scholarly journals Joint evolution of predator body size and prey-size preference

2007 ◽  
Vol 22 (6) ◽  
pp. 771-799 ◽  
Author(s):  
Tineke A. Troost ◽  
Bob W. Kooi ◽  
Ulf Dieckmann
Author(s):  
Ken H. Andersen

This chapter follows the size-structure of the entire marine ecosystem. It shows how the Sheldon spectrum emerges from predator–prey interactions and the limitations that physics and physiology place on individual organisms. How predator–prey interactions and physiological limitations scale with body size are the central assumptions in size spectrum theory. To that end, this chapter first defines body size and size spectrum. Next, it shows how central aspects of individual physiology scale with size: metabolism, clearance rate, and prey size preference. On that basis, it is possible to derive a power-law representation of the size spectrum by considering a balance between the needs of an organism (its metabolism) and the encountered prey, which is determined by the spectrum, the clearance rate, and the size preference. Lastly, the chapter uses the solution of the size spectrum to derive the expected size scaling of predation mortality.


2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.


2004 ◽  
Vol 25 (3) ◽  
pp. 287-302 ◽  
Author(s):  
Juan Pleguezuelos ◽  
Soumia Fahd

AbstractAlthough it is generally assumed that the Horseshoe Whip Snake (Coluber hippocrepis) originated in northern Africa, its biology and ecology has been studied mainly in southern Europe. In this paper we report on morphology, feeding, and reproductive ecology of Coluber hippocrepis in the Rif region (northern Morocco). Males attained larger sizes than did females, but there was no body-size difference between populations separated by the Strait of Gibraltar. The species feeds exclusively on vertebrates: mammals (45%), reptiles (28%), birds (17%), and amphibians (10%). There was an ontogenetic dietary shift in terms of frequency of prey consumed and in terms of prey size; moreover, an intersexual difference in prey frequency was found. Sexual maturity was attained at 540 mm snout-vent length (SVL) in males, and 720 mm SVL in females. Males showed a vernal spermatogenic cycle. Oviposition occurred at the beginning of summer, and offspring were observed in the field during September.


Ecology ◽  
1986 ◽  
Vol 67 (1) ◽  
pp. 260-261 ◽  
Author(s):  
Thomas W. Schoener ◽  
Jonathan Roughgarden ◽  
Tom Fenchel
Keyword(s):  

2005 ◽  
Vol 62 (3) ◽  
pp. 412-416 ◽  
Author(s):  
Daniel E. Duplisea

Abstract Predation size spectra were constructed for the northern Gulf of St Lawrence, covering prey size ranges that include pre-recruit cod. Predation by fish and harp seals was modelled with a log-normally distributed predator–prey size ratio along with a relationship between predator body size and the energy required. Fish concentrate predation on prey of weight 0.5–2 g, whereas harp seals prefer prey of 60–125 g. It is speculated that predation caused by harp seals on pre-recruits could be a major factor limiting cod recruitment in the system. The northern Gulf of St Lawrence is a cold boreal system with a large predatory seal population, and cod recruit older than elsewhere. Therefore, cod recruitment may be more strongly affected by predation in the northern Gulf of St Lawrence than in warmer systems such as the North Sea, where recruitment is strongly influenced by temperature.


Oikos ◽  
1984 ◽  
Vol 43 (3) ◽  
pp. 291 ◽  
Author(s):  
Dolph Schluter
Keyword(s):  

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e93088 ◽  
Author(s):  
Marie R. G. Attard ◽  
William C. H. Parr ◽  
Laura A. B. Wilson ◽  
Michael Archer ◽  
Suzanne J. Hand ◽  
...  

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