Saturday, March 31, 2012

Flamingo Tongue Snail

The Flamingo Tongue Snail, Cyphoma gibbosum, has a unique orange spotted pattern to what appears to be the outside of its shell.  But don’t be fooled!  The appealing bright coloration seen is part of the snail’s body.  Flamingo Tongue Snails wrap their mantel around the actual shell.  Surprisingly the shell itself is just plain white.  This might seem kind of strange, but there is a good reason behind this adaptation.  The orange spotted pattern is a warning sign for predators, because the body of the snail is toxic.  By wrapping the mantel of the snail around the shell, it allows potential predators to get a small taste of the toxins if the snail can not retract the mantel in enough time.  This turns the predators away and leaves little to no damage done to the shell.  The exposed mantle not only acts as a warning, but is also a tool used for respiration.  In fact the mantel functions as gills to bring oxygen in and to let carbon dioxide out.   
However, the Flamingo Tongue snail is not born toxic.  These animals are found in the Caribbean and southern Atlantic on coral reefs.  They feed on gorgonian octocorals.  The gorgonian octocorals contain high amounts allelochemicals, which are toxic to many other animals.  This snail also lays its eggs in the gorgonian corals.  They use the toxicity of the corals to protect the eggs from predators.  The hogfish, pufferfish, and Caribbean spiny lobster are some of the few natural predators of this snail.  Studies have shown that humans have recently been the greatest predator to this snail.  Divers have been over collecting this animal for its smooth white shell and some even collect the snails because they mistake the orange coloration as the shell.  

What Animal has the Sharpest Teeth?

When you think on an animal with sharp teeth, the first animals that come to mind are lions or snakes. This article is interesting because the animal with the sharpest teeth actually did not have a jaw. They actually have a circular mouth that would gnaw at its food. This bizarre animal is known as the Conodonts. They are long and slender like an eel. The animal lived 550 million years ago. There are numerous fossils that have been found. But, studies have recently found fossils that show evidence of the Conodonts’ teeth.
The study looked at the fossils from Wurmiella excavata. This is a species of the Conodonts. The researchers were able to show models of the animals’ teeth with the use of x-rays. There are three types of teeth formations that have been found: the single-cone, blade, and the platform type. The single-cone type has only one very sharp tooth. The blade type resembles a small saw. Finally the platform type with has a top and bottom that are slide past one another. (Muller 1978)
They are believed to be one of the first animals to have teeth. The teeth are shown in the picture below in a size comparison with a penny. The teeth are one-twelfth the width of a human hair. As you can see, the teeth are extremely small. The problem with these sharp teeth is that they are more prone to breaking. The teeth are able to sharpen themselves by rubbing together. They would slice food by sliding their teeth from left to right. The inter-angles of the blade-like teeth would have trapped the food in the back of the mouth and the slicing would move it the food forward. The fossilized teeth are very abundant in sedimentary marine rock. 

Bell, Alexandra, March 14, 2012 Jawless Vertebrate has the World’s Sharpest Teeth March 27, 2012

Tuesday, March 27, 2012

Coping With the Cold

         Ice presents a big problem for organisms that live in frigid climates. Once the temperature drops below freezing, ice crystals form within cells and eventually burst. However, to this day organisms are found living in these harsh conditions. So how do they do it? Organisms of all types including plants, animals, fungi and bacteria have developed ways to combat the threat of ice formation (Venkatesh,2008). One way organisms deal with these conditions is to produce antifreeze proteins (AFP’s). These are specialized proteins that aid in protecting the organism as the temperature drops. AFP’s do not stop the growth of ice crystals, but instead limit the growth to a point that doesn’t cause harm (Dalal, 2001). This is necessary because of ice’s ability to recrystallize. When water begins to freeze, many small crystals form, but then a few small crystals dominate and grow larger and larger, incorporating water molecules from the surrounding smaller crystals. Antifreeze proteins counteract this recrystallization effect and will bind to the surface of the small ice crystals and slow or prevent the growth into larger crystals (Griffith, 2004). This lowers the freezing point of water in the presence of ice while not affecting the melting point. This produces a difference between the freezing and melting points which is termed thermal hysteresis (Duman, 2004).

