Swordfish

Last updated

Swordfish
Temporal range: 3–0  Ma
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
↓
Early Pliocene to Present [1]
Xiphias gladius Linnaeus, 1758 2599925021.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Istiophoriformes
Family: Xiphiidae
Swainson, 1839
Genus: Xiphias
Linnaeus, 1758
Species:
X. gladius
Binomial name
Xiphias gladius
World distribution Swordfish.svg
Global distribution of swordfish in blue
Synonyms [3]
  • Xiphias imperator Bloch & Schneider, 1801
  • Tetrapterus imperator(Bloch & Schneider, 1801)
  • Xiphias rondeletii Leach, 1814
  • Phaethonichthys tuberculatus Nichols, 1923
  • Xiphias estaraPhillipps, 1932
  • Xiphias thermaicusSerbetis, 1951

The swordfish (Xiphias gladius), also known as the broadbill [4] in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood. These fish are found widely in tropical and temperate parts of the Atlantic, Pacific, and Indian Oceans, and can typically be found from near the surface to a depth of 550 m (1,800 ft), and exceptionally up to depths of 2,234 m. [2] They commonly reach 3 m (10 ft) in length, and the maximum reported is 4.55 m (14 ft 11 in) in length and 650 kg (1,430 lb) in weight. [3] [5]

Contents

They are the sole member of their family, Xiphiidae. [6]

Taxonomy and etymology

The swordfish is named after its long pointed, flat bill, which resembles a sword. The species name, Xiphias gladius, derives from Greek ξιφίας (xiphias, "swordfish"), itself from ξίφος (xiphos, "sword") and from Latin gladius ("sword"). [5] This makes it superficially similar to other billfish such as marlin, but upon examination, their physiology is quite different and they are members of different families. [7]

Several extinct genera are known, such as a large sized Xiphiorhynchus and Aglyptorhynchus . [8] Unlike modern taxa these have equally long lower jaws.[ citation needed ]

Description

They commonly reach 3 m (10 ft) in length, and the maximum reported is 4.55 m (14 ft 11 in) in length and 682 kg (1,500 lb) in weight. [3] [5] [9] The International Game Fish Association's all-tackle angling record for a swordfish was a 536 kg (1,182 lb) specimen taken off Chile in 1953. [2] Females are larger than males, and Pacific swordfish reach a greater size than northwest Atlantic and Mediterranean swordfish. [5]

They reach maturity at 4–5 years of age and the maximum age is believed to be at least 9 years. [5] The oldest swordfish found in a recent study were a 16-year-old female and 12-year-old male. Swordfish ages are derived, with difficulty, from annual rings on fin rays rather than otoliths, since their otoliths are small in size. [10]

Temperature regulation

Swordfish are ectothermic animals; however, along with some species of sharks, they have special organs next to their eyes to heat their eyes and brains. [11] [ page needed ] Their eyes are heated to temperatures measured between 10 and 15 °C (18 and 27 °F) above the surrounding water temperature, this heating greatly improves their vision, and consequently improves their ability to catch prey. [12] [13]

The swordfish is one of 22 fish, including the marlin, tuna, and some sharks, known to have a mechanism that conserves heat. [12] [13]

Behavior and ecology

Swordfish skeleton at the National Museum of Natural History, Washington, DC Swordfish skeleton.jpg
Swordfish skeleton at the National Museum of Natural History, Washington, DC

Movements and feeding

The popular belief of the "sword" being used as a spear is misleading. Their nose is more likely used to slash at its prey to injure the prey animal, to make for an easier catch. [5] The use as an offensive spear in case of dangers against large sharks or animals is under review.

Mainly, the swordfish relies on its great speed and agility in the water to catch its prey. It is no doubt among the fastest fish, but the basis for the frequently quoted speed of 100 km/h (60 mph) is unreliable. [14] Research on related marlin ( Istiophorus platypterus ) suggest a maximum value of 36 km/h (22 mph) is more likely. [15]

Swordfish are not schooling fish. They swim alone or in very loose aggregations, separated by as much as 10 m (35 ft) from a neighboring swordfish. They are frequently found basking at the surface, airing their first dorsal fin. Boaters report this to be a beautiful sight, as is the powerful jumping for which the species is known. This jumping, also called breaching, may be an effort to dislodge pests, such as remoras or lampreys.[ citation needed ]

A deep-diving swordfish, photographed in the eastern Gulf of Mexico at 701 meters below the surface. Swordfish natural environment.jpg
A deep-diving swordfish, photographed in the eastern Gulf of Mexico at 701 meters below the surface.

