Crusty Friends: The Isopod and the Giant "British" Spider Crab

This member of the Arthropod Phylum (right) was caught in the Pacific and presently makes it home in the National Sea Life Centre in Birmingham, Great Britain. The Japanese Spider Crab is considered a delicacy and hunted seasonally in crab fisheries in the Pacific.

It is growing stronger and bigger everyday and currently measures in at approximately 10' across and could grow to 15 feet in leg span. These somewhat lethargic predators in the briny deep inhabit depths up to 8 ,000 feet or more.

The beast on the top left is another member of the jointed-legged Arthropod Phylum, and is called an isopod, and inhabits the deep realms of the ocean bottom as well. This crustacean pictured above is approximately one foot in length.

Killer Whale Fatally Attacks Trainer in Orlando

The story broke on Wednesday, February 25, as an experienced trainer, 40-year old Dawn Brancheau, was twice dragged and drowned underwater by the 30-year old killer whale, Tilikum. Tilikum is one of the largest, and oldest, killer whales in captivity today.

Sea World in Orlando is struggling to deal with the incident and the controversies it faces with the public and with scientists.

Tilikum was captured in 1983 in Iceland at approximately 2 years of age. There are only six or seven, of the now 42, killer whales older than Tilikum presently in captivity around the world.

There are 42 Orcas in marine parks and zoos today in the world, and Tilikum is known as the one of the more controversial captive cetaceans, having already been implicated in the deaths of two people in '91 (female trainer in Sealand of the Pacific, British Columbia, Canada) and in a 27-year old visitor in Sea World Orlando in '99 (a man who had breached security and perhaps had jumped into the pool and died of hypothermia).

Tilikum weighs in at approximately 12,300 lbs. and is nearly 22' in length. Sea World in Orlando currently has eight Orcas, members of the Order of toothed whales, odontocetes, in captivity. Orca orcinus, is the largest member of the dolphin family, the Delphinidae.

Since 1960, over 150 killer whales have died while in captivity in ocean parks around the world. Scientists agree that females in the wild can live up to 50 years and males up to 30 years.

In 2004, this well documented attack in at Sea World in Texas involved trainer Steve Aibel and further illustrates the dangers of close contact and unpredictable work with these wild marine animals.
In 2006, Kasatka, a 30-year old killer whale in San Diego dragged an experienced 33-year old trainer underwater and held him at the bottom of the pool. The trainer escaped with his life fortunately.

Permian Extinction

What is Permian Extinction: Permian extinction, which occurred about 251 million years ago, is the greatest mass extinction that ever happened in the history of earth.

Immediate Consequence: Marine lives received the most damage from the mass extinction. The Permian extinction killed off at least 50 to 60 percent of all marine general, eliminating about 90 percent of marine species.

What caused it: It is accepted that a continental-scale volcanic eruption of lava in present-day Siberia caused the Permian extinction. Some examples of consequences were depletion of oxygen, acidification of ocean waters, global warming, and climate fluctuations. According to Sid Perkin's article in "Science News" Jan 14, 2010, Usually, the most limiting nutrient for phytoplankton is iron. However, acidification of ocean drops phytoplankton’s iron uptake, therefore dropping photosynthesis rate. This phenomenon further exacerbated oxygen depletion in the ocean during Permian extinction.

Post Permian: Animals became greatly more diversified as time passed.

- For example, according to an article (The New York Times, Sept 1 2009)by Henry Fountatin, while only three genera of one ammonoid suborder survived the extinction, after million years, more than 100 genera thrived.

- According to the article "The Search for Evidence of Mass Extinction"(Natural History, Sept 2009), in contrast to simple, filter-feeding, and sedentary benthic animals that dominated the Permian, after the mass extinction, more diverse group of mobile animals began to appear in abundance. Some of the new animals were highly sophisticated and bore better skeletal defenses.

post permian marine life

- According to the same source as above, there was a trend toward greater evenness in abundance. The ecological niche also became more diversified compared to the Paleozoic period when the majority of organisms competed for the same resources, which were matters floating in the water column.

- Post-Permian period, 251 millions years after the extinction, full-scale invasion of marine reptiles began. There were two reasons for this: one, the extinction wiped out nearly every marine creature, which meant that the sea was empty for colonisation. Two, the huge volcanic eruption brought up the global temperature, and the reptiles were able to thrive in ice-free environment. (James O-Donoghue, New Scientist, Oct 27 2009)

Concluding Comments: Despite intervals of decline due to mass extinctions, the most catastrophic being the permian extinction, marine genera increased overall since the Cambrian period. This trend highlights the resilience of nature, showing that survivors, no matter how decimated, will eventually evole new complex communities and will endure modern environmental degradation due to global warming.

