Thursday, January 5, 2012

Deep sea Angler fish (Melanocetus johnsoni)

Anglerfish belongs to the order Lophiiformes, which includes three suborders, 15 families, and about 215 species... (For all those who didn’t understand these scientific terms need not worry ;)…..)

Deep sea has scarcity of both light and food , thus organisms living here exhibit various adaptations ...



Male Angler Fish


Deep sea angler fish is also called as "common black devil". It is dark grey or black in color and the skin can reflect the blue light emitted by other bio luminescent organisms of deep, and thus can appear almost invisible to them.



Female Angler Fish


An important adaptation of the female angler fish is the elongated dorsal spine, wide mouth with needle like teeth, round and wide body and much larger than the male (female is around 10 cm in length whereas males ten times smaller). Elongated dorsal spine supports photophore that can produce blue green light by bioluminescence which helps to attract prey. This illuminated lure can be moved in any direction while the fish is stationary …such that they are not noticed.

It has soft bones, jelly like skin and powerful jaws which can be widened to such an extent that it can swallow prey twice the size of its entire body.

Male angler is very tiny as compared to female and is black in color. Soon after birth, male angler fish searches for female to attach itself with help of their pincer like mouth. This is so because as it matures its digestive system degenerates and it can’t feed on its own…. only option is to find a female or die. Once he bites into her skin to attach itself, he releases an enzyme that dissolves the skin of his mouth and that of her body. Almost all his parts r degenerated including eyes but only gonads remain. Thus he becomes part of her body as the blood vessels fuse. Male spends the rest of its life joined to the female like a parasite, getting all of his nourishment from her body an thus his growth is ceased except for the development of reproductive organs. A female can carry up to six males on her body at a time such that when female is ready to spawn she has fresh supply of sperms. Below picture shows female angler with males attached to her body.









The female lays her eggs in thin sheet of gelatinous material (one meter wide and nine meters long). this sheet of eggs floats free in the sea until the eggs hatch into tiny larvae. Once hatched , the larvae swim to the surface and feed on plankton, Once they mature , they then return to the deep sea.


Moeraki Boulders


If u happen to visit New Zealand don’t forget to put Moeraki, a small village on the coast south of Oamaru on your must see places list. What u will see here on the koekohe beach is the amazing grey colored, large and spherical boulders emerging from the sandstone cliffs occurring scattered on the beach.




They are mainly composed of mud, silt , clay and calcite and are 2-3 meters wide.These boulders are hollow inside and have large cracks called septeria.




These concretions originated near the surface of sea floor million of years ago. The process of crystallization of calcium and carbonates around charged particles in muddy undersea sediments gradually formed the boulders taking around 4 million years of time.




According to Māori mythology, the large sailing canoe named Āraiteuru carrying the chiefs was destroyed and the remains were washed ashore. The fishing net and the water gourd (calabash) of Āraiteuru were turned into stone at Moeraki in the South Island, where they can still be seen. The canoe itself remained at a place called Matakaea (Shag Point).

Although these boulders are said to be unique, but quite similar kind of boulders are also seen in Argentina, France, Russia, China and Bosnia.Concretions around 3 meter wide are seen along the cannonball river, North Dakota, (north-central United States) also concretions much wider than this is seen in western United States (Central Wyoming). Some boulders as wide as 6 meters are seen at rock city in Ottawa County, Kansas.

Surprisingly scientists have also found such kind of formations on mars too and have named them as martian blueberries (grey blue color hematite concretions).

Friday, June 24, 2011

Shark Liver Oil

Word shark reminds us about the the extremely horrific scenes from movies and many comic scenes in cartoons :p…..the famous shark dorsal fin that makes many cartoon characters run for their life in water (by the way shark fins are used to make soup :D…). Well u should be happy to know Shark has other uses too :P other than being dangerous creature but edible ……;)

There are 368 species of shark divided into 30 families. Their body is made up of cartilage and they show internal fertilization. They are mainly found at the depth of 2000 meters or so and in almost kinds of waters. Their size may range from 7 inches to 50 feet. Not all sharks are dangerous , only 25 species of shark are known to attack people out of which Bull shark is the most frequent attacker as it is found in shallower waters.

A shark's liver concentrates and stores oils and fatty acids. The liver functions in energy storage and buoyancy. It takes up 90% space inside the body cavity. Shark Liver oil is used for medical as well as nonmedical purposes . Liver oil is extracted from the species such as, the deep sea shark (Centrophorus squamosus), the dogfish (Sqaulus acanthias), and the basking shark (Cetorhinus maximus) .

