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Mark Briffa - One of the best experts on this subject based on the ideXlab platform.
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individual quality and personality bolder males are less fecund in the hermit crab pagurus bernhardus
Proceedings of The Royal Society B: Biological Sciences, 2015Co-Authors: Danielle Bridger, Simon J Bonner, Mark BriffaAbstract:One explanation for animal personality is that different behavioural types derive from different life-history strategies. Highly productive individuals, with high growth rates and high fecundity, are assumed to live life at a fast pace showing high levels of boldness and risk taking, compared with less productive individuals. Here, we investigate among-individual differences in mean boldness (the inverse of the latency to recover from a startling stimulus) and in the consistency of boldness, in male hermit crabs in relation to two aspects of life-history investment. We assessed aerobic scope by measuring the concentration of the Respiratory Pigment haemocyanin, and we assessed fecundity by measuring spermatophore size. First, we found that individuals investing in large spermatophores also had high concentrations of haemocyanin. Using doubly hierarchical-generalized linear models to analyse longitudinal data on startle responses, we show that hermit crabs vary both in their mean response durations and in the consistency of their behaviour. Individual consistency was unrelated to haemocyanin concentration or spermatophore size, but mean startle response duration increased with spermatophore size. Thus, counter to expectations, it was the most risk-averse individuals, rather than the boldest and most risk prone, that were the most productive. We suggest that similar patterns should be present in other species, if the most productive individuals avoid risky behaviour.
Danielle Bridger - One of the best experts on this subject based on the ideXlab platform.
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individual quality and personality bolder males are less fecund in the hermit crab pagurus bernhardus
Proceedings of The Royal Society B: Biological Sciences, 2015Co-Authors: Danielle Bridger, Simon J Bonner, Mark BriffaAbstract:One explanation for animal personality is that different behavioural types derive from different life-history strategies. Highly productive individuals, with high growth rates and high fecundity, are assumed to live life at a fast pace showing high levels of boldness and risk taking, compared with less productive individuals. Here, we investigate among-individual differences in mean boldness (the inverse of the latency to recover from a startling stimulus) and in the consistency of boldness, in male hermit crabs in relation to two aspects of life-history investment. We assessed aerobic scope by measuring the concentration of the Respiratory Pigment haemocyanin, and we assessed fecundity by measuring spermatophore size. First, we found that individuals investing in large spermatophores also had high concentrations of haemocyanin. Using doubly hierarchical-generalized linear models to analyse longitudinal data on startle responses, we show that hermit crabs vary both in their mean response durations and in the consistency of their behaviour. Individual consistency was unrelated to haemocyanin concentration or spermatophore size, but mean startle response duration increased with spermatophore size. Thus, counter to expectations, it was the most risk-averse individuals, rather than the boldest and most risk prone, that were the most productive. We suggest that similar patterns should be present in other species, if the most productive individuals avoid risky behaviour.
Bridget Carragher - One of the best experts on this subject based on the ideXlab platform.
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automated three dimensional reconstruction of keyhole limpet hemocyanin type 1
Journal of Structural Biology, 2003Co-Authors: Fabrice Mouche, Yuanxin Zhu, James Pulokas, Clinton S Potter, Bridget CarragherAbstract:Abstract We have reconstructed a three-dimensional map of keyhole limpet hemocyanin isoform 1 (KLH1), using our automated data collection software, Leginon, integrated with particle selection algorithms, and the SPIDER reconstruction package. KLH1, a 7.9 MDa macromolecule, is an extracellular Respiratory Pigment composed of two asymmetric decamers, and presents an overall D 5 point-group symmetry. The reconstruction is in agreement with previous data published on molluscan hemocyanins. The reconstructed map (11.3 A resolution, 3 σ criterion) was used to fit an available X-ray crystallography structure of Octopus dofleini Odg , solved at 2.3 A [J. Mol. Biol. 278 (4) (1998) 855], with satisfactory results. The results validate the approach of automating the cryoEM process and demonstrate that the quality of the images acquired and the particles selected is comparable to those obtained using manual methods. Several problems remain to be solved however before these results can be generalized.
