Fluid interactions that enable stealth predation by the upstream-foraging hydromedusa Craspedacusta sowerbyi.
Biol Bull
; 225(1): 60-70, 2013 Sep.
Article
em En
| MEDLINE
| ID: mdl-24088797
Unlike most medusae that forage with tentacles trailing behind their bells, several species forage upstream of their bells using aborally located tentacles. It has been hypothesized that these medusae forage as stealth predators by placing their tentacles in more quiescent regions of flow around their bells. Consequently, they are able to capture highly mobile, sensitive prey. We used digital particle image velocimetry (DPIV) to quantitatively characterize the flow field around Craspedacusta sowerbyi, a freshwater upstream-foraging hydromedusa, to evaluate the mechanics of its stealth predation. We found that fluid velocities were minimal in front and along the sides of the bell where the tentacles are located. As a result, the deformation rates in the regions where the tentacles are located were low, below the threshold rates required to elicit an escape response in several species of copepods. Estimates of their encounter volume rates were examined on the basis of flow past the tentacles, and trade-offs associated with tentacle characteristics were evaluated.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Comportamento Predatório
/
Hidrozoários
Limite:
Animals
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article