Difference between revisions of "Shark"
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===Orders and Families=== | ===Orders and Families=== | ||
====[[Squaliformes]]==== | ====[[Squaliformes]]==== | ||
| − | Dogfish; order representing 7 families and 113 species of shark, with the spiny dogfish possibly the most abundant fish of any kind in the world's oceans. | + | Dogfish; order representing 7 families and 113 species of shark, with the spiny dogfish possibly the most abundant fish of any kind in the world's oceans. They are characterized by a lack of an anal fin, and range in size from 7.5 inches (Dwarf lanternshark, ''Etmopterus perryi'') to 21 feet (Greenland shark, ''Somniosus microcephalus''). |
| − | *Bramble sharks (Echinorhinidae) | + | *Bramble sharks (Echinorhinidae, 2 species) |
| − | *Dogfish (Squalidae) | + | *Dogfish (Squalidae, 20 species) |
| − | *Roughsharks (Oxynotidae) | + | *Roughsharks (Oxynotidae, 5 species) |
| − | ====[[Hexanchiformes]]==== | + | *Gulper Sharks (Centrophoridae, 15 species) |
| − | *Frilled sharks (Chlamydoselachidae) | + | *Lantern Sharks (Etmopteridae, 51 species) |
| − | *Cow sharks (Hexanchidae) | + | *Sleeper sharks (Somniosidae, 18 species) |
| + | *Kitefin sharks (Dalatiidae, 10 species) | ||
| + | ====[[Hexanchiformes]]==== | ||
| + | Deep-water sharks, identifiable by the presence of six or seven gill slits (cow sharks); or a shape reminiscent of an eel (frilled sharks) | ||
| + | *Frilled sharks (Chlamydoselachidae, 2 species) | ||
| + | *Cow sharks (Hexanchidae, 3 species) | ||
====[[Pristiophoriformes]]==== | ====[[Pristiophoriformes]]==== | ||
| − | *Sawsharks (Pristiophoridae) | + | Sharks identified by a long snout bearing variably-sized teeth on either side, similar in appearance to [[sawfish]]. |
| + | *Sawsharks (Pristiophoridae, 6 species) | ||
====[[Squatiniformes]]==== | ====[[Squatiniformes]]==== | ||
| − | *Angelsharks (Squatinidae) | + | Identified by their flattened, ray-like appearance, lack of anal fins, and the lower lobe of the tail fin longer than the upper lobe. |
| + | *Angelsharks (Squatinidae, 16 species) | ||
====[[Heterodontiformes]]==== | ====[[Heterodontiformes]]==== | ||
| − | *Bullhead sharks (Heterodontidae) | + | Sharks which have a characteristic pig-like snout, short face, and bovine-like ridges above the eyes. All species have a spine in front of their dorsal fins. |
| + | *Bullhead sharks (Heterodontidae, 9 species) | ||
====[[Orectolobiformes]]==== | ====[[Orectolobiformes]]==== | ||
| − | *Collared carpetsharks (Parascyllidae) | + | Carpet sharks, so-named for the intricate patterns resembling oriental carpeting. Most species are small bottom dwellers; the exception is the whale shark (Rhincodon typus), at up to 60 feet in length it is the largest living fish. |
| − | *Blind sharks (Brachaeluridae) | + | *Collared carpetsharks (Parascyllidae, 8 species) |
| − | *Wobbegongs (Orectolobidae) | + | *Blind sharks (Brachaeluridae, 2 species) |
| − | *Bamboosharks (Hemiscyllidae) | + | *Wobbegongs (Orectolobidae, 12 species) |
| − | *Zebra | + | *Bamboosharks (Hemiscyllidae, 16 species) |
| − | *Nurse sharks (Ginglymostomatidae) | + | *Zebra shark (Stegostomatidae, 1 species) |
| − | *Whale shark (Rhiniodontidae) | + | *Nurse sharks (Ginglymostomatidae, 3 species) |
| + | *Whale shark (Rhiniodontidae, 1 species) | ||
====[[Lamniformes]]==== | ====[[Lamniformes]]==== | ||