         AFP’s are a prime example of convergent evolution, which is when unrelated organisms evolve similar traits due to their environment (Venkatesh, 2008). By examining the proteins used by different organisms, scientists have discovered many different proteins have been selected to perform the same function. All of these are small proteins with a flat surface that is rich in threonine which binds to the surface of ice crystals (Davies, 2002). Three examples that produce a variety of AFP include the Notothenioids, winter rye and the mealworm beetle.
         The specific structure of AFP’s varies among fish, insects and plants. The binding sites on AFP’s are relatively flat and comprise a substantial proportion of the surface area in fish and insects (Davies, 2002). The protein’s quaternary structure allows for an overall tight surface-surface complementary fit. Binding to the ice is stabilized by van der Waals and hydrophobic interactions from strategically arranged amino acids that match up with the spacing in the crystal lattice (Griffith, 2004). This results in a non-colligative (not relying on proportion to concentration ratio), non-equilibrium lowering of the freezing point and restricting growth of the ice crystals (Davies, 2002). The most effective antifreeze proteins are made by insects, which lower the freezing point by about 6 degrees (Venkatesh, 2008).
Notothenioid "Ice Fish"
Many types of organisms utilize AFP’s. The most well-known are the Notothenioids because AFP’s were first discovered in them. Notothenioids are Antarctic ice fish that inhabits temperatures between -2°C and 4°C (Eastman,2000). The notothenioid AFP exists in several isoforms of different sizes, but all composed of a simple glycotripeptide repeat with the disaccharide galactose-N-acetylgalactosamine attached to each Threonine, and the dipeptide Alanine-Alanine at the N terminus (Liangbiao,1997). Besides these anti-freeze glycotripeptide proteins (AFGPs), there are three other structurally different types of AFP’s from various polar fishes suggesting that these unique proteins evolved independently at least four times (Liangbiao,1997). While the exact method of evolution is unknown the most likely method of evolution was identified throughcharacterization and analyses of notothenioid AFP and trypsinogen genes. Other organisms using AFPs include plants, bacteria, fungi, insects and frogs!

        A great deal of research is being done to apply AFP’s to several applications including industrial, medical, and agricultural application in different fields, such as food technology, preservation of cell lines, organs, cryosurgery, and cold hardy transgenic plants and animals (Venkatesh, 2008). One area where AFP’s have been successfully implemented is the dairy industry. AFP’s purified from cold adapted ocean pout have been used as a preservative in ice cream (Regand, 2006). The proteins are added to the fine ice crystals to prevent it from recrystallizing during storage and delivery. Researchers are also experimenting with AFP’s as a way to preserve tissues and organs that are stored at low temperatures (Regand, 2006). Utilizing these unique proteins the possible damage from ice crystals could be successfully reduced and hopefully have a major impact on the medical field as research continues.

Monday, March 26, 2012

Shape Shifters of the Sea!

The Sand Dollar

It is typical that a juvenile or baby will look like its parents, at least to some degree. However, this isn't always the case, and it certainly is not the case with the sand dollar. Everybody knows what a sand dollar looks like. They are disc shaped with the little star or flower shape in the middle. They are flat on the bottom because they are bottom dwellers.

The sand dollar larvae however, are very different. They are “shuttlecock” shaped (shuttlecock is like the shape of a 'birdie' from bad-mitten) and float around freely in the water. They are planktonic and freely drift with the water currents. As the larvae develop, they will actually begin to grow some arms.

 They begin with four and will end up with eight. By the time that they have a total of eight, they have found their place on the seabed where they being their life as bottom dwellers. This method of development, although it may be strange, is not uncommon to find in many other organism. The question then is, why? What is the purpose and reasoning behind this odd method of development? To get a better understanding of this, studies were done on the swimming patterns of the different stages of larval development of the sand dollar.

It is known that they live in turbulent waters. They thought that maybe the shape of the sand dollar larva help save them from the fate of other types of larva in these types of waters. Commonly, larvae will get stuck in vertically moving water and are forced horizontally and eventually are sucked down. It was predicted that the sand dollar larva’s unique shape could help them into up-welling water instead of being sucked down.

