Predation and avoidance responses in the foraminifera of the Galapagos hydrothermal mounds

Abstract

Analysis of drilling predation patterns on the foraminifera
\nof the Galapagos hydrothermal mounds reveals
\nthat the predator is highly species-selective in its
\nchoice of prey, feeding almost exclusively on the most
\nabundant foraminiferal species, Siphouvigerina auberiana
\n(d'Orbigny). Predation is quite heavy; drillings
\noccur in 27% of the individuals, and most specimens
\nshow multiple holes. There are indications that the
\nprey rarely survive attacks. Evidence is presented suggesting
\npredator avoidance behavior in S. auberiana,
\nas well as behavioral countermeasures on the part of
\nthe predator. We suggest that the most likely predator
\nis probably the juvenile stage of a naticid gastropod.