. Commercial fisheries review. Fisheries; Fish trade. June 1958 COMMERCIAL FISHERIES REVIEW 11 ceases (Robertson 1938; Van Engel, personal observation). Occasionally in late Au- gust or early September large numbers of me galops appear along the ocean front at Virginia Beach, biting swimmers with their minute pinching claws and giving rise 'to numerous complaints of "water fleas" (Truitt 1939). No explanation has been ^>- 1^^ offered for these concentrations of meg- â¢â ^(^ #il»i ^IB alops in breaking waves. The megalops stage lasts only a few days. When it molts the "first
. Commercial fisheries review. Fisheries; Fish trade. June 1958 COMMERCIAL FISHERIES REVIEW 11 ceases (Robertson 1938; Van Engel, personal observation). Occasionally in late Au- gust or early September large numbers of me galops appear along the ocean front at Virginia Beach, biting swimmers with their minute pinching claws and giving rise 'to numerous complaints of "water fleas" (Truitt 1939). No explanation has been ^>- 1^^ offered for these concentrations of meg- â¢â ^(^ #il»i ^IB alops in breaking waves. The megalops stage lasts only a few days. When it molts the "first crab" appears, with the typical body shape of an adult crab. Migration of large numbers of adult females past the Capes to the ocean, and subsequent appearance of megalops along the ocean beaches, suggest that a sub- stantial amount of spawning may occur outside the Bay. As yet, no estimate of the importance of this ocean spawning in providing crabs to the Chesapeake Bay supply has been possible. Early in August, when many crabs reach the "first crab" stage, one-tenth of an inch wide, they begin migrating from the southern part of the Bay and the ocean adjacent to the Capes into the rivers and to the upper Bay. The first wave of migration reaches the rivers on the western shore of Virginia about the third week of August, and crabs one-quarter to one-half inch in width are commonly seen during September and October. In most years small crabs do not miigrate farther north than the mouth of the Potomac River before cold weather begins, and most of them remain in Virginia waters over winter. Movement up-Bay is resumed the following spring. Crabs one-half to one inch in width usually are first seen in the upper Bay in late April or May the year following the hatch (Hay 1905; Truitt 1934, 1939). GROWTH. MEGALOPS OF THE BLUE CRAB. Growth is rapid and adult size may be reached one year to a year and a half after hatching (fig. 6). Those hatched early, in late May, b
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