Patterns of larval release by the Asian shore crab Hemigrapsus sanguineus : periodicity at diel and tidal frequencies

Journal of Shellfisheries Research, August, 2005 by Susan Park, Charles E. Epifanio, Raymond B. Iglay

* Corresponding author. E-mail: epi@udel.edu

SUSAN PARK, CHARLES E. EPIFANIO * AND RAYMOND B. IGLAY Graduate College of Marine Studies, University of Delaware, 700 Pilottown Rd., Lewes, Delaware 19958

TABLE 1.
Results of circular statistics analysis of larval release time relative
to the high tide. Zero degrees represents the time of high tide;
29[degrees] = 1 h past high tide; 58[degrees] = 2 h past high tide;
etc.

                                        First Zoea          Full
                       First Flap         Present         Release

n                    57                57              57
Mean vector          332.95[degrees]   3.11[degrees]   30.86[degrees]
Corresponding time
  from high tide     -0:13              0:02            0:15
r-vector             0.94              0.92            0.91
Standard error of
  mean               2.72[degrees]     3.10[degrees]   3.36[degrees]
Rayleigh's test of
  uniformity (p)     <0.01             <0.01           <0.01