Preview

Ecological Niche of the Crab

Powerful Essays
Open Document
Open Document
1443 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Ecological Niche of the Crab
INVESTIGATING THE ECOLOGICAL NICHE OF THE CRAB USING A FAIR TEST

INTRODUCTION: The ecological niche of the crab Hemigrapsus edwardsi.

The crab is a member of the Crustacea phylum and is in the family Grapsidae. This crab species is found only in New Zealand on rocky shores. The rocky shore, where the crabs studied in this investigation were found is quite exposed. There is a large rock platform that provides small crevices and small rocks which help to protect them from wave action and predators. There are also sea lettuce, and other algae growing on parts of the rocks.

The crab has many adaptations that allow it to live on the rocky shore including: • grey/black colour for camouflage • food detection structures (antennae on its head and hairs on the mouth parts to sense chemicals in the sea water) • 4 pairs of legs with muscles that allow it to move sideways, as well as forwards and backwards • behavioural adaptations such as scuttling under rocks when the tide goes out or to avoid predators • freezing when being attacked (we noticed this when we touched some of them on their backs). This might confuse predators. • gills for gas exchange.

The rock pools provide a micro-climate where the temperature and salinity of the water will change, depending on the weather. If it was a really hot day, the rock pools will get warmer, more water will evaporate and the salinity will increase. The crab would have to be adapted to cope with these changes in salinity, otherwise, as the concentration of salt in the water around it changes, it will gain or loose mass due to osmosis. Through the process of osmoregulation, the crab is able to maintain a constant water balance in its body, but to do so requires energy and this could be measured by an increase in the respiration rate. This is what I am going to investigate.

Aim: To determine whether the respiratory rate of the crab changes in different salinities.

Hypothesis: The respiratory rate of the

You May Also Find These Documents Helpful

  • Satisfactory Essays

    1. The shrimp, like the crab and lobster, has a segmented body. All also have antennae, and use their antennae to feel out their environment.…

    • 268 Words
    • 1 Page
    Satisfactory Essays
  • Powerful Essays

    It was found that the adaptations to life on a rock platform varied through the size, feeding habits and habitats of these plants and animals through the certain needs of the plants and animals.…

    • 1970 Words
    • 8 Pages
    Powerful Essays
  • Better Essays

    Crayfish Lab Report

    • 2156 Words
    • 9 Pages

    related to lobsters, crabs, and shrimp. They breathe through the gills as they are aquatic…

    • 2156 Words
    • 9 Pages
    Better Essays
  • Powerful Essays

    The Rocky Shore is an ecosystem of great magnitude although it is filled with a number of smaller ecosystems with in that rocky shore. These smaller ecosystems are the tide and rock pools with in the rocky shore and are home to a large variety of different organisms. All these organisms are not there aimlessly, each and every organism affect one another wether it be plankton, seas squirts, red waratahs, wobbegong sharks, blue octopus etc. Even filtering creatures and plankton are a major part of the ecosystem and the food chain at the rocky shore. This is because if any creature gets abolished no matter what it may be then this creature’s predator’s food becomes scarce and this will result in this particular organism getting wiped out and so on and so forth. With in a food chain almost everything has a predator, unless this…

    • 4017 Words
    • 17 Pages
    Powerful Essays
  • Good Essays

    Mellita quinquiesperforata, commonly known as the sand dollar, is a familiar urchin on Florida coastlines. The species is flat and disk shaped that nestles into shallow sandy waters to protect itself from waves and predators. Dissodactylus mellitae is a parasitic crab that feeds on the spines of the hosting sand dollar where it remains its entire life. This study was arranged to observe the distribution patterns of crabs on various sizes of sand dollars. We hypothesized that the larger sand dollars would host more crabs because of the extended surface area available. We also predicted that the presence of adult sized crabs would limit the number of total crabs on the hosting sand dollar because of the larger size and resource demand leading to intraspecific competition among the crabs. Intraspecific competition occurs when members of the same species compete over limited resources considered vital for survival. These resources can be food, space, light, mates, anything necessary for the survival and reproduction of the individual. In our study the factors of interest are space and food.…

    • 772 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Kelp Crab Research Paper

