X+gladius



[|Xiphias gladius]-SWORDFISH

** Species: ** X. Gladius **Class:** Actinopterygii
 * Genus: ** Xiphias
 * Order:** Perciformes
 * Family:** Xiphiidae (Swordfish are the sole member of this family)

**Endangered Species Act:** Swordish were put on the endangered species list in 1996. The cause of this is because many swordfish are caught before they get the chance to breed and there is a strong demand for them in the fishing market.

-- Northern Alaska to Southern South America: 60 degrees North to 30 degrees South
 * // Habitat //**
 * Ecosystem**
 * The Swordfish is a worldwide fish that is found in all temperate and tropical oceans, especially the North and South Atlantic and the Pacific Oceans.
 * Pacific Ocean-- Asia to Americas: Between 30 degrees North and 60 degrees North
 * Physical Habitat: The Pacific Ocean**
 * Swordfish are found around frontal zones--area where ocean currents merge and form turbulence and drastic temperature changes
 * The Pacific Ocean, the habitat of many swordfish, has five important frontal zones
 * There are three main warm currents that affect the Pacific region: North Pacific Drift, Pacific Equatorial Counter Current, and the South Pacific Equatorial Current.
 * Tides:
 * the tides of the Pacific ocean are always changing depending on the position of the moon
 * however, timing of the high and low tides vary each day
 * the average tidal range at the coast is between 2.5 and 4 meters
 * Geologic Procesess:
 * The average depth of the Pacific Ocean is about 4,000 meters
 * Off the coast of North America is the East Pacific Rise-- ridge rises 2 km off ocean floor from Gulf of California to Southern South America and froms East and West Basins of the Pacific
 * The Pacific Shelf is divided into three main parts: Queen Charolette Shelf, Queen Charolette Sound, and Vancouver Island Shelf
 * The East Pacific Rise and the Pacific Coastal Shelf are the boundaries of the East Pacific Basin (a depression that slopes to the sea floor
 * Basic Abiotic Factors**
 * The average temperature of the Pacific Ocean between Asia and America is 20 degrees Celsius and between Alaska and Southern South America is 15 degrees Celsius.
 * The salinity of the Pacific Ocean between Asia and America is 33 ppt and between Alaska and Southern South America is 34 ppt.
 * Swordfish can be found at depths between 200 to 600 meters.


 * MIgration Patterns:**
 * Swordfish migrate from cool waters in summer to warmer waters in winter
 * **Mostly** found in shallow waters and where currents meet.
 * They travel alone (not schooling fish)

The average catches in the last six years have averaged 865 tons per year.**
 * Population Estimate of Swordfish: Unknown


 * Survival Trends:**
 * In the 1990s the Swordfish population was severely decreasing due to overfishing but has now regained 94% of it and close to the number ensuring their survival.


 * [[image:http://www.flmnh.ufl.edu/fish/gallery/Descript/Swordfish/swordfishtailburgess.JPG width="157" height="184" align="right" caption="Close up of the caudal fin"]] Appearance: **
 * Long, sword-life beak
 * No teeth or scales
 * Maximum length: 4.5 meters
 * Maximum weight: 650 kg
 * 2 dorsal and anal fins
 * Caudal Fin
 * Fins are brown
 * Dorsal side is blackish-brown
 * Ventral side is lighte brown
 * Large eyes


 * Reproduction:**
 * Fertilization is external and involves the single pairing of a male and female
 * Females release millions of eggs that flat in proximity to the sea surface during the day and move deeper during the night
 * The female reproduces frequently: once every three days for seven months
 * Swordfish do not have distinct reproductive grounds or seasons; occurs throughout the year in equatorial waters


 * Adaptations:**
 * " Sword" to help catch prey
 * Cold water adaption-- specialized tissue next to eyes that heats the eyes and the brain
 * Heating of eyes increases accuracy of vision
 * Helps catch prey
 * Jumps out of water ("breaching) to dislodge parasites or pests as well as to stun small fish as easy prey
 * Host 49 different parasites
 * cestodes (tapeworms), nematodes (roundworms) , tremodes (flukes), and copepods


 * Food Chain:**
 * Swordfish eat pelagic fishes, squids, and cephalopods
 * They use their rigid, sword like beak to kill large prey while eating small prey whole
 * Adult Swordfish Predators: killer whales and large sharks
 * Juvenile Swordfish Predators: sharks, sailfish, marlin, dolphinfish, and yellowfin tuna


 * Economic Importance**
 * Popular fish for cooking
 * They are relied on by many fisheries in the following countries: Spain, USA, Canada, Portugal, Japan, Brazil, Taiwan, Uruguay, Australia, New Zealand, Mexico, India, Sri Lanka, Saudi Arabia, and Eastern Africa
 * The demand is increasing in North America and Europe causing more pressure on fisheries especially in the future due to increasingly stricter quotas


 * Human Threats and Reason for Endangerment**
 * Fishermen had swordfish catches over the maximum sustainable yield (the amount of fish allowed to be caught without harming the ecological balance) AKA **overfishing**
 * Swordfish were removed without enough time to reproduce which caused a signfigcant decrease in the population
 * When the fishermen caught all the adult swordfish they started to target the juveniles--undermining the future breeding population
 * This also causes smaller swordfish in future years
 * Average weight in early 1900s: 300 lbs
 * Average weight in 1960: 266 lbs
 * Average weight in 1990s: 90 lbs


 * Conservation Efforts**
 * The Natural Resources Defense Council started a 30-month campaign with Seaweb that implemented new fishing restrictions on swordfish in 1997
 * "Give Swordfish A Break" Campaign
 * Two Objectives of the campaign were to restrict the international swordfish catch quota and to close off swordfish nurseries in U.S. waters
 * 700 chefs across the nation participated in "The Give Swordfish A Break Pledge" where they agreed not to serve swordfish in their restaurants


 * Solutions**
 * After the implementing the previous campaign, the swordfish population has increased dramatically. I believe that if nations around the world continue to have strict restrictions on swordfish quotas, the problem of overfishing will not happen again.

Swordfish swimming: media type="youtube" key="PGaQ13ft_Fc&hl=en" height="344" width="425"

"Swordfish (SWO)".6/13/08. <[|http://services.fish.govt.nz/fishresourcespublic/Plenary2006/SWO_06.pdf>.] "Swordfish". LandBigFish. 6/11/08 <[|http://www.landbigfish.com/images/fish/LBF_Swordfish.jpg>.] "The Truth About Swordfish". California Seafood Council. 6/11/08 <[|http://ca-seafood.ucdavis.edu/news/swftruth.htm>.] Herbert, Paul D. N. "Pacific Ocean". The Encyclopeida of Earth. 6/11/08 <[|http://www.eoearth.org/article/Pacific_Ocean>.] "Xiphias Gladius--Swordfish". MarineBio. 6/11/08 . "Threats to Aquatic Environments - Fishing—far-reaching Consequences". LibraryIndex. 6/11/08 <[|http://www.libraryindex.com/pages/3048/Threats-Aquatic-Environments-FISHING-FAR-REACHING-CONSEQUENCES.html>.] "North Atlantic Swordfish". Natural Resource Defense Council. 6/11/08 <[|http://www.nrdc.org/wildlife/fish/nswordbr.asp>.] "Swordfish". Florida Museum of Natural History. 6/11/08 <[|http://www.flmnh.ufl.edu/fish/gallery/Descript/Swordfish/Swordfish.html>.]
 * SOURCES**