Bonnie Hersman, age 13, of Ivydale, West Virginia, for her question:
How does a lobster take care of her young?
Most shellfish do not care whether their little ones live or die. Mrs. Lobster, however, has enough character to attack her foes and she is smart enough to bestow a great deal of motherly care on her offspring.
Lobsters hatch from eggs . eggs that become fertilized when sperm cells from the males unite with special cells from the females. A mother lobster spends almost half of her life tending those precious eggs and she produces only one brood of youngsters in two years. If she is a smallish lobster about five years old, there may be about 10,000 youngsters in the brood. As she grows older and bigger, her families increase. A mature lady lobster may produce 100,000 young ones at a time.
A grown lobster has foul pairs of walking legs and an over sized pair:" of claws. He also has a number of small appendages on the underside of his•. tail. These are his swimmerets and when his walking legs are not on solid ground they are used as swimming paddles. Mrs. Lobster uses her swimmerets for swimming and also to store sperm cells, maybe as long as two years. When time comes to lay her immense brood of eggs, the male cells to fertilize them are right at hand.
The fertilized eggs are small and round and the mother lobster secretes a strong glue to cement them firmly to her body. When the job is done, the swimmerets along the underside of her tail are encrusted with thousands and thousands of tiny eggs. She is called a berried lobster, no doubt because she seems to be covered with berries. This berried stage may last for ten or eleven months. Through the first summer, the eggs make little progress. As winter chills the water, they stop their development altogether. All this time, the mother is very aware of the precious eggs cemented to her body. When eels and other hungry foes approach, she bends her tail under to form a protective pocket. Her merciless claws are always ready to launch an attack to protect her unborn babes. lobster for prefers to have them hatch during the darkness and the Job may last through seven nights. As each group of wriggly youngsters emerges, she flicks and waves her tail to scatter them far and wide through the water. Then the dutiful mother waits until next spring to start a new family.
The infant lobsters do not resemble their crusty parents at all. In fact, they look somewhat like polliwog frogs. It takes three of them to measure an inch and each has a pair of startling green eyes. The young larvae swim around freely for a while, devouring drifting morsels of food. After two weeks they have molted their skins three times and grown to half¬ inch size. They now look somewhat like little lobsters. After a year and maybe 14 more moltings they may be three inches long.