Thursday, 29 October 2009

I Can Read Your Mind

Have you ever wish that you can read someone's mind and know what they are thinking? I am bringing you guys for a DEEP sea diving this time, so gear up and Let’s Dive Deep!


As we reach a depth of 600 meters… in absolute darkness….


Suddenly this tiny little creature swim up towards us...looking closer....it’s a fish with a transparent head !!




Say hello to the Barreleye Fish!





When you look closely at the barreleye's eyes and there is a good chance you are looking at its nose. What appear to be eyes, those small round objects just above its mouth, are basically its nostrils, called nares, which are equivalent to human nostrils.

The eyes are actually those green demi-spheres inside the top of its head!





Its eyes are shaped like barrels and thus its name. Spherical eyes are not as well adapted for the dark deeps in which it the barrel fish lives and its eye can swivel inside its fluid-filled head to look up, forward, or and even to backwards through the top rear of its cranium to see if there is anything coming from behind and above. The eyes are covered by bright green lenses. The eyes point upwards while hunting for food, but point forward when it’s eating its prey.

A team from the Monterey Bay Aquarium Research Insitute sent remotely operated vehicles to the ocean floor to study the Barreleye and make the remarkable discovery that the fish had a transparent skull and could rotate its eyes through many angles. They also managed to capture a live specimen, and over several hours observed the fish rotating its eyes. Such feature of the eyes are very important for survival as it will be very difficult for them to capture prey with their small, pointed mouths.

Enjoy the barreleye video captured by Monterey Bay Aquarium Research Institute !!





In addition to their amazing "headgear," barreleyes have a variety of other interesting adaptations to deep-sea life. Their large, flat fins allow them to remain nearly motionless in the water, and to maneuver very precisely .

Their small mouths suggest that they can be very precise and selective in capturing small prey. On the other hand, their digestive systems are very large, which suggests that they can eat a variety of small drifting animals as well as jellies. In fact, the stomachs of the two net-caught fish contained fragments of jellies.

Most of the time, the fish hangs motionless in the water, with its body in a horizontal position and its eyes looking upward. The green pigments in its eyes may filter out sunlight coming directly from the sea surface, helping the barreleye spot the bioluminescent glow of jellies or other animals directly overhead. When it spots prey (such as a drifting jelly), the fish rotates its eyes forward and swims upward, in feeding mode.

Deep sea creatures are fascinating and absolutely surprising with many special adaptive designs… What’s more lurking in the dark deep sea water ?? Join me for more in the next adventure.

Love the ocean. Protect the ocean.

Peace & Cheerios !


For more information, visit :

http://www.mbandf.com/parallel-world/categories/science-and-technology/index.php?article=229

http://www.mbari.org/news/news_releases/2009/barreleye/barreleye.html

Please leave your comments and thoughts in the chatbox at the bottom of page.
Thanks to all that support this page.

Saturday, 24 October 2009

Coral Reefs

Ever wonder are corals animal, plant or colourful rocks? My friends always get this question from me, and most of them are not quite right. The correct answer is animal. In fact, The Great Barrier Reef located in coral sea, off the coast of Queensland in Northeast Australia, is the biggest single living structure that can be seen from outer space!


The Great Barrier Reef from outer space


A coral polyp is a tubular saclike animal with a central mouth surrounded by a ring of tentacles. The end opposite the tentacles, called the base, is attached to the substrate.

Coral does not have a brain but it has a simple nervous system called a nerve net. The nerve net extends from the mouth to the tentacles. They can detect certain substances such as sugars and amino acids, this enables corals to detect prey. Tiny sensors in the ends of nematocysts in polyp's tentacles trigger the nematocyst to eject. This results in the tentacles to grab hold of its prey and transfer them into their mouth. The movements of the tentacles are delicate, requires detailed observation to notice them moving, they are not just swaying to the ocean current.
Reef-building corals have a mutualistic relationship with zooxanthellae, microscopic algae that live with coral polyp's tissues. Both the polyp and the zooanthellae benefit. For this reason, reef-building corals are found only in areas where symbiotic zooxanthellae can take in light for photosynthesis.

