Life cycles are composed of stages that can vary
dramatically in size, form, habitat, and functional attributes.
Such complex life cycles, and the series of functional and ecological
challenges they encompass, characterize most multicellular organisms
(Werner, 1988). Marine biphasic life cycles provide particularly diverse
examples of selection operating at different life-history stages. For
example, marine taxa commonly face challenges to fertilization of
free-spawned gametes, to nutrient acquisition during pelagic larval
development, to benthic site selection and juvenile survival, and to
adult reproductive location and timing. Within life-cycle functional
variation is fundamental to understanding ecological and evolutionary
processes at the organismal and population levels, given that the nature
and force of selection pressures can change more dramatically within
life cycles than among adults of different species.
Metamorphosis has traditionally been viewed as a means
of decoupling functional challenges during different parts of a life
cycle. Recent evidence from the marine literature, however, indicates
that consequences of variation in performance at one life-history stage
can “carry over” into significant effects on later stages. For example,
characteristics of eggs that influence fertilization success can also
influence the distribution of larval traits (Marshall et al. 2002,
Marshall and Keough 2003); embryonic experience can influence larval and
juvenile performance (Moran and Emlet 2001, Giménez and Anger 2003);
planktonic larval experience can influence benthic juvenile success (Qian
and Pechenik 1998, Pechenik and Rice 2001, Phillips 2002, Giménez et al.
2004); and adult reproductive timing or location can alter developmental
conditions for offspring (Li and Brawley 2004, Brawley et al. 1999,
Podolsky 2003). These examples illustrate how life cycle stages can be
functionally coupled, such that life cycle evolution is a more highly
integrated response to selection than can be deduced from the study of
individual stages. Nevertheless, traditional models of life history
evolution (e.g., Vance 1973, Christiansen and Fenchel 1979) and their
derivatives have tended to treat stages in isolation.
In marine organisms, much of what is known about
performance at early stages and functional links among stages comes from
studies in the laboratory, where small individuals can be cultured in
large numbers under controlled conditions. Relatively little is
understood about performance capacities or selection on functional
traits for these stages under natural conditions (Young 1990), and
relating laboratory results to field conditions has been problematic.
Unlike terrestrial organisms, marine organisms have early stages that
are often microscopic and widely dispersing, hence impractical for in
situ tests of performance. A handful of studies have successfully
examined gamete, larval, or juvenile performance in the context of field
conditions (e.g., Bingham and Young 1991, Meidel and Yund 2001, Moran
and Emlet 2001, Franke et al. 2002, Phillips 2002), but such examples
are vastly outnumbered by laboratory studies.
In this symposium, we aim to draw together and
synthesize recent and ongoing research on organismal performance at
different life-history stages--gametes, embryos, larvae, juveniles, and
adults--that emphasizes functional connections among stages. Our goal is
to highlight research that has been innovative in both (1) surmounting
the challenges of translating laboratory measures of performance into a
field context and (2) emphasizing how functional processes at one
life-history stage alter the conditions for performance and selection at
others. For this reason, the participants will cover a wide range
of organisms (fish, invertebrates, algae), life-history stages, and
research questions while offering a number of international
We thank SICB, the Division of Invertebrate Zoology,
the Division of Ecology and Evolution, and the
American Microscopical Society, for
their sponsorship and generous support.
Go here to see the press
release for this symposium.
Participants and topics
Bob Podolsky (College of Charleston) and Amy
Moran (Clemson University): Functional links between life-cycle
stages: carryover or compensation?
Phil Yund and Sheri Johnson (University
of New England): Multiple paternity and subsequent fusion/rejection
interactions in a colonial ascidian
Gareth Pearson (Universidade do Algarve, PT):
Revisiting synchronous spawning in seaweeds—is it just about sex?
Nicole Phillips and Jeff Shima (Victoria
University of Wellington, NZ): Causes and consequences of variability
in larval quality in mussels and reef fish
Carol Thornber (University of Rhode Island):
Functional properties of algal life cycles
Luis Giménez (Biologische Anstalt
Helgoland, DE): Functional links among life phases and the
consequences for individual performance in decapod crustaceans
Richard Emlet (University of Oregon):
Functional and ecological limits on size at metamorphosis of marine
Su Sponaugle (University of Miami):
Influence of early life history traits on recruitment success and early
survival in a coral reef fish
Dean Wendt (Cal Poly, San Luis Obispo):
Availability of dissolved organic matter (DOM) reduces carryover
performance consequences for the marine bryozoan Bugula neritina
Dustin Marshall (University of Queensland, AU):
Transgenerational offspring size effects in marine invertebrates
The symposium will be held during morning and
afternoon sessions on Friday, January 6th, 2006 (talk order to be determined). In addition to
organizing the symposium sessions, we encourage participation in
contributed paper and poster sessions that will be complementary to and
held after the
symposium. If you have already submitted an abstract but did not
indicate your preference to be part of these complementary sessions,
please contact SICB as soon as
possible. If you plan to participate in a complementary session,
please send a copy of your title and abstract to the symposium
co-organizer, Bob Podolsky.
Allen, J.D., Zakas, C. and R.D. Podolsky. In
press. Effects of egg size reduction and larval feeding on juvenile
performance in a sea urchin with facultative-feeding development.
Journal of Experimental Marine Biology and Ecology.
Bingham, B. L., and C. M. Young. 1991. Larval behavior of the ascidian
Ecteinascidia turbinata (Herdman): an in-situ experimental study
of the effects of swimming on dispersal. Journal of Experimental Marine
Biology and Ecology 145:189-204.
Brawley, S. H., L. E. Johnson, G. A. Pearson, V.
