Thermal preferences of resistant and susceptible strains ofBiomphalaria glabrata(Gastropoda) exposed toschistosoma mansoni(Trematoda)

Background. Availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10x10 Km2 resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized), the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve). Results. There is a large interspecific variability on the thermal preferences and specialization of species. Despite this large variability, there is a preponderance of positive relationships between species abundance and temperature, and on average species attain their maximum abundances in areas 1.9 ºC warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species, although both parameters are highly correlated. Discussion. Most species prefer the warmest environments to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, most individuals overwinter in locations colder than the species thermal preferences, probably reflecting a limitation of environments combining habitat and thermal preferences. Beyond these general trends, there is a high inter-specific variation in the versatility of species using the available thermal space .

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Physiological significance of behavioral hypothermia in hypoxic toads (Bufo marinus)

Journal of Experimental Biology ◽

10.1242/jeb.159.1.203 ◽

1991 ◽

Vol 159 (1) ◽

pp. 203-215 ◽

Cited By ~ 2

Author(s):

S. C. Wood ◽

G. M. Malvin

Keyword(s):

Behavioral Response ◽

Thermal Gradient ◽

Respiratory Exchange Ratio ◽

Ventilatory Response ◽

Respiratory Alkalosis ◽

Significant Rise ◽

Bufo Marinus ◽

Significant Drop ◽

Preferred Temperature ◽

Beneficial Response

We tested the hypotheses that hypoxic toads (Bufo marinus) in a thermal gradient would select a lower than normal temperature and that this behavioral response would be beneficial. Under normoxic conditions, selected body temperature was 24.2 +/− 3.6 degrees C. When inspired O2 was 10% or less, mean selected temperature decreased to 15.3 +/− 2.4 degrees C. The theoretical advantages of hypoxia-induced hypothermia we tested include (1) a reduction of oxygen uptake (VO2) by a Q10 effect; (2) increased arterial saturation (SaO2), (3) a decreased ventilatory response, and (4) a decreased stress response. Gas exchange, hematocrit, hemoglobin, SaO2, PaO2 and pH were measured at 25 degrees C (normal preferred temperature) and 15 degrees C (hypoxia preferred temperature) in toads breathing normoxic or hypoxic gas mixtures. During graded hypoxia at 15 degrees C, SaO2 was significantly increased and VO2 was significantly reduced compared with 25 degrees C. Graded hypoxia did not significantly affect VO2 at 25 degrees C, despite evidence for increased ventilation at that temperature (increased pH and respiratory exchange ratio, RE). At 15 degrees C, graded hypoxia had a significant effect on VO2 only at an inspired O2 of 4%. Increased RE with hypoxia was significant at 25 degrees C but not at 15 degrees C. Hematocrit and [hemoglobin] rose significantly during graded hypoxia at 25 degrees C but did not change at 15 degrees C. Toads exposed to 10% O2 (the value that elicits behavioral hypothermia) showed a significant respiratory alkalosis at 25 degrees C but not at 15 degrees C. Likewise, hypoxia caused a significant drop in SaO2 and PO2 at 25 degrees C. Cooling to 15 degrees C during hypoxia caused a significant rise in SaO2 but no change in PaO2. In conclusion, behavioral hypothermia is a beneficial response to hypoxia in Bufo marinus.

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Preferred temperature and thermal breadth of birds wintering in peninsular Spain: the limited effect of temperature on species distribution

PeerJ ◽

10.7717/peerj.2156 ◽

2016 ◽

Vol 4 ◽

pp. e2156 ◽

Cited By ~ 7

Author(s):

Luis M. Carrascal ◽

Sara Villén-Pérez ◽

David Palomino

Keyword(s):

Species Abundance ◽

Bird Species ◽

Effect Of Temperature ◽

Response Curves ◽

Limited Effect ◽

Preferred Temperature ◽

Mean Temperature ◽

The Mean ◽

Thermal Preferences ◽

Peninsular Spain

Background.The availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments.Methods.We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10 ×10 km2resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized), the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve).Results.Temperature explains a low proportion of variation in abundance. The most significant effect is on limiting the maximum potential abundance of species. Considering this upper-limit response, there is a large interspecific variability on the thermal preferences and specialization of species. Overall, there is a preponderance of positive relationships between species abundance and temperature; on average, species attain their maximum abundances in areas 1.9 °C warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species.Discussion.Many species prefer the warmest areas to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, one third of species overwinter in locations colder than their thermal preferences, probably reflecting the interaction between habitat and thermal requirements. There is a high inter-specific variation in the versatility of species using the available thermal space, and the limited effect of temperature highlights the role of other environmental factors determining species abundance.