Through photosynthesis, zooxanthellae convert carbon dioxide and water into oxygen and carbohydrates. The coral polyp uses carbohydrates as a nutrient. The polyp also uses oxygen for respiration and in turns, returns carbon dioxide to the zooxanthella. Through this exchange, coral saves energy that would otherwise be used to eliminate the carbon dioxide.
Zooxanthellae also promote polyp calcification by removing carbon dioxide during photosynthesis. Under optimum conditions, this enhanced calcification builds the reef faster than it can be eroded by physical or physical or biological factors.


Heart Reef -Australia

Some corals eat zooplankton (tiny drifting animals) or small fishes. Others consume organic debris. Coral polyps are generally nocturnal feeders. At night, they extend their tentacles to capture food with the aid of nematocysts. That is the reason why divers go night diving, cause the coral reefs look very different from daytime as they are nocturnal and hunts for food at night, revealing their soft bodies and colourful and graceful tentacles.


Some corals secrete films or strands of mucus to collect fine organic particles. In reef-building corals, to mobile filaments originating from the stomach cavity can capture larger food particles. These filaments are also capable of digestion. The stomach cavities of colonial corals are interconnected. Food obtained by one polyp can be passed to other polyps in the colony (how cool is that). It excretes solid wastes through its mouth.

Corals can reproduce both sexually and asexually. An individual polyp may use both reproductive modes within its lifetime.

Corals reproduce sexually by either internal or external fertilization. The reproductive cells are borne on mesenteries (membranes) that radiate inward from the layer of tissue that lines the stomach cavity.

a. Internally fertilized eggs are brooded by the polyp for days to weeks. Free-swimming larvae are released into the water and settle within hours.

b. Externally fertilized eggs develop while adrift. After a few days, fertilized eggs develop into free-swimming larvae. Larvae settle within hours to days.

Synchronous spawning occurs in many corals. Polyps release eggs and sperm into the water at the same time. This spawning method disperses eggs over a larger area.

Sometimes, newly developing coral colonies split and form separate colonies. Budding occurs when a portion of the parent polyp pinches off to form a new individual. This is when asexual reproduction occurs.Budding enables the polyp to replicate itself several times and at the same time maintain tissue connections within the colony. Later, the same polyp may reproduce sexually.

Coral colonies growing in shallow water are often heavily branched. In contrast, deeper water corals often grow in sheets or plates. These flattened forms allow for more efficient use of lower light intensities in deeper waters. The growth rate of corals and coral reefs depends on factors such as light intensity, water temperature, salinity, turbidity, food availability, competition for space, and predation. Upward growth of coral colonies is generally between 0.5 to 4 in. (1-10 cm) a year.

Respiration (gas exchange) takes place through the body surface.

At one time it was mistakenly thought that coral grew at the bottom of deep tropical seas and succeeding generations grew on top of the dead calcium carbonate skeletons. This idea was dispelled by dredging operations that indicated that reef corals were able to grow only in shallow water.

Naturalist Charles Darwin's theory of coral formation is widely accepted. This theory recognizes three types of reefs: the fringing reef, the barrier reef, and the atoll.

a. The first type is a fringing reef. Fringing reefs border shorelines of continents and islands in tropical seas. Fringing reefs are commonly found in the South Pacific Hawaiian Islands, and parts of the Caribbean.

b. The next type is the barrier reef, which occurs farther offshore. Barrier reefs form when land masses sink, and fringing reefs become separated from shorelines by wide channels. Barrier reefs are common in the Caribbean and Indo-Pacific. The Great Barrier Reef off northern Australia in the Indo-Pacific is the largest barrier reef in the world. This reef stretches more than 1,240 miles (2,000 km).

c. If the land mass is a small island, it may eventually disappear below the ocean surface, and the reef becomes an atoll. Atolls are reefs that surround a central lagoon. The result is several low coral islands around a lagoon. Atolls commonly occur in the Indo- Pacific. The largest atoll, named Kwajalein, surrounds a lagoon over 60 miles (97 km) long.

The 3 types of coral reefs. (from left : fringing, barrier and atoll)

Little is known about the lifespan of corals. Generally, coral colonies may live for several decades to centuries.

