WOW what a week – thresher sharks, blue ringed octopus and launching of another dive boat. See my earlier posting for details about the blue-ringed octopus.
We had close encounters with threshers harks twice this week on the east side of Pescador island between 8 to 12m where they were feeding off of the sardines. I hope to add a video to the blog soon.
The genus and family name derive from the Greek word alopex, meaning fox. Indeed the long-tailed thresher shark is named the fox shark by some authorities. The common name is derived from a distinctive thresher-like tail which can be as long as the body of the shark itself. Thresher sharks are active predators; the tail is actually used as a weapon to stun prey.
Thresher sharks are fairly slender, with small dorsal fins and large, curved pectoral fins. With the exception of the Bigeye thresher, these sharks have relatively small eyes positioned to the forward of the head. Coloration ranges from brownish, bluish or purplish gray dorsally with lighter shades ventrally. The three species can be roughly distinguished by the main color of the dorsal surface of the body. Common threshers are dark green, Bigeye threshers are brown and Pelagic threshers are generally blue. Lighting conditions and water clarity can affect how any one shark appears to an observer, but the color test is generally supported when other features are examined.
Pelagic schooling fish (such as bluefish, juvenile tuna, sardines and mackerel), squid and cuttlefish are the primary food items of the thresher sharks. They are known to follow large schools of fish into shallow waters. Crustaceans and the odd seabird are also taken.
No distinct breeding season is observed by thresher sharks. Fertilization and embryonic development occur internally; this live-bearing mode of reproduction results in a small litter (usually 2 to 4) of large well-developed pups. The young fish exhaust their yolk sacs while still inside the mother, at which time they begin feeding on the mother's unfertilized eggs.
Thresher sharks are slow to mature, males reaching sexual maturity between 7 and 13 years of age and females between 8 and 14 years in Bigeye threshers. They may live for 20 years or more.
They do not appear to be a threat to humans, although some divers have been hit with the upper tail lobe.
This information was edited from Wikipedia - follow this link for more information Thresher shark informationLaunching of New Dive Boat
We launched another outrigger dive boat this week with the help of our neighbors who moved it from the field where it was built, down a short slipway and into the sea. The launching went smoothly and the new boat floated easily on the high tide. The new 75hp outboard was fitted and the boat went on its inaugural sailing. We just need a few hours to run in the new engine before the boat is ready to join its sister boat
You can staill enjoy a vacation at Turtle Bay Dive Resort with the 20% summer promo discount which runs until September 30, 2011.