Mobilization of Calcium Across Mineralized Tissues in Yellow Perch, Perca flavescens

Bones in many higher teleost fish, such as percids and centrarchids, lack osteocytes that function as both chemo- and mechano-sensors, and thus, are not actively involved in homeostasis of blood calcium level. Nonetheless, the vertebrae of yellow perch, Perca flavescens (P. flavescens), living in darker and low calcium (Ca) water, have demonstrated adaptive modeling and remodeling of vertebrae to be more mineralized and thus enhance transmission of the axial muscle torque into the thrust force for the C-start predator escape behavior. The prey-predator interaction is expected to occur at closer range between prey fish and predator fish in darker water, and therefore, darker water may impose greater selection pressure on maximizing the escape performance. It is not well-known what serves as the Ca reservoir for calcium homoeostasis and bone modeling and remodeling in teleost fish. In this study, we used an Agilent 4200 MP-AES (microwave induced plasma atomic emission spectrometer) and determined the concentration of mineralized Ca in several mineralized tissues (vertebrae, scales, and skin) of P. flavescens living in darker and low Ca water, as well as P. flavescens residing in water with high visibility and high Ca bioavailability. More specifically, specific regions of the sample’s vertebral column were analyzed (UT, MT, LT, CP). The results indicated no significance between vertebral samples of the different populations as shown by a non-parametric Mann-Whitney U test. However, within P. flavescens samples living in the darker environment, CP vertebrae had higher Ca concentrations than UT vertebrae, suggesting an increased mineralization for increased thrust speed.