| Tarpon | |
|---|---|
 | |
| Atlantic tarpon | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Superorder: | Elopomorpha |
| Order: | Elopiformes |
| Family: | Megalopidae D. S. Jordan, 1923 |
| Genus: | Megalops Valenciennes, 1847 |
| Species | |
| |
| Synonyms [3] | |
| |
Tarpon are fish of the genus Megalops. They are the only members of the family Megalopidae. Of the two species, one (M. atlanticus) is native to the Atlantic, and the other (M. cyprinoides) to the Indo-Pacific Oceans.
The two species of tarpon are M. atlanticus (Atlantic tarpon) and M. cyprinoides (Indo-Pacific tarpon):
Both species are found in marine and freshwater habitats, usually ascending rivers to access freshwater marshes. [5] They are able to survive in brackish water, waters of varying pH, and habitats with low dissolved O
2 content due to their swim bladders, which they use primarily to breathe. They can also rise to the surface and take gulps of air, giving them a short burst of energy. The habitats of tarpon vary greatly with their developmental stages. Stage-one larvae are usually found in clear, warm, oceanic waters, relatively close to the surface. Stage-two and -three larvae are found in salt marshes, tidal pools, creeks, and rivers. Their habitats are characteristically warm, shallow, dark bodies of water with sandy mud bottoms. Tarpon commonly ascend rivers into fresh water. As they progress from the juvenile stage to adulthood, they return to the ocean's open waters, though many remain in freshwater habitats. [6] [7]
Fossils of this genus go back to the Cretaceous during the Albian stage 113.0 million years ago (Mya). [8] [9]
Tarpon grow to about 4–8 ft (1.2–2.4 m) long and weigh 60–280 lb (27–127 kg). They have dorsal and anal soft rays and bluish or greenish backs. Tarpons possess shiny, silvery scales that cover most of their bodies, excluding the head. They have large eyes with adipose eyelids and broad mouths with prominent lower jaws that jut out farther than the rest of the face. [4] [5] [6]
Tarpon breed offshore in warm, isolated areas. Females have high fecundity and can lay up to 12 million eggs at once. They reach sexual maturity once they are about 75–125 cm (30–50 in) in length. Spawning usually occurs in late spring to early summer. [6] Their three distinct levels of development usually occur in varying habitats. Stage one, or the leptocephalus stage, is completed after 20–30 days. It occurs in clear, warm oceanic waters, usually within 10–20 m of the surface. The leptocephalus shrinks as it develops into a larva; the most shrunken larva, stage two, develops by day 70. This is due to a negative growth phase followed by a sluggish growth phase. By day 70, the juvenile growth phase (stage three) begins, and the fish grows rapidly until sexual maturity. [4] [11]
Stage-one developing tarpon do not forage for food but instead absorb nutrients from seawater using integumentary absorption. Stage-two and -three juveniles feed primarily on zooplankton, insects, and small fish. As they progress in juvenile development, especially those developing in freshwater environments, their consumption of insects, fish, crabs, and grass shrimp increases. Adults are strictly carnivorous and feed on midwater prey; they hunt nocturnally and swallow their food whole. [6] [7]
The main predators of Megalops during stage-one and early stage-two development are other fish, depending on their size. Juveniles are subject to predation by other juvenile Megalops and piscivorous birds. They are especially vulnerable to birds such as ospreys or other raptors when they come to the surface for air due to the rolling manner in which they move to take in air, as well as the silver scales lining their sides. [12] Adults occasionally fall prey to sharks, porpoises, crocodiles, and alligators.
