EARLY DEVELOPMENT OF THE GRUBBY, MYOXOCEPHALUS AENAEUS (MITCHILL)

¹ University of Connecticut, Marine Research Laboratory, Noank, Connecticut, 06340

1. The grubby spawns over the four-month period of December through March in the Mystic River, Connecticut. The spherical, adhesive eggs are light green, red, white, and sometimes yellow in color and are found in small clumps attached to many different substrates.

2. Eggs were artificially fertilized on four occasions over a two-month period. The average water temperatures during development ranged from 4.6 to 6.0° C. The first cleavage occurred between 8 and 10 hours after fertilization and progressed to the multicellular stage at 33 to 96 hours. Gastrulation was first observed at about 174 hours, and the total developmental period varied from 34 to 57 days with most hatching between 40 and 44 days.

3. Prolarvae ranged between 4.7 and 6.3 mm TL, and the yolk sacs were absorbed in about five days. All fins were developed in approximately 55 days. During the period between 55 and 108 days, pigmentation was completed and the young took on the typical adult coloration.