Swordfish prefer water temperatures between 18 and 22 °C (64 and 72 °F), [2] but have the widest tolerance among billfish, and can be found from 5 to 27 °C (41 to 81 °F). [5] This highly migratory species typically moves towards colder regions to feed during the summer. [5] Swordfish feed daily, most often at night, when they rise to surface and near-surface waters in search of smaller fish. During the day, they commonly occur to depths of 550 m (1,800 ft; 300 fathoms) and have exceptionally been recorded as deep as 2,878 m (9,442 ft; 1,574 fathoms). [2] Adults feed on a wide range of pelagic fish, such as mackerel, barracudinas, silver hake, rockfish, herring, and lanternfishes, but they also take demersal fish, squid, and crustaceans. [3] [5] In the northwestern Atlantic, a survey based on the stomach content of 168 individuals found 82% had eaten squid and 53% had eaten fish, including gadids, scombrids, butterfish, bluefish, and sand lance. [16] Large prey are typically slashed with the sword, while small are swallowed whole. [5]

Threats and parasites

Almost 50 species of parasites have been documented in swordfish. In addition to remoras, lampreys, and cookiecutter sharks, this includes a wide range of invertebrates, such as tapeworms, roundworms, Myxozoans and copepods. [5] [17] A comparison of the parasites of swordfish in the Atlantic and in the Mediterranean indicated that some parasites, particularly Anisakis spp. larvae identified by genetic markers, could be used as biological tags and support the existence of a Mediterranean swordfish stock. [18]

Stuffed broadbill swordfish Swordfish-0046.jpg
Stuffed broadbill swordfish

Fully adult swordfish have few natural predators. Among marine mammals, killer whales sometimes prey on adult swordfish. [5] The shortfin mako, an exceptionally fast species of shark, sometimes take on swordfish; dead or dying shortfin makos have been found with broken-off swords in their heads, revealing the danger of this type of prey. [19] Juvenile swordfish are far more vulnerable to predation, and are eaten by a wide range of predatory fish. [5] [20] Intensive fishery may be driving swordfishes and sharks into harder competition for reduced amounts of prey and therefore pitting them to fight more. [20]

Human fishery is a major predator of swordfishes. The annual reported catch in 2019 of the North Atlantic swordfish amounted to a total of 1.3 million kilograms (2.9 million pounds). [21]

Breeding

In the North Pacific, batch spawning mainly occurs in water warmer than 24 °C (75 °F) during the spring and summer, and year-round in the equatorial Pacific. [2] In the North Atlantic, spawning is known from the Sargasso Sea, [22] and in water warmer than 23 °C (73 °F) and less than 75 m (246 ft; 41 fathoms) deep. [2] Spawning occurs from November to February in the South Atlantic off southern Brazil. [2] Spawning is year-round in the Caribbean Sea and other warm regions of the west Atlantic. [5]

Large females can carry more eggs than small females, and between 1 million and 29 million eggs have been recorded. [2] The pelagic eggs measure 1.6–1.8 mm (1⁄16–5⁄64 in) in diameter and 2+1⁄2 days after fertilization, the embryonic development occurs. [22] [5] The surface-living and unique-looking larvae are 4 mm (5⁄32 in) long at hatching. [3] [5] The bill is evident when the larvae reach 1 cm (3⁄8 in) in length. [3]

Fisheries

Felucca used in the Strait of Messina to hunt swordfish Barca pescespada 3.jpg
Felucca used in the Strait of Messina to hunt swordfish
Global capture of swordfish in tonnes reported by the FAO, 1950-2009 Fisheries capture of Xiphias gladius.png
Global capture of swordfish in tonnes reported by the FAO, 1950–2009

Swordfish were harvested by a variety of methods at small scale (notably harpoon fishing) until the global expansion of long-line fishing. They have been fished widely since ancient times in places such as the Strait of Messina, where they are still fished with traditional wooden boats called feluccas and are part of the cuisine in that area. [24] [25] [26]

Swordfish are vigorous, powerful fighters. Although no unprovoked attacks on humans have been reported, swordfish can be very dangerous when harpooned. They have run their swords through the planking of small boats when hurt. In 2015, a Hawaiian fisherman was killed by a swordfish after attempting to spear the animal. [27]

Recreational fishing

Recreational fishing has developed a subspecialty called swordfishing. Because of a ban on long-lining along many parts of seashore, swordfish populations are showing signs of recovery from the overfishing caused by long-lining along the coast.

