Basking sharks filter up to 1,500 gallons of water per hour

The smallest is a lantern shark, averaging just 8 inches

The largest fish in the world is the whale shark and can reach lengths of over 40 to 60 feet

The fastest shark is the Mako, which has reached speeds of more than 45 miles per hour

Blue sharks have been tracked swimming more than 10,000 miles

Sharks may hear a fish a mile away

Sharks can smell blood in the water from 1/3 of a mile away

The Spiny dogfish has a gestation period close to 2 years, which makes it one of the longest of any animals

Spiny dogfish females are thought to reach breeding age at 35 years

Dusky shark females reach breeding age at 20 years

The smalltooth sawfish population has declined by 99%

The IUCN estimates that 20% of sharks are in danger of extinction

Worldwide shark takes have tripled since 1985

Tens of millions of sharks are accidentally caught as bycatch in commercial fisheries each year

According to Oceana, “estimates of the total number of sharks killed each year for their fins range from 26 to 73 million per year.”

Data: Ocean Conservancy and Oceana

credit: Karl Kaufman

From 1961 to 1973, bluefin tuna represented 45 to 80% of the U.S. western Atlantic catch of large pelagic species.

Since 1980, the percentage has dropped to less than 15%, reflecting a combination of the decline in the bluefin tuna population, the impact of catch restrictions, and the increasing harvests of alternative species.

Landings for 2005, 2006, and 2007 were 718, 472, and 758 metric tons, respectively.

Data: NOAA/ICCAT

77 A.D.  – ~144 known species
1976 – 18,818 known species, 450 families
1984 – 21,723 known species, 445 families
1994 – 24,618 known species, 482 families
2006 – 27,977 known species, 515 families

Of the total species formally described in 2006, 42.7% (11,952) of species live in freshwater, 55.5% (15,520) of species live in seawater, and 1.8% (505) of species move between freshwater and oceans during their lifecycles. 

• The largest order of fishes is Perciformes that is comprised of 10,033 species, and includes 160 families. Perciformes include fresh and salt water fishes such as gobies, wrasses, sea basses, and cichlids.
• The smallest orders of fishes is Amiiformes  with only 1 specie.  The Amiiformes order is comprised solely with the bowfin, Amia calva which is distributed over the eastern half of North America.
• The greatest diversity geographically is found in the tropics, with the most marine species found in Indo-West Pacific (western Pacific Ocean, Indian Ocean, Red Sea), and the most freshwater species located in Southeast Asia, South America, and Africa.
• The fish found at the highest altitude is the nemacheiline river loach that inhabits hot springs in Tibet at an elevation of just over 17,000 feet (5200 meters).
• At 26,246 feet (8000 meters) below the  surface of the ocean, the cusk-eels are the deepest living fishes.
• Of the total described species, 970 are cartilaginous sharks, skates, rays  and chimaeras.
• The largest living fish is the whale shark which can grow over  40 feet (12 meters) long.
• One of the smallest fish and vertebrate known, with the smallest mature female measuring just  7.9 mm is the Indonesian minnow Paedocypris progenetica.

References:
Nelson, J. S.: Fishes of the World, John Wiley & Sons, Inc. 2006
Helfman, G.S.: The Diversity of Fishes, Blackwell Science, Inc. 1999