New Predator of the Deep

South Carolina Hammerhead (Photo credit to South Carolina University)

            Scientists are buzzing about a new species of hammerhead shark discovered in South Carolina. Joe Quattro, an ichthyologist from the University of South Carolina, takes claim to this amazing discovery. To officially classify it as a new species it required extensive fieldwork, genetic testing, and literature research. This rare species, Sphyrna gilberti, is now called the South Carolina hammerhead. The species is very similar in appearance to the common scalloped hammerhead, so genetic evidence was needed to prove they were two different species. The story Quattro relays about the time and dedication it took to confirm the new shark species is just as impressive as the discovery itself. Quattro accomplished an amazing feat and this addition to the science community will make a lasting impact on marine biology research in the future.

            Quattro has been a biologist at USC since 1995 and has focused his research on fish populations in freshwater rivers that connect to the ocean. His main fields of interest as a scientist are conservation, genetic diversity, and taxonomy. His research focuses on the four South Carolina river basins, the Pee Dee, Santee, Edisto, and Savannah. He spent many hours on the rivers collecting genetic data from mainly pygmy sunfishes and basses.  Then he branched out to study short-nosed sturgeon and shark pups.

            The South Carolina coast is a popular breeding ground for several shark species. Hammerheads, specifically, will birth their young at the boarder of the ocean and estuary. After birth, the shark pups remain local for roughly a year until they grow larger enough to enter the open ocean ecosystem.

            Quattro and his student, William Driggers III, studied and collected genetic data from these hammerheads regularly. Genetic analysis showed that the common scalloped hammerhead, Sphyrna lewini, had two different genetic signatures in both the mitochondrial and nuclear genomes. Quattro and Driggers resorted to old literature to try to answer the genetic differences. They found that Carter Gilberti, a curator at the Florida Museum of Natural History from 1961-1998, described a hammerhead that had 10 fewer vertebrae than the common hammerhead. The hammerhead was found in 1967 near Charleston, S.C. At that time science and technology was not as advanced as it is today, so scientists never determined if it was a different species.

            This discovery is truly an accomplishment for Quattro and Driggers and the scientific community because it furthers our knowledge of the ocean and its species. To honor Gilberti, Quattro and Driggers named the species after him, Sphyrna gilberti, because he unknowingly helped them solve the mystery. Further research needs to be conducted on the South Carolina hammerhead as a population. Quattro wants to learn more about their population numbers and their place in the ocean ecosystem. Finding a new shark species is not only a huge success for Quattro, but it brings awareness to the South Carolina hammerhead as a species.

 

Photo Credit to University of South Carolina

University of South Carolina. "New species of shark: Carolina hammerhead." ScienceDaily, 7 Nov. 2013. Web. 12 Nov. 2013.

www.sciencedaily.com/releases/2013/11/131107170959.htm

Ant Defenders

Stem cavity of the Ecuador laurel tree

Azteca ant detects a caterpillar on a leaf of the Ecuador laurel tree.

            The Ecuador laurel tree, Cordia alliodora, developed an interesting and effective method to protect itself from herbivore predators. During the dry season the tree has two main threats, lack of water and herbivore consumers, so the tree devised a defense strategy to mitigate the lost of leaves to predators. The Ecuador laurel tree created a mutualistic relationship with Azteca pittieri ants that in exchange for living in the tree offer protection against herbivores.

The ants nest in the stem cavities of the tree and feed on the pink scale insects that also live within the tree. The pink scale insects feed on the sap secreted by the tree and produce a sugary substance called honeydew that serve as the ant’s food source.  The ants are small in size compared to other herbivores, but they work in groups to attack predators. For example, they will surround a leaf-eating caterpillar and bite its underside until it falls off the leaf.

This relationship guarantees the tree protection, but it comes at an ecological cost. The pink scale insects consume the tree’s sap, so the tree is constantly using its energy reserves to produce more sap. It is arguable that the tree would seem better off to hoard its sap during the dry season because if the sap supply is depleted, then the tree will die. Furthermore, even if the tree did not perish, a low supply of carbon would be detrimental for the rainy season. This relationship is unusual and requires a delicate balance for survival.

Researchers wanted to investigate this relationship further, so they observed the tree and ant behavior in 26 sites, all with varying precipitation levels. They reported that in the drier areas the tree and ant relationship was stronger than in the wetter regions. It was also observed that in the drier sites there were more pink scale insects, thus supporting a larger ant population. The researchers observed that the ants in the drier regions were much better defenders, with quicker reaction times and defense movements, than in the wetter regions.

It can be gathered that the ants serve as “tree insurance” because the cost of herbivory is high. The cost of sustaining the ants is cheaper than replacing leaves that herbivores eat. The tree would have to replace the leaves each time with energy from the sun. The process of growing a new leaf is not practical, so the tree invests in defense. Although this relationship is peculiar and defies common ecological trends, it has led to the success of the Ecuador laurel tree.

