The Life History of Procambarus hayi

The- life history of Procambarus hayi (Faxon) was studied for 2 years near State College, Miss. Seasonal and temporal changes within the populations were determined from periodic field samples and laboratory observations. The known geographic range of the species was defined and its preference for lentic and sluggish lotic waters was in- dicated. P. hayi bred in spring and summer and oviposited and hatched from late summer to autumn. A study of monthly ovarian egg development confirmed the period of oviposition. Oviposition and the first juvenile molts occurred within the burrow. Upon reaching the 3rd instar, juveniles became independent of the female and entered the open water from mid-September through Novem- ber. Most became adults during May and June of the following year after attaining a carapace length of 36.0 to 45.0 mm. Most crawfish reproduced 8 to 10 months after hatching, lived to reproduce again the following summer at 18 to 20 months, then died during the following autumn at approximately 24 months. A few apparently reproduced a third time and died after 36 months.