Showing papers on "Uca pugilator published in 2017"
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TL;DR: The results suggest the potential for S. reticulatum to negatively impact marsh stability, and that effects of crab foraging behavior may be heightened by increased inundation.
13 citations
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TL;DR: This work analyzes how temperature shapes crabs’ behavior at 2 different times of the year and shows that a transition from constant cold to constant warm water temperature leads to increased locomotor activity levels throughout the day in fiddler crabs collected during the summer, while colder temperatures during the cold season favor a more prominent diurnal behavior.
Abstract: Animals living in the intertidal zone are exposed to prominent temperature changes. To cope with the energetic demands of environmental thermal challenges, ectotherms rely mainly on behavioral responses, which may change depending on the time of the day and seasonally. Here, we analyze how temperature shapes crabs’ behavior at 2 different times of the year and show that a transition from constant cold (13.5°C) to constant warm (17.5°C) water temperature leads to increased locomotor activity levels throughout the day in fiddler crabs (Uca pugilator) collected during the summer. In contrast, the same transition in environmental temperature leads to a decrease in the amplitude of the daily locomotor activity rhythm in crabs collected during the winter. In other words, colder temperatures during the cold season favor a more prominent diurnal behavior. We interpret this winter-summer difference in the response of daily locomotor activity to temperature changes within the framework of the circadian thermoenergetics hypothesis, which predicts that a less favorable energetic balance would promote a more diurnal activity pattern. During the winter, when the energetic balance is likely less favorable, crabs would save energy by being more active during the expected high-temperature phase of the day—light phase—and less during the expected low-temperature phase of the day—dark phase. Our results suggest that endogenous rhythms in intertidal ectotherms generate adaptive behavioral programs to cope with thermoregulatory demands of the intertidal habitat.
12 citations
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TL;DR: The results show that the impact of exaggerated structures on energy expenditure may depend on exercise intensity and highlight the need to examine various locomotory intensities when attempting to assess the costs of bearing a sexually selected trait.
Abstract: Models proposed to explain sexually selected structures assume that these traits are costly. However, studies investigating the impact of such structures on locomotory costs have produced inconsistent results. Male fiddler crabs possess a large sexually selected claw and are ideal for assessing the impact of a sexually selected trait on the cost of locomotion. Here, we measured the energy expenditure of clawed, declawed and artificially loaded crabs during sustained exercise by measuring oxygen consumption and blood lactate levels. We also measured blood lactate levels of clawed and declawed crabs following a sprint and forced walk to assess energy expenditure during non-sustainable, strenuous locomotion. Clawed and declawed crabs consumed the same amount of oxygen and had the same blood lactate concentration during sustained locomotion, suggesting that the large claw does not increase energetic costs during sustainable locomotion. Following non-sustainable, strenuous locomotion, however, there was a trend for clawed crabs to have higher concentrations of lactate in their blood than declawed crabs, suggesting that bearing a large claw may increase energetic costs during strenuous locomotion and lengthen recovery time. Artificially loaded crabs produced more lactic acid than clawed and declawed crabs during sustainable locomotion, suggesting that compensatory traits help mitigate the energetic cost of carrying the large claw. Overall, our results show that the impact of exaggerated structures on energy expenditure may depend on exercise intensity and highlight the need to examine various locomotory intensities when attempting to assess the costs of bearing a sexually selected trait.
10 citations
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TL;DR: Fiddler crabs can serve as a laboratory model for investigating H. perezi infections and may be useful for comparative studies with blue crabs.
3 citations
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TL;DR: Results suggest that, for U. pugilator, body size plays a large role in the preference for exposed habitat, and interacts between origin habitat and carapace width and activity level.
Abstract: Recognizing which phenotypic traits are predictors for habitat choice can have important implications for understanding population dynamics. This study determined whether body size, sex, activity level, or origin habitat affected the preference of the fiddler crab, Uca pugilator, in selecting either a marsh or open mudflat, two habitats differing in risk level and food availability. Combining field and laboratory experiments, this study indicated a significant difference in body size and activity level of crabs between habitats. Further investigation of phenotypic dependency on habitat preference resulted in interactions between origin habitat and carapace width and activity level. When split by origin habitat, habitat preference for the open mudflat was predicted by body size for crabs originating from the open mudflat and by activity level for the crabs originating from the Spartina marsh. These results suggest that, for U. pugilator, body size plays a large role in the preference for exposed habitat.
1 citations
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22 Nov 2017
TL;DR: In the fiddler crab, Uca pugilator, growth of the regenerating structures is accelerated, while growth of non-regenerating structures can be slowed or inhibited as mentioned in this paper.
Abstract: Autotomy and regeneration of the large male cheliped and/or numerous walking legs disrupts normal growth parameters in the fiddler crab, Uca pugilator. Growth of the regenerating structures is accelerated, while growth of non-regenerating structures can be slowed or inhibited. These perturbations are not limited to the molt immediately following autotomy but also can affect growth allometry for two or more molt cycles subsequent to autotomy. The disruptions are due to variations in the distribution of body fluids following molt.
1 citations