Final answer:
Chromatophores use different hormones to disperse or aggregate their pigment granules. Melanophores disperse their pigment granules when stimulated by melanocyte-stimulating hormone (MSH) and erythrophores disperse their pigment when stimulated by adrenaline.
Step-by-step explanation:
Chromatophores, which are responsible for the color changes in animals like reptiles, fish, and cephalopods, use different hormones to disperse or aggregate their pigment granules. The specific hormones involved can vary depending on the type of chromatophore and the animal species.
One example is melanin, which is responsible for dark colors in melanophores. These cells disperse their pigment granules when stimulated by the hormone melanocyte-stimulating hormone (MSH), which is produced by the pituitary gland. When the pigment granules are aggregated, the cell appears darker.
Another example is erythrophores, which contain red pigment granules. These cells disperse their pigment when stimulated by the hormone adrenaline (epinephrine), which is produced by the adrenal glands. When the pigment granules are aggregated, the cell appears more red or pink.