Predation By The Oyster Toadfish Opsanus tau (Linnaeus) On Blue Crabs And Mud Crabs, Predators Of The Hard Clam Mercenaria mercenaria (Linnaeus, 1758)

Authors

Robert Bisker, Virginia Institute of Marine Science
Mary Gibbons, Virginia Institute of Marine Science
Michael Castagna, Virginia Institute of Marine Science

Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

1989

Journal

Journal of Shellfish Research

Volume

8

Issue

1

First Page

25

Last Page

31

Abstract

The oyster toadfish, Opsanus tau (Linne), reduces predation by xanthid and portunid crabs on juvenile hard clams, Mercenaria mercenaria (Linne), in field cultures. This study examined the influence of size and species on the predator-prey relationship between toadfish and crabs. The mud crabs Eurypanopeus depressus (Smith), Neopanope sayi (Smith), and Panopeus herbstii Milne Edwards of 5-40 mm carapace width and blue crabs Callinectes sapidus Rathbun of 77-105 mm carapace width were offered to toadfish of 70-322 mm total length. Toadfish predation rates on mud crabs were higher with increasing toadfish size and lower with increasing crab size. Toadfish injured or killed mud crabs that were one tenth of their total length or approximately one half of their mouth width. Predation of juvenile hard clams by blue crabs was reduced when toadfish were present.

Keywords

predation, toadfish, Opsanus, crabs, hard clams, Mercenaria

Recommended Citation

Bisker, Robert; Gibbons, Mary; and Castagna, Michael, Predation By The Oyster Toadfish Opsanus tau (Linnaeus) On Blue Crabs And Mud Crabs, Predators Of The Hard Clam Mercenaria mercenaria (Linnaeus, 1758) (1989). Journal of Shellfish Research, 8(1), 25-31.
https://scholarworks.wm.edu/vimsarticles/1285