Various ways are used to fish for swordfish, but the most common method is deep-drop fishing, since swordfish spend most daylight hours very deep, in the deep scattering layer. The boat is allowed to drift to present a more natural bait. Swordfishing requires strong fishing rods and reels, as swordfish can become quite large, and it is not uncommon to use 2.5 kg (5 lb) or more of weight to get the baits deep enough during the day, up to 460 m (1,500 ft) is common. [28] Night fishing baits are usually fished much shallower, often less than 90 m (300 ft; 50 fathoms). Standard baits are whole mackerel, herring, mullet, bonito, or squid; one can also use live bait. Imitation squids and other imitation fish lures can also be used, and specialized lures made specifically for swordfishing often have battery-powered or glow lights. Even baits are typically presented using glow sticks or specialized deepwater-proof battery operated lights.

As food

Swordfish are classified as oily fish. [29] Many sources, including the United States Food and Drug Administration, warn about potential toxicity from high levels of methylmercury in swordfish. [30] [31] The FDA recommends that young children, pregnant women, and women of child-bearing age not eat swordfish. [32]

The flesh of some swordfish can acquire an orange tint, reportedly from their diet of shrimp or other prey. Such fish are sold as "pumpkin swordfish", and command a premium over their whitish counterparts.[ citation needed ]

Swordfish is a particularly popular fish for cooking. Since swordfish are large, meat is usually sold as steaks, which are often grilled. Swordfish meat is relatively firm, and can be cooked in ways more fragile types of fish cannot (such as over a grill on skewers). The color of the flesh varies by diet, with fish caught on the East Coast of North America often being rosier.

Kashrut

A dispute exists as to whether swordfish should be considered a kosher fish according to the laws of kashrut. Standard Orthodox opinion is that swordfish is not kosher, while Conservative Judaism does consider swordfish kosher. All kosher fish must have both fins and scales. The Talmud and the Tosefta are believed by some to present swordfish ("achsaftias") as an example of a kosher fish without scales because swordfish are born with scales they later shed once attaining a length of about 1 meter. The 17th-century Turkish Sephardi halakhic authority Rabbi Chaim ben Yisrael Benvenisti wrote that "It is a widespread custom among all Jews to eat the fish with the sword, known in vernacular as fishei espada, even though it does not have any scales. Because it is said that when it comes out of the water, due to its anger, it shakes and throws off its scales." A 1933 list of kosher fish published by the Agudas HaRabbonim includes swordfish. The following year, Rabbi Yosef Kanowitz published the same list of kosher fish with swordfish still included. Swordfish was widely considered kosher by halakhic authorities until the 1950s. Orthodox opinion began to shift in 1951, when Rabbi Moshe Tendler examined swordfish and decided it was not kosher due to the lack of scales. Tendler's opinion provoked strong debate among halakhic authorities during the 1960s. [33] [34] Among Mediterranean Jews there was a longstanding minhag of considering swordfish kosher. Swordfish was and possibly still is consumed by Jews in Italy, Turkey, Gibraltar, Morocco, Tunisia, and England. Due to Tendler's opinion, swordfish are generally not considered kosher by Orthodox Jews in the United States and Israel. [35]

Conservation status

Swordfish on deck during long-lining operations Xiphias gladius.jpg
Swordfish on deck during long-lining operations

In 1998, the U.S. Natural Resources Defense Council and SeaWeb hired Fenton Communications to conduct an advertising campaign to promote their assertion that the swordfish population was in danger due to its popularity as a restaurant entree. [36]

The resulting "Give Swordfish a Break" promotion was wildly successful, with 750 prominent U.S. chefs agreeing to remove North Atlantic swordfish from their menus, and also persuaded many supermarkets and consumers across the country.

The advertising campaign was repeated by the national media in hundreds of print and broadcast stories, as well as extensive regional coverage. It earned the Silver Anvil award from the Public Relations Society of America, as well as Time magazine's award for the top five environmental stories of 1998.

