scholarly journals Consistent individual differences in haemolymph density reflect risk propensity in a marine invertebrate

2015 ◽  
Vol 2 (6) ◽  
pp. 140482 ◽  
Author(s):  
Ines Fürtbauer
Keyword(s):  
Individual Differences ◽  
Physiological Condition ◽  
Marine Invertebrate ◽  
Coping Styles ◽  
Carcinus Maenas ◽  
Risk Propensity ◽  
Future Studies ◽  
Novel Environment ◽  
Shore Crabs ◽  
Individual Consistency

While the literature on consistent individual differences in correlated suites of physiological and behavioural traits is steadily growing for vertebrates, invertebrates have received less attention. The few studies that do exist have measured temporary physiological states (or responses), rather than consistent individual physiological traits. Here, I explore the consistency of individual differences in physiology and behaviour of n =53 shore crabs ( Carcinus maenas ) by repeatedly measuring haemolymph density (HD) and the crabs' responses to a novel environment. In crustaceans, HD is directly proportional to protein concentrations, and thus indicative of physiological condition. HD was highly repeatable, and crabs showed consistent individual differences in their behavioural responses to a novel environment, thus indicating individual consistency in both physiology and behaviour. Furthermore, HD was significantly correlated with the crabs' risk propensity, i.e. individuals with higher HD spent more time near shelter. Overall, this provides the first evidence for consistency in an endogenous physiological trait in an invertebrate. The link between consistent physiology and behaviour, i.e. coping styles, analogous to those found in vertebrates, suggests metabolic and/or immunological correlates of personality which offer great potential for future studies.

Implications of habitat-specific growth and physiological condition on juvenile crab population structure

2008 ◽  
Vol 59 (8) ◽  
pp. 726 ◽  
Author(s):  
Valter Amaral ◽  
Henrique N. Cabral ◽  
José Paula
Keyword(s):  
Physiological Condition ◽  
Size Structure ◽  
Marine Invertebrate ◽  
Carapace Width ◽  
Carcinus Maenas ◽  
Early Juvenile ◽  
Abundance Patterns ◽  
Sandy Habitat ◽  
Survival Potential ◽  
Competition For Resources

Post-settlement processes can regulate the size and structure of marine invertebrate and fish populations. Faster growth and better physiological condition generally increase the survival potential of early juveniles, being usually associated with structurally complex habitats. Successive cohorts of early juvenile Carcinus maenas were followed in sandy and seagrass (Zostera noltii) habitats in the Mira Estuary, Portugal, to estimate growth and physiological condition (evaluated by RNA/DNA ratio) of juvenile populations. Mean cohort growth was similar in both habitats. However, in the sandy habitat, population size structure progressed to cohorts of larger carapace width (CW) and the RNA/DNA ratio was always higher than in the Z. noltii habitat. In this habitat, cohorts of low CW prevailed throughout and RNA/DNA ratio only increased after ~5.0 mm CW. Higher densities characterising seagrass areas may result in higher competition for resources, limiting growth and condition and leading to dispersal to less populated habitats. Larger juveniles had the best physiological condition, especially early in the season. Seagrass habitats do not necessarily yield enhanced growth rates and physiological condition of early juvenile crabs in relation to sandy areas. Knowledge of such trends is vital to understand distribution and abundance patterns of fish and marine invertebrate populations.

Exploring the Effects of Individual Differences in Function Structure Modeling Behaviors

2021 ◽  
Author(s):  
Apurva Patel ◽  
Joshua D. Summers
Keyword(s):  
Individual Differences ◽  
Goal Orientation ◽  
Structure Modeling ◽  
Risk Propensity ◽  
Input Process ◽  
Function Structure ◽  
Modeling Process ◽  
Survey Instruments ◽  
Process Output ◽  
Protocol Study

Abstract This paper presents an exploratory study conducted to understand the role of individual differences between designers in the function modeling process and with respect to final models. An input-process-output framework of function modeling is proposed to systematically approach this theory building and discovery research study. Four measures of individual differences are identified of interest. These include the systemizing quotient, goal orientation, risk propensity, and concept design thinking style. Each metric is composed of multiple items that can be assessed through survey instruments. A previously developed protocol study is used to capture function modeling behaviors and a final function structure model. Data collected from the survey instruments and protocol study is processed to generate input, process, and output measures. A regression-based analysis is used to identify correlations in three groups: input-process, input-output, and process-output. Potential correlations of interest are identified within each group. Implications of these correlations are discussed from a function structure modeling perspective and hypotheses for future research are identified based on the patterns observed in this study. Three testable hypotheses are proposed for future investigation: (1) Goal orientation has no effect on activity distribution in the function modeling process, (2) Thinking style has no effect on the function modeling process, and (3) Risk propensity has no effect on element distribution in the function modeling process. Finally, an anticipated experiment is outlined to investigate one of the potential relationships discovered in this study.

scholarly journals Influence of temperature on intraspecific, unbalanced dyadic contests between crabs

