Bivalves In Burrowing Organisms

First, the author asserts that being the kind of creature with so much mass, Brachiosaurus needed long legs to support them on land, yet the buoyancy would help share this burden. In the lecture, however, the professor indicates that Brachiosaurus were able to walk on land with the fossil tracks of such creatures

“Crabs Dig Holes According to the Size of Their Shells” Have you ever wondered how many people don’t reach goals or dreams due to their mindset? The answer is more than you ever imagined. The most human ability is the capability to recognize one’s limits and exceed them. The essay “Crabs Dig Holes According to the Size of Their Shells” will showcase how someone has recognized limitations but does nothing to go beyond them. McPherson’s main message in “Crabs Dig Holes.”

One hundred and fifty million years ago, large aquatic species of reptile such as the Plesiosaur dominated the ocean, and were pre-eminent predators of the sea. The branch of now extinct Plesiosaurs, or ‘near lizards', evolved into variant closely related species specialised to take different niches in the food chain. Such species of Plesiosaur include the phenotypically similar Plesiosauroid and Pliosauroid. The physiological adaptations of the long necked variant, the Plesiosauroid, as it relates to deep sea diving, will be addressed in depth.

In marine mammal biology a large portion of the study is dedicated towards the study of adaptations to the marine environment. By comparing the anatomy between marine mammals and terrestrial mammals scientists can better understand evolutionary history of how these two categories of mammals diverged from one another. The purpose of this lab was to study the anatomy of different marine and terrestrial mammals and compare their similarities and differences in homologous traits and how adaptations were made specifically for marine mammals to survive the aquatic environment. To accomplish this bones of different species of animals were studied since these structures serve as the basis for comparison across species as well as an indicator of each animal’s individual morphology and physiology. A standard measurement protocol for bones of particular regions of the skeleton was established with emphasis on length versus width ratio as well as it’s overall size relative to its more complex features, i.e. humerus length versus hand length.

Today’s eastern oysters range from 3 to 5 inches in length, sometimes as much as 8 inches, although the oysters present during the colonization of the New World were documented to grow much larger (“Oyster History”). Oysters have many great characteristics in regard to their utility for humans as well as wildlife. The build ups of oyster bars, reefs, and beds provide habitat for many aquatic lifeforms and the filtration capabilities they possess is quite remarkable; as filter feeders, oysters feed on phytoplankton and small organisms while removing nutrients from the waters the inhabit, leaving them clear and pristine; just one oyster can filter more than 50 gallons in a day (“Oyster History”). Alas, it was a palatable constitution that made the eastern oyster so popular, creating an extensive economy based on its harvest. Unfortunately, this considerable popularity would ultimately bring the oyster’s

The most likely environment in which these organisms lived would not be terrestrial or freshwater but a coastal marine environment with varying levels of salinity since the sea water would advance and retreat with the tides. The gastropods would require moisture from the ocean to prevent desiccation while the bivalves would be able to survive longer periods exposed since the shell could be closed temporarily until conditions were favourable.

An investigation into the effects of varying seawater concentrations on two marine invertebrates’ osmoregulatory abilities; Carcinus maenas and Arenicola marina.

b) Connell showed that the realized niche of the barnacle semibalanus was the same as its fundamental niche by clearing the upper tidal reach of Cthamalus so

Pinnotheres pisum resides as a parasite inside of bivalves (i.e., mussels, clams, oysters). The relationship between the pea crab and the bivalve is one of parasitism. The pea crab relies on the host (the bivalve) for protection, nutrients, and oxygen, which is harmful to the host.

Chelonibia is a genus of acorn barnacles in the family Chelonibiidae of the subphylum Crustacea, which up until 1830’s was considered in the subphylum molluscs because of their calcareous shell and sessile pattern ( source). Chelonibia members are epibionts that fasten themselves to many marine vertebrates such as whales, manatees, crabs, horseshoe crabs and turtles (source). They have also been documented on sea snakes, alligators and inanimate substrates, but are not typically found on classic barnacle habitat such as boats, rocks, or docks (source). These motile substrates enable epibionts to gather nutrients from the water flow and some of these organism support abundant and diverse epibiont communities (source). Five living species of Chelonibia have been described, Chelonibia ramose, Chelonibia careta, Chelonibia manati, and Chelonibia testudinaria, all of whom are obligate commensal with particular hosts- ranging from custaceans and chelicerates to sea turtles and sirenians (sourece). Not one of these barnacle species occur on all documented hosts; though C. testudinaria is found on all species of sea turtles (source).

9.1 Hypothesis: My hypothesis behind the pattern of distribution is that the Semibalanus are better survivors at the lower region of the rock surface because of their diamond like structure which allows it to be opened when underneath water and close shut when exposed to air. They would rather settle for the bottom region where they aren’t exposed to air as much. The Chthamalus have better chance of settling and surviving at the top region because there won’t be much competition with the Semibalanus barnacles because they can handle air exposure as well as thrive in warm waters which is seen at the top of the rock surface because

<b>Introduction</b><br>Think of a world which existed 290 million years ago. As you look out over the terane in front of you, you think that you are on an alien planet. You see volcanoes spewing ash and lava. Beside them is the ocean which is swarming with many different species of echinoderms, bryozoans and brachiopods. As you look down onto the sea floor you are amazed at the countless number of starfish and urchins. Some animals leave you can't even describe and you have no idea even what phylum they belong to. This is a world at its height in diversity of oceanic species. Millions of wonderous species existed at this time in the ocean and most of them will never appear again in earth's history. In the geologic time scale, a million

Insects that live in water also exchange gases with the environment through the trachea. Air can be carried with the insect or it can diffuse into the tracheal system from the water. An example of this are diving beetles. Diving beetles carry a bubble of air under the elytra (wing covers) or trap the bubble of air against their body by specialised hairs. The bubbles one or more spiracle so that the insect can breathe air from the bubble when submerged in water. The air bubble only provides the diving beetle with a short- term supply of oxygen, therefore the bubble is also able to collect some of the oxygen molecules dissolved in the surrounding water. In effect, the bubble acts as a physical gill as it replenishes its supply of oxygen through

The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.

     Coral animals begin life as free-floating larvae, but settle on the sea floor in sedentary colonies. The term "coral" applies both to these animals and to their skeletons, particularly the skeletons of stone-like corals (Discover 1997).