In bony fishes,<unk>  is the principal hormone that regulate calcium level. Even though other calcium-decreasing hormone, calcitonin, is also present, these fishes require more efficient hormone as calcium rapidly enters into their blood through their gills and intestinal wall. Hence, the target sites of<unk>  are gill and intestine, where uptake (absorption) of calcium is directly inhibited. Increase in the serum calcium triggers the release of<unk> . Unlike calcitonin, it also regulates phosphate level. It inhibits excretion of phosphate from the kidney.
Stanniocalcin
Modulin
Hippulin
Calcitriol
Erdosteine
Hydroxyapatite
Demineralized bone matrix
Thyroglobulin