- Marine life is concerned with the plants, animals and other organisms that live in the ocean. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy. For this reason marine life encompasses not only organisms that can only live in a marine environment, but also those whose lives revolve around the sea.
- At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms produce much of the oxygen we breathe and probably help regulate the earth's climate. Shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land.
- Marine biology covers a great deal, from the microscopic, including plankton and phytoplankton, which can be as small as 0.02 micrometres and are both hugely important as the primary producers of the sea, to the huge cetaceans (whales, dolphins and porpoises) which reach up to a reported 33 metres (109 feet) in length in the case of the blue whale.
Carcinus maenas is a common littoral crab, and an important invasive species. It is listed among the 100 "world's worst invasive alien species".
C. maenas is known by different names around the world. In the British Isles, it is generally referred to simply as the shore crab. In North America and South Africa, it bears the name green crab or European green crab. In Australia and New Zealand, it is referred to as either the European green crab or European shore crab.
C. maenas has a carapace up to 60 mm long and 90 mm wide, with five short teeth along the rim behind each eye, and three undulations between the eyes. The undulations, which do not protrude beyond the eyes are the simplest means of distinguishing C. maenas from the closely-related C. aestuarii, which can also be an invasive species. In C. aestuarii, the carapace lacks any bumps and extends forward beyond the eyes. The other character for distinguishing the two species is the form of the first and second pleopods (collectively the gonopods), which are straight and parallel in C. aestuarii, but curve outwards in C. maenas .
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Rachel Louise Carson (27 May 1907 – 14 April 1964) was a Pittsburgh, Pennsylvania-born zoologist and marine biologist whose landmark book, Silent Spring, is often credited with having launched the global environmental movement. Silent Spring had an immense effect in the United States, where it spurred a reversal in national pesticide policy.
Rachel Carson was born in 1907 on a small family farm near Springdale. As a child, she spent many hours learning about ponds, fields, and forests from her mother. She originally went to school to study English and creative writing, but switched her major to marine biology. Her talent for writing would help her in her new field, as she resolved to "make animals in the woods or waters, where they live, as alive to others as they are to me". She graduated from the Pennsylvania College for Women, today known as Chatham College, in 1929 with magna cum laude honors. Despite financial difficulties, she continued her studies in zoology and genetics at Johns Hopkins University, earning a master's degree in zoology in 1932.
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- Triggerfishes are the brightly coloured fishes of the family Balistidae. (pictured)
- The sea otter often keeps a stone tool in its armpit pouch.
Photo credit: Tokugawapants
The Green Sea Turtle (Chelonia mydas) is a large sea turtle, the only member of the genus Chelonia (Brongniart, 1800). This turtle grows to 1-1.5 m in length, and can weigh 200 kg, making it the largest of the hard-shelled turtles. Its distribution extends throughout tropical, subtropical and some warmer temperate waters. Females lay their eggs on traditional nesting beaches, and the turtles often bask in the sand to warm their ectothermic bodies, but otherwise this species is entirely marine.
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