|Do intertidal snails spawn in the right places?|
Spight, T.M. (1977). Do intertidal snails spawn in the right places? Evolution 31(3): 682-691
In: Evolution. Society for the Study of Evolution: Lancaster. ISSN 0014-3820, more
Thais lamellosa embryos are unable to tolerate normal stresses of exposure during long low tide periods. Since they must remain fixed in place for 3-5 months, their survival depends upon the quality of the site the parents choose for spawning. Adults typically pick sites that allow relatively few embryos to survive (on average, only 57% and, regularly, none). Most of the 50 breeding groups used high mortality sites rather than nearby low mortality sites in each of six years. However, good sites for embryos are less suitable for spawning adults and newly hatched snails. Site usage patterns appear to be a compromise among the needs of these three life history stages; thus, in this situation, T. lamellosa is unable to optimize individual omponents of fitness.