maturation in yellow perch (Perca flavescens) and walleye (Stizostedion vitreum)
Authors: Goetz Frederick W. , Bergman Harold L.
Published: August 2008

The in vitro effects of various gonadotropin and pituitary preparations on germinal vesicle breakdown (GVBD) were investigated in yellow perch (Perca flavescens) and walleye (Stizostedion vitreum). All preparations tested were effective in walleye; however, none of the preparations induced significant GVBD in yellow perch.
Integumentary glands of Columbian ground squirrels (Spermophilus columbianus): Sciuridae
Authors: Kivett V. Keith
Published: August 2008

The integumentary glands of Columbian ground squirrels (Spermophilus columbianus) were examined histologically. In addition to sebaceous glands associated with hair follicles, gland complexes were found in the oral angle, dorsal, and anal regions. The oral angle gland, located immediately posterior to the oral angle, was an apocrine-type gland consisting of three lobes each drained by a separate duct. Approximately 60 individual, oval-shaped glands, extending posterior from the scapular region, made up the dorsal gland field. These glands exhibited an apocrine secretory process and were drained by single ducts. The anal glands were located in retractable papillae near the anal aperture, one median ventral and two lateral. Equal portions of sebaceous and apocrine elements made up the anal glands. Sweat glands were found on the volar surface of the foot pads. Gland structure and location are discussed in relation to behavior patterns that appear to involve secretions from these glands. Possible functions of scent from these integumentary glands are considered briefly.
Some aspects of overwintering in Peromyscus maniculatus
Authors: Stebbins Lucius L.
Published: August 2008

Seasonal changes in growth and food consumption of captive deer mice Peromyscus maniculatus, caged in a seminatural environment were measured at Lethbridge, Alberta, Canada. Significant decreases in growth and in weight-specific food consumption occurred in winter months. Daily caloric consumption was not significantly lower in winter than in the fall but increased significantly in spring concurrently with both significant increases in weight and weight-specific food consumption. Results are discussed relative to the need for conservation of energy in winter and the contribution reduced growth and activity could make toward such a saving.
Structure and innervation of a crustacean neurosecretory cell
Authors: Andrew R. David , Saleuddin A. S. M.
Published: August 2008

The crayfish medulla terminalis X organ contains type 1 neurosecretory somata which are distinguishable by size, location, and ultrastructure and which have homologues in the eyestalks of other decapods. Neurosecretory (NS) vesicles (140 nm diameter) in these somata are structurally similar to those in the X organ–sinus gland (Xo-sg) tract and the neurohemal sinus gland. Cobalt iontophoresis into type 1 somata shows that their axons traverse the underlying neuropil of the medulla terminalis as the Xo-sg tract before emerging to the surface of the ganglion and terminating in the sinus gland. The proximal third of these type 1 axons branches extensively in the ganglionic neuropil; only in the neuropil adjacent to Xo-sg tract does electron microscopy reveal many fine postsynaptic neurites containing NS vesicles. Serial thin sections show continuity between these neurites and the Xo-sg tract. Structural evidence suggests that this fine arborization is dendritic and represents the site of informational input from the central nervous system to the Xo-sg complex. This study supports previous electrophysiological recordings within Xo somata which indicate synaptic input to these neuroendocrine cells.
Effect of photoperiod on body weight in the vole, Microtus montanus
Authors: Petterborg Larry J.
Published: August 2008

Body weight in voles exposed to various photoperiodic treatments is shown to be significantly affected by the length of the photoperiod. Animals raised under a long (18 h per day) photoperiod gained weight more rapidly than animals raised under a short (6 h per day) photoperiod. Body weight of animals maintained outdoors appeared to fluctuate as a function of decreasing and increasing day length. Adults lost weight and subadults stopped gaining weight during the fall and early winter. All animals gained weight following the winter solstice during the coldest part of the winter. Thyroxine levels as determined by radioimmunoassay were significantly lower in voles maintained under a short (8 h per day) photoperiod than in voles maintained under a long (16 h per day) photoperiod.
Digenea, Nematoda, and Acanthocephala of two species of ducks from Ontario and eastern Canada
Authors: Mahoney Shane P. , Threlfall William
Published: August 2008

Sixty ducks (34 Anas rubripes, 26 Bucephala clangula), collected at three localities in Ontario and eastern Canada, were examined for helminth parasites. Twenty-three genera of parasites (17 of Digenea, 5 of Nematoda, 1 of Acanthocephala) were recovered. Eighteen of the recoveries represent new host records (11 digeneans, 5 nematodes, 2 acanthocephalans).Eighty-eight percent of both host species were infected. The number of parasite species per infected bird ranged from 1–9 (mean 4) for A. rubripes and 1–7 (mean 2) for B. clangula. Preferred age and sex of host and site of infections for each parasite species was noted.
The life history of Thysanoessa inermis (Krøyer) in the Bay of Fundy
Authors: Kulka David W. , Corey S.
Published: August 2008

