Orconectes rusticus, also known as Rusty crayfish, are freshwater benthic omnivores that are important in the lentic ecosystem (Nilsson, E, et al, 2012). Nilsson et al, observed how the Rusty crayfish that are native to the Ohio River valley in North America are dispersing to other lakes and becoming an invader of that ecosystem. Rusty crayfish feed on the microphytes, (Nilsson, E, et al, 2012) which are aquatic plants that enhance water transparency and aquatic biodiversity in fresh water ecosystems (Peeters Ehm, et al. (2013)). Microphytes also provide shelter and food for native fishes such as lepomis. Lepomis also prey on the juvenile rusty crayfish. Abundances of rusty crayfish, macrophytes and Lepomis were associated by a feedback that …show more content…
regulates the abundance of all three species. A strong predation on the juvenile crayfishes by Lepomis control the abundance of crayfish in the North American north temperate-lake (Roth B.M, et, al, 2007). Nilsson et, al examined the rusty crayfish relative abundance and considered how non-native species alters the benthic macroinvertebrate’s abundance corresponding to the “fish tropic position (TP) and benthivory” (Nilsson et, al 2012). There was a strong correlation between the increasing densities of invasive crayfish and the overall benthic macroinvertebrate. As the density of crayfish increased, the overall benthic macroinvertebrate density and species richness decreased. This result supports the Authors overarching hypothesis that the rusty crayfish are regulating factor on macroinvertebrate communities in the lakes that the crayfish invaded. As for the fish tropic position, the addition of the invasive crayfish to the food web increased the possible number of consumer steps, this resulted in the increase of TP of consumers of crayfish. There were some limitations that the Authors faced during their experimentation. They stated that there must be additional controlled experiments and landscape-level surveys that need to be done to understand what goes on in the real ecosystem. There should be further studies on how “perturbations” such as species invasion affect the flow of energy pathways and using stable isotopic data prior to invasion from archived samples (Nilsson et, al 2012). The addition of the exotic species of rusty crayfish to the lake resulted in the decrease in the benthic macroinvertebrate density and species richness due to predation of microphytes and other invertebrates that resided in the northern lake in Wisconsin.
Rusty crayfish species are better competitor than the native crayfish and have a high metabolic rate which allows them to grow large and strong. Rusty cray drives out the native crayfish from their habitat which makes them venerable for predation. These invasive species of crayfish have an extensive negative impact on the native species of plants and animals which can decline the biodiversity in the freshwater …show more content…
ecosystem. There are various methods of eradicating the invasive rusty crayfish but preventative measure appears to be more prevalent and effective. The return of submerged macrophytes is the target of many lake restoration projects since they enhance aquatic biodiversity (Peeters Ehm, et al. (2013)). There are chemicals that can be used to kill the rusty crayfish but are not very selective and impacts other biology in the freshwater. Further scientific research is needed to effectively eradicate the infested areas of rusty crayfish. Invasive species are not just limited to freshwater crustaceans, there are various microorganism that negatively impacts the fresh water ecosystem. Although microorganism such as the Nostocales are small but have the ability to synthesize toxins and when contaminated in fresh water, it can kill many aquatic and terrestrial animals. Assaf Sukenik et al, examined invasion of two Nostocales genera, Cylindrospermopsis and Aphanizomenon.
(Assaf Sukenik, et al 2012). The most important freshwater invasive Nostocales are the tropical species C. raciborskii and Aph. Ovalisporum. Numerous reports have been filed from all over the world about the invasion of cyanobacteria. Studies with isolated strands of cyanobacteria have shown that invasive species have robust competitive abilities under changing environments. Under lower temperature native cyanobacteria outcompete the invasive species but under high temperatures invasive species outcompeted the native stand. The authors could demonstrate that with increase of 4 degree Celsius in the water temperature, the invasive C. raciborskii would outcompete the native (Aph.