To test and study this method, computer simulations of the movements of all three larval life stages were down. Then, real larvae bobbing about in a tank were filmed and were compared to the simulations. Doing this, allowed them to determine how all three life stages moved. It was found that the larvae went into up-welling flows in mild turbulence like predicted. However, as the turbulence of the water increased, it was discovered that the larvae with four and eight arms were forced horizontally until they became trapped in down flow of the water. It was the larva with six arms that was drawn toward up-welling flows.
Even though differences were expected, these differences were much more extreme. The drastic differences in the swimming behavior of the different stages of larva indicated that their strange shapes do indeed change the ways in which they swim. It can allow them to choose where they swim to in the water column depending on their stage of development.

It is apparent that there is a significant reason as to why this organism has such a different method of larval development. The point is so that the larvae can choose where they travel to in the water column. Maybe different swimming behaviors are better at different stages to ensure an optimal spot to settle down on the on the seafloor to live the remainder of their lives as bottom dwellers.

Clay, T. W. and Grünbaum, D. (2010). Morphology–flow interactions lead to stage-selective vertical transport of larval sand dollars in shear flow. J. Exp. Biol. 213, 1281-1292.

Hydrothermal Seeps, the New Vents

When talking about the deep sea, most people think that life decreases the further down it goes and would eventually die out when there is not enough light or debris to support it. This is not true, however, since it has been proven that deep sea vents create their own biomes in which they support life that no one would have normally suspected. The hydrothermal vents create a biome in which the water is rich in heavy metals, minerals, and hydrogen sulfide. The base of the food chain in this biome is bacteria that are able to use the energy created from oxidizing the hydrogen sulfide. Organisms are then able to feed on the bacteria, and the food chain goes from there.
The organisms that live in this biome must have the adaptation to survive in such a harsh environment. These adaptations differ from the species that we normally encounter on Earth. This makes the hydrothermal vent biomes a large point of interest. These hydrothermal vents have been studied since the 70s, but hydrothermal seeps have not been studied until recently.
 Hydrothermal seeps are similar to vents in the fact that they support a biome in the deep seas where life would not be expected. 
These “cold vents” release methane which is used to support the life present. Vents and seeps are normally found together in the same areas, but there are cases in which a hydrothermal seep can be found alone. These seeps are able to support tube worms, deep-sea fish, mussels, clam beds, and crabs. There are many new species in the seeps as well. These species must adapt to the colder environment of the seeps from the extremely hot environment of the hydrothermal vents. It is amazing to find so much life in such a unique area of the world. It draws scientists to the question of whether systems like this are capable of occurring on different planets. This eliminates the need for the sun and can be formed due to tectonic plate interactions causing the release of chemicals and heat from the planet’s core. These conditions may be possible on other planets.


Sunday, March 25, 2012

It Will Cost You Your Arm

You hear of animals losing their limbs when being attacked by predators all the time. Lizards lose their tails, lobsters and octopuses losing legs... But nothing is more bizarre than an animal willingly removing an appendage after being attacked.
 The above video shows female boobys defending their nests from thieving crabs. The crabs take quite the hit from the birds and end up damaging their claws. Initially, I thought that maybe the damaged claws might be nurtured and eventually usable as before.  To my surprise, the crab simple popped off it's own arm; ripped right out of the socket.  The reasoning behind this is quite simple. Crabs go through a process called molting which regenerates the carapace that protects the crab's body as well as its other appendages. So, with each molt a new portion of the crab's appendage would be restored and eventually fully restored and fully functional.

The regrowth of an appendage begins with a bud in the place of the old appendage. This is evidence that the crab removed the appendage on its own accord. However, there are some creatures that suffer the removal of their appendages not by their choice and so the regrowth process is much different.
Sometimes, individual crabs have to regenerate both of their claws. In this case, the crabs become more of scavengers rather than predators. This would make defending themselves incredibly difficult but the regeneration process is not incredibly long (around a year) and in due time the crabs would have their appendages back and ability to defend themselves. Good things this is a quick process because it may have hosted an arm AND a leg.

Friday, March 23, 2012

Don't Let Looks Distract You....the Venomous Lionfish

The lionfish is one of the most venomous fish in the ocean.  It can have up to eighteen dorsal pins that are needle like. These numerous dorsal fins contain the harmful venom.  This venom is used as a defense against predators, but is not used to capture pray; it has very few predators.  Instead the lionfish uses its red and white zebra stripped pattern to blend into the surrounding habitat and has very fast motions when hunting.  Lionfish swallow their prey all in one motion.  
Although the spiky fins are not a threat to its prey, the venom of the lion fish can be lethal to predators and dangerous to humans.  Lionfish come in second for the greatest number of stings annually.  In a year, there are 40,000-50,000 people who report getting stung by a lionfish throughout the world.  The sting of a lion fish lasts for fifteen to twenty minutes and has a firing burn.  In some cases the sting of a lionfish may hospitalize victims or even result in death.  There is currently no anti-venom to this sting. 