| − | *Sandtigers (Odontaspididae) | + | Mackerel sharks. Most species identified by a robust appearance; all lack a nictating membrane over the eyes. |
| − | *Goblin shark (Mitsukurinidae) | + | *Sandtigers (Odontaspididae, 4 species) |
| − | *Crocodile shark (Pseudocarchariidae) | + | *Goblin shark (Mitsukurinidae, 1 species) |
| − | *Megamouth shark (Megachasmidae) | + | *Crocodile shark (Pseudocarchariidae, 1 species) |
| − | *Thresher sharks (Alopiidae) | + | *Megamouth shark (Megachasmidae, 1 species) |
| − | *Basking shark (Cetorhinidae) | + | *Thresher sharks (Alopiidae, 3 species) |
| − | *Mackerel sharks (Lamnidae) | + | *Basking shark (Cetorhinidae, 1 species) |
| + | *Mackerel sharks (Lamnidae, 5 species) | ||
====[[Carcharhiniformes]]==== | ====[[Carcharhiniformes]]==== | ||
| − | *Catsharks (Scyliorhinidae) | + | Ground or common sharks, characterized by a nictating membrane over the eyes; several species have been implicated in attacks on man. |
| − | *Finback catsharks (Proscylliidae) | + | *Catsharks (Scyliorhinidae, 150 species) |
| − | *False catsharks (Pseudotriakidae) | + | *Finback catsharks (Proscylliidae, 7 species) |
| − | *Barbelled houndshark (Leptochariidae) | + | *False catsharks (Pseudotriakidae, 4 species) |
| − | *Houndsharks (Triakidae) | + | *Barbelled houndshark (Leptochariidae, 1 species) |
| − | *Weasel sharks (Hemigaleidae) | + | *Houndsharks (Triakidae, 40 species) |
| − | *Requiem sharks (Carcharhinidae) | + | *Weasel sharks (Hemigaleidae, 8 species) |
| − | *Hammerhead sharks (Sphyrnidae) | + | *Requiem sharks (Carcharhinidae, 52 species) |
| + | *Hammerhead sharks (Sphyrnidae, 9 species) | ||
== Behavior == | == Behavior == | ||
Revision as of 04:22, December 7, 2011
| Shark | |
|---|---|
| |
| Oceanic whitetip shark (Carcharhinus longimanus) | |
| Scientific classification | |
| Kingdom Information | |
| Domain | Eukaryota |
| Kingdom | Animalia |
| Subkingdom | Biliteria |
| Branch | Deuterostomia |
| Phylum Information | |
| Phylum | Chordata |
| Sub-phylum | Vertebrata |
| Infraphylum | Gnathostomata |
| Class Information | |
| Class | Chondrichthyes |
| Sub-class | Elasmobranchii |
| Order Information | |
| Superorder | Selachimorpha |
| Population statistics | |
Sharks are approximately 350 species of cartilaginous fish of the order Selachimorpha, inhabiting the world's oceans and several freshwater lakes and rivers.
Description
Sharks vary in appearance, shape, and size, so there is no absolute description of a typical shark. In general, all sharks with several exceptions share the following characteristics:
- A skeletal system made entirely of cartilage, with the vertebrate extending to and forming the claudal (tail) fin's upper lobe.
- A ventrally-located mouth with the upper jaws unattached to the skull, enabling the animal to extend both jaws forward to take in prey.
- Skin covered with denticals, a type of placoid scale rough to the feel and related to teeth.
- Teeth arranged in a "conveyor belt"-fashion, enabling continual replacement over the lifetime of the animal.
Orders and Families
Squaliformes
Dogfish; order representing 7 families and 113 species of shark, with the spiny dogfish possibly the most abundant fish of any kind in the world's oceans. They are characterized by a lack of an anal fin, and range in size from 7.5 inches (Dwarf lanternshark, Etmopterus perryi) to 21 feet (Greenland shark, Somniosus microcephalus).