    • 635 Words
    • 3 Pages

    Causing its predators to be able to eat them because they can swim higher up in the water. The amount of rain also makes the water cooler because then the bottom doesn't get enough sunlight. The water temperature also affects the Giant kelp fish because when the water gets warmer the giant kelp fish die off which causes the crab population to go up but the kelp population to go down also. When it gets warmer the water gets warmer and then the glaciers melt causing the water in Monterey bay to also increase. When monterey bay gets cold in December, January, February, and into early march the water doesn't freeze over so nothing major happens except the fish population goes down a little bit. Climate isn't the only thing affecting monterey bay humans also have their…

    • 635 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Chapter 37 Study Guide

    • 1372 Words
    • 5 Pages

    The adaptations of both predators and prey tend to be refined through natural selection; Some prey gain protection through camouflage and mimicry…

    • 1372 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Crayfish Research Paper

    • 618 Words
    • 3 Pages

    Crayfish are close relatives of the Lobster and resemble a small shrimp. They live in freshwater habitats in North America and Europe.…

    • 618 Words
    • 3 Pages
    Good Essays
  • Better Essays

    When a second invasive species is introduced in the same environment the effects can become magnified tremendously, creating a serious cause for concern. 1 The European green crab (Carcinus maenas) invaded the Atlantic waters of North America in the early 1800s. The green crab is an omnivorous predator and has shown consumptive and noncomsumptive impacts throughout local ecosystems. 1 These same ecosystems were invaded two decades ago by a second omnivorous predatory crab, the Asian shore crab (H. sanguineus). Today, the Asian shore crab is well established and is becoming a dominant crab species in Massachusetts, as well as much of New England. The species has become such a threat because it can tolerate vast ranges of salinity and temperature, is an opportunistic omnivore with a broad diet, females have a high fecundity with a breeding season twice as long as native crab species, and there are no natural predators in the non-native range. A broad diet creates the potential to significantly disrupt the food web, ultimately affecting indigenous crab, fish and shellfish species. A steady increase in population since being introduced raises concerns of how this species is affecting the ecosystem and native…

    • 1651 Words
    • 7 Pages
    Better Essays
  • Satisfactory Essays

    Giant peni$

    • 4440 Words
    • 11 Pages

    Many organisms that live in the rocky intertidal zone are adapted to cling to the rocks to withstand the a.pounding of the waves.b.changes in salinity.c.periods of being underwater and exposed to air.d.changes in density. ____…

    • 4440 Words
    • 11 Pages
    Satisfactory Essays
  • Good Essays

    Crinoids Research Paper

    • 602 Words
    • 3 Pages

    Most modern crinoids have more flexible arms than the fossil species and do not have stalks (at least as adults), but are free to swim or crawl over the sea floor. These types of crinoids are known as ‘feather stars’ and are related to sea stars, sea cucumbers and sea…

    • 602 Words
    • 3 Pages
    Good Essays
  • Good Essays

    The Chesapeake Bay produces the largest amount of crabs in the United States. The Blue Crab or Callinectes sapidus, are mainly found in the deep waters of the open Bay among the waving strands of the bay grasses. The Blue Crab takes advantage of its' opportunities when it comes to food and feeds on live and dead fish, crabs, clams, snails, eelgrass, sea lettuce, and decayed vegetation and other foods which it is able to consume. Blue Crabs grow by the process of molting in which they shed or take off their outer hard shell and the soft shell under it eventually becomes another hard shell to help protect it from dangers which lurk and try to feed off the crabs. The difference between the male and female blue crabs can be told by the abdominals…

    • 1114 Words
    • 5 Pages
    Good Essays
  • Good Essays

    provides food and shelter for a wide variety of aquatic life, such as omnivores and grazers.…

    • 818 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Unit 9 Mass Extinctions

    • 812 Words
    • 4 Pages

    moving their habitats and taking their food. They are even consuming a lot of animals…

    • 812 Words
    • 4 Pages
    Good Essays
  • Good Essays

    biology

    • 947 Words
    • 4 Pages

    They are similar because the mating was random; however, there is selection for thicker shell crabs which mostly eat thinner shells. Thicker ones got to live and pass off traits to their offspring. Thin…

    • 947 Words
    • 4 Pages
    Good Essays