Among the perciform sub-order Notothenioidei, a variety of adaptations to cold temperatures exist (Coscia et al. 2011; di Prisco et al. 2007), with the most dramatic of these exemplified in the highly specialised crown group Channichthyidae (icefishes) (Tota et al 1997; Cheng et al. 2009). Consider the icefish Chionodraco hamatus, endemic to the frigid waters of the Antarctic in the Southern Ocean (Garofalo et al 2009). This species can survive in temperatures approaching -2.5 °C (Bilyk and DeVries 2010) and hence, is well suited to meet the demands of cold temperature survival. The major adaptation of C. hamatus for survival in cold temperatures is the expression of antifreeze glycoproteins (AFGPs) (Bilyk and DeVries 2010) which are absent in most teleosts but necessary for survival in frigid waters (DeVries 1988). Further adaptations of the icefish clade relate to the distinguishing synapomorphy of the group (di Prisco et al. 2007; Verde et al. 2004; Tota et al. 1997), the uniform absence of haemoglobin (Ruud 1954 in Holeton 1970). These adaptations, involving modified circulatory, respiratory, and integumentary systems, enable sufficient oxygenation of the tissues in the absence of haemoglobin (Eastman 1993, in Kock 2005). I will focus on two major functions of these adaptations: increased oxygen transport and increased oxygen uptake. This report will discuss how AFGPs, in addition to the myriad adaptations for increased oxygen transport and uptake, enable C. hamatus to successfully endure the frigid waters of the Antarctic
a) Antifreeze glycoproteins increase freeze tolerance in icefish blood and body fluids
To survive in the frigid waters of the Antarctic, C. hamatus utilizes an evolutionary key innovation shared by all ...
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...ology. 209 (10): 1791-1802. doi:10.1242/jeb.02091.
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Calyptorhynchus banksii, or red-tailed black-cockatoo, has coped with extreme variations in its environment. Much like the plant species of Australia, the red-tailed black-cockatoo has evolved physiological and anatomical adaptations that have allowed it to survive in changing surroundings. One of the most prevalent adaptations was that seen in the beak apparatus. Changes in the beak allowed the cockatoos to consume the newly evolved sources of food. The metabolic requirements of the cockatoos and the availability of food are also forces that have influenced the beak apparatus and the distribution of red-tailed black-cockatoos throughout Australia.
The movie that shocked thousands of Americans with the secrets of SeaWorld became one of the most talked about movies of its century. Blackfish came out in July of 2013 with shocking evidence of the mistreatment of Orcas, also known as killer whales, and the dangers imposed on the whale trainers. The movie had several strategies to appeal to its audience. These strategies included the three pillars of writing; logos, ethos, and pathos. Although the overall theme of Blackfish was to inform the viewers of the treatment Seaworld imposes on Orcas, the fundamentals of the movie actively used the three pillars; ethos, logos, and pathos to effectively catch the attention of the viewers and keep them drawn into the movie; the most prominent pillar was pathos followed
The ocellaris clownfish (Amphiprion ocellaris) is also known as the common clownfish or false percula clownfish, and was named by Georges Cuvier in 1830. It belongs to the Amphiprion genus, which consists of 29 extant species. However, the subfamily Amphiprioninae also contains another genus, Premnas, which has a single member. They are closely related to damselfishes with which they create the Pomacentridae family. The ocellaris clownfish is oftentimes confused with A. percula, the orange clownfish, which is similar in colour and pattern, but has thicker black outlines, less dorsal spines.
The cold water experimental group had the lowest respiration rate with an average of 85 operculum contracts per minute. When the temperature of water is decreased, the metabolic rate of the goldfish also decreases since they are ectothermic, meaning their regulation of body temperature depends on external sources from the environment. Since they are metabolizing at a slow pace, their need for oxygen is
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The discoverer of the titanic, Dr Robert Ballard famously referred to the deep sea as ‘far more alien than going to mars or the moon.’ The deep sea is one of the largest virtually unexplored ecosystems on the planet; it is found at a depth of 1000 fathoms [1] and is subject to adverse changes in temperature, pressure and light penetration amongst other factors. Therefore as expected fish decrease in abundance, and species diversity. This trend is prominent as in order to survive the harsh conditions of the deep sea, fish need a number of specific adaptations. Allowing them to ultimately survive, feed, and reproduce.
