Remora Life Cycles

Whether you call them sharksuckers or suckerfish, the remora is one of the ocean's most interesting residents. With its modified dorsal fin, it attaches itself to larger creatures and hitches a ride as they travel. In fact, some researchers suspect that the remora's life cycle depends on the very hosts it hitch-hikes upon.

  1. What Is a Remora?

    • A remora is a bony fish that is easily recognized by the suction pad on the top of its head. The pad is a modified fin that has changed over time into an effective suction device. When the fish wants to attach itself, it presses the pad against the host animal and raises the slats, creating a suction force so strong that fishermen have used remoras to haul in sea turtles.

      The common name "remora" is used to refer to both true remoras (in the genus Remora) and to the sharksuckers, more slednder fish that are in a different genus (Echeneis), but within the same family. There are two sepcies of sharksuckers: E. naucrates (the sharksucker) and E. neucratoides (the whitefin sharksucker). There are five species in the genus Remora: the remora (R. remora), the whalesucker (R. australis), the marlinsucker (R. osteochir), the spearfish remora (R. brachyptera) and the Celyonese remora (R. suctata).

    Reproduction

    • The sexes are separate in the remoras. Spawning occurs during the spring and early summer, although among species found in the Mediterranean, it may happen as late as autumn.

    Eggs and Young

    • After being fertilized externally, the eggs develop a durable shell that keeps them from drying out even if they wash onto the shore. Hatchlings are approximately 5 mm long. They live as part of the plankton for the first year, until they develop a sucker disk. Then, when they are about 3 cm long, they find a host and attach themselves. At this stage, they look similar to adults.

    Behavior

    • Remoras are best known for their ability to attach themselves to larger objects and travel long distances without using much energy. They have a symbiotic relationship with their hosts, but they aren't considered parasites; the host benefits from the remora's presence, because the fish eats parasites off the host's skin. Remoras can be found attached to whales, dolphins, sharks, rays, sea turtles and even ships and buoys.

    Geographic Range

    • Remoras are considered common in the world's oceans. They are found in the Atlantic, Pacific, and Indian Oceans, as well as in the Mediterranean. While usually found in the open ocean attached to their hosts, they are often found around coral reefs and in shallow inshore waters as well. One researcher reported finding a remora in the Hudson River attached to its host.