Erin Kelly - Crab Lab  St. Francis College, Loretto, PA     Blue
crab, callinectes sapidus , megalopae in the wild exhibit daily
swimming patterns with peak swimming at night (Forward et al
1996). Swimming patterns are very important to the blue crab in
their early life stages. However, considering that hatchery blue
crabs do not spend their early life cycle in the wild there is
concern that they will not have experience to the photoperiod
cues to ensure higher chances of survivorship. In this study,
swimming patterns of C2 and C4 hatchery raised crabs were
analyzed throughout a 24 hour period using video surveillance.
Two video sessions occurred in daylight and two during the
night. To see if there was any indication of endogenous swimming
patterns, there was an additional treatment of constant
darkness. Each treatment was done for four trials; each trial
consisting of a 24 hour period. Six crabs were used in each
trial (3 C2/3C4) and each placed in their own individual
plexiglass chamber (4.6cmX4.6cmX35cm).