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.
Crayfish, also called crawfish or crawdad, any of numerous crustaceans (order Decapoda, phylum Arthropoda) constituting the families Astacidae (Northern Hemisphere), Parastacidae, and Austroastracidae (Southern Hemisphere). They are closely related to the lobster.