Frilled Shark

The frilled shark (Chlamydoselachus anguineus) is one of two extant species of shark in the family Chlamydoselachidae, with a wide but patchy distribution in the Atlantic and Pacific Oceans. This rare species is found over the outer continental shelf and upper continental slope, generally near the bottom, though there is evidence of substantial upward movements. It has been caught as deep as 1,570 m (5,150 ft). In Suruga Bay, Japan it is most common at depths of 50–200 m (160–660 ft). Exhibiting several "primitive" features, the frilled shark has often been termed a "living fossil". It reaches a length of 2 m (6.6 ft) and has a dark brown, eel-like body with the dorsal, pelvic, and anal fins placed far back. Its common name comes from the frilly or fringed appearance of its six pairs of gill slits, with the first pair meeting across the throat.

Seldom observed, the frilled shark may capture prey by bending its body and lunging forward like a snake. The long, extremely flexible jaws enable it to swallow prey whole, while its many rows of small, needle-like teeth make it difficult for the prey to escape. It feeds mainly on cephalopods, leavened by bony fishes and other sharks. This species is aplacental viviparous: the embryos emerge from their egg capsules inside the mother's uterus where they survive primarily on yolk. The gestation period may be as long as three and a half years, the longest of any vertebrate. Litter sizes vary from two to fifteen, and there is no distinct breeding season. Frilled sharks are occasional bycatch in commercial fisheries but have little economic value. The International Union for Conservation of Nature (IUCN) has assessed it as Near Threatened, since even incidental catches may deplete its population given its low reproductive rate. This shark, or a supposed giant relative, is a suggested source for reports of sea serpents.

With its elongated, eel-like body and strange appearance, the frilled shark has long been likened to the mythical sea serpent. The head is broad and flattened with a short, rounded snout. The nostrils are vertical slits, separated into incurrent and excurrent openings by a leading flap of skin. The moderately large eyes are horizontally oval and lack nictitating membranes (protective third eyelids). The very long jaws are positioned terminally (at the end of the snout), as opposed to the underslung jaws of most sharks. The corners of the mouth are devoid of furrows or folds. The tooth rows are rather widely spaced, numbering 19–28 in the upper jaw and 21–29 in the lower jaw. The teeth number around 300 in all; each tooth is small, with three slender, needle-like cusps alternating with two cusplets. There are six pairs of long gill slits with a "frilly" appearance created by the extended tips of the gill filaments, giving this shark its name. The first pair of gill slits meet across the throat, forming a "collar".

The long jaws of the frilled shark are highly distensible with an extremely wide gape, allowing it to swallow whole prey over one-half its size. However, the length and articulation of its jaws means it cannot deliver as strong a bite as more conventionally built sharks. Most captured individuals are found with no or barely identifiable stomach contents, suggesting a fast digestion rate and/or long intervals between feedings. This species preys upon cephalopods, bony fishes, and smaller sharks.

The frilled shark has seldom been encountered alive, and thus poses no danger to humans (though scientists have accidentally cut themselves examining its teeth). On August 27, 2004, the first observation of this species in its natural habitat was made by the ROV Johnson Sea Link II, on the Blake Plateau off the southeastern United States. On January 21, 2007, a Japanese fisherman discovered a 1.6 m (5.2 ft) long female alive at the surface, perhaps there because of illness or weakness from the warm water. It was brought to Awashima Marine Park in Shizuoka, where it died after a few hours.

Japanese fishers regard it as a nuisance, as it damages the nets. This shark is sometimes sold for meat or processed into fishmeal, but is not economically significant. Because of its very low reproductive rate and the continuing expansion of commercial fisheries into its habitat, the International Union for Conservation of Nature (IUCN) has listed it as Near Threatened.

Wikipedia

Kathy Dowsett
www.kirkscubagear.com

Eunice aphroditois aka 'bobbit worm'

Eunice aphroditois :: apparently given the nickname by an underwater photographer two decades ago.

It snares its prey using a complex feeding apparatus with two sharp mandibles which snap shut like a pair of scissors

The ocean floor is home to many weird and terrifying predators, many of which could discourage anyone from ever setting foot into the sea again.

This creature is Eunice aphroditois - also known as the Bobbit worm, apparently after an underwater photographer decided two decades ago that its hunting methods were similar to the Bobbitt family incident of 1993.

That incident involved Lorena Bobbitt slicing nearly half her husband's member off. E. aphroditois is similar, according to a 2011 paper in Revista de Biologia Tropical, 'because either the widely open jaw pieces resemble scissors, or because the exposed portion resembles an erect penis.'

The nickname is inaccurate - Mrs Bobbitt inflicted the grievous injury on her husband using a knife rather than scissors - but it has stuck nevertheless.

And it is perhaps a close enough comparison to dissuade any man from skinny dipping in warm waters near the sea floor at depths of 30 to 130ft, where the long-living nocturnal worm is generally found.

The creature, which spends its life mostly buried beneath the sand of the sea-floor, sticks just a portion of its body up into the water where it has five antennae to sense its prey, usually smaller worms and fish.

Mammoth: A scientists poses with the 10ft-long E. aphroditois discovered in Japan's Seto Fishing Harbour in 2009.

It snares its prey using a complex feeding apparatus called a pharynx which can turn inside-out, like the fingers of a glove, and has sharp mandibles on the end which snap shut like scissors.