One of the unique features of Megalops is the swim bladder, which, in addition to controlling the buoyancy, can be used as an accessory respiratory organ. It arises dorsally from the posterior pharynx, and the respiratory surface is coated with blood capillaries with a thin epithelium over the top. This is the basis of the alveolar tissue found in the swim bladder and is believed to be one of the primary methods by which Megalops "breathes". This trait is essential due to the mangrove and marsh ecosystems the fish use as nursery habitats, which often have stagnant waters low in oxygen. The young fish will also ride the water into remote semi-landlocked ponds during storms and king tides, where they will stay from one to three years. These ponds, some of which are brackish or freshwater, often become so low in oxygen that tarpons and snooks are the only fish able to survive in these environments. The juveniles therefore face fewer competitors and predators, but need to breathe atmospheric oxygen to survive. [13] [14] The ability to breathe air is retained in the adults. Even if they live in more oxygenated marine coastal habitats, they have high rates of aerobic metabolism and also occasionally occur in hypoxic waters. [15] These fish are obligate air breathers and will die without sufficient access to the surface. Gas exchange occurs at the surface through a rolling motion commonly associated with tarpon sightings. This "breathing" is believed to be mediated by visual cues, and the frequency of breathing is inversely correlated to the dissolved O
2 content of the water in which they live. [6] [16]
Tarpon are considered some of the greatest saltwater game fishes, prized not only because of their great size but also because of their fight and spectacular leaping ability. After the International Game Fish Association took responsibility for fly fishing records in salt water (1978), fly fishing for tarpon became increasingly popular, despite declining populations (correlated with the decline of freshwater rivers flowing into the seas around Florida.) [17] Tarpon meat is not desirable, so most are released after being caught. [ citation needed ] Numerous tournaments are focused on catching tarpon. [18]
The Atlantic tarpon adapts well to water bodies in urban and suburban environments due to their tolerance for boat traffic and low water quality. Around humans, Atlantic tarpon are primarily nocturnal. [19]
Since tarpon are not commercially valuable as a food fish, very little has been documented concerning their geographical distribution and migrations. They inhabit both sides of the Atlantic Ocean, and their range in the eastern Atlantic has been reliably established from Senegal to the Congo. Tarpon inhabiting the western Atlantic are principally found to populate warmer coastal waters, primarily in the Caribbean, Gulf of Mexico, Florida, and the West Indies. Nonetheless, tarpon are regularly caught by anglers at Cape Hatteras and as far north as Nova Scotia, Bermuda, and south to Argentina. Scientific studies [20] indicate that schools of tarpon have routinely migrated through the Panama Canal from the Atlantic to the Pacific and back for over 70 years. However, they have not been found to breed in the Pacific Ocean. Nevertheless, anecdotal evidence from tarpon fishing guides and anglers would tend to validate this notion, as over the last 60 years, many small juvenile tarpon as well as mature giants have been caught and documented principally on the Pacific side of Panama at the Bayano River, the Gulf of San Miguel and its tributaries, Coiba Island in the Gulf of Chiriquí, and Piñas Bay in the Gulf of Panama. Since tarpon tolerate wide ranges of salinity throughout their lives and eat almost anything dead or alive, their migrations seemingly are only limited by water temperatures. [ citation needed ] Tarpon prefer water temperatures of 72 to 82 °F (22 to 28 °C); below 60 °F (16 °C) they become inactive, and temperatures under 40 °F (4 °C) can be lethal.[ citation needed ]
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root brak. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it can be damaging to the environment.
The frilled shark, also known as the lizard shark, is one of the two extant species of shark in the family Chlamydoselachidae. The frilled shark is considered a living fossil, because of its primitive, anguilliform (eel-like) physical traits, such as a dark-brown color, amphistyly, and a 2.0 m (6.6 ft)–long body, which has dorsal, pelvic, and anal fins located towards the tail. The common name, frilled shark, derives from the fringed appearance of the six pairs of gill slits at the shark's throat.
Hemiramphidae is a family of fishes that are commonly called halfbeaks, spipe fish or spipefish. They are a geographically widespread and numerically abundant family of epipelagic fish inhabiting warm waters around the world. The halfbeaks are named for their distinctive jaws, in which the lower jaws are significantly longer than the upper jaws. The similar viviparous halfbeaks have often been included in this family.
The silky shark, also known by numerous names such as blackspot shark, gray whaler shark, olive shark, ridgeback shark, sickle shark, sickle-shaped shark and sickle silk shark, is a species of requiem shark, in the family Carcharhinidae, named for the smooth texture of its skin. It is one of the most abundant sharks in the pelagic zone, and can be found around the world in tropical waters. Highly mobile and migratory, this shark is most often found over the edge of the continental shelf down to 50 m (164 ft). The silky shark has a slender, streamlined body and typically grows to a length of 2.5 m. It can be distinguished from other large requiem sharks by its relatively small first dorsal fin with a curving rear margin, its tiny second dorsal fin with a long free rear tip, and its long, sickle-shaped pectoral fins. It is a deep, metallic bronze-gray above and white below.
The common snook is a species of marine fish in the family Centropomidae of the order Perciformes. The common snook is also known as the sergeant fish or robalo. It was originally assigned to the sciaenid genus Sciaena;Sciaena undecimradiatus and Centropomus undecimradiatus are obsolete synonyms for the species.
The white marlin, also known as Atlantic white marlin, marlin, skilligalee, is a species of billfish that lives in the epipelagic zone of the tropical and subtropical Atlantic Ocean. They are found between the latitudes of 45° N and 45° S in waters deeper than 100 m. Even though white marlin are found in bodies of water that are deeper than 100 m they tend to stay near the surface. White marlin have been found near banks, shoals, and canyons, but they are not limited to those locations. They prefer warm surface temperatures greater than 22 °C.