Subsequently, the U.S. National Marine Fisheries Service proposed a swordfish protection plan that incorporated the campaign's policy suggestions. Then-US President Bill Clinton called for a ban on the sale and import of swordfish and in a landmark decision by the federal government, 343,600 km2 (132,670 sq mi) of the Atlantic Ocean were placed off-limits to fishing as recommended by the sponsors.

In the North Atlantic, the swordfish stock is fully rebuilt, with biomass estimates currently 5% above the target level. [37] No robust stock assessments for swordfish in the northwestern Pacific or South Atlantic have been made, and data concerning stock status in these regions are lacking. These stocks are considered unknown and a moderate conservation concern. The southwestern Pacific stock is a moderate concern due to model uncertainty, increasing catches, and declining catch per unit effort. Overfishing is likely occurring in the Indian Ocean, and fishing mortality exceeds the maximum recommended level in the Mediterranean, thus these stocks are considered of high conservation concern. [38]

In 2010, Greenpeace International added the swordfish to its seafood red list. [39]

Extinct

In culture

Related Research Articles

<span class="mw-page-title-main">Bluefish</span> Species of marine pelagic fish (Pomatomus saltatrix)

The bluefish is the only extant species of the family Pomatomidae. It is a marine pelagic fish found around the world in temperate and subtropical waters, except for the northern Pacific Ocean. Bluefish are known as tailor in Australia and New Zealand, elf and shad in South Africa. It is a popular gamefish and food fish.

<span class="mw-page-title-main">Shortfin mako shark</span> Species of shark

The shortfin mako shark, also known as the shortfin mako, blue pointer, or bonito shark, is a large mackerel shark. It is commonly referred to as the mako shark, as is the longfin mako shark. The shortfin mako can reach a size of 4 m (13 ft) in length and weigh 570 kg (1,260 lb). The species is classified as Endangered by the IUCN.

<span class="mw-page-title-main">Yellowfin tuna</span> Species of fish

The yellowfin tuna is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide.

<span class="mw-page-title-main">Porbeagle</span> Species of shark (Lamna nasus)

The porbeagle or porbeagle shark is a species of mackerel shark in the family Lamnidae, distributed widely in the cold and temperate marine waters of the North Atlantic and Southern Hemisphere. In the North Pacific, its ecological equivalent is the closely related salmon shark (L. ditropis). It typically reaches 2.5 m (8.2 ft) in length and a weight of 135 kg (298 lb); North Atlantic sharks grow larger than Southern Hemisphere sharks and differ in coloration and aspects of life history. Gray above and white below, the porbeagle has a very stout midsection that tapers towards the long, pointed snout and the narrow base of the tail. It has large pectoral and first dorsal fins, tiny pelvic, second dorsal, and anal fins, and a crescent-shaped caudal fin. The most distinctive features of this species are its three-cusped teeth, the white blotch at the aft base of its first dorsal fin, and the two pairs of lateral keels on its tail.

<span class="mw-page-title-main">White marlin</span> Species of fish

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.

<span class="mw-page-title-main">Atlantic blue marlin</span> Species of fish

The Atlantic blue marlin is a species of marlin endemic to the Atlantic Ocean. It is closely related to, and usually considered conspecific with, the Indo-Pacific blue marlin, then simply called blue marlin. Some authorities consider both species distinct.

<span class="mw-page-title-main">Billfish</span> Group of fishes

The billfish are a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than 4 m (13 ft). Extant billfish include sailfish and marlin, which make up the family Istiophoridae; and swordfish, sole member of the family Xiphiidae. They are often apex predators which feed on a wide variety of smaller fish, crustaceans and cephalopods. These two families are sometimes classified as belonging to the order Istiophoriformes, a group which originated around 71 million years ago in the Late Cretaceous, with the two families diverging around 15 million years ago in the Late Miocene. However, they are also classified as being closely related to the mackerels and tuna within the suborder Scombroidei of the order Perciformes. However, the 5th edition of the Fishes of the World does recognise the Istiophoriformes as a valid order, albeit including the Sphyraenidae, the barracudas.

<span class="mw-page-title-main">Pelagic fish</span> Fish in the pelagic zone of ocean waters

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.

<span class="mw-page-title-main">Marlin fishing</span>

Marlin fishing or billfishing is offshore saltwater game fishing targeting several species of fast-swimming pelagic predatory fish with elongated rostrum collectively known as billfish, which include those from the families Istiophoridae and Xiphiidae (swordfish). It is considered by some fishermen to be a pinnacle of big-game fishing, due to the size, speed and power of the billfish and their relative elusiveness.

