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Contributions of growth, stasis, and reproduction to fitness in brooding and broadcast spawning marine bivalves
Author(s) -
Ripley Bonnie J.,
Caswell Hal
Publication year - 2008
Publication title -
population ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 59
eISSN - 1438-390X
pISSN - 1438-3896
DOI - 10.1007/s10144-008-0075-7
Subject(s) - biology , marine invertebrates , reproduction , semelparity and iteroparity , ecology , invertebrate , temperate climate , reproductive season , trade off , zoology
Reproductive modes in marine invertebrates can be generally grouped into two types: those brooding larvae and those broadcast‐spawning gametes into the water. We asked if these different life‐history strategies differ based on how contribution to fitness is partitioned between growth, stasis, and reproduction. To investigate this question, we used published demographic data on ten diverse species of marine bivalves. We parameterized simple matrix‐population models and calculated the sums of elasticities to growth, stasis, and reproduction parameters and plotted the results on triangular axes. We also assessed whether contribution patterns were correlated with reproductive mode and tropical, temperate, or polar environments. We found that some of the broadcast spawners fell in the region of the plot with high elasticities for stasis and that some of the brooders fell in the region of the plot with higher growth and reproduction elasticities than stasis ones. However, instead of a sharp dichotomy, we found a continuum in contributions of stasis parameters with long‐lived brooders and short‐lived broadcast spawners in the same region of the plot. There was no clear pattern of reproductive mode associated with any particular environment, but we think these preliminary results are intriguing and that further work on comparative demography of marine invertebrates is warranted.