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 Appearance. The crayfish is typical of most shrimplike crustaceans and is characterised by a joined head and thorax, or midsection, and a segmented body, which is sandy yellow, green, white, pink or dark brown in colour. Crayfish are usually about 7.5 cm (3 inches) long.Among the smallest is the 2.5-centimetre-long Cambarellus diminutus of the south-eastern United States. Among the largest is Astacopsis gouldi of Tasmania; its length may reach 40 cm and its weight about 3.5 kg (8 pounds).he crayfish is typical of most shrimplike crustaceans and is characterised by a joined head and thorax, or midsection, and a segmented body, which is sandy yellow, green, white, pink or dark brown in colour. Crayfish are usually about 7.5 cm (3 inches) long.