scholarly journals Are brown recluse spiders, Loxosceles reclusa (Araneae, Sicariidae) scavengers? The influence of predator satiation, prey size, and prey quality

2008 ◽  
Vol 36 (1) ◽  
pp. 140-144 ◽  
Author(s):  
Kenneth L. Cramer
Keyword(s):  
Prey Size ◽  
Predator Satiation ◽  
Prey Quality ◽  
Loxosceles Reclusa

THE EFFECT OF PREDATOR AGE ON THE FUNCTIONAL RESPONSE OF PODISUS MACULIVENTRIS TO THE PREY SIZE OF GALLERIA MELLONELLA

1969 ◽  
Vol 101 (3) ◽  
pp. 314-327 ◽  
Author(s):  
M. K. Mukerji ◽  
E. J. LeRoux
Keyword(s):  
Functional Response ◽  
Galleria Mellonella ◽  
Prey Size ◽  
Podisus Maculiventris ◽  
Adult Males ◽  
Predator Satiation ◽  
Attack Model ◽  
Males And Females ◽  
The Relationship ◽  
Effect Of Age

AbstractExperiments were carried out to determine the effect of age on the functional response of the pentatomid predator Podisus maculiventris (Say), reared in a simple glass jar universe on different prey sizes of Galleria mellonella (L.). Holling’s (1959) ’disc’ equation accurately described the predator’s response at all prey sizes up to 50 days of life. For nymphs, the calculated ’rate of discovery’, a, increased as the predator age increased, but the time of handling prey, b, decreased; for both adult males and females, these calculated values increased gradually up to the 50th day. The relationship between predator age and numbers of prey killed, and predator age and amount of prey body contents consumed (food consumption), was linear at all prey sizes, but mainly negatively so. Prey size was an important component of the predation process for all stages of the predator.It is concluded that ’hunger’ is an important parameter of the attack model since the degree of predator satiation bears directly on b-type activities which in turn affects a-type activities. These findings indicate that under field conditions P. maculiventris will kill more small-sized lepidopterous prey larvae than large-sized ones, and that, because of the greater prey defense of the latter, their survival from predator attacks will increase. These actions may be of considerable importance in the survival of lepidopterous host species.

Ultrastructural Alterations in Hela Cells Induced by Spider Venom

1967 ◽  
Vol 25 ◽  
pp. 20-21
Author(s):  
Dale E. McClendon ◽  
Paul N. Morgan ◽  
Bernard L. Soloff
Keyword(s):  
Growth Medium ◽  
Mammalian Cells ◽  
Carcinoma Cells ◽  
Venom Protein ◽  
Sterile Saline ◽  
Carbon Coated ◽  
Available Information ◽  
Loxosceles Reclusa ◽  
Essential Growth ◽  
Solution Cultures

It has been observed that minute amounts of venom from the brown recluse spider, Loxosceles reclusa, are capable of producing cytotoxic changes in cultures of certain mammalian cells (Morgan and Felton, 1965). Since there is little available information concerning the effect of venoms on susceptible cells, we have attempted to characterize, at the electron microscope level, the cytotoxic changes produced by the venom of this spider.Cultures of human epithelial carcinoma cells, strain HeLa, were initiated on sterile, carbon coated coverslips contained in Leighton tubes. Each culture was seeded with approximately 1x105 cells contained in 1.5 ml of a modified Eagle's minimum essential growth medium prepared in Hank's balanced salt solution. Cultures were incubated at 36° C. for three days prior to the addition of venom. The venom was collected from female brown recluse spiders and diluted in sterile saline. Protein determinations on the venom-were made according to the spectrophotometric method of Waddell (1956). Approximately 10 μg venom protein per ml of fresh medium was added to each culture after discarding the old growth medium. Control cultures were treated similarly, except that no venom was added. All cultures were reincubated at 36° C.

scholarly journals Prey Size Decline as a Unifying Ecological Selecting Agent in Pleistocene Human Evolution

Quaternary ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 7
Author(s):  
Miki Ben-Dor ◽  
Ran Barkai
Keyword(s):  
Prey Size ◽  
Prey Availability ◽  
Stone Tool ◽  
Foraging Efficiency ◽  
Energetic Cost ◽  
Large Prey ◽  
Biomass Density ◽  
Cultural Changes ◽  
Progressive Decline ◽  
Brain Expansion

We hypothesize that megafauna extinctions throughout the Pleistocene, that led to a progressive decline in large prey availability, were a primary selecting agent in key evolutionary and cultural changes in human prehistory. The Pleistocene human past is characterized by a series of transformations that include the evolution of new physiological traits and the adoption, assimilation, and replacement of cultural and behavioral patterns. Some changes, such as brain expansion, use of fire, developments in stone-tool technologies, or the scale of resource intensification, were uncharacteristically progressive. We previously hypothesized that humans specialized in acquiring large prey because of their higher foraging efficiency, high biomass density, higher fat content, and the use of less complex tools for their acquisition. Here, we argue that the need to mitigate the additional energetic cost of acquiring progressively smaller prey may have been an ecological selecting agent in fundamental adaptive modes demonstrated in the Paleolithic archaeological record. We describe several potential associations between prey size decline and specific evolutionary and cultural changes that might have been driven by the need to adapt to increased energetic demands while hunting and processing smaller and smaller game.

Does prey abundance affect prey size selection by the Eagle Owl (Bubo bubo)?

2021 ◽  
Author(s):  
Jorge Tobajas ◽  
Carlos Rouco ◽  
Javier Fernandez-de-Simon ◽  
Francisco Díaz-Ruiz ◽  
Francisca Castro ◽  
...  
Keyword(s):  
Prey Size ◽  
Prey Abundance ◽  
Bubo Bubo ◽  
Size Selection ◽  
Eagle Owl

scholarly journals Prey identity but not prey quality affects spider performance

2021 ◽  
pp. 100013
Author(s):  
Gina M. Wimp ◽  
Danny Lewis ◽  
Shannon M. Murphy
Keyword(s):  
Prey Quality

Does prey size induce head skeleton phenotypic plasticity during early ontogeny in the snake Boa constrictor ?

2005 ◽  
Vol 267 (04) ◽  
pp. 363 ◽  
Author(s):  
Gordon W. Schuett ◽  
David L. Hardy ◽  
Ryan L. Earley ◽  
Harry W. Greene
Keyword(s):  
Phenotypic Plasticity ◽  
Prey Size ◽  
Early Ontogeny ◽  
Boa Constrictor ◽  
Head Skeleton

scholarly journals Changes in foraging mode caused by a decline in prey size have major bioenergetic consequences for a small pelagic fish

2021 ◽  
Author(s):  
Elisa Thoral ◽  
Quentin Queiros ◽  
Damien Roussel ◽  
Gilbert Dutto ◽  
Eric Gasset ◽  
...  
Keyword(s):  
Prey Size ◽  
Pelagic Fish ◽  
Small Pelagic Fish ◽  
Foraging Mode
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