Related Video Link: http://www.youtube.com/watch?v=hDbz2dpebhQ

Primary Source:
Scott, Peter J., Matthew A. Kosnik, “The Search for Evidence of Mass Extinction.” Natural History (September 2009): 26-32. Feb 8, 2010.
Supplementary Sources:
1. James O-Donoghue. “Real Sea monsters: The hunt for predator X.” New Scientist. Oct 27, 2009. Feb 11, 2010.
2. Sid Perkins. “Acidifying Ocean May Stifle Phytoplankton.” Science News. Jan 14, 2010. Feb 11, 2010.
3. Henry Fountain. “Some Mollusks Thrived After a Mass Extinction.” The New York Times. Sept 1, 2009. Lexis-Nexis. Cox Milton Library. Feb 11, 2010.
Image Sources:
http://web.uvic.ca/~stucraw/Lethbridge/MyArticles/GlobalEconomy_files/IMAGE006.JPG
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWG7U2IjWBz6MpRIKeu89legAJ2u3wPBN90N64jZ2Ls4jzsUj6_ViiwyA2E6HPueART36XRxSwqKrKjz8Na57pi10zpsRjLzCqu_8hpD8SAinyACKO0cij_zzQ4RA4sM94ZZtfO0Yx2IQ/s320/permian_marine.jpg

Whale Falls: Not Just a Carcass

Dead whales that have sunk to the bottom of the ocean have been investigated in the past. But not until 1987 did researchers come to understand what an important role whale falls play in the oceans. In 1987, researchers discovered a dead and decaying whale on the typically “nutrient-poor” seafloor in Catalina Basin, off the shore of southern California. Unlike the usual barren, lifeless seafloor, the area surrounding the dead whale was surrounded by a diverse population of organisms (1). Hag fish, sharks, snails, bristle worms, and “zombie” worms surrounded the carcass, giving the researchers to believe that the dead whale was an important part in the survival of many organisms living in the deep seas harsh conditions.


Smith, an oceanographer from the University of Miami at Manoa, returned to the site of the whale fall to investigate the remains about a year later. Smith and his team discovered several previously unknown species. Other species found at the site were usually only found in areas rich in nutrients. This dive helped Smith and his team to see that whale falls, in fact, do release necessary nutrients into the surrounding waters instead of just being a waste product on the sea floor.

Whale falls are observed in three different stages (1):
1. Mobile scavenger stage- many hagfish and sleeper shark bite or take away large pieces of meat.
2. Enrichment opportunist stage- Lasts up to two years. High density of low diversity animals colonize the area.
3. Sulfophilic stage- Longest stage. Bacteria break down lipids in the bone. This stage generates energy for growth.

Whale fall community

They found new species of worm living in the dead carcasses of whales off the coasts of Sweden, Norway, and California. One of the new species found was called the Vigtorniella ardabilia, a chrysopetalid annelid. The massive bodies of whales, after falling to the sea floor, can provide nutrients to surrounding marine life for up to 8 years.
Unfortunately, the whale population has decreased in size. According to Smith and his team, whaling has caused more 40% of North Atlantic whale fall species to go extinct (6). Major whaling countries such as Japan, hunt for whales because of the large amounts of valued meat and oil.Each year, the hunting of whales is a heated topic. People hold various arguments. Some say that whaling is just wrong, some say that killing more whales will give a higher yield in fish, and some say that killing whales will bring back more fish to the sea (5). Many whales have died being beached. As they were washed up, their great weight crushes the internal organs after being washed up on land. After being washed up on land, the whales body temperature changes to a temperature they are not used to. The fluctuation of the temperatures through out the day is something the whale is not used to. An interesting point to wonder about is "The whales do not die because they are stranded; they are stranded because they are dying" (4). It is unfortunate that many of the whales get seriously injured by nets or pollution in the ocean and whale enthusiasts such as the men and women on the show "Whale Wars" are taking steps in preventing whaling.