The ladyfish or tenpounder is a species of fish in the genus Elops, the only genus in the monotypic family Elopidae.
The tarpon is a species of a large, herring-like fish of the genus Megalops.
Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that live on or near the bottom, and reef fish that are associated with coral reefs.
The bigeye tuna is a species of true tuna of the genus Thunnus, belonging to the wider mackerel family Scombridae. In Hawaiian, it is one of two species known as ʻahi, the other being the yellowfin tuna. Bigeye tuna are found in the open waters of all tropical and temperate oceans, but not in the Mediterranean Sea.
Slickheads, also known as nakedheads or smoothheads, are deep water fishes that belong to the family Alepocephalidae. They are most commonly found in the bathypelagic layer, which is approximately 3000m below the surface. They get their name from the lack of scales on their heads. Similarly, the scientific name is from the Greek ᾰ̓- (a-, "not"); λέπος (lepos, "scale"); and κεφαλή (kephalē, "head"). It has about 22 genera with ca. 96 species.
The Pacific ladyfish, also known as the Pacific tenpounder and machete, is a species of ray-finned fish in the genus Elops, the only genus in the monotypic family Elopidae. The Pacific ladyfish can be found throughout the southwest U.S. and other areas in the Pacific Ocean.
The Atlantic tarpon is a ray-finned fish that inhabits coastal waters, estuaries, lagoons, and rivers. It is also known as the silver king. It is found in the Atlantic Ocean, typically in tropical and subtropical regions, though it has been reported as far north as Nova Scotia and the Atlantic coast of southern France, and as far south as Argentina. As with all elopiformes, it spawns at sea. Its diet includes small fish and crustaceans.
The Indo-Pacific tarpon, also known as the oxeye herring or simply herring due to its superficial resemblance to the true herrings, of which it is not a member, is the smaller of the two species of tarpon and lives in Indo-Pacific waters.
The Lessepsian migration is the migration of marine species along the Suez Canal, usually from the Red Sea to the Mediterranean Sea, and more rarely in the opposite direction. When the canal was completed in 1869, fish, crustaceans, mollusks, and other marine animals and plants were exposed to an artificial passage between the two naturally separate bodies of water, and cross-contamination was made possible between formerly isolated ecosystems. The phenomenon is still occurring today. It is named after Ferdinand de Lesseps, the French diplomat in charge of the canal's construction.
The blackfin tuna is a species of tuna in the family Scombridae. It is occasionally referred to as the Bermuda tuna, blackfinned albacore, or deep bodied tunny. They are the smallest tuna species in the genus Thunnus, generally growing to a maximum of 100 cm (39 in) in length and weighing 21 kg (46 lb).
The Gobiiformes are an order of fish that includes the gobies and their relatives. The order, which was previously considered a suborder of Perciformes, is made up of about 2,211 species that are divided between seven families. Phylogenetic relationships of the Gobiiformes have been elucidated using molecular data. Gobiiforms are primarily small species that live in marine water, but roughly 10% of these species inhabit fresh water. This order is composed chiefly of benthic or burrowing species; like many other benthic fishes, most gobiiforms do not have a gas bladder or any other means of controlling their buoyancy in water, so they must spend most of their time on or near the bottom. Gobiiformes means "goby-like".
A warm core ring is a type of mesoscale eddy which forms and breaks off from an ocean current, such as the Gulf Stream or the Kuroshio Current. The ring is an independent circulatory system of warm water that can persist for several months before losing its distinctive identity. Warm core rings can be detected using infrared satellites or sea height anomalies resulting from and are easily identifiable against the surrounding colder waters. In addition, warm core rings are also distinguished by their low levels of biological activity. This type of system is thought to have helped develop several hurricanes, most notably Hurricane Katrina, into significantly stronger storms due to the abundance of warmer ocean water reaching down to a significant depth, which in turn fuels and intensifies the hurricane. Warm core rings are also known for affecting wildlife, having the capacity to bring wildlife from typically warm waters to areas typically dominated by cold waters.
The Atlantic needlefish is a common demersal needlefish species common in marinas and other areas with minimal currents. Its extremely long jaw and body set this fish apart from other predators. Atlantic needlefish are found from Maine to Brazil and have been known to venture into fresh water for short periods.
The Pacific spiny lumpsucker is a species of bony fish in the family Cyclopteridae.
Elopomorph genera | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||||||||||
| Authority control databases: National |
|---|