 Photo Credit to Science News

Zielinski, Sarah. In dry times, these trees invest in ants. Science News: Magazine of the Society for Science and the Public. Science News, 7 Nov. 2013. Web. 9 Nov. 2013.

https://www.sciencenews.org/blog/wild-things/dry-times-these-trees-invest-ants

The cavemen might have had company

Picture courtesy of Science News

            Scientists are in awe over the recent discovery of a new translucent snail species that resides in the underground caves of Croatia. The snail, officially named Zospeum tholussum, is a terrestrial snail that occupies wet subterranean areas. The snail is completely translucent with an average shell height of 1.55 millimeters, which is comparable to the thickness of a penny. The unearthing of this extraordinary species is due to the work of Alexand Weigand of Goethe University in Frankfurt, Germany.

            Wiegand found the snail while exploring the Lukina jama-Trojama cave system which has an average air temperature of 3.3°C, a water temperature of 5.1 °C, and a humidity level of 100%. Wiegand captured the only living specimen at 800 meters for further research. Wiegand continued down the cave system and discovered vast quantities of empty shells 800 to 1400 meters down. The inter-workings of the Lukina jama-Trojama cave system and the snail's location are depicted in Figure 1. While Wiegand travelled throughout the cave system he noticed that all the empty shells had a milky white appearance, which could be attributed to aging after the snail deceased. 

            Scientists believe that the new snail species is similar to the common terrestrial snail because of shared characteristics. For example, the Zospeum tholussum demonstrates a sedate lifestyle with limited mobility. The living specimen and array of shells were found in mud by running water, which suggests that they relied on the cave water systems for transportation. The snail and its biological role in the cave system are still under investigation. Further research needs to be conducted to determine their range within the cave system and explain the great quantity of shells Weigand found.

Figure 1.  The Lukina jama-Trojama cave system and snail depths.

Picture courtesy of Science News

Bohac, Allison. "Clearly New Snail." Science News: Magazine of the Society for Science and the Public. Science News, 2 Nov. 2013. Web.  3 Nov. 2013.

https://www.sciencenews.org/article/clearly-new-snail

           

Beauty Sleep isn’t just for Princesses

Picture provided by Science News. Depicts colored tracers penetrate more deeply into a mouse’s brain when it’s asleep (left, red tracer) than awake (right, green tracer).

Sleep has always been a significant biological process that has intrigued people from ancient to modern times. Ancient cultures held different views on sleep depending on their nomadic or sedentary lifestyle and survival needs. Sleep is an important part of our circadian rhythm and holds natural rejuvenating qualities. Many of the benefits of sleep are being revealed with the aid of new technologies. Dr. Maiken Nedergaard, from the University of Rochester Medical Center, is a pioneer in the scientific community. Her research team recently conducted a study to determine if during sleep the brain cleanses itself by flushing out unwanted toxins that accumulate during active hours. In order to study this, the research team injected dye into mice’s cerebrospinal fluid, which is the clear liquid that surrounds the brain and spinal cord, to observe the travel route of the dye through the brain. The data showed that the dye flowed when the mice were asleep or unconscious and remained stagnant when the mice were awake. This helped support their hypothesis because the cell structure must have shifted during sleep creating space between the brain cells, which allowed the dye to be flushed out. The increase in space between the brain cells is most likely controlled by the glymphatic system, which regulates the flow of cerebrospinal fluid in the brain. To further investigate the increased space between the brain cells, the researchers tested it with electrodes. They inserted the electrodes into both alert and unconscious mice’s brain and measured the distance.  The scientists compared the results and the space increased by 60% in sleeping mice. Additional support of this is that the glia cells control the shrinking and swelling of the glymphatic system. When noradrenaline, an arousal hormone responsible for increasing the control cell volume, is blocked it induces asleep or unconsciousness and increases fluid flow and brain cell spacing. Lastly, researchers conducted a test to see if there is a connection between the glymphatic system and neurodegenerative disorders. They injected beta-amyloid, which is a protein associated with Alzheimer’s disease, into the brain to measure how long it remained in the brain when asleep or awake. Scientists observed that the beta-amyloid was flushed out quicker when the mice were asleep. This outcome supports that the brain normally clears out toxic molecules from the brain. The glymphatic system could be the new target for treating disorders and be a major breakthrough in the medical field. There are many aspects and complex workings of the brain we have not discovered yet but we are slowly gaining more understanding of the biological processes.

Saey, Tina Hesman. Sleep allows brain to wash out junk. Science News. Science News Magazine of the Society for Science and the Public, 17 Oct. 2013. Web. 23 Oct. 2013.