gracile). The invasion processes involve various interactions between the invader, which is the cyanobacteria and physio-biological environment. Invasion can be accomplished via the dispersal by the wind or by human activates, migrating birds and animals. Nostocalesas have two unique traits that allow them to survive and support proliferation. The first ability is to form akinetes, which are dormant cell that remain dormant until environmental conditions are favorable to growth and proliferation. The second ability is to fix atmospheric nitrogen when inorganic sources are scarce. Both C. raciborskii and Aph. ovalisporum
The Artemia franciscana can survive in extreme conditions of salinity, water depth, and temperature (Biology 108 laboratory manual, 2010), but do A. franciscana prefer these conditions or do they simply cope with their surroundings? This experiment explored the extent of the A. franciscanas preference towards three major stimuli: light, temperature, and acidity. A. franciscana are able to endure extreme temperature ranges from 6 ̊ C to 40 ̊ C, however since their optimal temperature for breeding is about room temperature it can be inferred that the A. franciscana will prefer this over other temperatures (Al Dhaheri and Drew, 2003). This is much the same in regards to acidity as Artemia franciscana, in general thrive in saline lakes, can survive pH ranges between 7 and 10 with 8 being ideal for cysts(eggs) to hatch (Al Dhaheri and Drew, 2003). Based on this fact alone the tested A. franciscana should show preference to higher pH levels. In nature A. franciscana feed by scraping food, such as algae, of rocks and can be classified as a bottom feeder; with this said, A. franciscana are usually located in shallow waters. In respect to the preference of light intensity, A. franciscana can be hypothesized to respond to light erratically (Fox, 2001; Al Dhaheri and Drew, 2003). Using these predictions, and the results of the experimentation on the A. franciscana and stimuli, we will be able to determine their preference towards light, temperature, and pH.
The documentary Blackfish by Gabriela Cowperthwaite is a gripping documentary about orca whales in captivity at SeaWorld and other sea parks around the world that shows the disturbing effects that can be caused from having these animals in a place where they shouldn’t be.
Known as Pterois Volitans in the animal kingdom, also called the red lionfish, is a sight to behold in the tropical waters as they swim like an underwater butterfly in the sea. In waters not native to their origin, as they are from the Pacific and have predators that will have them for a snack. Invasive to the Caribbean Sea they have rapidly reached the Gulf of Mexico and far south, spreading to parts of South America. The lionfish has become a persistent pest that’s more trouble than what it appears to be, attractive yet deceptive with a striking pattern of white and red stripes. In the New York Times article, A Call to Action… and Even Rodeos, scientists say that, “from 2005 onward, lionfish have become the most numerous nonnative invasive species in the world.” The average pound fish is one of nature’s clever creations, a venomous foe with spines and an infinite appetite that reproduce quickly. Invasive species are notorious because they have no or almost nonexistent natural predators and they are adapt to their new home very well. The biological adaptations of this fish has caused both ecological and economical mayhem, serious measures have been taken up to control their population as well as to protect our coral reefs.
Zebra Mussels also known as Dreissena polymorpha are small freshwater mollusk that have been invading America’s rivers and lakes. They originated from the Balkans, Poland and Soviet Union. In 1988, they were found in a small body of water connecting Lake Huron and Lake Erie, known as Lake St. Clair. Biologists believe that European port in the ballast water of a ship, dis...
This vegetation also provides much cover for fish. The aquatic plants provide a great source of food supply and act as a nursery for young fish (“Native” par. 5). Vegetation serves many purposes in fish habitat; besides keeping fish safe. It also helps keep the lakes clean. Aquatic plants cycle the water and help absorb pollutants. Another great benefit of these aquatic plants are that they help hold sediment and the banks of the lakes in place while providing oxygen into the water (“Invasive” par. 7-8). Unfortunately invasive species are destroying such vegetation. The Common Carp or “Cyprinus carpio” is one such fish that is causing great damages to lakes all around the world.