A 4-year study of the life history of Thysanoessa inermis was conducted in Passamaquoddy Bay. A comparison of the growth pattern and eye morphology showed that Th. inermis in Passamaquoddy Bay is part of a Bay of Fundy population centered in the Grand Manan Basin. Spawning occurs in the spring and the young stages are found near the surface during the summer. Thysanoessa inermis lives for 2 years in the Bay of Fundy and spawns at the end of the 1st and 2nd years. Gonadal development is described in detail. Growth in both years is rapid during the summer months with little or no increase in size during the winter. The growth rate of the female surpasses that of the males in the 2nd year. The neglecta form of Th. inermis (year class 0 animals) lives in the middle to upper layers and is morphologically different from the inermis form (year class I animals) which lives in the deepest layers.
An efficient technique for laboratory rearing of Simulium verecundum S. &J. (Diptera: Simuliidae)
Authors: Colbo M. H. , Thompson B. H.
Published: August 2008

A series of 10 similar rearing vessels, each containing 500 ml of water circulated by a rotating magnetic stirring bar, was used to rear cohorts of 50 first-instar Simulium verecundum larvae to adults. Ground 'TETRA' tropical fish meal was used as food. The culture water was replaced daily to remove toxic nitrogenous products excreted by the larvae. In three experiments, the mean [Formula: see text] survival rates were 71.60 ± 3.19%, 81.73 ± 2.78%, and 66.60 ± 2.60%; larval development was reasonably synchronous and the median periods required for growth from first instar to adult were 25, 22, and 21 days.
The functional significance of the aphakic space of the fish eye
Authors: Sivak J. G.
Published: August 2008

The localized aphakic (lensless) space of the fish eye has been credited with enlarging the binocular field of vision or enhancing the relative level of illumination of a portion of the retina. By relating pupil shape to the direction and magnitude of accommodative lens movement in fishes it may be shown that localized aphakic spaces exist as a means of facilitating lens movement.
An unusual intramembranous structure in the renal tubule of a snake
Authors: Peek William D.
Published: August 2008

Freeze–fracture revealed unusual structures of unknown origin in plasma membranes of proximal tubular cells in the nephron of the garter snake. These areas are closely associated with gap junctions and are characterized primarily by the relative paucity of intramembranous particles.
Hair-fan patterns in the Chaetognatha
Authors: Feigenbaum David L.
Published: August 2008

Chaetognaths are important marine predators which rely on external sensory hairs to receive prey-produced vibrations, enabling them to recognize and locate their food. Hair-fan patterns are mapped for both larvae and adults of Sagitta hispida, Sagitta enflata, and Spadella schizoptera, for several sizes of Sagitta elegans, and for adults of Spadella cephaloptera. The fans are arranged in regular transverse and longitudinal rows with the pattern species specific, but similar, for all species studied. Larvae possess relatively longhair fans at hatching and the number of fans increases with size in the species of Sagitta, but is constant in juveniles and adults of the species of Spadella.
Metamorphosis in the anadromous sea lamprey, Petromyzon marinus L.
Authors: Potter I. C. , Wright G. M. , Youson J. H.
Published: August 2008

A study has been made of metamorphosis in anadromous sea lampreys in New Brunswick between 1973 and 1976. The stages (1–7) commence with the recently described 'prometamorphic ammocoete' (Youson, J. H., G. M. Wright, and E. C. Ooi. 1977. The timing of changes in several internal organs during metamorphosis of anadromous larval lamprey Petromyzon marinus L. Can. J. Zool. 55: 469–473.) and conclude with one similar to the newly metamorphosed landlocked sea lamprey (Manion, P. J., and T. M. Stauffer. 1970. Metamorphosis of the landlocked sea lamprey, Petromyzon marinus. J. Fish. Res. Board Can. 27: 1735–1746.). Most of the marked quantitative changes exhibited by certain regions of the body can be directly related to adaptations for suctorial feeding, increased activity, and a predaceous mode of life. Reductions in the prebranchial length are almost certainly associated with changes in the pharyngeal basket which facilitate alterations in the direction of the respiratory water flow. The timing of metamorphosis was remarkably synchronous both within and between years, representatives of the earliest stages (1–2) being found only between July 7 and 28 while after September 14 only stage 7 animals were caught. During metamorphosis the lengths of the animals changed little whereas their weights declined significantly. The weights and condition factors of stage 1–2 animals were significantly greater than those of larvae of comparable length. This feature, presumably related to lipid accumulation at the end of larval life, is discussed in the context of factors influencing the onset of metamorphosis.
A serological study of prey selection by Nephelopsis obscura Verrill (Hirudinoidea)
Authors: Davies Ronald W. , Wrona F. J. , Everett R. P.
Published: August 2008

