The effect of non-immune stresses on the development of Strongyloides ratti

Parasitology ◽  
2005 ◽  
Vol 131 (3) ◽  
pp. 383-392 ◽  
Author(s):  
M. CROOK ◽  
M. E. VINEY
Keyword(s):  
Immune Response ◽  
Parasitic Nematode ◽  
Host Immune Response ◽  
Natural Host ◽  
Adult Males ◽  
Free Living ◽  
Developmental Effects ◽  
Adult Females ◽  
Males And Females ◽  
Living Adult

Strongyloides ratti is a parasitic nematode of rats. The host immune response against S. ratti affects the development of its free-living generation, favouring the development of free-living adult males and females at the expense of directly developing, infective 3rd-stage larvae. However, how the host immune response brings about these developmental effects is not clear. To begin to investigate this, we have determined the effect of non-immune stresses on the development of S. ratti. These non-immune stresses were subcurative doses of the anthelmintic drugs Ivermectin, Dithiazanine iodide and Thiabendazole, and infection of a non-natural host, the mouse. These treatments produced the opposite developmental outcome to that of the host immune response. Thus, in infections treated with subcurative doses of Ivermectin, Dithiazanine iodide and in infections of a non-natural host, the sex ratio of developing larvae became more female-biased and the proportion of female larvae that developed into free-living adult females decreased. This suggests that the mechanism by which the host immune response and these non-immune stresses affect S. ratti development differs.

Adrenal response in a wild Microtus population: seasonal aspects

1978 ◽  
Vol 56 (6) ◽  
pp. 1433-1440 ◽  
Author(s):  
Robert W. Seabloom ◽  
Stuart L. Iverson ◽  
Brian N. Turner
Keyword(s):  
Microtus Pennsylvanicus ◽  
Early Summer ◽  
Significant Decline ◽  
Adult Males ◽  
Free Living ◽  
Adult Females ◽  
Adrenal Response ◽  
Males And Females ◽  
Nonpregnant Adult ◽  
Seasonal Aspects

Adrenal response was determined during a 13-month period in a population of southern Manitoba meadow voles (Microtus pennsylvanicus) as a preliminary part of a study to determine the effects of chronic ionizing radiation on free-living mammals. Livetrapped voles were subjected to behavioral tests, killed, and their isolated adrenals superfused and stimulated with ACTH. Superfusates were assayed fluorometrically for corticosterone. Peaks of adrenal response occurred during spring in both adult males and females, followed by a significant decline into early summer. Subadult males exhibited a peak response in early summer. Corticosterone levels of adults were generally higher than those of juveniles in the same season. Levels of nonpregnant adult females were higher than those of pregnant voles. Observed differences over the annual cycle were attributed to the behavioral and hormonal states of various age and sexual components of the population.

The reversibility of constraints on size and fecundity in the parasitic nematode Strongyloides ratti

Parasitology ◽  
2006 ◽  
Vol 133 (4) ◽  
pp. 477-483 ◽  
Author(s):  
M. E. VINEY ◽  
M. D. STEER ◽  
C. P. WILKES
Keyword(s):  
Immune Response ◽  
Parasitic Nematode ◽  
Host Immune Response ◽  
Parasitic Nematodes ◽  
Per Capita ◽  
And Control

The size and fecundity of parasitic nematodes are constrained by the host immune response. For the parasitic nematode of rats, Strongyloides ratti, parasitic females infecting immunized rats are smaller and less fecund than those infecting naïve rats. Here, we investigated whether these constraints on size and fecundity are life-long. This was done by comparison of worms from different immunization and immunosuppression regimes. It was found that the per capita fecundity of parasitic females of S. ratti is fully reversed, but that their size is only partially reversed, if previously immunized hosts are subsequently immunosuppressed, suggesting that fecundity is not subject to life-long constraints. The host immune response also resulted in allometric changes in the parasitic females. The significance of these results with respect to the growth and control of nematode fecundity are discussed.

