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Fauchald and Jumars (1979) described P. elegans as the most versatile of spionids
with respect to its feeding mechanisms. It can filter-feed by building a mucus net
within its tube, suspension-feed by trapping plankton with its palps or it can feed as a
selective deposit-feeder (Hannerz, 1956; Hempel, 1957; Sanders et al., 1962;
Fauchald and Jumars, 1979).
Reproduction in P. elegans is varied and different strategies are employed by different
populations. The species can reproduce sexually, producing either planktotrophic
larvae (3-6 setigers) which spend several weeks in the water column (Hannerz, 1956;
Anger et al., 1986) or benthic larvae (12-20 setigers, Hannerz, 1956; Hempel, 1957;
Rasmussen, 1973). The type of larvae produced mainly depends upon the population,
although some populations have been shown to produce both types depending on the
time of year (e.g., Gudmundsson, 1985; Ragnarsson, 1996). Furthermore, in most
studies investigating sexual reproduction in P. elegans the timing of reproductive
activity has been shown to vary. P. elegans can also reproduce asexually by
individuals fragmenting into several sections, each fragment being capable of forming
a new individual within 8 days at 20°C (Rasmussen, 1953). Fragmentation has been
experimentally shown to depend upon the population density and food supply
(Wilson, 1985) and in the field to depend upon season (Gudmundsson, 1985).
Asexual reproduction has been reported as being essentially the sole method of
reproduction in some populations (Hobson and Green, 1968). The reproductive
strategies of P. elegans are discussed in more detail in Chapter 3.
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