Sqaulus acanthias


Centrophorus squamosus

Cetorhinus maximus


The liver oil obtained from cold-water sharks is a rich source of alkylglycerols (group of ester-linked glycerol), squalamine, and squalene, chemicals that could be used to cure cancer by killing tumour cells indirectly and also to reduce the side effects of chemotherapy. White blood cells play important role in immunity and most of them are killed during chemotherapy.These chemicals are also used to stimulate immune system by increasing the biosynthesis of the platelet activating factors and may be effective against diseases like AIDS, arthritis, chronic fatigue, fibromyalgia, or psoriasis. Still a lot of research is going on this topic and the evidences in support are fewer.

It has antioxidant properties and is used to maintain healthy skin and also for treating acne. Skin cancer patients apply oil directly to skin. It is the source of vitamin A and D which is required for healthy skin.

Shark liver oil is used in the tanning and textile industries, as a lubricant and also as a rich source of vitamin A. It is used as high-grade machine oil in textile industries and also to coat the hull of wooden boats.

Shark oil barometers are used to know weather conditions in Bermuda . It is said that Shark liver oil changes from clear to cloudy with electrical changes in atmosphere. These changes alert the shark about the upcoming storm so that shark moves to safer place as deep water, this property of oil is retained even after extraction from shark.

Tuesday, February 22, 2011

Poison Dart Frogs

Have ull Nytime thought how poisonous a frog could be ?? What if I say that frog could be listed in top ten most poisonous creatures on earth?

Well…obviously all frogs are not poisonous …I am here talking specifically about Poison Dart frogs also called as poison arrow frogs….which belong to Family Dendrobatidae exhibiting aposmatic coloration(to warn predators frm attacking) and have bright colors.

They are small in size ranging from one inch to two nd half inches and known to be active during daytime.....usually found close to ground some species may be found at upto 10 meters height on trees ….Their average lifespan is 1-3 yrs in wild forests whereas upto 25 yrs when bred in captivity..

Natural habitats include subtropical or tropical moist lowland forests, subtropical or tropical high-altitude shrubland, subtropical or tropical moist montanes and rivers, freshwater marshes, intermittent freshwater marshes, lakes and swamps……..

Golden dart frogs (Phyllobatus terribilis) are one of the most poisonous and are found in the rainforests and known to be endemic to Pacific coast of Columbia…..they usually feed on ants and insects or small beetles …the alkaloid poison is stored in skin glands.

Their mode of reproduction is external fertilization..males use vocal sounds to attract the females..often there r fights too between males....nd da stronger one gets da gal!!! :D


Have a nice look at the picture :) as one Golden Dart frog has enough poison to kill 10 human beings…Even if this frog walks over a piece of cloth and your pet comes in contact with the cloth , it would result in the death of ur pet..:(….

Its also interesting to know that in earlier times locals of Columbia rainforests used the frog venom for hunting….The Emberá people exposed frog to the heat of a fire, and the poisonous fluid that was released was collected. The tips of weapons such as arrows and darts were dipped in the fluid, and used to hunt. The poison effect was more than 2 yrs….


Toxins from the frog are being investigated for uses as muscle relaxers, pain relievers and appetite reducers.Some species like Epipedobates tricolor are useful ..as chemicals derived from them i.e epibatidine is a powerful painkiller….

Snake called as Liophis epinephelus has developed resistance against the toxin of these frogs and feeds on them..although it is not completely immune to high quantities of toxin…. Some large spiders also feed on blue poison dart frogs…tadpoles are devoid of any poison and thus fall prey to snakes and flies too…

Wednesday, April 7, 2010

Corals


We all r familiar with the word “coral”… although some do get confused whether it is grouped under plant or animal kingdom (if u take it in scientific  sense as there are exceptions ) because….. (When I asked my sister whether she had heard about coral she told me,”yea… I know… it’s a software rite?”).
Thus for those who haven’t heard about corals here are some pictures…


Yellow scroll

Stony coral


Smooth flower coral


Sea rod


Boulder coral


Apo coral


Mushroom coral


Pillar coral


Brain coral

Well, corals were first believed to be plant but later on were grouped under animal kingdom as animal cell membranes were found in them. They are found in shallow  and clear waters in colonies .

Uses
Corals not only play an important role as the habitat for various other organisms but also have
 a great economical importance as well  i.e. for trade, jewelleries and for aquarium purpose (live corals).

