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.
Crabs and crayfish are crustaceans, a subdivision of arthropods â the large group of animals without backbones (invertebrates) that includes insects, spiders, mites, scorpions and springtails.