Fecundity and spawning of the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Cape Cod, Massachusetts, USA
Figure 2: Egg diameter in the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Massachusetts during the spawning season (May 2003), and after the main spawning season in August 2003 and winter 2003-2004. (11.10Kb)
Figure 3: Egg number vs. female size in the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Massachusetts on different collection dates during the 2003 spawning season (14 May-17 June). (13.07Kb)
Figure 4: Potential fecundity (top) and realized fecundity (bottom), in the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Massachusetts. (10.74Kb)
Figure 5: . Percent of total eggs laid (realized fecundity divided by potential fecundity x 100) vs. size in Limulus polyphemus, in Pleasant Bay, Massachusetts. (10.13Kb)
Figure 6: Frequency histogram of number of eggs per batch in clutches excavated from marked nests after crabs finished spawning. (10.66Kb)
Figure 7: Percent of females (normalized by percent of population) by size recaptured in our mark and recapture study. (10.66Kb)
Figure 8: Egg number vs. female size in the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Massachusetts for crabs coming in on the rising tide, and those leaving the beach on the outgoing tide. (14.47Kb)
Figure 9: Size distribution of female Atlantic horseshoe crabs, Limulus polyphemus, in amplexus and presumed to be actively spawning, collected at our study site throughout the 2003 spawning season. (10.28Kb)
MetadataShow full item record
This study provided the first comprehensive analysis of Atlantic horseshoe crab (Limulus polyphemus) fecundity. Limulus appear to be determinate spawners, maturing all their eggs for the breeding season before spawning begins. On average, larger females held a larger number of eggs (63,500) than smaller females (14,500). By the end of the breeding season there was an average of 11,600 mature eggs female-1 left undeposited, regardless of female size. Larger females laid a higher percentage of the eggs they contained. Thus they not only contain more eggs, but are more effective at laying them as well. Size of spawning females ranged from about 185-300 mm prosomal width, with by far the highest concentration in the mid-size ranges. Although on an individual basis large females carry and lay the greatest number of eggs, mid-size crabs as a group contributed more to the horseshoe crab population in Pleasant Bay because they were more plentiful (net fecundity was highest for mid-size crabs). These results have implications for the management of this important species, which is harvested for bait, scientific, and biomedical uses. Incorporation of these results into models and other management tools can help predict growth rates, effects of size-selective harvest, reproductive value, and stable stage distribution of populations.
Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Blackwell for personal use, not for redistribution. The definitive version was published in Marine Ecology 27 (2006): 54-65, doi:10.1111/j.1439-0485.2005.00053.x.