Speransky, R. Li, and E. Serrao. 1999. Gamete release at low tide in
fucoid algae: Maladaptive or advantageous? American Zoologist 39:218-229.
Christiansen, F. B., and T. M. Fenchel. 979.
Evolution of marine invertebrate reproductive patterns. Theoretical
Population Biology 16:267-282.
Franke, E. S., R. C. Babcock, and C. A. Styan.
2002. Sexual conflict and polyspermy under sperm-limited conditions: In
situ evidence from field simulations with the free-spawning marine
echinoid Evechinus chloroticus. American Naturalist 160:485-496.
Giménez, L. 2002. Effects of prehatching salinity
and initial larval biomass on survival and duration of development in
the zoea 1 of the estuarine crab, Chasmagnathus granulata, under
nutritional stress. Journal of Experimental Marine Biology and Ecology
Giménez, L. 2004. Marine community ecology:
importance of trait-mediated effects propagating through complex life
cycles. Marine Ecology Progress Series 283: 303-310.
Giménez, L., and K. Anger. 2003. Larval performance
in an estuarine crab, Chasmagnathus granulata, is a consequence of both
larval and embryonic experience. Marine Ecology Progress Series 249:251-264.
Giménez, L., K. Anger, and G. Torres. 2004. Linking
life history traits in successive phases of a complex life cycle:
Effects of larval biomass on early juvenile development in an estuarine
crab, Chasmagnathus granulata. Oikos 104:570-580.
Hentschel, B. T. and R. B. Emlet 2000.
Metamorphosis of barnacle nauplii: Effects of food variability and a
comparison with amphibian models. Ecology (Washington D C) 81(12):
Li, R. and S. H. Brawley 2004. Improved survival
under heat stress in intertidal embryos (Fucus spp.)
simultaneously exposed to hypersalinity and the effect of parental
thermal history. Marine Biology 144: 205-213.
Marshall, D. J., C. A. Styan, et al. 2000.
Intraspecific co-variation between egg and body size affects
fertilisation kinetics of free-spawning marine invertebrates. Marine
Ecology Progress Series 195: 305-309.
Marshall, D. J., and M. J. Keough. 2003. Sources of
variation in larval quality for free-spawning marine invertebrates: Egg
size and the local sperm environment. Invertebrate Reproduction and
Marshall, D. J., C. A. Styan, and M. J. Keough.
2002. Sperm environment affects offspring quality in broadcast spawning
marine invertebrates. Ecology Letters 5:173-176.
Meidel, S. K., and P. O. Yund. 2001. Egg longevity
and time-integrated fertilization in a temperate sea urchin (Strongylocentrotus
droebachiensis). Biological Bulletin 201:84-94.
Moran, A. L., and R. B. Emlet. 2001. Offspring size
and performance in variable environments: Field studies on a marine
snail. Ecology (Washington D C) 82:1597-1612.
Pechenik, J. A., T. Gleason, et al. 2001. Influence
of larval exposure to salinity and cadmium stress on juvenile
performance of two marine invertebrates (Capitella sp. I and
Crepidula fornicata). Journal of Experimental Marine Biology and
Ecology 264(1): 101-114.
Pechenik, J. A., and M. E. Rice. 2001. Influence of
delayed metamorphosis on postsettlement survival and growth in the
sipunculan Apionsoma misakianum. Invertebrate Biology 120:50-57.
Phillips, N. E. 2002. Effects of nutrition-mediated
larval condition on juvenile performance in a marine mussel. Ecology
(Washington D C) 83:2562-2574.
Phillips, N. E., and S. D. Gaines. 2002. Spatial
and temporal variability in size at settlement of intertidal mytilid
mussels from around Pt. Conception, California. Invertebrate
Reproduction and Development 41:171-177.
Podolsky, R. D. 2003. Integrating development and
environment to model reproductive performance in natural populations of
an intertidal gastropod. Integrative and Comparative Biology 43:450-458.
Qian, P.-Y., and J. A. Pechenik. 1998. Effects of
larval starvation and delayed metamorphosis on juvenile survival and
growth of the tube-dwelling polychaete Hydroides elegans (Haswell).
Journal of Experimental Marine Biology and Ecology 227:169-185.
Searcy, S. P., and S. Sponaugle. 2001. Selective
mortality during the larval-juvenile transition in two coral reef
fishes. Ecology (Washington D C) 82:2452-2470.
Sponaugle, S., and D. R. Pinkard. 2004. Impact of
variable pelagic environments on natural larval growth and recruitment
of the reef fish Thalassoma bifasciatum. Journal of Fish Biology
Strathmann, R. R. 1990. Why life histories evolve
differently in the sea. American Zoologist 30:197-207.
Thornber, C. S., and S. D. Gaines. 2003. Spatial
and temporal variation of haploids and diploids in populations of four
congeners of the marine alga Mazzaella. Marine Ecology Progress
Thornber, C. S., and S. D. Gaines. 2004. Population
demographics in species with biphasic life cycles. Ecology (Washington D
Vance, R. R. 1973. On reproductive strategies in
marine benthic invertebrates. American Naturalist 107:339-352.
Werner, E. E. 1988. Size, scaling, and the
evolution of complex life cycles. Pages 60-81 in B. Ebenman and
L. Persson, editors. Size-structured populations. Springer-Verlag,
Wilbur, H. M. 1980. Complex Life Cycles. Annual
Review of Ecology and Systematics 11:67-94.
Yund, P. O. 2000. How severe is sperm limitation in
natural populations of marine free-spawners? Trends in Ecology and
Yund, P. O., and S. K. Meidel. 2003. Sea urchin
spawning in benthic boundary layers: Are eggs fertilized before
advecting away from females? Limnology and Oceanography 48:795-801.