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Transmission of Schistosoma mansoni under experimental conditions using the bovine - Biomphalaria glabrata - bovine model

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46651993000100002 ◽

1993 ◽

Vol 35 (1) ◽

pp. 11-16 ◽

Cited By ~ 4

Author(s):

Celina M. Modena ◽

Paulo Marcos Z. Coelho ◽

Frederico S. Barbosa ◽

Walter S. Lima

Keyword(s):

Life Cycle ◽

Schistosoma Mansoni ◽

Endemic Area ◽

Experimental Period ◽

Biomphalaria Glabrata ◽

Snail Population ◽

Experimental Conditions ◽

Worm Recovery ◽

The Mean

Three calves experimentally infected with Schistosoma mansoni, and passing viable eggs in feces, as well as 5 normal calves (coming from a non-endemic area for schistosomiasis) kept as controls, were maintained in an enclosure (850 m² in area). In this enclosure, a tank with water received 500 laboratory reared Biomphalaria glabrata. All the control calves were infected for a period ranging from 79 to 202 days after the beginning of the experiment, and afterwards presented viable S. mansoni eggs in feces. The mean worm recovery was 555. The snail population increased throughout the experimental period, showing a high number of B. glabrata infected with S. mansoni (42% on average). According to the present study, bovine has been suggested as having potentially a role in the maintenance of the life cycle of S. mansoni

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Increased oviposition and growth in immature Biomphalaria glabrata after exposure to Schistosoma mansoni

Parasitology ◽

10.1017/s0031182000081166 ◽

1986 ◽

Vol 93 (3) ◽

pp. 443-450 ◽

Cited By ~ 52

Author(s):

Joyce A. Thornhill ◽

Janet T. Jones ◽

J. R. Kusel

Keyword(s):

Schistosoma Mansoni ◽

Biomphalaria Glabrata ◽

Median Number ◽

Egg Laying ◽

Exposed Group ◽

Control Group ◽

Egg Mass ◽

Trematode Parasite ◽

Compensatory Response ◽

The Mean

SUMMARYBiomphalaria glabrata snails are known to be castrated by infection with the trematode parasite Schistosoma mansoni 4–6 weeks post-infection. The pattern of oviposition in the first 35 days post-exposure (p.e.) was investigated, in snails aged 14 weeks and measuring 7–10 mm diameter which had not commenced egg-laying, by counting the numbers of eggs laid in 7-day intervals. A group of exposed snails was compared with a control non-exposed group. The exposed group included both parasitized and non-parasitized snails, and showed a significant increase in the median number of eggs laid during the periods 14–21 and 22–28 days p.e. Throughout the entire 35-day period exposed non-parasitized snails laid significantly more eggs than control snails, while parasitized snails laid significantly more eggs than controls during days 22–28 p.e. and significantly fewer during days 29–35 p.e. Parasitized snails also laid significantly more eggs/egg mass in the period 16–28 days p.e. than did control snails. Growth of the snails was measured. By day 28 p.e. the mean diameter of the exposed group was significantly greater than that of the control group. The increase in oviposition by snails soon after exposure is discussed in terms of a compensatory response for expected future suppression of egg-laying. The fact that parasitized and non-parasitized snails both show increased oviposition indicates that normal development of the parasite is not necessary to trigger the response.

