THE EXTERNAL MORPHOLOGY OF THE THIRD AND FOURTH ZOEAL STAGES OF THE BLUE CRAB, CALLINECTES SAPIDUS RATHBUN

Abstract

The 3d zoea was reared in the laboratory from blue crab eggs. The 4th zoea was found in plankton near Cape Henry, Va. They differ from the 3d and 4th zoeae assigned to the blue crab by Churchill (1942) by lacking dorsal spines on the 5th abdominal segment and having an antennal exopodite no longer than in the 2d zoea. The 3d zoea has 8 swimming hairs on both maxillipeds, The 4th zoea has 8 hairs on the first maxilliped, 10 on the 2d. Churchill''s 3d, 4th and 5th zoeae do not belong to the blue crab.