REPORT OF COMMISSIONERS OF INLAND FISHERIES. 127 



12 inches, and thinks that 10^ inches is the average length at sexual 

 maturity. 



8. Spawning Habits. 



The female lobster spawns once in two years. (Plate XIII.) The 

 eggs as a rule are laid during July and August, but some few lobsters 

 lay them later in the fall or winter. Hatching occurs the following 

 summer, at a time determined by the temperature of the water. In 

 Narragansett Bay it takes place from the first of May to the middle 

 of July. 



The lobster therefore carries its eggs for a period of 10 or 1 1 months 

 before they hatch. The number of eggs carried by a lobster varies 

 according to the size of the lobster; thus, according to Herrick, 

 assuming that an 8-inch lobster has on the average 5,000 eggs, 

 a 10-inch lobster would have 10,000, a 12-inch lobster 20,000, etc. 

 A lobster about 16 inches long would thus lay about 80,000 eggs. 

 This is, however, a low average. Lobsters 16 inches in length may 

 have 100,000 eggs. When the female lobster is bearing eggs, she 

 usually frequents some rocky shore where she can better protect 

 herself. 



9. Larval Stages. 



During the first two weeks which follow hatching, the lobster 

 passes through a larval period, during which it molts 3 times before 

 it takes on the general external appearance of the adult. In 

 each period it differs in form and habits as well as size. The main 

 characteristics are as follows:* 



First Stage. (Plate XXVI.) In this stage the lobster swims 

 rather feebly at the surface by the use of the outer branches of the 

 thoracic appendages. The last segment of the abdomen bears one 



*For a more complete account of the larval stages see article, Changes in Form and Color in 

 Successive Stages of the American Lobster, by P. B. Hadley in the Report of Commissionera 

 of Inland Fisheries of Rhode Island, made to the General Assembly, 1905. 