Crabeater seals are a smaller species of pack-ice seals that feed primarily on Antarctic krill (Siniff, et al., 2008). This means any environmental changes that will affect the availability of Antarctic krill will probably have an impact on crabeater seals. This (along with changes to ice floes which significantly impact the crabeater seal’s pupping and protection behaviours) mean that it is likely that this species of seal will experiences a decline in abundance as the Antarctic continues to be effected by climate change (Siniff, et al.,
The Order Cetacea is one of the most distinctive and highly specialized groups of mammals. Over the course of evolutionary history, cetaceans have become adapted to surviving and prospering in a vast aquatic environment. One of the most important obstacles they have overcome is the ability to be obligate ocean dwellers while still breathing oxygen. Cetaceans are able to remain underwater for extended periods of time, returning only to the surface to exhale. Diving beneath the surface is an essential component of life for these species since almost all of their food sources are found under the surface of the ocean.
Osmoregulation is an example of an organism maintaining homeostasis. More specifically, osmoregulation involves an animal regulating osmotic pressure, or its fluid content. Brine shrimp, Artemia, use osmoregulation to regulate the saline levels of fluid within their body. Because brine shrimps live in seawater, an environment with a high saline concentration, they must actively excrete excess salt. Brine Shrimps use metepipodites as the location of the ion pump which secretes sodium. This is an active transport of ions because it is moving against the gradient, a higher salt content outside the body. The two following studies describe the environmental conditions ideal for brine shrimp and the possible genetic explanation for the osmoregulation of brine shrimp, respectively.
Marine organisms continue to amaze scientists with their physiological adaptations that allow them to live and thrive in the largest unexplored habitat known to man. Carl Zimmer argues that “most fish without lungs die” because “lungless fish pump their blood in a simple loop.” Therefore, fish are restrained by a lack of oxygenated blood flow that the heart can receive and will die if they exercise too hard because the heart simply won’t receive enough oxygen to sustain intense exercise. In order to solve this problem many species of teleosts and chondrichthyes possess adaptations that allow them to continue exercising at extremely high speeds without necessarily dying. Tunas, for example, are pelagic thunniform swimmers that have evolved these special adaptations that allow them to maintain high cruising speeds and high metabolic rates. They possess special adaptations in muscle, cardiovascular, and respiratory physiology that set them apart from many other species of teleosts.
As many know, there are places on this earth where conditions are too inhospitable for humans to live. There are places with skull crushing depths, boiling water and high methane concentrations, where no human could survive. Survival in such hostile conditions was thought to be impossible for any organism; until the late 1960’s when bacterial microorganisms were found living in scalding thermal environments above 70 degrees Celsius, in Yellowstone National Park (Madigan & Marrs, 1997). These microorganisms were later termed extremophiles for their “love” of environments that are too hostile for other organisms to tolerate. Therefore, the capabilities and differences among extremophiles deserves a thorough investigation compared to the most adaptable species on the planet, humans.
The increase of open ice areas can affect arctic species that rely mostly on sea ice to live. For example, the ice itself serves as a barrier and surface for hauling out, whelping and molting define these terms. It also serves as a platform for hunting, mating, and foraging, among other activit...
It is important to notice that the opening chapter acts essentially as an introduction to a wider discussion throughout his book. In an effort to give his exploration some order and consistency, Bluestone organizes his discussion under five sections. He identifies five main points, which composes the process of adaptation. Despite these efforts to contain each discussion under such headings, Bluestone’s discussion goes off track during his analysis, which only makes the laws that govern adaptation harder to underst...