Intertidal Community Project [pic] Pablo Robledo Period 3 Ms. Ashley February 10, 2010 Introduction The intertidal zone, or littoral zone, is a slim perimeter along the shoreline. The intertidal zone is located between the highest and the lowest tides. Since the intertidal zone is located between the highest and the lowest tides it has many abiotic factors that make life challenging for the intertidal organisms, therefore the organisms must be well adapted to the intertial zone in order to survive.
Intertidal organisms experience emmersion and immercion, meaning that they are being exposed to air and they are being submerged, thus the organisms must be adapted to emmersion in order to avoid desiccation, or drying up. Some examples of intertidal organisms are sea anemones, sea stars, sea urchins, crabs, mussels, barnacles, limpets, chitons, and algae. Each one of them has different adaptations to survive different abiotic factors that make life challenging for them like temperature, wave action, currents, competition for space, desiccation, and salinity.
For example sea stars developed tube feet to attach to hard surfaces, in addition chitons developed a muscular foot to attach to rocks. The intertidal community is important to me because it is part of the planet I live in, because the environmental and species interactions are unique, because the organisms have developed amazing adaptations for the harsh environment, and because I live on the coast. I am connected to the intertidal community because it is part of the world I live in and because I live near it.
Vertical Zonation One special characteristic that the rocky intertidal community is that it is typically divided into sections, or zones, vertically thus biologists have named this arrangement vertical zonation. Rocky shores have four main sections, which are the splash zone, upper intertidal, the middle intertidal, and the lower intertidal. The upper limit is generally determined by physical factors, since it experiences a lot of emersion, therefore the lower limit is determined by biological factors, like predation.
For example mussels usually live above the lower intertidal since sea stars inhabit the zone, in that case predation a biological factor is prevention mussels from living below the lower intertidal. [pic] Chiton (Tonicella lineata) Lined chiton, or Tonicella lineata, is a species of chiton, which has a peculiar line pattern. They have overlapping shell plates that cover their dorsal surface. Lined chitons are classified in kingdom Animalia, phylum Molluca, class Polyplacophora, order Neoloricata, family Lepidochitonidae, genus Tonicella, and species Lineata.
Lined chitons lives covered with coralline algae in the low intertidal to subtidal zone, in shallow hard bottoms mostly. Lined chitons have a rasping radula, wich they use to eat coralline algae. In the website http://www. wallawalla. edu/academics/departments/biology /rosario/inverts/Mollusca/Polyplacophora /Tonicella_lineata. html, the author describes, “its main predators are seagulls, sea stars, crabs, lobsters, and fish”. Lined chitons protect themselves from predators by camouflaging on coralline algae using their reddish brown zig zag lines in their overlapping shell plates.
Lined chitons can survive the harsh condition of the intertidal community by using their muscular foot to attach to rocks and avoid currents and waves; they can survive the loss of 75% percent of water in their tissues to prevent desiccation; they have overlapping shell plates to regulate their body and avoid temperature changes; they camouflage in coralline algae to fight against competition for space; and they deal with salinity by using their gills.
One interesting fact about lined chiton is that they release their sperms and eggs into water, therefore fertilization is external. Jetty Field Trip Data In the jetty field trip we experienced how the intertidal zone is divided into different zones, in other words vertical zonation. We also analyzed how physical factors determined the upper limit, for example temperature and desiccation, and how biological factors determine the lower limit, for example predation and competition.
We also found out that there are more mussels in the mid-tide zone than the low tide zone because of the biological factor of predation, which in this case applies for sea stars eating mussels. [pic] Bibliography Castro, Peter, and Huber, Michael. Marine Biology. New York, NY: McGraw-Hill Companies, 2008. http://www. beachwatchers. wsu. edu/ezidweb/animals/Tonicellalineata. htm. Mary Jo Adams. 11/22/05. Beachwatchers. http://www. wallawalla. edu/academics/departments/biology/rosario/inverts/Mollusca/Polyplacophora/Tonicella_lineata. html. Dave Cowles. 2005. Wallawalla.