Habitat use and life history of the vernal crayfish, Procambarus viaeviridis (Faxon, 1914), a secondary burrowing crayfish in Mississippi, USA
The Lower Mississippi Alluvial Valley (LMAV) is a species-rich region in North America, but its crayfish community has not been extensively sampled. We investigated the annual life cycle, habitat use, and some morphological characteristics of the vernal crayfish, Procambarus viaeviridis (Faxon, 1914), in the Dahomey National Wildlife Refuge, Bolivar County, Mississippi. The refuge was located in the central LMAV near the southern limit of the species. Crayfishes were captured in minnow and habitat traps in three seasonally flooded habitat types: wooded (bottomland hardwood forests), trail, and open habitats. Procambarus viaeviridis was the most abundant crayfish in these locations. The species had a two- to three-year lifespan, maturing at the end of the first or the beginning of the second year. Form I males were collected throughout the study, and the smallest had a postorbital carapace length of 15.8 mm. Abundance patterns of form I males and laboratory evidence suggested that breeding peaked in May. Small juveniles became abundant in January and February. No ovigerous females were collected; however, dissection of females held in captivity revealed 106–134 ovarian eggs per female. Pool depth, dissolved oxygen, and pH levels were related to the abundance of P. viaeviridis. Collections of P. viaeviridis were also common in pools containing the crayfishes P. acutus (Girard, 1852) or Cambarellus puer Hobbs, 1945.