Sea urchin

Introduction Sea urchin gametes are an excellent model for observing vertebrate development. Sea urchins are a low cost species that can be maintained in a laboratory environment, have external fertilization and have distinct stages for viewing development in offspring. They are external breeders, so when the gametes are mature, they are released into seawater. The seawater carries the gametes where they will fertilize and develop. How does the sperm find the eggs? The jelly coating on the mature eggs produce a chemical signal that attracts sperm (Gilbert, 2000). This method of sperm finding egg must have a protection mechanism for the right sperm to find the right egg. The sea urchins have a particular bindin receptors that look specifically…

aspects of vertebrate development. Because of their rapid development and their aquatic nature, sea urchins may be particularly sensitive and useful for studying the effects of environmental toxicants on early development. Materials and Methods Harvesting and Culturing Cells/Embryos/Eggs/Sperm Sea urchins were inverted, oral side facing upward, Aristotle’s lantern and the peristomial membrane visible. Urchins were injected with 2 mL of 0.53M KCl through the peristomial membrane into the…

creatures is the Sea Urchin. Sea Urchins are classified in the kingdom of animalia and their phylum is Echinodermata. While usually known as the Sea Urchin their scientific name is Echinus esculentus. Echinus esculentus’ meaning is “a Sea Urchin that can be eaten”. Sea Urchins may not seem like an existing animal but they are one of the most unique animals in the sea. The Sea Urchin has very unique and interesting characteristics. Sea Urchins can be black,brown,green, white and many more…

Sea Otters are a very well known example of a keystone predator and often utilized by textbooks to illustrate the concept. Sea Otters “Enhydra Lutris” are involved in maintaining the population of macrobenthic grazers such as sea urchins “Strongylocentrotus polyacanthus” and mussels. Sea urchins and mussels are the dominant species in these shallow water benthic ecosystems. Left unchecked, the sea urchins overgraze the benthic vegetation and the kelp forests. Kelp forests provide habitat for…

Sea otters spend most their time in the water. Sea otters often float on the surface of the water on their backs. Sea otters eat up to 35% of their weight in fish, crabs, sea urchins, and lobster. Sea otters eat so much that they caused the fish population to decrease significantly. If sea otters were to go extinct then there would be major effects on the ecosystem. Sea otters eat a variety of things, but a big part of their diet is sea urchins. Sea urchins eat plants. If sea otters went extinct…

definition of a trophic cascade as an ecological phenomenon triggered by the addition, or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling (huffingtonpost.com).” For that reason, in today’s society we have witnessed numerous trophic cascades that occur all over the world, specifically sea otters, blue crabs, jaguars, and as we…

There are many scenarios that could occur if sea otters disappeared in the ecosystems where they currently exist. Sea otters are considered a keystone species in these ecosystems, so the entire eco-system could be altered drastically and one can expect multiple species to be negatively affected which may diminish diversity. To start with, the most likely immediate effect would be the top down impact discussed above. Free from predators, the sea urchin population would explode (assuming that a…

the chain keeps on going also in life if you treat someone well or poorly that might affect how they treat you in the future. Nature was beautiful in BC, it was amazing to see the old growth forest and that that was one of the few ones in the world meaning most forests are man-made. The natives of kyuquot use all things and don’t waste anything like when they make or find food, shelter, and transportation. Everything is connected was mentioned a lot over our time at spring island first, dave…

This organism can be found along the shores of the Chesapeake Bay and throughout lakes, streams, and almost anywhere. The organism is most commonly known as the common otter, North American river otter or scientifically known as Lontra Canadensis. The Northern river otter has a dark brown fur wither lighter brown along the face and belly. They have thick fur to help them keep warm while swimming in cold waters to catch fish. Their webbed feet allows them to swim faster in the water and they also…

The text and the lecture are about reasons that caused sea otters declination. The text provide two reasons ro suppot the pollution theory of otters declining. However, the lecturer refutes this theoty and states that three reason is predator, ocra. First, the text says thata lot of sourses of chemical pollution are allonf the Alaskan coast. Thus the chemical pollution could cause immune system of sea otters and as a result to decline populatiion. However, the lecture says thatit it have not…