Search results for "Body size"
showing 10 items of 205 documents
Factors influencing infection patterns of trophically transmitted parasites among a fish community: host diet, host-parasite compatibility or both?
2011
20 pages; International audience; Parasite infection patterns were compared with the occurrence of their intermediate hosts in the diet of nine sympatric fish species in a New Zealand lake. Stomach contents and infection levels of three gastrointestinal helminth species were examined from the entire fish community. The results highlighted some links between fish host diet and the flow of trophically transmitted helminths. Stomach contents indicated that all but one fish species were exposed to these helminths through their diet. Host feeding behaviour best explained infection patterns of the trematode Coitocaecum parvum among the fish community. Infection levels of the nematode Hedruris spi…
<p><strong>A new species of the genus <em>Glischrochilus</em> Reitter (Coleoptera: Nitidulidae: Cryptarchinae) from China<…
2016
The cosmopolitan genus Glischrochilus Reitter, 1873 (Nitidulidae: Cryptarchinae) is distributed in Holarctic and Oriental regions. According to the most recent catalogue (Jelinek & Audisio 2007), 32 species are known from the Palaearctic region. In China the genus is represented by 13 species, most of which were described by Jelinek (1975, 1982, 1999) and Lason (2009).
Size does matter — the eco-evolutionary effects of changing body size in fish
2020
Body size acts as a proxy for many fitness-related traits. Body size is also subject to directional selection from various anthropogenic stressors such as increasing water temperature, decreasing dissolved oxygen, fisheries, as well as natural predators. Changes in individual body size correlate with changes in fecundity, behaviour, and survival and can propagate through populations and ecosystems by truncating age and size structures and changing predator–prey dynamics. In this review, we will explore the causes and consequences of changing body size in fish in the light of recent literature and relevant theories. We will investigate the central role of body size in ecology by first discu…
Experimental size-selective harvesting affects behavioral types of a social fish
2019
In most fisheries, larger fish experience substantially higher mortality than smaller fish. Body length, life history, and behavioral traits are often correlated, such that fisheries-induced changes in size or life history can also alter behavioral traits. However, empirical evidence regarding how size-selective harvesting alters the evolution of behavioral traits in exploited stocks is scarce. We used experimental lines of Zebrafish Danio rerio that were exposed to positively size-selective, negatively size-selective, or random harvest over five generations. Our aim was to investigate whether simulated fishing changed the mean personality of the surviving females five generations after ini…
Species interactions, environmental gradients and body size shape population niche width
2021
1. Competition for shared resources is commonly assumed to restrict population-level niche width of coexisting species. However, the identity and abundance of coexisting species, the prevailing environmental conditions, and the individual body size may shape the effects of interspecific interactions on species’ niche width. 2. Here we study the effects of interspecific and intraspecific interactions, lake area and altitude, and fish body size on the trophic niche width and resource use of a generalist predator, the littoral-dwelling large, sparsely rakered morph of European whitefish (Coregonus lavaretus; hereafter LSR whitefish). We use stable isotope, diet and survey fishing data from 14 …
The torso integration hypothesis revisited in Homo sapiens: Contributions to the understanding of hominin body shape evolution.
2018
Objectives: Lower thoracic widths and curvatures track upper pelvic widths and iliac blades curvatures in hominins and other primates (torso integration hypothesis). However, recent studies suggest that sexual dimorphism could challenge this assumption in Homo sapiens. We test the torso integration hypothesis in two modern human populations, both considering and excluding the effect of sexual dimorphism. We further assess covariation patterns between different thoracic and pelvic levels, and we explore the allometric effects on torso shape variation. Material and Methods: A sex-balanced sample of 50 anatomically connected torsos (25 Mediterraneans, 25 Sub-Saharan Africans) was segmented fro…
Childhood growth predicts higher bone mass and greater bone area in early old age: findings among a subgroup of women from the Helsinki Birth Cohort …
2017
Abstract Summary: We examined the associations between childhood growth and bone properties among women at early old age. Early growth in height predicted greater bone area and higher bone mineral mass. However, information on growth did not improve prediction of bone properties beyond that predicted by body size at early old age. Introduction: We examined the associations between body size at birth and childhood growth with bone area, bone mineral content (BMC), and areal bone mineral density (aBMD) in early old age. Methods: A subgroup of women (n = 178, mean 60.4 years) from the Helsinki Birth Cohort Study, born 1934–1944, participated in dual-energy X-ray absorptiometry (DXA) measuremen…
Body dimensions of the extinct giant shark Otodus megalodon: a 2D reconstruction
2020
AbstractInferring the size of extinct animals is fraught with danger, especially when they were much larger than their modern relatives. Such extrapolations are particularly risky when allometry is present. The extinct giant shark †Otodus megalodon is known almost exclusively from fossilised teeth. Estimates of †O. megalodon body size have been made from its teeth, using the great white shark (Carcharodon carcharias) as the only modern analogue. This can be problematic as the two species likely belong to different families, and the position of the †Otodus lineage within Lamniformes is unclear. Here, we infer †O. megalodon body dimensions based on anatomical measurements of five ecologically…
Prenatal Ambient Air Pollution, Placental Mitochondrial DNA Content, and Birth Weight in the INMA (Spain) and ENVIRONAGE (Belgium) Birth Cohorts
2016
The research leading to these results was funded by the Spanish Ministry of Health (FIS-PI11/00610, FIS-PI041436, FIS-PI081151, FIS-PI042018, and FIS-PI09/02311), the European Union (EU) (FP7-ENV-2011 cod 282957 and HEALTH.2010.2.4.5-1), the Instituto de Salud Carlos III (Red INMA G03/176, CB06/02/0041, FIS-FEDER 03/1615, 04/1509, 04/1112, 04/1931, 05/1079, 05/1052, 06/1213, 07/0314, 09/02647, 11/01007, 11/02591, CP11/00178, FIS-PI06/0867, and FIS-PS09/00090), the Conselleria de Sanitat Generalitat Valenciana, the Generalitat de Catalunya-CIRIT (1999SGR 00241), the Obre Social Cajastur, the Universidad de Oviedo, the Department of Health of the Basque Government (2005111093 and 2009111069),…
Re-thinking the effects of body size on the study of brain size evolution
2018
Body size correlates with most structural and functional components of an organism’s phenotype – brain size being a prime example of allometric scaling with animal size. Therefore, comparative studies of brain evolution in vertebrates rely on controlling for the scaling effects of body size variation on brain size variation by calculating brain weight/body weight ratios. Differences in the brain size-body size relationship between taxa are usually interpreted as differences in selection acting on the brain or its components, while selection pressures acting on body size, which are among the most prevalent in nature, are rarely acknowledged, leading to conflicting and confusing conclusions. …