 Lionfish are native to the Indian Ocean and the tropical Pacific Ocean.  This fish finds its habitat in coral reefs and shallow bays.  They have a life span of five to ten years and on average grow to be about a foot in length.  Lionfish use external fertilization to reproduce.  The eggs that are released by the females are then fertilized by the male as soon as the female releases them.  For twenty five to thirty days the eggs float in the ocean currents and as they hatch the larvae make their way back to the coral reefs to take refuge.  It takes a lionfish one to two years to fully mature.

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Wednesday, March 21, 2012

Similar to a Million Fireflies... in the Ocean

Bioluminescence of Firefly squid
Watasenia Scintillans, also known as the firefly or sparking enope squids, are cephalopods that have the ability to produce bioluminescence due to their photophores.  These photophores, covering their entire body, are controllable and are used as a lure for prey, a distraction of predators and as a means of communication with others.  The largest photophores are found near the eyes and on the tentacles.  The eyes of this squid contain double layered retinas and three different light-sensitive cells (or pigments), which may allow them to see simple color, and to
Firefly squid without bioluminescence
further distinguish between fellow firefly squid or a predator.  This is rare, and is not normally an ability of other squids because other squids only have one visual pigment.  They are relatively small, reaching a maximum length of about 7 cm.  The firefly squid resides in the Western Pacific Ocean near Japan and lives in depths ranging from 200 - 400 m.  During the day, firefly squids stay near the deeper parts of the ocean to avoid any predators.  However, at night and during the time of spawning, they head to the shallower parts.  At night they head to the surface to feed.  The life span of a firefly squid is, sadly, only a year.  This is because once they reproduce, the squids die.  On the bright side (ha), they produced many eggs to stabilize, or increase, their population.  During this time of reproduction, between March and May, the squids gather in Toyama Bay in Japan, and perform a kind of "light show" from their flashing of the photophores, which can occur in unison or alternately.   The light produced is a deep blue color.
Namerikawa Museum
Also during this season, the squids are heavily fished.  Predators of the firefly squid include sperm whales, sharks, larger fish, other squid, humans.  The firefly squid is a delicacy in Japan, and is referred to as "Hotaru-ika." 
Namerikawa is the home of the only museum, in the world, dedicated to firefly squids.  (The website for this museum is completely in Japanese and is not helpful for further description of the museum.)  Tourists interested in seeing this phenomenon are able to sign up for a 3AM sightseeing boat trip!  (3AM!)

The Japanese Dish, "Hotaru-Ika"

I was unable to find a video on youtube that I actually liked, but this works too.

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Sunday, March 18, 2012

Crouching Tiger, Hidden Dragon

      This dragon is one of the most incredibly camouflaged animals of the sea. The leafy sea dragon, Phycodurus eques, or commonly called Glauert’s sea dragon, is in the same family as sea horses and pipefishes. They aren’t too terribly large, only growing to about 14 inches. The leafy sea dragons are only found in certain areas. They are all over southern Australia, but are known to be from Geraldton in Western Australia, which is where its name comes from, to the Bellarine Peninsula, Victoria. They tend to live in shallower rocky reefs, seaweed beds, sea grass meadows, and structures primarily composed of seaweeds, hence, their intricate camouflage. Their bodies are covered with many leaf-like appendages.

These leaf-like appendages are extremely realistic. In fact, they are so realistic that many animals and organisms swarm to it for shelter and food because it just looks so real. Their many realistic seaweed-like appendages are not used in propulsion for swimming. They are only used as a camouflage mechanism and thus, cause this sea dragon to be quite difficult to find in its natural habitat. The leafy sea dragon also comes in a variety of colors which all are dependent upon location, diet, and age. They can range anywhere from yellowish-brown to green, or any typical algae coloration.  In addition, another defense mechanism is that they are covered in jointed plates instead of your typical scale. They also have sharp spines that line their bodies. With the combination of the intense camouflage, plates, and spines, they do an outstanding job at avoiding predation. In fact, they may not even have any serious type of natural predator. Their only downfall is that they are slow movers, so they heavily rely on their camouflage as a primary key defense mechanism against predators. Their little dorsal and pectoral fins do not provide strong swimming; rather they cause the leafy sea dragon to swim awkwardly. Thus, this sea dragon kind of bounces, tumbles, and drifts along in the water. These fins are also transparent meaning their predators cannot see them. Again, this is just another thing that allows these sea dragons to be so well camouflaged. Even the way the swim is seaweed-like!  Now that’s incog- NEATO!!