Lionfish are not currently listed as threatened in their native range. However, the increase in pollution in coral reefs can negatively affect the lionfish's primary food sources (NOAA, 2011). If lionfish are unable to adapt to declines in their prey species, their numbers will decrease. Although between the increasing reef pollution and the Lionfish’s voracious appetite reef populations will more than likely be damaged beyond repair, they may even be close to elimination by the time the Lionfish population actually declines (Albins, 2013).
Scorpaenidae are mostly marine fish,very few found in fresh and brackish water. The family have around around 45 different genera and 380 different species. They are mostly found in the India Ocean and the Pacific Ocean. Most of them lives in coral, tropical reefs and shallow waters, warmer areas. Not all of the family fish lives in the shallow water, small portion of the Scorpaenidae live deep as around 7,000 feet. Just like most of the coral reef fish are, Scorpaenidae have camouflaged body. Their characteristic reflects their name, they have sharp spine that can sting other organisms. Their spine are covered with venomous mucus just like how some other kind of fish are covered with the venomous mucus. Their body are covered with scales. Generally speaking, the Scorpaenidae family fish have different number of spines over the course of the body. Most known type pf Scorpaenidae are lionfish and scorpionfish. Lionfish have preorbital bone with 3 spines, spines and third below the diagonal; , big mouth, end position, oblique fissure. Mandible, vomer and jaw bone with villiform teeth group. Gill openings are wide, tetrabranchiate membranes without the isthmus, pre-opercular margin with 5 spines. Body are ctenoid scales, round head. On the side, there are about eight to nine dorsal fin, fin spines and rays of an anal fin; five to six pectoral fins, they are large, round, and are branched from the upper fin rays. There are about one to five pelvic, sub thoracic; caudal fin rounded truncate. Reef stonefish are extremely camouflaged, they could look exactly like a rock when hiding for predation. The spines of Scorpaenidae are hard and rough, some of their fin spines have poison, can cause serious pain, swells and fatal wounds. Some of ...
The Black carp originated in many of the Pacific drainage areas of eastern Asia, China, and parts of Russia and Vietnam. Black carp was introduced to the United States in the 1970’s to fish hatcheries and to control the populations of disease carrying snails in ponds. Flooding is the main factor to thank for the release of the black carp, which quickly turned into an invasion of the waterways. The Black carp is a medium size fish with the opportunity to become an extremely large fish if the conditions are favorable. “Based on Asian records, large adults may be more than 1.5 m total length and 70 kg or more in weight”(Nico,L.G). The black and grass carp is close to identical in regard to the characteristics of one another. However, the black carp is a slightly lighter color of black, with extremely large scales on the entire body. A black carp has human like molars as teeth that are used to crush snails and mollusks. With a slightly pointed snout that is a likely adaptation used to filter through the bottom of water bodies in search of food. The physical build of a black carp exhibits the design of a bottom-dwelling feeder. Sporting a long snout, large powerful human molar like teeth the black carp is built to succeed in water full of snails and mollusks. This means that the populations of already near extinct native snails and mollusks are at great risk of being
In The Rainbow Fish by Marcus Pfister tells how a beautiful, extraordinary, yet, self-centered blue fish learns that being beautiful isn’t the key to happiness. The blue fish came to find this lesson when he lost his friends. Pfister takes a simple ocean setting and explores the consequences of an individual’s arrogance toward their peers, the process of humbling of oneself, and the tremendous reward one feels when they learn to share. The story achieves these morals by the author’s use of detailed imager and also, the influence of minor characters on the antihero in order to reveal to the audience the true thematic message; selfish actions bring true happiness.
You probably think horseshoe crabs are crustaceans, but you’d be wrong. They actually aren’t crabs at all, and there’s more about the horseshoe crab that you wouldn’t believe. This weird-looking marine animal survived two mass extinctions and lived in the Ordovician Period.