scholarly journals The Diet and Sexual Differences of the Caspian Bent-Toed Gecko,Tenuidactylus caspius(Squamata: Gekkonidae), in Northern Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Vida Hojati ◽  
Reza Babaei Savasari
Keyword(s):  
Sexual Dimorphism ◽  
Culex Pipiens ◽  
Tail Length ◽  
Adult Males ◽  
Northern Iran ◽  
Widespread Distribution ◽  
Adult Females ◽  
Significant Difference ◽  
Males And Females ◽  
Prey Items

The Caspian bent-toed gecko,Tenuidactylus caspius, is one of the most common nocturnal lizards of Iran with widespread distribution especially in the northern provinces. This research was done in order to study the diet and sexual dimorphism of this species in Sari County from 5 May to 20 October. During this research, 40 specimens of them including 20 males and 20 females were studied for diet and 140 specimens including 70 adult males and 70 adult females were studied for sexual dimorphism. Prey items identified were insects that belong to 15 species of 8 families and 6 orders. The most common prey items wereCulex pipiensandMusca domestica. There is no significant difference between diets of males and females. Results show that the adult males in addition of having the apparent femoral and preanal pores are heavier than females and have larger body, head, and tail length.

Home-Range Size and Fidelity of Western Grey Kangaroos (Macropus Fuliginosus) Living in Remnants of Wandoo Woodland and Adjacent Farmland.

1992 ◽  
Vol 19 (2) ◽  
pp. 137 ◽  
Author(s):  
GW Arnold ◽  
DE Steven ◽  
A Grassia ◽  
J Weeldenburg
Keyword(s):  
Home Range Size ◽  
Home Ranges ◽  
Adult Males ◽  
The Core ◽  
Adult Females ◽  
Radio Transmitters ◽  
Core Areas ◽  
Males And Females ◽  
Eucalyptus Wandoo ◽  
Older Males

The home ranges were studied from 1977 to 1981 of western grey kangaroos (Macropus fuliginosus) living in a 300-ha remnant of wandoo [Eucalyptus wandoo] surrounded by farmland at Baker's Hill, Western Australia. The M. fuliginosus population varied from 140 to 200 animals during the study. In 1979, four females (>30 kg) and 2 adult males (31 kg and 47 kg) were fitted with radio-transmitters and their movements recorded. The home ranges of these animals varied from 39 to 70 ha; the average overlap in the area used during the day and that used at night was 16.4%. Many of the kangaroos fed on farmland at night. The night ranges of 51 marked kangaroos were recorded using a spotlight. The animals showed a strong fidelity to their home ranges. Only 3 males (about 5-yr-old) shifted their night ranges; the centres of the ranges moved only 600-800 m. Older males had significantly larger night ranges than younger males and females. Individual females and the younger males showed preferences for using particular access points to get onto farmland; the older males showed no preferences. The core areas of the night ranges of many adult females overlapped closely in 'groups', but there was no evidence of 'mob' home ranges that were socially separated.

Effects of Alcohol and Sex Hormones on Host Immune Response in Males and Females

1994 ◽  
pp. 215-239 ◽  
Author(s):  
Charles J. Grossman ◽  
Gary Roselle ◽  
Mark Nienaber ◽  
Gary Schmitt
Keyword(s):  
Immune Response ◽  
Sex Hormones ◽  
Host Immune Response ◽  
Males And Females

scholarly journals Toxicological and biochemical effects of some insecticides on peach fly, Bactrocera zonata (Diptera: Tephritidae)

2011 ◽  
Vol 47 (No. 3) ◽  
pp. 121-130 ◽  
Author(s):  
Y.Y. Mosleh ◽  
L.H. Yousry ◽  
A. Alo-El-Elaa
Keyword(s):  
Fruit Fly ◽  
Post Treatment ◽  
Adult Males ◽  
Glutamic Oxaloacetic Transaminase ◽  
Peach Fruit ◽  
Biochemical Effects ◽  
Adult Females ◽  
Bactrocera Zonata ◽  
Wide Range ◽  
Males And Females