Sources:

1. (Primary) http://www.scientificamerican.com/article.cfm?id=the-prolific-afterlife-of-whales
2. http://www.scientificamerican.com/blog/post.cfm?id=new-worm-species-found-in-unusual-h-2009-09-25
3.
http://www.uwrf.edu/biology/electives_dir/444_dir/VSmith/Page1.html
4.
http://www.time.com/time/magazine/article/0,9171,847940,00.html
5. "http://www.sciencemag.org/cgi/content/full/sci;323/5916/880?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=whale&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT"
6. http://www.sciencemag.org/cgi/content/full/sci;307/5713/1190c?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=whale&searchid=1&FIRSTINDEX=10&resourcetype=HWCIT

Jellyfish: A Thriving Species
Jellyfish are a fascinating and mysterious creature belonging to the phylum cnidaria. Lacking a brain, they rely on a central nervous system that has receptors, which are able to detect light, odor, and other responses. Though jellyfish lack complete control of their movement, they use their radial symmetry to detect food and danger at all angles as they range from shallow waters to depths below 12,000 feet. Jellyfish reproduce sexually, as the gonads of males release sperm, which is swept into the mouth of females, and warm climates are usually better suited for breeding.

As global warming causes ocean temperatures to rise and the pollution of ocean waters causes the rise of plankton, in addition to the overfishing of jellyfish predators, jellyfish have been “invading” the seas across the globe. Not only have scientists seen an increase in this species belonging to the phylum Cnidaria, but they have also seen a greater area covered with migration patterns. In Northern Ireland “a salmon farm lost its more than 100,000 fish to an attack by the mauve stinger, a jellyfish normally known for stinging bathers in warm Mediterranean waters” (Michael Casey, Boston Globe). Such problems are not isolated in the Northern Atlantic, but across the globe off the coasts of China, Korea and Japan. Fisherman have seen the Normura jellyfish, the worlds largest jellyfish growing up to a diameter of 2 meters and 450 pounds, decimate their catch. These gigantic jellyfish find themselves caught in the fisherman’s nets and either crush the fish sought after due to their immense size, or sting the fish until dead. These jellyfish invasions have “cost the industry up to 332 million a year” and have even put fisherman’s lives in danger as “jelly filled nets capsized a ten ton trawler off the east coast as the crew tried to pull them up” (Michael Casey, Boston Globe) however all of the fisherman were rescued.

‘

Casey, Michael. “Jellyfish thrive as seas warm, threatening fishing industry worldwide.” The Boston Globe. Proquest Direct Multidisciplinary. November 27, 2009. Viewed February 18, 2010.
South Carolina Department of Natural Resources, Sea Science. “An Information/Education Series from the Marine Resources Division: Jellyfish;” 2005. Viewed February 18th, 2010.

Hydrothermal Vents

Recently, scientists have discovered and recorded the deepest erupting volcano yet found. The eruption occurred in the Pacific Ocean almost 4,000 feet below the surface near the islands of Samoa, Fiji and Tonga.
The scene was extraordinary. Scientists saw “large molten bubbles approximately three feet across bursting into cold seawater.” The sea vents produced massive amounts of red, hot lava, which traveled across the deep-ocean seafloor. Since the water near the eruption is so acidic (between battery acid and stomach acid), Tim Shank, a biologist at WHOI, was surprised to find that shrimp were the only animals living and thriving in this area. Julie Huber, a microbial oceanographer at MBL, was able to sample the fluids around the eruption for microbe life. She found that most of the microbes collected were dominated by bacteria; however she also realized that compared to other vent sites studied, the bacteria diversity was relatively low. This suggests that the microbial community at this specific site (West Mata volcano) could potentially be in the early stages of development. Scientists believe that most (almost 80% of) eruptive activity on Earth occurs in the ocean. Furthermore, most of the volcanoes are in the deep sea.
Living conditions at a hydrothermal vent is very extreme: “Pitch darkness, poison gas, heavy metals, extreme acidity, enormous pressure, water at turns frigid and searing.” One of the most prominent ingredients among the deadly toxicants that come from the vents is hydrogen sulfide. This gas is lethal to most organisms but the creatures and microbes depend on it. Because hydrogen sulfide reacts with oxygen, when the fluids from the vents come in contact with the ocean water, a reaction occurs, which releases energy. The microbes capitalize on this reaction by creating organic compounds with the use of carbon dioxide. Larger creatures then use these organic compounds, which are essential for them to live.