<span class="mw-page-title-main">Common thresher</span> Species of shark

The common thresher, also known as Atlantic thresher, is the largest species of thresher shark, family Alopiidae, reaching some 6 m (20 ft) in length. About half of its length consists of the elongated upper lobe of its caudal fin. With a streamlined body, short pointed snout, and modestly sized eyes, the common thresher resembles the pelagic thresher. It can be distinguished from the latter species by the white of its belly extending in a band over the bases of its pectoral fins. The common thresher is distributed worldwide in tropical and temperate waters, though it prefers cooler temperatures. It can be found both close to shore and in the open ocean, from the surface to a depth of 550 m (1,800 ft). It is seasonally migratory and spends summers at lower latitudes.

<span class="mw-page-title-main">Longfin mako shark</span> Species of shark

The longfin mako shark is a species of mackerel shark in the family Lamnidae, with a probable worldwide distribution in temperate and tropical waters. An uncommon species, it is typically lumped together under the name "mako" with its better-known relative, the shortfin mako shark. The longfin mako is a pelagic species found in moderately deep water, having been reported to a depth of 220 m (720 ft). Growing to a maximum length of 4.3 m (14 ft), the slimmer build and long, broad pectoral fins of this shark suggest that it is a slower and less active swimmer than the shortfin mako.

Stomias boa boa, also called the scaly dragonfish or boa dragonfish, is a subspecies of abyssal barbeled dragonfish of the family Stomiidae. It is found at great depths worldwide in tropical to temperate oceans but is absent from the northern Pacific and northwest Atlantic Oceans.

<span class="mw-page-title-main">Night shark</span> Species of shark

The night shark is a species of requiem shark, in the family Carcharhinidae, found in the temperate and tropical waters of the Atlantic Ocean. An inhabitant of the outer continental shelf and upper continental slope, this shark most commonly occurs at depths of 50–600 m (160–1,970 ft) and conducts a diel vertical migration, spending the day in deeper water and moving into shallower waters at night. Off northeastern Brazil, large numbers congregate around seamounts of varying depths. A slender, streamlined species, the night shark typically reaches a length of 2 m (6.6 ft). It can be identified by its long, pointed snout and large, green eyes, and is dark grayish blue or brown above and white below.

<span class="mw-page-title-main">Portuguese dogfish</span> Species of shark

The Portuguese dogfish or Portuguese shark, is a species of sleeper shark of the family Somniosidae. This globally distributed species has been reported down to a depth of 3,675 m (12,057 ft), making it the deepest-living shark known. It inhabits lower continental slopes and abyssal plains, usually staying near the bottom. Stocky and dark brown in color, the Portuguese dogfish can be distinguished from similar-looking species by the small spines in front of its dorsal fins. Its dermal denticles are also unusual, resembling the scales of a bony fish. This species typically reaches 0.9–1 m (3.0–3.3 ft) in length; sharks in the Mediterranean Sea are much smaller and have distinct depth and food preferences.

<span class="mw-page-title-main">Little tunny</span> Species of fish

The little tunny, also known as the false albacore, little tuna, bonita, or erroneously as the blue bonito, is a species of tuna in the family Scombridae. It can be found in the Atlantic Ocean and the Mediterranean and Black seas; in the western Atlantic, it ranges from Brazil to the New England states. The little tunny is a pelagic fish that can be found regularly in both offshore and inshore waters, and it is classified as a highly migratory species. The little tunny is best identified by the "worm-like" markings on its back and the dark spots appearing between its pectoral and ventral fins.

<span class="mw-page-title-main">Bait ball</span> Defense mechanism used by small schooling fish

A bait ball, or baitball, occurs when small fish swarm in a tightly packed spherical formation about a common centre. It is a last-ditch defensive measure adopted by small schooling fish when they are threatened by predators. Small schooling fish are eaten by many types of predators, and for this reason they are called bait fish or forage fish.

<i>Brama</i> (fish) Genus of fishes

Brama is a genus of marine ray-finned fishes from the family Bramidae, the pomfrets. Currently, there are 8 species within the genus.

Brachioteuthis riisei, is a species of squid in the family Brachioteuthidae.