The peach fruit fly, Bactrocera zonata (Saunders, Diptera: Tephritidae), has been a serious pest in the last decade attacking a wide range of fruits in Egypt. The toxicity of Malathion, Diazinon, Methoxyfenozide and Lufenuron to adult males and females of B. zonata was studied under laboratory conditions. The results showed that Diazinon was the most toxic among the tested compounds followed by Malathion, Lufenuron and Methoxyfenozide. LC<sub>50</sub> values for adult males and females were 0.20 ppm, 0.09 ppm and 0.02 ppm (for males), 0.91 ppm, 0.14 ppm and 0,01 ppm (for females), respectively. The results showed that the level of glutamic oxaloacetic transaminase (GOT) of treated adult males and females in 24 h, 48 h, and 72 h post treatment increased compared to untreated adults. The highest activities of GOT in treated adult males in 24 h, 48 h, and 72 h were 92.11&micro;M, 101.99&micro;M and 112.21&micro;M pyruvate released &times; 10<sup>3</sup>/min/g FW (fresh weight), respectively, for Methoxyfenozide LC<sub>10</sub>, and in treated adult females after 24 h, 48 h, and 72 h they were 84.24&micro;M, 94.33&micro;M, and 111.12&micro;M pyruvate released &times; 10<sup>3</sup>/min/g FW, respectively, for Diazinon LC<sub>25</sub>. The activities of acetylcholine esterase of treated adults decreased compared to untreated adults. The highest activities of acid phosphatase in adult males after 24 h and 48 h were 249.43 &micro;g and 270.52 &micro;g AchI hydrolysed/min/g FW, respectively, for Methoxyfenozide LC<sub>25</sub>. The highest activities of alkaline phosphatase in adult males were 139.04 &micro;g, 175.67 &micro;g, and 199.29 &micro;g phenol &times; 10<sup>3</sup>/min/g FW for Malathion LC<sub>10</sub> and in adult females they were 123.31 &micro;g, 162.10 &micro;g and 199.59 &micro;g phenol.10<sup>3</sup>/min/g FW, respectively, for Lufenuron LC<sub>25</sub> in 24 h, 48 h, and 72 h post treatment.

scholarly journals Comparative toxicity of certain pesticides to peach fruit fly, Bactrocera zonata Saunders (Diptera: Tephritidae) under laboratory conditions

2011 ◽  
Vol 47 (No. 3) ◽  
pp. 115-120 ◽  
Author(s):  
Y.Y. Mosleh ◽  
S.F.M. Moussa ◽  
L.H.Y. Mohamed
Keyword(s):  
Fruit Fly ◽  
Post Treatment ◽  
Adult Males ◽  
Peach Fruit ◽  
Laboratory Conditions ◽  
Adult Females ◽  
Comparative Toxicity ◽  
Bactrocera Zonata ◽  
Wide Range ◽  
Males And Females

Peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae), has been a serious pest in the last decade attacking a wide range of fruits in Egypt. The toxicity of Malathion, Diazinon, Methoxyfenozide, and Lufenuron to adult males and females of Bactrocera zonata was studied under laboratory conditions. Diazinon was the most toxic among the tested compounds followed by Malathion, Lufenuron and Methoxyfenozide to Bactrocera zonata at 24 h post treatment, the respective LC<sub>50</sub> values were 0.20 ppm, 0.48ppm, 8.97ppm, and 9.73ppm for males and 0.26 ppm, 0.91ppm, 11.26ppm, and 14.12ppm for females. At 48 h post treatment Diazinon was the most toxic followed by Malathion, Methoxyfenozide and Lufenuron to Bactrocera zonata, LC<sub>50</sub> values were 0.09ppm, 0.34ppm, 1.60ppm, and 1.88 ppm for males and 0.14 ppm, 0.44ppm, 1.68ppm and 2.17 ppm for females. At 72&nbsp;h post treatment Diazinon was the most toxic followed by Malathion, Lufenuron and Methoxyfenozide to Bactrocera zonata, LC<sub>50</sub> values were 0.02 ppm, 0.13ppm, 0.22ppm and 0.51ppm for males and 0.07 ppm, 0.16ppm, 0.55 ppm and 0.62 ppm for females. It is observed that LC<sub>50</sub> values for treated adult females increased more than in the treated adult males at 24 h, 48 h, and 72 h post treatment. It means that the adult males were more susceptible to the tested insecticides than the adult females.

