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07-20-2006, 12:34 AM
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Sharks pack a full underwater arsenal
Sharks pack a full underwater arsenal - By Capt. Mark Sampson - Original Link
Mid-July the waters are warm and it's now that time of year when coastal anglers, whether they're fishing in the bay or ocean, could intentionally or uninten-tionally hook a shark. Certainly most folks are well aware of the ability of sharks to smell and home in on their prey -- sometimes from miles away. Their keen sense of smell is well documented and has been compared to that of a super-sensitive bloodhound on a hot trail. But what isn't so widely known is that the sense of smell is only one tool in the arsenal of sensory receptors that allow sharks to locate and capture their next meal. Look at any shark and it's not hard to figure out where their sense of smell starts. Like most fish, sharks have two obvious nostrils on the underside of their snout. Scent is a shark's long-range prey detector and smelling its prey may be the first indication to a shark that there is a potential meal in the vicinity. As a shark moves closer it will eventually get within "ear-shot" of whatever it's tracking. Sound travels well underwater and sharks are especially adept at picking up on the low frequency sounds often produced by injured or struggling fish. Of course sharks don't have external ears, but if you look real closely at the center of their head and a little in front of an imaginary line drawn between their eyes, you can see two pinhole-sized openings, one half to two inches apart (depending upon the size of the shark). These are the openings to the ear canals. Sounds and smells help a shark get within the general vicinity of their prey, but after that they have a few more tricks up their fins to help put the food in their mouths. Running down the middle of each side of a fish is an area known as the "lateral line." On sharks, this line is covered by very small receptors that pick up vibrations in the water. These receptors run directly to the brain and tell a sharks that it's getting closer to its prey. The vibrations also help inform the shark as to what its intended meal is doing -- struggling, fleeing, casually swimming or possibly feeding. The eyes of sharks are very different from species to species. Open water pelagic sharks like makos and blues have large eyes that help them to see their prey in the clear waters they typically inhabit. But a lot of sharks, particularly those that frequent the murky nearshore waters, make do with relatively small eyes because clearly seeing their prey is not as important as being able to sense it. Smelling, hearing and feeling the vibrations gets a shark awfully close to its lunch, but it still has to be able to pinpoint its precise location at close range so that the shark will know when and where to bite, even in times of zero visibility. For this, sharks use a barrage of electro-sensory receptors known as "ampullae of Lorenzini." "They use What?" OK, let's simplify and just call them ampullae, which are in fact hundreds of tiny jelly-filled pores located on and below the head and snout of every shark. Ampullae actually pick up the minute electrical fields that are generated by, and surround, every living thing in the water. Like the ear openings, the ampullae look like small pinholes. Take a look at any shark, even a little sand shark, and you'll easily identify the ampullae sprinkled about its head and jaw area. As a matter of fact, skates are close relatives of sharks, and if you look at the underside of a skate's head area you'll see not only the ampullae, but also a trace of the canal that leads from it directly to the animal's brain. With the ampullae spread across its broad head, a shark is able to determine the exact location of fish in murky water, a crab buried under the sand, or a squid in total darkness. At close range a shark feels its prey's electrical energy and knows exactly where to bite. Pretty cool stuff, and to think all this sensory reception comes together to put a shark onto its next meal, or maybe on a fisherman's hook -- whether the angler appreciates it or not. Originally published Friday, July 14, 2006
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~Sam - Pray for East Wind!  
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07-20-2006, 07:42 AM
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Quote:
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I can fix anything. Where are my zip ties and duct tape? 
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07-20-2006, 08:21 AM
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yeah I had a post about making my chum for the fling. It was basically a bucket full of my left over tuna heads that I chopped up along with some hacked up bunker, skate and fish oil. 5 gals of nastiness.
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07-20-2006, 08:24 AM
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I'll be there and plan on fishing one rod wth a Sabiki rig catching bait fish from the get-go. all that I catch will go towards use as live bait, cut bait, chum or the grill
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07-20-2006, 08:49 AM
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sweet, I figure I will be the skate wrangler also so I can fill my next bucket. Half a small shrimp will get a skate within 2 mins it seems. Fish bites for real/bait fish. Should be plenty fun.
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07-20-2006, 08:56 AM
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ok, cool
 + I'll have a 8lb bucket of that dry-chum and @3/4 gal of menhaden oil, so yeah, we should have some good slicks going on now Im also guessing the chum & chum slick works best on the out going tide, so no need todo one on the incomming tide, wadda' you all think 
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