The Condor seamount is a submarine mountain located at 17 kilometres (11 mi) west-southwest of Faial Island in the Azores. It is approximately 1,800 metres (5,900 ft) high, 39 kilometres (24 mi) long and 23 kilometres (14 mi) wide, stretching from a depth of 185 metres (607 ft) up to 2,003 metres (6,572 ft). It is an elongated shaped volcano, oriented east-west, with the top relatively flat with smooth sedimentary flanks. Most seamounts lie in deep sea and/or open ocean, and thus are inaccessible and difficult to study. The Condor bank, constitutes an interesting case study due to its accessibility, located close to Faial island.

<i>Billfish in the Indian Ocean</i> Species of billfish found in the Indian ocean

Of the twelve species of billfish, there are six species of Billfish in the Indian Ocean.

References

  1. ↑ Fierstine, Harry L. (1990). "A paleontological review of three billfish families (Istiophoridae, Xiphiidae, and Xiphiorhynchidae)" (PDF). Biological Sciences: 11.
  2. 1 2 3 4 5 6 7 8 9 Collette, B.B; Di Natale, A.; Fox, W.; Graves, J.; Juan Jorda, M.; Pohlot, B.; Restrepo, V.; Schratwieser, J. (2022). "Xiphias gladius". IUCN Red List of Threatened Species . 2022. doi: 10.2305/IUCN.UK.2022-1.RLTS.T23148A46625751.en . Retrieved 14 October 2022.
  3. 1 2 3 4 5 6 Froese, Rainer; Pauly, Daniel (eds.) (2018). "Xiphias gladius" in FishBase. February 2018 version.
  4. ↑ Grey, Zane (2000). Tales of Swordfish and Tuna. Lanham, Maryland and New York, New York, USA: The Derrydale Press. p. 107. ISBN   9781493048809.
  5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Gardieff, S. "Swordfish". Florida Museum of Natural History. Archived from the original on 9 August 2015. Retrieved 26 December 2011.
  6. ↑ Froese, Rainer, and Daniel Pauly, eds. (2011). "Xiphiidae" in FishBase . December 2011 version.
  7. ↑ Pepperell, J. 2010. Fishes of the Open Ocean: A Natural History and Illustrated Guide. ISBN   978-0-226-65539-0
  8. ↑ Fierstine, Harry L. (2006). "Fossil History of Billfishes (Xiphioidei)". Bulletin of Marine Science. S2CID   20606448.
  9. ↑ Flindt, Rainer (21 December 2006). Amazing Numbers in Biology. Springer Science & Business Media. p. 12. ISBN   978-3-540-30147-9.
  10. ↑ Marsh, Jesse; Stiles, Margot (2007). "Seafood Watch, Seafood Report, Monterey Bay Aquarium" (PDF). Archived from the original (PDF) on 2 February 2017.
  11. ↑ Sherwood, Lauralee; Klandorf, Hillar; Yancey, Paul. Animal Physiology: From Genes to Organisms (2nd ed.). Cengage Learning. ISBN   9781133784579.
  12. 1 2 Fritsches, K. A.; Brill, R. W.; Warrant, E. J. (January 2005). "Warm eyes provide superior vision in swordfishes". Current Biology. 15 (1): 55–58. doi: 10.1016/j.cub.2004.12.064 . PMID   15649365. S2CID   14070646.
  13. 1 2 Hopkin, Michael (January 2005). "Swordfish heat their eyes for better vision". Nature. doi:10.1038/news050110-2.
  14. ↑ "Haulin' Bass". ReefQuest Centre for Shark Research. Retrieved 26 December 2011. The 60 mph figure listed for the swordfish is based on a corrupted version of calculations made by Sir James Gray to estimate the impact speed necessary for a hypothetical 600 lb [270 kg] swordfish to embed its sword 3 feet [90 cm] in the timbers of ships, as has been known to occur; the figure seems to have entered the literature without question.
  15. ↑ Svendsen, Morten B. S.; Domenici, Paolo; Marras, Stefano; Krause, Jens; Boswell, Kevin M.; Rodriguez-Pinto, Ivan; Wilson, Alexander D. M.; Kurvers, Ralf H. J. M.; Viblanc, Paul E.; Finger, Jean S.; Steffensen, John F. (15 October 2016). "Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited". Biology Open. 5 (10): 1415–1419. doi:10.1242/bio.019919. ISSN   2046-6390. PMC   5087677 . PMID   27543056.