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Preferred temperature and thermal breadth of birds wintering in peninsular Spain – the limited effect of temperature on species distribution

10.7287/peerj.preprints.1880v1 ◽

2016 ◽

Author(s):

Luis M. Carrascal ◽

Sara Villén-Pérez ◽

David Palomino

Keyword(s):

Species Abundance ◽

Bird Species ◽

Effect Of Temperature ◽

Response Curves ◽

Large Variability ◽

Preferred Temperature ◽

Mean Temperature ◽

The Mean ◽

Thermal Preferences ◽

Peninsular Spain

Background. Availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10x10 Km2 resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized), the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve). Results. There is a large interspecific variability on the thermal preferences and specialization of species. Despite this large variability, there is a preponderance of positive relationships between species abundance and temperature, and on average species attain their maximum abundances in areas 1.9 ºC warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species, although both parameters are highly correlated. Discussion. Most species prefer the warmest environments to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, most individuals overwinter in locations colder than the species thermal preferences, probably reflecting a limitation of environments combining habitat and thermal preferences. Beyond these general trends, there is a high inter-specific variation in the versatility of species using the available thermal space .

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Influence of intramolluscan larval stages of Echinostoma liei on the infectivity of Schistosoma mansoni cercariae

Journal of Helminthology ◽

10.1017/s0022149x00011925 ◽

1990 ◽

Vol 64 (1) ◽

pp. 71-74 ◽

Cited By ~ 6

Author(s):

J. Jourdane ◽

J. B. Mounkassa ◽

D. Imbert-Establet

Keyword(s):

Schistosoma Mansoni ◽

Interspecific Competition ◽

Control Experiment ◽

Marked Decrease ◽

Biomphalaria Glabrata ◽

Strong Decrease ◽

Larval Stages ◽

The Mean

ABSTRACTDuring co-infection of Biomphalaria glabrata with Schistosoma mansoni and Echinostoma liei, S. mansoni cercariae released before the complete resorption of S. mansoni sporocysts show a very strong decrease of their infectivity in mice. Under conditions of high interspecific competition (i.e. when the snails are infected by E. liei 8 days after infection by S. mansoni), the mean overall worm return is five times lower than that of the control experiment. A marked decrease of the infectivity of cercariae is also noted when snails, infected exclusively with either sporocysts of S. mansoni or rediae of E. liei, are associated in the same tank.

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Evaluation of sow thermal preference across three stages of reproduction

Journal of Animal Science ◽

10.1093/jas/skab202 ◽

2021 ◽

Author(s):

Lindsey A Robbins ◽

Angela R Green-Miller ◽

Donald C Lay Jr ◽

Allan P Schinckel ◽

Jay S Johnson ◽

...

Keyword(s):

Thermal Gradient ◽

Late Gestation ◽

Thermal Preference ◽

Comfort Zone ◽

Temperature Preference ◽

Preferred Temperature ◽

Metabolic Heat ◽

If Current ◽

Three Stages ◽

Thermal Preferences

Abstract The metabolic heat production of modern pigs has increased by an average of 16%, compared to sows of thirty years ago. Therefore, it is likely that temperature recommendations require updating to meet the needs of modern pigs. The objective of this study was to evaluate whether different reproductive stages of sows altered thermal preference and if current recommendations required updating. Twenty multi-parous sows (3.4 ± 1.2 parity) in different reproductive stages (non-pregnant: n=7; mid-gestation: 58.5 ± 5.68 d, n=6; and late-gestation: 104.7 ± 2.8 d, n=7) were tested. Thermal preference was individually tested and sows could freely choose a temperature, using a thermal gradient between 10.4 to 30.5°C. Sows were given 24 h to acclimate to the thermal apparatus. Before testing began, sows were given daily feed allotment and returned to the apparatus. Video from the 24 h test period was used to record sow behavior (time spent inactive), posture (upright, sternal and lateral lying), and location using instantaneous scan samples every 15 min. Data were analyzed using PROC MIXED in SAS 9.4. A cubic regression model was used to calculate the sow’s most preferred temperature based on the location, or temperature, in which they spent the most time. The preference range was calculated using peak temperature preference ±SE for each sow. The reproductive stage altered where sows spent their time within the thermal gradient (P < 0.01). Late-gestation sows preferred cooler temperatures (14.0°C) than mid-gestation (14.8°C; P < 0.01) and non-pregnant sows (14.8°C; P < 0.01). In summary, sow thermal preferences were within the lower half of the current recommended range (10 to 25°C). This indicates that temperatures at the higher end of the recommended range could be uncomfortable to sows and that the thermal comfort zone of sows may be narrower than recommendations indicate.

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