Skip to main content

Free Content Foraging Behavior of the Blue Crab, Callinectes Sapidus, on Juvenile Oysters, Crassostrea Virginica: Effects of Prey Density and Size

Download Article:
 Download
(PDF 1188.6064453125 kb)
 

Abstract:

Blue crabs (Callinectes sapidus) are major predators of juvenile oysters (Crassostrea virginica) in Chesapeake Bay, yet little information exists on the foraging behavior and predator–prey dynamics for this predator-prey system. Laboratory experiments assessed functional responses of blue crabs to six densities of three size-classes of juvenile American oysters. Behavioral subcomponents of the crabs' functional response were quantified: total and successful encounter rates, proportional attack success, persistence time in unsuccessful encounters, and breaking, eating and handling times in successful encounters. Specific opening techniques were used by crabs for the three oyster size-classes. Blue crabs exhibited a hyperbolic type II functional response regardless of oyster size, with an inverse relationship between predation rates and increasing oyster size. Crab persistence times with oysters were positively correlated with attack success rates at three oyster size-classes, and inversely related to prey density, suggesting higher selectivity by blue crabs at higher oyster densities. Oysters >30 mm shell-height may be near the critical size for crushing by large crabs as a result of increased variations in (1) shell to crab strength ratios, (2) opening techniques with oyster attachment site and growth geometry, and (3) oyster density. These findings indicate that crab acceptance or rejection sequences of bivalve prey depend on prey density and size, that predation by large male C. sapidus can lead to local extinction of juvenile oysters (x=15–35 mm SH) regardless of density and, that increasing shell-height provides a refuge from predation.

Document Type: Research Article

Publication date: 1990-01-01

More about this publication?
  • The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • Terms & Conditions
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free ContentFree content
  • Partial Free ContentPartial Free content
  • New ContentNew content
  • Open Access ContentOpen access content
  • Partial Open Access ContentPartial Open access content
  • Subscribed ContentSubscribed content
  • Partial Subscribed ContentPartial Subscribed content
  • Free Trial ContentFree trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more