Zebra Mussels pose two primary ecological dangers. The first being drawing water into their bodies and filtering out the food of microscopic plants and animals, subsequently depleting the food supply for other aquatic organisms and increasing the water clarity which allows higher light penetration to inhibit predatory fish in their food-searching endeavors. Secondly, they can attach to the shells of native mussels and smother them. In analyzing the physical composition of Zebra Mussels, their one-eighth to two inch yellow/brown striped exterior can be deduced. Different approaches can be considered to control this invasive species. Mechanical control can be implemented by way of preventative measures (especially because Zebra Mussels are extremely difficult to control once they have infiltrated a body of water)., including industrial vacuums and backflushing. Chemical control, summarized by the use of chlorine, bromine, potassium, permanganate, and other resources, is another
Species such as the zebra mussel, quagga mussel, urasian malfoil, sea lamprey, and asian carp reproduce and spread. These invasive miscreants ultimately degrade habitat, outcompete the native species, not to mention short-circuiting food webs. When a new and aggressive species is introduced into an ecosystem, it might not have any natural predators or controls. It can breed and spread relatively fast, taking over an area. Native wildlife may not have evolved defenses against the invader or they cannot compete with a species that has no predators.They threaten and hurt the Great Lakes economy by damaging critical industries such as fisheries, agriculture, and tourism. There are a couple of ways that these unwanted species are introduced to the Great Lakes region. Ships can carry aquatic “hitchhikers”in its ballast water. A ballast tank is used to balance big ships. When a ship empties it’s ballast tank, invasive species may have traveled unknowingly with the ship and then are released with all of the water into the Great Lakes. Zebra mussels first came to the U.S. from Eurasia in ship ballast water released into the Great Lakes in the 1800’s. Since then, they have spread dramatically, outcompeting native species for food and habitat. Zebra mussels can attach to almost any hard surface, a nuisance to the communities in the Great Lakes region and the animals. They clog water intake and discharge pipes, attach themselves to boat hulls and docks, and they even attach to native mussels and crayfish. Plants can get stuck on boat propellers and then fall off accidentally into a new body of water. Invasive species can alter the diversity of species that are important for native wildlife. Aggressive plant species like Urasian Malfoil can quickly replace a diverse ecosystem with a monoculture of just Urasian Malfoil. Another species named Asian Carp are a fast growing
Introducing exotic species has been a highly debated issue. Why should we bring another animal or plant into a region to eradicate another species? That’s the question that people have been asking for ages. Of course, there are positives to bringing in another species, but many times, there are just as many negatives. Also, these species can be introduced accidentally or intentionally. The new organism may cause no obvious problems and eventually, it will be considered “native” to the area. For example, corals are “perhaps the oldest animals on the planet, and these long-lived corals have evolved in one of the Earth’s most stable environments” (Eichenberg, p.2). If a new type of fish were to be put into the ecosystem with the corals, the coral would be affected. First, the fish might eat the coral. Second, they could use the coral for shelter, and possibly damaging it that way. Third, the fish could bring predators that might also eat the coral. Introducing an exotic species has the “rippling affect” of dropping a stone into a pool of water. Everything outside the epicenter is affected. A study was done at Cornell University, and they estimated that $120 billion per year are spent fixing the problems caused by exotic species” (Chiras, p.
Invasive alien species are disrupting and changing the normal ecological functions of biomes, ecosystems, and the biosphere as a whole (CBD, 2009). They are a threat to biodiversity and can cause damage to, or even eradicate native species which natural cycles and other organisms depend on. While disrupting energy flow, food chains, and shaking the structure of ecosystems to the core, invasive species create not only ecological, but also a whole host of social, economical, and health issues that affect the livelihood of almost every organism on earth, including humans (CBD, 2009).
Elizabeth Bishop’s “The Fish” is a poem about catching a fish and then choosing to release him. Upon observation of the fish it is apparent that he has survived numerous struggles. Elizabeth Bishop survived several struggles in her own life. Her father died when she was a baby, and her mother suffered from mental illness. Due to these problems Bishop was sent to live with extended family.