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7845
Author(s):  
Allan T. Souza ◽  
Felipe O. Ribas ◽  
João F. Moura ◽  
Claudia Moreira ◽  
Joana Campos ◽  
...  
Keyword(s):  
Carapace Width ◽  
Carcinus Maenas ◽  
Individual Characteristics ◽  
The Body ◽  
Shore Crab ◽  
Temperature Conditions ◽  
Red Color ◽  
Shore Crabs ◽  
Influence Of Temperature On ◽  
Globally Distributed

Intraspecific agonistic interactions are widespread across the animal kingdom, with many individual morphological and physiological characteristics playing important roles in the fate of disputes. Additionally, changes to environmental conditions can influence the outcomes of animal contests. The shore crab (Carcinus maenas) is a globally distributed species, present in numerous coastal and estuarine temperate systems around the world. Although shore crabs are highly tolerant to changes in temperature, this parameter has important physiological effects on the species’ ecology, while its effects on behavior are not fully understood. Our study aims to investigate how different individual characteristics (such as sex, color morphotype, carapace and chela morphology) and temperature conditions affect the dyadic interactions between shore crabs when disputing food resources. In general, the differences in carapace width between opponents, their sexes, color morphotypes and the temperature conditions interacted and were important predictors of the contest fate. We found that the body size and color morphotype of C. maenas determined the fate of dyadic disputes. However, the higher temperatures disrupted the well-established dominance of the larger red color morphotype individuals. Overall, the agonistic contest results suggest higher plasticity than previously acknowledged.

Individual differences in cortisol levels and behaviour of Senegalese sole (Solea senegalensis) juveniles: Evidence for coping styles

2010 ◽  
Vol 124 (1-2) ◽  
pp. 75-81 ◽  
Author(s):  
Patrícia Isabel Mota Silva ◽  
Catarina I.M. Martins ◽  
Sofia Engrola ◽  
Giovanna Marino ◽  
Øyvind Øverli ◽  
...  
Keyword(s):  
Individual Differences ◽  
Coping Styles ◽  
Solea Senegalensis ◽  
Senegalese Sole ◽  
Cortisol Levels

scholarly journals Habituation is not neutral or equal: Individual differences in tolerance suggest an overlooked personality trait

2020 ◽  
Vol 6 (28) ◽  
pp. eaaz0870
Author(s):  
Andrew T. L. Allan ◽  
Annie L. Bailey ◽  
Russell A. Hill
Keyword(s):  
Individual Differences ◽  
Behavioral Ecology ◽  
Personality Trait ◽  
Convergent Validity ◽  
Neutral Stimulus ◽  
Related Phenomenon ◽  
Future Studies ◽  
Behavioral Studies ◽  
Observer Effects ◽  
Group Members

In behavioral studies, observer effects can be substantial, even for habituated animals, but few studies account for potential observer-related phenomenon empirically. We used wild, habituated chacma baboons to explore two key assumptions of behavioral ecology (i) that observers become a “neutral” stimulus and (ii) that habituation is “equal” across group members. Using flight initiation distance (FID) methods within a personality paradigm, the behavioral responses of baboons suggested that observers were not perceived as neutral but instead viewed as a high-ranking social threat. Habituation was also not equal across group members, with repeatable individual differences more important than contextual factors (e.g., habitat) in determining the distance at which baboons visually oriented or displaced from observers. A strong correlation between individual visual tolerance and displacement tolerance (i.e., convergent validity) indicated a personality trait. We offer several suggestions for how to account for these factors and minimize potential bias in future studies.

scholarly journals Mycosis Is a Disease State Encountered Rarely in Shore Crabs, Carcinus maenas

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 462
Author(s):  
Charlotte E. Davies ◽  
Sophie H. Malkin ◽  
Jessica E. Thomas ◽  
Frederico M. Batista ◽  
Andrew F. Rowley ◽  
...  
Keyword(s):  
Immune Cell ◽  
Fungal Infections ◽  
Novel Species ◽  
Carcinus Maenas ◽  
Shore Crab ◽  
Marine Animals ◽  
Cell Reactivity ◽  
Shore Crabs ◽  
Swansea Bay ◽  
Disease Signatures

There is a paucity of knowledge regarding the diversity and impact(s) of disease-causing fungi in marine animals, especially shellfish. In efforts to address this knowledge gap for the shore crab Carcinus maenas, a year-long disease screen was carried out across two sites in Swansea Bay (Wales, UK) with a view to characterising putative fungal infections. Crabs were sampled between November 2017 and October 2018, and screened systematically for disease signatures using haemolymph (blood) preparations, targeted PCR and tissue histopathology. Strikingly, mycosis was confirmed in ~0.4% of total crabs tested (n = 1191) and restricted to one location only (Mumbles Pier). Clinical infections were observed in four out of four infected crabs. In these animals, the gills and hepatopancreas were congested with fungal morphotypes. In addition, some evidence indicates haemocyte (immune cell) reactivity toward the fungi. Phylogenetic placement of the partial internal transcribed spacer (ITS1) gene regions amplified from three mycotic crabs revealed the causative agent to be related to hypocrealean fungi, thereby representing a novel species.

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