Every spring the barn swallows return to the marine lab, not exactly on the first day of spring as in San Juan Capistrano, but I always know it’s really spring when they arrive. They build their mud nests against the eaves of the buildings, and spend time chattering at us from the fences. However, the…
Day: June 9, 2012
Veligers!
The marine gastropods and bivalves go through a larval stage called a veliger. This larva gets its name from the ciliated structure, called a velum, that the animal uses for swimming. Veligers have shells–1 for gastropods and 2 for bivalves–and can withdraw the velum into the shell. Even gastropods that lack shells as adults, such…