Invariant size-frequency distributions along a latitudinal gradient in marine bivalves.
In the most extensive analysis of body size in marine invertebrates to date, we show that the size-frequency distributions of northeastern Pacific bivalves at the provincial level are surprisingly invariant in modal and median size as well as size range, despite a 4-fold change in species richness from the tropics to the Arctic. The modal sizes and shapes of these size-frequency distributions are consistent with the predictions of an energetic model previously applied to terrestrial mammals and birds. However, analyses of the Miocene-Recent history of body sizes within 82 molluscan genera show little support for the expectation that the modal size is an evolutionary attractor over geological time.
Roy
K
K
Section of Ecology, Behavior, and Evolution, Division of Biology, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA. kroy@ucsd.edu
Jablonski
D
D
Martien
K K
KK
D000818:Animals; D001824:Body Constitution; D017753:Ecosystem; D005843:Geography; D008974:Mollusca / Q000033:anatomy & histology / Q000502:physiology; D010140:Pacific Ocean