Ladies tend to prefer wearing coral jewelleries as some people believe that wearing red coral gives protection and power( in astrology) , also it is used to reduce the anger …people with “vrishchika rashi - scorpio“ are adviced to wear this gemstone by astrologers (I knw this since I am a scorpion too..).

Coral sand mining is extensively done in certain countries whereas coral rock is also extensively used for building purposes. ( some fishes take up the limestone skeletal material of coral, digest  the living tissue and excrete inorganic components as silt and sand).

 Reef-building corals from shallow waters are known to contain a suite of water soluble compounds (collectively named S-320) which strongly absorb near-UV light. Compounds of this type have now been isolated from the Pacific staghor coral. (W. C. Dunlap ,et.al.)Thus these substances can be used as sunscreen agents.

 Substances such as Prostaglandins (anti cancer drugs )can be also obtained from corals .
Various studies showing corals as a source of prostaglandins are done one such example is
 “A Rare Prostaglandin from the Soft Coral  of the Indian Ocean”A. S. R. Anjaneyulu, et.al.

 There have been many studies for the use of coral calcium for bone transplants. A biomaterial derived from natural corals with surgical applications is the calcium carbonate Biocoral. This substance has been used in surgeries and proved to b successful…(Natural coral calcium carbonate as alternative substitute in bone defects of the skull -Soost F et.al).
The structure of the commonly used coral, Porites, is similar to that of cancellous bone and its initial mechanical properties resemble those of bone.( “Natural coral exoskeleton as a bone graft substitute: a review”. -Demers C,et.al.)

Some coral communities called as microatolls can be used for radioactive carbon dating .

Some of the threats to coral ecosystem could be :
Due to change in temperature or salinity (salt content of water in simple language )
Corals could be affected if the water temperature increases than the optimum required even by one or 2 degrees. Decrease in salinity could also affect.

Pollution
 Land surface  runoff carrying nutrient rich soil can enhance the growth of certain algae and their overgrowth may lead to oxygen depleted conditions  and also affect penetration of sunlight into the water. Some nutrients may be harmful. Phosphates in higher concentration may slower growth of coral skeleton whereas high nitrate levels may turn out to be toxic.

Increase in CO2
Carbon dioxide  absorbed into the ocean from the atmosphere reduces calcification rates in reef-building. The dissolved carbon dioxide gas reacts with the water to form  carbonic acid and thus acidifies the ocean which reduces the pH of ocean surface waters. Reduction in pH can cause dissolution of carbonate ion.

Coral bleaching
Corals exhibit an endosymbiotic(give nd take relationship by staying within da organism) relationship with photosynthetic microalgae having color called as “zooxanthellae”.(zooxanthellae live inside the coral tissue).
During the daytime coral polyps utilize the products of photosynthesis given out by zooxanthellae and during the night they feed on plankton by using their tentacles. Zooxanthellae is benefited by the waste products like N, P, CO2  which it requires to grow. During the time of higher photosynthetic rate zoozanthellae are expelled from the tissue by corals in order to maintain balance, this is known as coral bleaching but when the photosynthetic rate goes still higher and more than necessary zooxanthellae are expelled it may lead to loss of co phototsynthetic pigments and the color. If such kind of condition prevails foe long time then it may lead to death of colony.
  Global Warming, thought to be the main cause of coral bleaching, weakens corals which are then prone to diseases including black band disease,white band disease and skeletal eroding band.
Overfishing
Certain fishing methods such as cyanide fishing and dynamite fishing may cause damage to reefs.
If only one kind of fish is targeted for fishing then it alters the food chain and might encourage the growth of corallivores( coral predators).One such eg.is  crown of thorns starfish which is normally fed upon by sea snail called Giant triton but they r  overfished. And thus starfish shows excessive growth due to reduced predator pressure.







Friday, February 12, 2010

Beautiful cloud patterns at Equatorial Indian Ocean....

We had around 36 days cruise at Equatorial Indian Ocean.....during the entire cruise, one of the things that i found very interesting ( other den my work , experiments and results) is the clouds in da sky during the day and da stars at night....the reason i might have noticed da beauty of clouds to such an extent,could be because da only thing u can see during da cruise is da huge sky above and water below...whichever direction u might see den...ofcourse no land to be seen during da entire cruise...

On da ship during the night time....star gazing is what we find people doing which includes even those fellows who were never interested in such stuff.......especially wen it is a high time during da long cruises nd u r homesick already.....

Here are some pics of the cloud patterns tht were clicked during the entire span of dis cruise....









































Isnt this a real beauty??