- Bramble sharks (Echinorhinidae, 2 species)
- Dogfish (Squalidae, 20 species)
- Roughsharks (Oxynotidae, 5 species)
- Gulper Sharks (Centrophoridae, 15 species)
- Lantern Sharks (Etmopteridae, 51 species)
- Sleeper sharks (Somniosidae, 18 species)
- Kitefin sharks (Dalatiidae, 10 species)
Hexanchiformes
Deep-water sharks, identifiable by the presence of six or seven gill slits (cow sharks); or a shape reminiscent of an eel (frilled sharks)
- Frilled sharks (Chlamydoselachidae, 2 species)
- Cow sharks (Hexanchidae, 3 species)
Pristiophoriformes
Sharks identified by a long snout bearing variably-sized teeth on either side, similar in appearance to sawfish.
- Sawsharks (Pristiophoridae, 6 species)
Squatiniformes
Identified by their flattened, ray-like appearance, lack of anal fins, and the lower lobe of the tail fin longer than the upper lobe.
- Angelsharks (Squatinidae, 16 species)
Heterodontiformes
Sharks which have a characteristic pig-like snout, short face, and bovine-like ridges above the eyes. All species have a spine in front of their dorsal fins.
- Bullhead sharks (Heterodontidae, 9 species)
Orectolobiformes
Carpet sharks, so-named for the intricate patterns resembling oriental carpeting. Most species are small bottom dwellers; the exception is the whale shark (Rhincodon typus), at up to 60 feet in length it is the largest living fish.
- Collared carpetsharks (Parascyllidae, 8 species)
- Blind sharks (Brachaeluridae, 2 species)
- Wobbegongs (Orectolobidae, 12 species)
- Bamboosharks (Hemiscyllidae, 16 species)
- Zebra shark (Stegostomatidae, 1 species)
- Nurse sharks (Ginglymostomatidae, 3 species)
- Whale shark (Rhiniodontidae, 1 species)
Lamniformes
Mackerel sharks. Most species identified by a robust appearance; all lack a nictating membrane over the eyes.
- Sandtigers (Odontaspididae, 4 species)
- Goblin shark (Mitsukurinidae, 1 species)
- Crocodile shark (Pseudocarchariidae, 1 species)
- Megamouth shark (Megachasmidae, 1 species)
- Thresher sharks (Alopiidae, 3 species)
- Basking shark (Cetorhinidae, 1 species)
- Mackerel sharks (Lamnidae, 5 species)
Carcharhiniformes
Ground or common sharks, characterized by a nictating membrane over the eyes; several species have been implicated in attacks on man.
- Catsharks (Scyliorhinidae, 150 species)
- Finback catsharks (Proscylliidae, 7 species)
- False catsharks (Pseudotriakidae, 4 species)
- Barbelled houndshark (Leptochariidae, 1 species)
- Houndsharks (Triakidae, 40 species)
- Weasel sharks (Hemigaleidae, 8 species)
- Requiem sharks (Carcharhinidae, 52 species)
- Hammerhead sharks (Sphyrnidae, 9 species)
Behavior
Many species of sharks give birth to a few dozen live young, others lay a similarly small number of eggs; these are often washed ashore and are known as mermaid's purses.
Sharks are reputed to be able to detect minute amounts of blood in water, and to be able to follow blood trails for miles. In fact, although sharks can detect blood at concentrations of as little as a few parts per billion, a very considerable quantity must be spilt before it is detectable amongst billions of gallons of seawater. Sharks actually use sounds and vibrations to locate most of their prey.
Classification
Sharks belong to the holobaramin that also includes skates and rays.
Environmental Concerns
Worldwide, sharks suffer threats from over-fishing, mercury poisoning, ocean acidification, and habitat disruption. [1]. Many individual shark species are currently threatened or endangered, often because of human activities such as careless fishing practices and coal fired plants dumping tones of toxic mercury into the oceans.