Three of the best understood deep-sea creatures are: tubeworms, clams and mussels. Tubeworms are the most abundant animals. Baby tubeworms can swim; however, the adults are sessile and have no mouth, gut or anus. Thus, they must rely on the bacteria that live within them to provide them with a source of nutrition. They use their tip to take up sulfide and oxygen from the vent water. Then the bacteria convert these chemicals into food for the tubeworms. Like tubeworms, mussels and clams rely on a symbiotic relationship with bacteria. Since mussels are filter feeders, they are able to use more than one bacterial symbiont, and thus, they are able to survive further away from direct source of vent water.

http://www.noaanews.noaa.gov/stories2009/videos/west_mata_eruptionweb.mov

Sources
Primary: http://www.noaanews.noaa.gov/stories2009/20091217_volcano2.html, Scientists Discover and Image Explosive Deep-Ocean Volcano, February 22, 2010.
1. http://www.mbl.edu/news/press_releases/2009/2009_pr_12_21.html, Gina Hebert, MBL Scientist Helps Discover Deep-Ocean Volcano, Finds Thriving Population of Extreme Microbes, February 22, 2010.
2. http://www.pbs.org/wgbh/nova/abyss/life/extremes.html, Peter Tyson, Living at Extrremes, February 22, 2010.
3. http://www.amnh.org/nationalcenter/expeditions/blacksmokers/life_forms.html, Deep Sea Hydrothermal Animals, February 22, 2010.

Creatures of the Deep

For years people thought that life could not exist in places without light, at just above freezing temperatures and at crushing pressures so powerful that some minerals simply dissolve. But we were wrong. Scientists have recently found that life can exist at depths of 11 km under the ocean’s surface, the Challenger Deep, with the discovery of single celled foraminifera; these microscopic creatures use debris that falls from above to build their homes. Technically deep-sea creatures occupy a zone 1800 m below the surface, but in this blog I will be covering a wide variety of creatures that live in or below the photic zone, a depth where the light is insufficient for photosynthesis to occur. Such fish as Fangtooth, anoplogaster cornuta, or the deep-sea Angler, Melanocetus johnsonii, both of which occupy the midwater range, 700-1000 m.

Because there is no light where these fish live, they have to rely on methods other than sight to catch their prey. Many fish have evolved their eyes making them larger so as to catch the bioluminescent light that fish like the anglers give off: this adaptation is used by both prey, as a way to communicate during mating season, and predators as a way of attracting potential food. The angler literally fishes for his food: he uses a glowing appendage called a photophore to attract his prey, waving it back and forth as a lure.

It is not uncommon for fish living below the photic zone to prey on fishthat are bigger than itself: gulper eels have evolved to have detachable jaws so they can swallow prey 3x bigger than themselves. Other fish have oversized teeth so they can rip and tear at preys much larger than themselves. One example of this is the Fangtooth fish, which has a jaw filled with teeth capable of taking down large prey. The Fangtooth has some of the nastiest teeth in the entire ocean: according to BBC’s Blue Planet the Fangtooth has the largest teeth in the entire ocean proportional to its body. The Fangtooth fish is part of a group of deep-sea fish that are diel migration fish: they spend the day in the deepest parts of the ocean, but at night they migrate to shallower waters to feed.

Recently there have been thousands of discovered creatures that live below the photic zone, but scientists say that there is even more to come. Some marine biologists hypothesize that there are millions of unidentified species living in the deepest parts of the ocean.

http://www.britannica.com/EBchecked/topic/457662/photic-zone

http://www.sciencedaily.com/releases/2007/05/070516133018.ht http://www.smithsonianmag.com/science-nature/deep.htmlhttp://www.montereybayaquarium.org/animals/AnimalDetails.aspx?enc=Z5SIVkZ+n+WJB8kogvD/1A==

http://deepsealife.net/

http://dsc.discovery.com/convergence/blueplanet/photo/photo.html

In defining the general topic of a-sexuality, the Britannica Encyclopedia explains that parthenogenesis is the

“biological reproduction that involves development of a female (rarely a male) gamete (sex cell) without fertilization. It occurs commonly among lower plants and invertebrate animals, particularly rotifers, aphids, ants, wasps, and bees. An egg produced parthenogenetically may be either haploid (i.e., with one set of dissimilar chromosomes) or diploid (i.e., with a paired set of chromosomes).” In larger animals, however, few are able to parthenogenetically produce offspring that will flourish to the same extend as sexually-produce offspring. One species that has the ability to reproduce without the male gamete is the Komodo dragon. The “reproductive plasticity” indicates that the female Komodo Dragons have the ability to switch between asexual and sexual reproduction, depending on the availability of a mate. Similarly to the dragons, some species of snakes maintain similar abilities. Parthenogenesis, although noted in various reptiles, is most notably seen in New World lizards of the Teiidae family, Old World lizards of the Lacertidae family, and the Brahminy blind snake, and within these populations, all of the snakes are composed entirely of genetically identical female individuals, or clones. Although recent research has shown other types of snakes to reproduce asexually and still maintain males, I found the first three to be the most interesting. The populations lack the necessity of males as they can reproduce perfectly without the male gamete, and each offspring has identical DNA. Sharks, however, primarily rely on sexual reproduction of offspring, with some exceptions (cases in which no males are available for mating). A recent study shows that some parthenogenetically reproduced sharks are viable offspring, with life spans similar to sexually produced sharks. After studying the first known case of a virgin female shark producing multiple offspring that survived, scientists found that two of the offspring have survived five years since birth. Earlier research found that the offspring of parthenogenetically reproduced sharks did not survive, making the recent study the first known of its kind. In order to be certain that the sharks indeed had no father, scientists examined the DNA of the offspring and found all areas of the genome to be inherited from the mother. The new development in shark studies indicates that parthenogenesis is an active participant in shark life, and not merely a death sentence for the offspring.