Friday, March 16, 2012

Shark fin soup

Sharks are some of the most magnificent creatures that have ever roamed this earth. They have flourished since before the dinosaurs. However, modern man has caused those numbers to drastically decline. One of the main reasons for the massive decline of shark population is shark fin soup. It is estimated that every years tens of millions of sharks die of a slow death due to this practice. The sharks are unable to catch prey without being able to swim. They drown if they stop swimming because they do not have a swim bladder. Or they are simply eaten by other predators because they are inferior now. Some shark populations have decreased by as much as 95%! Fortunately, there are various organizations dedicated to stopping this barbaric practice.

            Shark fin soup is an Asian delicacy that is usually served at special banquets such as weddings. With the modernization and growing economy in China, the demand for shark fin soup has greatly risen. Due to this, shark levels have unfortunately dropped as well. However, the fins themselves in the soup are virtually tasteless, it simply adds texture. The actual taste of the soup comes from the other ingredients. The Chinese also value shark fins for their alleged benefits such as to boost sexual potency, enhance skin quality, increase one's qi or energy, prevent heart disease, and lower cholesterol says Joyce Woo in her article in the Washington Post. However, shark fin soup actually has a significantly less amount of vitamins and minerals than normal shark fin soup. The demand for these shark fins is said to have doubled in the last decade.
            Shark fin soup is an extremely important battle for wildlife conservationists. In most cases when the shark is caught the dorsal fin is cut off and then the shark is tossed back into the water and left for dead. It is not like the fishermen just use extra fins from sharks that are already caught and being sold to supermarkets for the actual meat. Fortunately, a few states in America have banned the sale of shark fins, with California just passing a law outlawing the sale. Even some major supermarkets in China have outlawed the sale of shark fins. On the other hand, some opponents of the shark fin sale band say it is discriminatory to the Chinese culture since they have been consuming shark fin soup since the Middle Ages. In my presentation I will discuss the impact that shark fin soup has had on shark populations and explain the controversy of both sides.

Ocean Chemistry

The recent climate changes in the world have have lead to a change in the ocean chemistry. The marine animals are able to adapt to the salt water because of a process called "osmoregulation." This idea is not new the aquatic marine animals have always been able to live in salt water because of the diffusion of water from high to low salt concentrations. Salt is not the only aspect pertaining to the marine life, oxygen plays a major role as well. Deeper in the ocean an animal lives the less oxygen is available. The biochemistry within a marine animal is unique because studies show each animal has a different chemistry depending on how deep in the ocean they live. The oxygen minim zone occurs, but also CO2 starts to become important. The oceans release CO2 back into the atmosphere making the ocean a major driving force for the life on earth. CO2 is released impacting not only the animals but the pH of the surface.
Humans have a major impact of the acidity of the surface water.The ocean takes up about one third of all human carbon emissions. This number is decreasing due to not only the changing temperatures but the ocean chemistry shifting. Ocean chemistry is an area that has not been studied much. In the last three decades the most research has been done. The results show that the "rising temperatures are slowing the carbon absorption across a large portion of the subtropical North Atlantic. Warmer water cannot hold as much carbon dioxide, so the ocean's carbon capacity is decreasing as it warms." Because the warm water cannot hold as much CO2 the department of Global Ecology had predict that the amount of Ca and other elements would change within the ocean. The researchers proved this to be correct.
Because water is such a unique molecule the studies become more difficult. Water is able to dissolve substances, so salt and minerals become important. Water is an element that can be present in all forms, a liquid, solid, and gas. The ocean will contain water in all three forms making the chemistry of the water a challenge to study. Density differences between different masses of seawater are one of the major driving forces of deep-sea circulation. Ocean chemistry is an area that can be studied much more, because there is so much yet to learn about the ocean and how the chemistry will play a role for the future of the ocean and the world.