Control and consequences of alternative developmental modes in a poecilogonous polychaete

Levin, LA, Bridges TS.  1994.  Control and consequences of alternative developmental modes in a poecilogonous polychaete. American Zoologist. 34:323-332.


capitella sp, dendraster-excentricus, development, larval, lecithotrophic development, marine-invertebrates, planktotrophy, reproduction, sand dollar, spionidae, streblospio-benedicti polychaeta


The poecilogonous polychaete Streblospio benedicti (Webster) exhibits both planktotrophic and lecithotrophic modes of larval development. The alternative trophic modes are associated with differences in age and size at maturation, offspring number, size and energetic investment, larval planktonic period, morphology and survivorship. This paper reviews a decade of research into the control and consequences of the traits associated with planktotrophy and lecithotrophy in S. benedicti. The dominant control on reproductive and developmental characters is genetic. Significant additive genetic variance has been detected for egg diameter, fecundity, larval planktonic period and aspects of larval morphology. However, environmental factors such as temperature, food quality and photoperiod, and intrinsic factors such as maternal age, exert considerable influence on non-trophic developmental traits (e.g., offspring number, size and energy content). Demographic consequences of development mode are reviewed for field and laboratory demes of S. benedicti dominated by individuals exhibiting either planktotrophy or lecithotrophy. Similar population size structure, fluctuations in abundance, P:B ratios, and estimated population growth rates are achieved through trade-offs between survivorship and fecundity. Development mode may best be viewed as a complex set of traits that are intimately linked developmentally and evolutionarily to other aspects of an organism's life history. Greater insight into the control and consequences of development mode should result from further investigation of these linkages.