Nature Journal, viewed February 10, 2010

http://www.nature.com/nature/journal/v444/n7122/abs/4441021a.html

Gordon W. Schuett on September 16, 1997, as reported in The Sonoran Herpetologist, the Newsletter of the THS, Vol.11, No.9, September, 1998.

Science Daily, viewed February 8, 2010

http://www.sciencedaily.com/releases/2010/01/100125094518.htm

Britannica Encyclopedia. Viewed on February 8, 2010. http://www.britannica.com/EBchecked/topic/444810/parthenogenesis

Images via google images

Giant Squids

Just last year in September 2009, the National Oceanic and Atmosphere Administration (NOAA) caught a Giant squid (Architeuthis) when they were doing research off the coast of Louisiana in the Gulf of Mexico. Measuring 19.5 feet from fin to tentacle, NOAA caught the giant squid in a trawl 1500 meters deep. Just like any other squid, the Giant squid has the fin, the mantle, the head, the arms and the tentacles. Their skin has a hint of pink because the ocean quickest absorbs the red wavelengths. Therefore, the squid becomes practically invisible in the deeps sea. Giant squid as suspected to live near continental-slope areas where the shallow water drops off a cliff into deep water. This has been one of few rare sightings of a Giant squid. Hence, the giant squid has always been a mysterious creature to us.

One of the mythologies of the Giant squid is the Kraken. Giant squids are known to feed on shrimp, fish, and other squids. However, there have been sightings of Giant squid attacking sperm whales. In 1966, two South African lighthouse keepers witnessed a young sperm whale struggling against a Giant squid. The fight went on for half an hour and finally the Giant squid won and dragged the whale down in the depths. In 1965, a Soviet whaler watched a battle between a Giant squid and a 40-ton sperm whale. Both the squid and the whale died. The Giant squid’s head was in the sperm whale’s stomach and the Giant squid’s tentacles were around the neck of the sperm whale. Scientist believe that these whale attacks have some relation to the horror stories of the Kraken. Because the bows of ships looked like whales, scientists hypothesize that Giant squid attack ships thinking that the ships are sperm whales.

Sightings of the Giant squid are rare and there is little we know about the Giant Squid. We still have much to learn about this mysterious deep-sea creature. Having said that, we can safely say that the legendary Kraken can be given the benefit of the doubt that it is not an aggressive sea creature that feeds off humans.

Sources:

Museum of Unnatural History. "The Giant Squid” Viewed February 6, 2010.

Annonymous “Rare Giant Squid captured in US Gulf of Mexico” Ocean and Technology (Dec 2009) Vol. 15, Iss 8, pg. 17

Viegas, Jennifer “Giant Squid caught off coast of Louisiana” MSNBC (Sep 23, 2009)

Images Via Google Images

Cephalopod I: The Enigmatic Cuttlefish

Sepiodea Family: Cuttlefish

The Order of Cephalopods known as the cuttlefish are a remarkably intelligent and agile invertebrate that can manipulate their buoyancy with carefully controlled gas-to-lquid ratios within their internal cuttlebone (made of porous argonite). They possess three hearts, two to enhance flow and pressure to their gills, and use hemocyanin pigmented, blue-green blood to carry the vital hormones and nutrients that allow them to be the sophisticated hunters in the oceans.
Roger Hanlon describes some of the interesting features of the cuttlefish:

Cuttlefish employ the use of a sepia-colored ink stored in an ink sac that can be used to confuse and deter predators when accurately and forcefully squirted. They have eight, sucker-laced arms and two, impressively quick and accurate tentacles for capturing and holding onto prey once it has been caught. Their reinforced beaks and effective tongue-teeth, known as radula (pictured above), make quick mince meat out of their favorite crustacean prey item.

The following clip shows a brave, feisty cuttlefish attacking an octopus.

Click this link to show the fascinating workings of the 200 cells/square millimeter chromatophores that allow a cuttlefish to produce the dazzling array of colors.