Date of Award

Fall 1977

Document Type


Degree Name

Master of Science (MS)


Ocean & Earth Sciences



Committee Director

Anthony J. Provenzano

Committee Member

H. H. White

Committee Member

R.E. Johnson

Committee Member

R. B. Manning

Call Number for Print

Special Collections LD4331.O35 M76


Larvae of Sguilla empusa were collected from the plankton and were reared in the laboratory to describe the pelagic larval development and the postlarval stage. Nine pelagic stages are passed through before the postlarval stage is attained.

The larvae reared for descriptive purposes were subjected to sixteen combinations of temperature and salinity to determine their tolerance to the two parameters. Larvae survived longer and molted more frequently when reared at 25°/oo and 20°C or 25°C, which corresponds to the natural conditions of the Chesapeake Bay when the larvae were collected.

A three year planktonic survey conducted in the lower region of the bay by the Virginia Institute of Marine Science was compared to a survey made at the baymouth in 1976. Sguilla empusa larvae appeared in the 1976 survey from the last week of July and persisted until the first week of October with a peak abundance occurring about the first week of September. The peak abundance in the lower region of the bay was 3.6 larvae/m3 in 1971 and 6.3 larvae/m3 in 1972. Four of the nine stages were not captured. Collections taken at the baymouth in 1976 with a half-meter net captured all stages and the peak abundance was determined to be 0.3 larvae/m3. The larvae are distributed throughout the lower Chesapeake Bay without being concentrated in any particular region.


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