  16. ↑ Stillwell; Kohler (1985). "Food and feeding ecology of the swordfish Xiphias gladius in the western North Atlantic Ocean with estimates of daily ration". Mar. Ecol. Prog. Ser. 22: 239–241. Bibcode:1985MEPS...22..239S. doi: 10.3354/meps022239 .
  17. ↑ Bolin, Jessica A.; Cummins, Scott F.; Mitu, Shahida A.; Schoeman, David S.; Evans, Karen J.; Scales, Kylie L. (11 June 2021). "First report of Kudoa thunni and Kudoa musculoliquefaciens affecting the quality of commercially harvested yellowfin tuna and broadbill swordfish in Eastern Australia". Parasitology Research. 120 (7): 2493–2503. doi:10.1007/s00436-021-07206-8. ISSN   1432-1955. PMID   34115215. S2CID   235404099.
  18. ↑ Mattiucci, S.; Garcia, A.; Cipriani, P.; Santos, M. N.; Nascetti, G.; Cimmaruta, R. (2014). "Metazoan parasite infection in the swordfish, Xiphias gladius, from the Mediterranean Sea and comparison with Atlantic populations: implications for its stock characterization". Parasite. 21: 35. doi:10.1051/parasite/2014036. PMC   4109596 . PMID   25057787.
  19. ↑ The Shark Trust. "Shortfin mako". Archived from the original on 14 July 2011. Retrieved 26 December 2011.
  20. 1 2 Sokol, Joshua (27 October 2020). "Sharks Wash up on Beaches, Stabbed by Swordfish". The New York Times. Retrieved 5 January 2023.
  21. ↑ "North Atlantic Swordfish | FishWatch". www.fishwatch.gov. Retrieved 14 May 2021.
  22. 1 2 Froese, Rainer; Pauly, Daniel (eds.) (2011). "Xiphias gladius" in FishBase . December 2011 version.
  23. ↑ "Aquatic species: Xiphias gladius (Linnaeus, 1758)". Food and Agriculture Organization . Retrieved 5 January 2023.
  24. ↑ "La Pesca del Pescespada". Archived from the original on 26 April 2012. Retrieved 30 December 2011.
  25. ↑ "La pesca del pesce spada". www.biologiamarina.eu.
  26. ↑ "La tecnica per la pesca del pescespada e la "Feluca" - Ganzirri, il Peloro e lo Stretto di Messina". www.ganzirri.it.
  27. ↑ Preuss, Andreas; Marco, Tony (1 June 2015). "Swordfish kills fisherman in Hawaii". CNN.com.
  28. ↑ "Daytime Swordfish Tactics That Work Like a Charm". FishingBooker.com. 13 October 2018.
  29. ↑ "What's an oily fish?". Food Standards Agency. 24 June 2004. Archived from the original on 10 December 2010. Retrieved 8 July 2009.
  30. ↑ FDA (1990–2010). "Mercury Levels in Commercial Fish and Shellfish". Food and Drug Administration . Retrieved 14 September 2011.
  31. ↑ EPA. "What you need to know about mercury in fish and shellfish" . Retrieved 14 September 2011.
  32. ↑ FDA (2 July 2019). "Advice About Eating Fish". FDA . Retrieved 27 September 2019.
  33. ↑ "Swordfish: The Fish of Legends". The Biblical Museum of Natural History. Retrieved 8 April 2023.
  34. ↑ "Is Swordfish Kosher?" . Retrieved 8 April 2023.
  35. ↑ "The Turning of the Tide: The Kashrut Tale of the Swordfish" (PDF). Bar-Ilan University . Retrieved 8 April 2023.
  36. ↑ "Swordfish". Fenton Communications. Archived from the original on 31 December 2007.
  37. ↑ "Species directory: North Atlantic Swordfish". NOAA.gov. 28 December 2022. Retrieved 5 January 2023.
  38. ↑ "Seafood Watch – Seafood Report – Swordfish" (PDF). Monterey Bay Aquarium. Archived from the original (PDF) on 14 July 2007. Retrieved 16 July 2008.
  39. ↑ "Greenpeace International Seafood Red List" (PDF). October 2010. Archived from the original (PDF) on 10 November 2011. Retrieved 14 September 2012.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.