Zoology A Closer Look: Pristis pectinata (Sawfish)

Discussion in 'Zoology' started by mscbkc070904, Feb 9, 2005.

  1. mscbkc070904

    mscbkc070904 Premium Member

    Endangered Species
    On April 1, 2003, the National Marine Fisheries Service (NOAA Fisheries) announced its final determination to list smalltooth sawfish as an endangered species under the Endangered Species Act (ESA). NOAA Fisheries has prepared a press release for this determination.

    For more pictures and information on sawfish biology and research, visit Mote Marine Laboratory's sawfish webpage.

    The smalltooth sawfish was added to the candidate species list in 1991, removed in 1997, and placed back on the list again in 1999. In November 1999, NOAA Fisheries received a petition from the Ocean Conservancy (formerly the Center for Marine Conservation) requesting that this species be listed as endangered under the ESA. NOAA Fisheries completed a status review for smalltooth sawfish in December 2000, and published a proposed rule to list this the U.S. population of this species as endangered under the ESA on April 16, 2001.

    Sawfish biology
    Sawfish, like sharks, skates and rays, belong to a class of fish called elasmobranchs, whose skeletons are made of cartilage. Sawfish are actually modified rays with a shark-like body, and gill slits on their ventral side. Early sawfish arose around 100 million years ago, but these first sawfish are actually a distant cousins to the modern day sawfishes, which first appeared around 56 million years ago. Sawfish get their name from their "saws" - long and flat snouts edged with pairs of teeth which are used to locate, stun and kill prey. Their diet includes mostly fish but also some crustaceans.
    Smalltooth sawfish is one of two species of sawfish that inhabit U.S. waters. Smalltooth sawfish commonly reach 18 ft (5.5 m) in length, and may grow to 25 ft (7 m). Little is know about the life history of these animals, but they may live up to 25-30 years and mature after about 10 years. Like many elasmobranchs, smalltooth sawfish are ovoviviparous, meaning the mother holds the eggs inside of her until the young are ready to be born, usually in litters of 15 to 20 pups.

    Distribution and Abundance
    Sawfish species inhabit shallow coastal waters of tropical seas and estuaries throughout the world. They are usually found in shallow waters very close to shore over muddy and sandy bottoms. They are often found in sheltered bays, on shallow banks, and in estuaries or river mouths. Certain species of sawfish are known to ascend inland in large river systems, and they are among the few elasmobranchs that are known from freshwater systems in many parts of the world.
    Smalltooth sawfish has been reported in both the Pacific and Atlantic Oceans, but the U.S. population is found only in the Atlantic. Historically, the U.S. population was common throughout the Gulf of Mexico from Texas to Florida, and along the east coast from Florida to Cape Hatteras. The current range of this species has contracted to peninsular Florida, and smalltooth sawfish are relatively common only in the Everglades region at the southern tip of the state. No accurate estimates of abundance trends over time are available for this species. However, available records, including museum records and anecdotal fisher observations, indicate that this species was once common throughout its historic range and that smalltooth sawfish have declined dramatically in U.S. waters over the last century.

    Good Pics on here of them.