The prey range of Nephelopsis obscura was determined in three limnologically similar field sites using a serological technique. At each site the relative magnitude of utilization from highest to lowest was Chironomidae, Oligochaeta, Amphipoda, Copepoda–Cladocera, and Gastropoda respectively. When the three sites were compared, the relative proportions of these prey categories were shown to differ. Feeding activity was highest in the spring and summer and lowest in the fall and winter. Within each weight class of N. obscura, the Chironomidae, Amphipoda, and Oligochaeta were eaten most frequently. The Gastropoda and Copepoda–Cladocera were preyed upon more intensely by the smaller weight classes. The smaller (0–30 mg) and the larger (180−200+ mg) weight classes displayed proportionately higher feeding activity than the intermediate weight classes. Site-specific differences in weight class utilization of prey were recorded, indicating that generalizations on feeding activity of N. obscura are difficult to make even in similar field sites located in the same geographical area.
Hematozoa of some birds of New Jersey and Maryland
Authors: Williams Norman A. , Bennett Gordon F.
Published: August 2008

A total of 8170 birds of 153 species, representing 41 families, from Maryland and New Jersey, were examined for blood parasites. Eighty-eight species were sampled in New Jersey and 128 in Maryland; 63 species were common to both areas. Ten percent (833) of the birds harbored one or more parasite species of the following genera: Haemoproteus (4.3%), Leucocytozoon (3.9%), Plasmodium (1.9%), Trypanosoma (0.3%), Lankesterella (=Atoxoplasma) (0.04%), and unidentified microfilariae (0.3%). Prevalences from both areas were similar, but were markedly lower than previously recorded. The coefficient of community, an ecological measure of similarity, was applied to both bird and parasite faunas within the two study areas, and indicated that because of the high degree of specificity of parasites to their hosts only birds shared by the two samples had the same parasites. This measure also revealed the absolute necessity of using only similar taxa in any comparison of hematozoan prevalence in different avifaunas in different geographic regions.The Maryland sample was unique in that it allowed a comparison of prevalences over a 30-year period, revealing that years with larger samples generally exhibited a uniform geographic prevalence. The New Jersey sample was obtained from different topographic regions; the results confirm the concept that prevalence of hematozoa is correlated with regional topography, even in areas closely juxtaposed.
The effect of mebendazole on different developmental stages of Hymenolepis diminuta cysticercoids
Authors: Novak Marie , Evans W. S.
Published: August 2008

Tribolium confusum beetles infected with Hymenolepis diminuta were fed continuously from day 1, 3, 5, 6, or 7 to day 10 post infection (p.i.) on a mixture composed of two parts Telmin (containing 16.67% of mebendazole) and one part flour. The drug inhibited the worm development and this effect decreased as the age of larvae at the time of the first exposure increased. Lowered incidence of infection, decreased population size, and retarded development were apparent when the beetles were given drug from day 3 p.i. or earlier. Retarded development was also observed in cysticercoids from beetles given drug from day 5 p.i. When given from day 6 or later, it had no effect on worm development. However, when compared with larvae from beetles fed only flour, cysticercoids exposed to the drug from day 6 or later showed reduced infectivity and a decrease in their ability to excyst in vitro. Fully developed infective cysticercoids exposed to the drug from day 10 p.i. or later were not affected by it.
Systematic position of Urocleidus adspectus Mueller, 1936 (Monogenea: Ancyrocephalinae) of Perca flavescens
Authors: Cone D. K.
Published: August 2008

Urocleidus adspectus Mueller, 1936 (Monogenea: Ancyrocephalinae), on the gills of yellow perch (Perca flavescens) in North America, is redescribed. Contrary to previous belief, the accessory piece articulates with the cirrus base and the vas deferens loops around the left intestinal crus.
Bioenergetics of granivorous beetles, Cryptolestes ferrugineus and Rhyzopertha dominica (Coleoptera: Cucujidae and Bostrichidae)
Authors: Campbell A. , Sinha R. N.
Published: August 2008

The weights and caloric values of insects and exuviae, the food consumed and egested, and oxygen respired were estimated at regular intervals for all stages of the rusty grain beetle, Cryptolestes ferrugineus, reared on wheat kernels. Immature stages assimilated between 66 and 79% of the food consumed and the proportion of assimilated energy converted into tissue growth increased from 3 to 23% during development. Similar observations were made for the lesser grain borer, Rhyzopertha dominica, but the food consumed and egested was not measured because much of the kernel chewed by this insect was not ingested, leaving a frass of white powder difficult to separate from the rejecta. For R. dominica a maximum of 38% of the energy assimilated during development was converted into tissue. Adults of both species used most energy to produce eggs. The net efficiencies of the use of energy for reproduction are higher in some stored-product beetles whose populations increase more rapidly than those which increase more slowly.