Sadly, corals are in danger…


Ocean pollution poisons coral polyps. Pollution takes on many forms including oil slicks, pesticides and other chemicals, heavy metals, and garbage.

1. Ocean pollution poisons coral polyps. Pollution takes on many forms including oil slicks, pesticides and other chemicals, heavy metals, and garbage.

2. Fertilizer runoff and untreated sewage introduce added nutrients to coastal ecosystems. These elevated nutrient levels promote algae growth. Unfortunately, high concentrations of algae or solid sewage can overwhelm and smother the polyps.

3. Deforestation degrades more than just land habitats. When tropical forests are cut down to clear land for agriculture, pasture, or homes, topsoil washes down rivers into coastal ecosystems. Soil that settles on reefs smothers coral polyps and blocks out the sunlight needed for corals to live.

4. Coastal development and dredging ravages reefs. This development includes building seaside homes, hotels, and harbors.

5. Fishing with dynamite, cyanide, or bleach has killed coral reefs in the Indo-Pacific region. Between 1986 and 1991, half of the coral reefs in the Philippines have been demolished by these and other destructive fishing methods.

6. Besides fishes, fishermen harvest a variety of exotic seafood from the reef including conchs and lobsters. Overharvesting could lead to these species' demise. Careless handling of nets, lines, and lobster traps has led to some reef damage.

International seashell and aquarium trades have put a strain on coral reefs and reef inhabitants. Excessive collecting decimates reef species and upsets the balance of the reef ecosystems. a. The souvenir trade has created an international market for coral skeletons, shells, sponges, and other reef animals.b. Coral skeletons are also sold as "live rock" Live rock is popular in home saltwater aquariums because it is permeated with living bacteria and algae and acts a natural biological filter. The tropical fish trade has created a demand for reef fishes.

Careless water recreationist damage reefs. Divers and snorklers that stand on, sit on, or handle corals can injure the delicate polyps. Dropped boat anchors can gouge the reef and crush corals.
Divers should rest by floating or standing on the sandy bottom. They should be very careful not to grab on to any coral formations.)


A turtle chewing on a plastic bag which looks a lot like its favourite food-jellyfish.


NATURAL DISASTERS

a. A drop in sea level exposes corals.

b. A rise in sea level decreases the amount of available sunlight and may inhibit growth. Added emissions of carbon dioxide and other trace gases (called greenhouse gases) into our atmosphere may be causing a gradual warming of our planet. This warming could cause the polar ice caps to melt, thereby raising sea level.

c. Rises in sea level can also release nutrients trapped in soil.

d. Coral diseases can wipe out entire strands of coral reefs. Diseases may be connected to the sea level rise and nutrient level increase.

e. Coral bleaching occurs when coral expels its symbiotic zooxanthellae. As a result, the coral loses its coloration. Without zooxanthellae, the coral polyps have little energy available for growth or reproduction. Scientists aren't sure why bleaching occurs. Hypotheses include elevated water temperatures, ultraviolet radiation, and diseases or viruses affecting the zooxanthellae.

f. Major tropical storms can strip corals from miles of reef habitat.

That’s it about our beautiful coral reefs.

Here are videos on youtube perfect for introduction to coral reefs :








For more information, visit http://www.seaworld.org
and http://www.advancedaquarist.com/2007/12/aafeature2

Do leave any comments and thoughts as I continue dive depths to search for our next animal in view.

Do tell me if there is any particular animals that you are interested to know more about.

Have a nice day!
Cheerios!

Friday, 23 October 2009

Dive Into The Ocean with me

Hello mates... Dive Into The Ocean with me is a page specially dedicated to the ocean and marine animals. I have been a marine enthusiast since young, yet I have not been able to do much for the ocean. I would love to learn more about them and would love to share what i learn about them with you. I hereby invite you to join me as I dive the depths of the ocean in search of the wonderful secrets of the fascinating marine lives. The ocean is suffering in silence. It needs help from us. Hopefully through understanding, it can help reduce harm to them. I hope you will love the ocean and make your life as exciting and meaningful as much as it has done for me.