Marinero de Agua Dulce

Marine science, biology of the seas, some dissident info and riot are here


Almost all cetaceans have a dorsal fin, which acts as a surface to control attitude and prevent roll, yaw, and side-slip.

 Among odontocetes, only right whale dolphins, the finless porpoise and both members of Monodontidae, the beluga or white whale and narwhal, lack a dorsal fin.

 Both beluga and narwhal possess, like finless porpoise, an irregular, notched dorsal ridge running along the caudal portion of the back, but the low (4–5 cm high) dorsal ridge of monodontids (also called a cuticular crest) appears insufficiently large to act as a suitable hydrodynamic control surface on these 4–5 m long odontocetes.

Researchers suggest that these fat pads, when elevated, form a pair of prominent vertical stabilizers that (perhaps in conjunction with the dorsal ridge) enhance an animal’s ability to control heading and limit roll.