Humpback Whales are Rock and Rollin' on the Seafloor

Picture from FreeDigitalPhotos.net

Picture from FreeDigitalPhotos.net

Humpback whales are one of the most admired ocean mammals due to their tremendous size and grace.  They are known for their surface feeding including acrobatic jumps, which has helped spark the success of the whale watching industry. Humpbacks are known for capturing fish in their large mouths by creating bubble nets with the assistance of other whales in the pod. Humpbacks utilize the lunge feeding method for retrieving prey, primarily herring and sand lance, which entails the whales speeding through large numbers of fish condensed into a “bait ball” with their mouths open. Once inside the humpback’s mouth, baleen plates separate the fish from the water, which is then squirted out of the blowhole, while the fish are passed through the whale’s throat to the stomach. For years scientists believed this was their main technique of acquiring food but the humpbacks that inhabit the Gulf of Maine are proving them wrong. The Stellwagen Bank National Marine Sanctuary and the Great South Channel monitor the local humpbacks using tags and critter cams to track their location and migration patterns. After the data is collected the results are three dimensionally mapped for a visual representation. Recently new data surprised scientists and sparked an entirely new investigation of the humpback whales. The maps showed humpbacks swimming to uncommon depths between 11:00 p.m. and 4:00 a.m. The scientists relied on the critter cams for answers. It showed that the whales were engaging in “bottom side rolls” because the whale’s rostrum, a snot-like projection, hit the seafloor and the whale’s ventral pleats expanded indicating feeding. The scientists theorized that the humpbacks somehow acquired this new skill of shaking up the sand to expose the hidden sand lance, which normally gather around the seafloor at night. The whales perform the bottom side rolls at a rate of 30 rolls per hour at about 1-2 meters above the sea floor. Furthermore, the whales execute the bottom side roll as a group to uncover a larger portion of the sand lance. They speculate that the whales must have a previous family or close bond to have learned this behavior . The same family relationships are viewed during surface feeding when the bubble net is implemented. Humpback whales are a family oriented species that communicate new feeding and survival skills to each other. The scientists investigated other Gulf of Maine humpbacks that focused on herring as a main food source and this behavior was not witnessed.  This discovery will open new doors for understanding the behaviors of the humpback whales and fuel continued research. The only concern with this observed behavior is the risk of the whales becoming entangled in seafloor fishing gear such as, gillnets and trap fisheries. More research needs to be conducted to determine exactly why the humpbacks have resorted to this behavior. A possibility is that the food source at the surface is not as plentiful or the whales are not as successful in capturing prey due to anthropogenic causes. 

National Oceanic & Atmospheric Administration. “Research reveals   bottom feeding techniques of tagged humpback whales in   Stellwagen Bank National Marine Sanctuary.” NOAA: National   Marine Sanctuaries, 26 Sept. 2013. Web. 18 Oct. 2013.

Zieliniski, Sarah. “The bottom feeding behavior of humpback   whales.” Science News: Magazine of the Society for   Science &   The Public, 8 Oct. 2013. Web. 18 Oct. 2013.

Building Blocks Literally Made Out of Rock

Picture Provided by FreeDigitalPhotos.net

Scientists recently discovered the components of water circulating within the rubble of a star. The GD 61 white dwarf star shattered an asteroid due to its gravitational pull, exposing the asteroid’s contents. A white dwarf star is classified as a dying star that has a strong pull, which draws in neighboring asteroids and planets. GD 61 is 150 light-years away from the constellation Perseus. Perseus, named after a Greek mythological figure, is found in the northern sky and is 250 million light-years away from Earth. Even though the distance away from Earth is so extensive, the Hubble Space Telescope was able to identify the contents of the asteroid rubble. They were determined to be iron, magnesium, and oxygen. The presence of oxygen shocked scientists and led them to only one conclusion. Water had to be present at one point in time for oxygen to be found in the asteroid. Oxygen is vital for the basis of life and its development. Oxygen is one of the main elements found in water, H₂O, and it allows for organisms to flourish in aerobic conditions. On Earth the accumulation of oxygen in the atmosphere allowed terrestrial organisms to sustain through respiration. Oxygen is the explanation as to why organism evolved, developed, and reached their success today. The discovery of oxygen in the asteroid is very crucial in understanding the beginning and evolution of life. Finding oxygen ultimately leads to water, which is metaphorically the match that can spark life on a planet. The possibility of life in other areas of the universe is exhilarating and evidence such as this fuels continued research. Scientists believe the amount of water stored in these rocks could have filled massive bodies of water, creating speculation that a planet similar to Earth once orbited GD 61. It is difficult to prove completely if this is the reason there is water in the asteroid, but it is a theory that provides hope and inspiration to the scientific community.

J. Farihi, B.T. Gänsicke and D. Koester. Evidence for water in the rocky debris of a disrupted extrasolar minor planet. Science. Vol. 342, October 11, 2013, p. 218. doi: 10.1126/science.1239447.