Unlucky creatures are sometimes sliced in two because of the speed and strength of the worm's attacks, and it can dish out nasty bites to any humans who stray too close.

One the prey is caught, the worm shoots back into its burrow to feed. When prey is scarce it also feeds seaweed and other sea plants, and will scavenge for morsels around the surface of its burrow.

Noted for its unusually large body size and length, E. aphroditois is found in warm waters all over the world.

Since the 19th century, marine biologists have recognised it has having one of the longest bodies among polychaetes - a class of segmented, mostly marine worms.

They average a length of about one metre, but specimens measuring as long as three metres have been discovered.

The creature, which spends its life mostly buried beneath the sand of the sea-floor, sticks just a portion of its body up into the water where it has five antennae to sense its prey, usually smaller worms and fish.

It snares its prey using a complex feeding apparatus called a pharynx which can turn inside-out, like the fingers of a glove, and has sharp mandibles on the end which snap shut like scissors.

Unlucky creatures are sometimes sliced in two because of the speed and strength of the worm's attacks, and it can dish out nasty bites to any humans who stray too close.

One the prey is caught, the worm shoots back into its burrow to feed. When prey is scarce it also feeds seaweed and other sea plants, and will scavenge for morsels around the surface of its burrow.

Noted for its unusually large body size and length, E. aphroditois is found in warm waters all over the world.

Since the 19th century, marine biologists have recognised it has having one of the longest bodies among polychaetes - a class of segmented, mostly marine worms.

They average a length of about one metre, but specimens measuring as long as three metres have been discovered.

A report by Hiro'omi Uchida, assistant director of the Kushimoto Marine Park Centre in Japan, describes one such mammoth worm found hiding in one of the floats of a mooring raft in Japan's Seto Fishing Habour in 2009.

'[I]it is uncertain when the individual first entered the mooring raft and fish corral during the 13 years the structure sat in the harbour,' he writes.

'It is also uncertain whether the worm arrived by larval settlement or at a semi-adult stage of development. Nonetheless, the individual surely had been living in its comfortable floating home for a quite a long time.'

At 9ft 10in long, about a pound in weight and with 673 segments, the worm they discovered was one of the largest specimens of E. aphroditois ever found.

That same year, a report in MailOnline Science detailed how a 4ft-long specimen was unearthed in a Newquay, Cornwall aquarium that was attacking coral and prize fish.

Workers at the attraction had been left scratching their heads as to why the coral had been left devastated and - in some cases - cut in half. After staking out the display for several weeks, the last resort was to completely dismantle it, rock by rock.

Matt Slater, the aquarium's curator, said: 'Something was guzzling our reef but we had no idea what, we also found an injured Tang Fish so we laid traps but they got ripped apart in the night.

'That worm must have obliterated the traps. The bait was full of hooks which he must have just digested.'

Staff believe the beast - which they nicknamed Barry - arrived by hitching a ride into the aquarium hiding inside a piece of coral when it was young and grew enormous over a number of years.

Mr Slater added: 'It really does look like something out of a horror movie.

Thanks to the Daily Mail

Kathy Dowsett

www.kirkscubagear.com

10 Tips to see the most when you scuba dive

The best way to see any dive site is with a guide who knows the area and the native wildlife or coral formations in the area. Don’t be afraid to ask them about the site or tell them what you are interested in.

1. Relax and take things slowly when you dive. Remember you are a stranger with lots of bubbles in the underwater world, so by relaxing and not appearing as a threat you will get more fish remaining for you to enjoy.

2. You are in the homes of the fish, turtles and other marine life that you are looking at. Respect that as you would a friends house. Do not disturb the natural surroundings, avoid kicking up sand and definitely not the coral. So practice your buoyancy away from the reef. Give the fish and reef some distance between you and them about 3 ft or 1 metre.

3. Do not poke, prod or harass the fish. This can be dangerous to their health and sometimes yours. They will also swim away and maybe relocate so other divers will not get to see them later.

4. Always allow the marine life a clear exit path. Make sure you and your dive buddy or group stay to one side and do not surround the animal you are looking at. If the fish or turtle doesn’t feel threatened it will remain for longer and allow you a better experience.

5. Do not feed the fish, apart from it being bad for the natural ecosystem, you do not get to see the natural behaviour of fish if they are being attracted to divers for the food.

6. Move along slowly in the water and pay close attention to the seascape around you. This helps your navigation but more importantly gives you time to really pay attention to the smaller creatures such as beautiful nudibranchs. Initially frightened fish may pop back out or come back to take a closer look at you.

7. Get into routines for checking your gauges. The best equipment designers in the world not make gauge better looking then the reef that surrounds you, so spending time fiddling with your gauges unnecessarily is time wasted. You can play with your dive computer on the boat as much as you want.

8. Spend some time before you get in the water and on the surface to double check you are comfortable with your equipment. Spending time “playing” with your dive gear underwater distracts you form the dive and also makes you consume air more rapidly.

9. Don’t be afraid to stop in a spot to look more closely and examine the coral formations for starfish, crabs and other beauties that make their homes under the coral. Again relax and practice your buoyancy.

10. Stick with your buddy and take the time to point out the cool things you have found. Four eyes are better then two. Agree with your buddy before you dive on some certain types of marine life that you are interested in. By looking at the same type of marine life you both will focus on areas likely to have the creatures.

Most of all have fun and don’t be nervous!!!

Thanks to New Horizon

Kathy Dowsett

www.kirkscubagear.com