1 The posterior pituitary lobe releases two hormones that are produced in the hypothalamus:  Oxytocin, which is responsible for stimulation of milk ejection (milk letdown) and for stimulation of uterine smooth muscle contraction at birth.
Crayfish and crawfish are crustaceans living in freshwater with a great resemblance of the lobsters. However, their size is smaller compared to the lobsters.
In the Eastern United States, crayfish is more common in the north, while crawdad is heard more in central and southwestern regions, and crawfish further south, although there are considerable overlaps.The study of crayfish is called astacology.n Australia many of the better-known crayfish are of the genus Cherax, and include the marron from Western Australia (now believed to be two species, Cherax tenuimanus and C. cainii), red-claw crayfish (Cherax quadricarinatus), common yabby (Cherax destructor) and western yabby (Cherax preissii).