C R Bridges - One of the best experts on this subject based on the ideXlab platform.
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properties of Respiratory Pigments in bimodal breathing animals air and water breathing by fish and crustaceans
Integrative and Comparative Biology, 1994Co-Authors: Stephen Morris, C R BridgesAbstract:SYNOPSIS. Oxygen is nearly 30 times more available in air compared with water, whereas the carbon dioxide capacity of water is ˜28.5-fold greater than for oxygen, presenting bimodal breathing species with two very different Respiratory milieus. The Respiratory Pigment plays a variable role in animals switching between the two media. In vertebrates the transition to air breathing involves two main strategies: a decrease in oxygen affinity and changes in other haematological parameters such as haematocrit. When appropriately analyzed, data reveal a decrease in blood oxygen affinity during transition to air. This may arise via differences in the intrinsic affinity as occurs in some amphibians, or be due to increasesin the organic phosphate: haemoglobin ratio when acclimating to air breathing. Adopting air breathing often promotes increased haematocrit. It is difficult to discern trends in haemocyanin functioning. Many but not all bimodal and air breathingspecies of crab contain haemocyanin with high affinity for oxygen. As with haemoglobin there is some tendency for blood haemocyanin concentration to increase with air breathing but bimodal species are quite variable in this regard. Different strategies for breathing air are employed by various bimodal crustaceans, some of which involve modulation of haemocyanin oxygenaffinity. The exact mechanisms are often species dependent and in all bimodal breathing organisms the role of the Pigment is best appreciated when the demands of the local environment and the behaviour of the species are considered.
Jean N Lamy - One of the best experts on this subject based on the ideXlab platform.
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occurrence of two architectural types of hexagonal bilayer hemoglobin in annelids comparison of 3d reconstruction volumes of arenicola marina and lumbricus terrestris hemoglobins
Journal of Molecular Biology, 2001Co-Authors: Ludovic Jouan, Jeanchristophe Taveau, Francois H Lallier, Sergio Marco, Jean N LamyAbstract:A 3D reconstruction at 25 A resolution of native hemoglobin of the polychaete worm Arenicola marina was carried out from frozen-hydrated specimens examined in the electron microscope. The reconstruction volume of this large extracellular multimeric Respiratory Pigment appears as a hexagonal bilayer structure with eclipsed vertices in its upper and lower hexagonal layers. Conversely, in hemoglobins of oligochaetes, achaetes, and vestimentiferans and in chlorocruorins of the Sabellidae (polychaete) family, the vertices of the upper layer are 16° clockwise rotated with respect to those of the lower layer. The fact that two other polychaete hemoglobins (Alvinella pompejana and Tylorrhynchus heterochaetus) have the same architecture as Arenicola led us to define two types of hexagonal bilayer hemoglobins/chlorocruorins: (i) type-I present in oligochaete, achaete, and vestimentiferan hemoglobins and in Sabellidae chlorocruorins; and (ii) type-II present in polychaete hemoglobins. A comparative study of the hemoglobins of Lumbricus terrestris (type-I) and Arenicola marina (type-II) showed that only two small differences located in the c4 and c5 linking units are responsible of the important architectural difference present in oligomers. A likely scheme proposed to explain the phylogenic distribution of the two types suggests that Clitellata, Sabellida (polychaete), and vestimentiferan hemoglobins and chlorocruorins derive from a type-I ancestral molecule, while Terebellida (Alvinella), Phyllodocida (Tylorrhynchus), and Scolecida (Arenicola) and possibly other polychaetes derive from an ancestor molecule with type-II hemoglobin. The architectures of the hollow globular substructures are highly similar in Arenicola and Lumbricus hemoglobins, with 12 globin chains and three linking units (c3a, c3b, and c4). The central piece of Arenicola hemoglobin is an ellipsoid while that of Lumbricus is a toroid. No phylogenic correlation could be found between the structure of the central pieces and the architecture type.