The remoras , sometimes called suckerfish , is a ray-finned ( Echeneidae) family in the order of Perciformes. They grow up to 7-75 cm (2.8 inches-5.5 feet) in length. Their distinctive first dorsal fin takes the form of a modified oval organ, such as a sucker with a slat-like structure that opens and closes to create suction and holds the skin of a larger sea creature. The disc consists of a strong and flexible membrane that can be lifted and lowered to produce suction. By shifting backwards, the remora can increase suction, or may escape by swimming forward. Remoras are sometimes attached to small boats, and have been observed attached to divers as well. They swim well in themselves, with twisting, or curving motions.
Video Remora
Characteristics
Front dorsal fin remora have evolved to allow them to survive with suction for smooth surfaces and they spend their lives attached to host animals such as whales, turtles, sharks or rays. This may be a mutualistic arrangement because the remora can move around the host, removing ectoparasites and loose skin flakes, while benefiting from the protection provided by the host, and the constant flow of water across the gills. Although it was initially believed that remoras were fed particulate matter from the host's food, this has shown falsehood; in reality their food consists mainly of the feces of the host instead.
Maps Remora
Habitat
Remoras are tropical open sea inhabitants, but are sometimes found in temperate or coastal waters if they have been attached to large fish that have wandered into these areas. In mid-Atlantic, spawning usually occurs in June and July; in the Mediterranean, it occurs in August and September. The suction discs begin to appear when the young fish has a length of about 1 cm (0.4 inches). When the remora reaches about 3 cm (1.2 inches), the disk is completely formed and the remora can be attached to other animals. The lower lower jaw projected beyond the top, and the animal did not have a swim bladder.
Some remoras associate with specific host species. They are generally found attached to sharks, manta rays, whales, turtles, and dugongs (hence the common names of "sharksucker" and "whalesucker"). Smaller remora also bind fish such as tuna and swordfish, and some small remoras travel in the mouths or gills of large manta rays, sea mollas, swordfish and sailfish.
The relationship between remora and its host is most often regarded as one of commensalism, especially phoresy.
Physiology
Research in remora physiology has provided significant benefits to the understanding of the cost of ventilation in fish.
Remoras, like other fish, has two different ventilation modes. Ram ventilation is a process in which at higher speeds, the remora uses the force of water moving through it to create fluid movement in the gills. Or, at low speed, the remora will use an active venting form, in which the fish actively moves the liquid through its gills. To use active ventilation, fish should actively use energy to move liquids; However, determining the cost of this energy is usually tricky because of the movement of the fish when using one of the methods. As a result, remora has proved invaluable in discovering these cost differences (because they will stick to sharks or tubes, and therefore remain silent despite movement or lack of water). Experimental data from the study on remora found that the associated costs for active ventilation created a 3.7-5.1% increase in energy consumption to maintain the same amount of liquid flow as the fish obtained by using the ram ventilation.
Other research into remoriscist physiology arises as a result of a cross-taxa study, or using remora as an outsider for a particular evolutionary study. Regarding the latter case, remoras is used as an outgroup when investigating tetrodotoxin resistance in remoras, pufferfish, and related species, finding remoras (in particular Echeneis naucrates ) has resistance of 6.1-5.5 ÃÆ'â € < > 10 - 8 Ã, M.
Use for fishing
Some cultures use remoras to catch turtles. The rope or rope is fastened to the tail of the remora, and when the tortoise is seen, the fish is released from the boat; usually go straight to the tortoise and tie themselves to the tortoise shell, and then the remora and tortoise are captured. Small turtles can be pulled fully into the boat by this method, while larger ones are transported in the distance of the mount. This practice has been reported throughout the Indian Ocean, mainly from eastern Africa near Zanzibar and Mozambique, and from northern Australia near Cape York and Torres Strait.
Similar reports come from Japan and from America. The first few notes of "fish fisher" in Western literature stem from the stories of Christopher Columbus's second voyage. However, Leo Wiener considers Columbus accounts as apocryphal: what is taken for American accounts may, in fact, Columbus's record derive from the East Indies account, the goal he wants.
Mythology
In ancient times, remora was believed to have stopped the ship from sailing. In Latin, remora means "delay", while the genus name Echeneis comes from the Greek ?????, echein ("to hold ") and ????, naus (" a ship "). In an important note by Pliny the Elder, remora was blamed for Mark Antony's defeat at the Battle of Actium and, indirectly, for Caligula's death. The modern version of this story was given by Jorge Luis Borges at the Book of Imaginary Beings (1957).
Gallery
Timeline
See also
- List of fish families
- Ram-air intake
References
External links
- Photos tagged with "remora" on Flickr
- National Aquarium Articles About Remoras
Source of the article : Wikipedia
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