Hydrogen bonding is a kind of interaction dipole-dipole, that means that 2 molecules attract each other because the have partial charges.
In the picture we can see 4 molecules of water, red circles are oxygens and white circles are hydrogens. In this bonding, Oxygen due to its size, and atomic number is more electronegative than hydrogen, then in water molecule is formed a partial negative charge in oxygen and a partial positive charge in hydrogen.
Finally, because of this partial charge, one oxygen can bond to one hydrogen of another molecule.
The lateral line is a system of sense organs found in aquatic vertebrates, used to detect movement, vibration, and pressure gradients in the surrounding water. ... For example, fish can use their lateral line system to follow the vortices produced by fleeing prey