Growth of the tropical sand lizard Liolaemus lutzae in southeastern Brazil

1995 ◽  
Vol 16 (3) ◽  
pp. 257-264 ◽  
Author(s):  
Carlos Frederico Duarte Rocha
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
Southeastern Brazil ◽  
Adult Males ◽  
Adult Females ◽  
Sand Lizard ◽  
Males And Females ◽  
Specific Growth Rates ◽  
Janeiro State

AbstractThe growth of males and females of the tropidurid lizard Liolaemus lutzae was studied in the seasonal tropical habitat of the restinga da Barra de Maricá, Rio de Janeiro State, southeastern Brazil. Growth rates of lizards decreased with size in both sexes; the size specific growth rates of females were significantly lower than those of males. Adult males were larger than adult females. The data indicate that despite maturing at a larger size, males grow faster than females and mature at similar ages. There was a significant relationship between amount of rainfall and lizard growth rate in both sexes.

scholarly journals Effects of variation in forest fragment habitat on black howler monkey demography in the unprotected landscape around Palenque National Park, Mexico

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9694
Author(s):  
Keren Klass ◽  
Sarie Van Belle ◽  
Alvaro Campos-Villanueva ◽  
Fernando Mercado Malabet ◽  
Alejandro Estrada
Keyword(s):  
Population Size ◽  
National Park ◽  
Forest Composition ◽  
Adult Males ◽  
Forest Fragment ◽  
Differential Effects ◽  
Adult Females ◽  
Anthropogenic Habitat ◽  
Males And Females ◽  
Black Howler

Habitat loss and fragmentation are leading threats to biodiversity today, and primates are particularly vulnerable to anthropogenic habitat disturbance. However, few studies have examined how differential effects of variation in forest fragment characteristics on males and females in a primate population may affect demography and population persistence. We quantified the effects of variation in forest fragment characteristics on the within-fragment demography of black howler monkeys (Alouatta pigra) in forest fragments around Palenque National Park, Mexico, and how these effects differed between adult males and females. We quantified forest loss in the landscape between 2000 and 2017, and used a redundancy analysis to examine the effects of 15 variables quantifying fragment dimensions, forest composition and physical structure, and isolation on fragment population size and density, the proportion of adult males and females in the fragment population, and the mean number of adult males and females per group in 34 fragments (N = 393 monkeys). We hypothesized that (i) population size is positively correlated with fragment area, while population density is negatively correlated, and (ii) the composition of fragment populations results from differential effects of fragment variables on adult males and females. Forest cover decreased by 23.3% from 2000 to 2017. Our results showed a significant effect of fragment variables on population demography in fragments, accounting for 0.69 of the variance in the demographic response variables. Population size increased with fragment area and connectivity, while density decreased. Larger, less isolated fragments with better connectivity, characteristics indicative of abundant secondary growth, and those with more diverse vegetation but lower Simpson’s evenness indices tended to have more adult females per group and a higher proportion of adult females in the population. In contrast, fragments that were largely similar in characteristics of forest composition and structure, but that were more isolated from nearby fragments, had more adult males per group and a higher proportion of adult males. These results may stem from black howler females preferentially remaining in natal groups and fragments when possible, and dispersing shorter distances when they disperse, while males may be more likely to disperse between fragments, traveling longer distances through the matrix to more isolated fragments. These differential effects on males and females have important conservation implications: if females are more abundant in larger, less isolated fragments, while males are more abundant in more isolated fragments, then to effectively conserve this population, both landscape connectivity and fragment areas should be maintained and increased.

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