FRANCES WALDEN CONSERVATION BIOLOGY WRITE UP OF ENDANGERED SPECIES DECEMBER 6TH, 2007 THE ANGEL SHARK (Squatina squatina). In the past few decades, the interest by many in protecting and preserving the world’s biodiversity have increased. Human activities, around the globe, possess a threat to biological communities. It has been proposed that many biological species will go extinct in the coming decades (Richard Primack, 2004). One such biological species which is going extinct is the angel shark.
They have no natural enemies except man and power boats which are responsible for most manatee deaths- (in 1990, 218 manatees or 12 % of the total population were killed by boats), though the red tide (toxins released from the bloom of dinoflagellates) of 1982 and1996 killed over 15% of the population. It is suspected that environmental pollutions create disease vulnerability in marine mammals with manatees being no exception. An example is when 10,000 seals died in 1988 in Denmark and Sweden from viruses related to canine distemper. High concentrations of PCB’s were detected in necropsies of these seals, presumably from the water and fish they ate. Other threats include accidental
They accomplish this by feeding on algae and bacteria. 8 Species of mussels are native to the river. The most prevalent are the eastern elliptio mussel and the eastern lamp-mussel. Mussels are eaten by a variety of birds, turtles, fish, muskrats and other mammals. Zebra Mussels are an invasive species that can cause harm to native species by attaching themselves to their shells preventing free movement and can even cut off their oxygen
Scientists were studying this correlation and discovered some of the reasons for this higher mortality rate. Some otters are caught and killed in fishermen’s nets, some drown in lobster pots, and predators such as sharks kill some. A final explanation for their low population in California is infectious diseases, which mostly kills
It has red or orange antennae, lacks hair, and its claws seem rough or grainy. This hermit crab will pick a shell it can pull its entire body back into. I saw both P. hirsutiusculus and P. granosimanus in the same tidepool at Rosario recently. A third species to watch for is Pagurus beringanus. This species is usually subtidal but may occasionally be seen in very low subtidal areas.
Younger lionfish have a unique tentacle above their eye sockets, which differs in appearance between species, but studies show that this tentacle has evolved over time in each species serving to attract new prey. Juvenile lionfish eat mostly invertebrates, but shift their diet to fish as adults and eat reef fish. Adult lionfish spread their pectoral fins and use them to "herd" prey. This is a very effective predatory style because it is unfamiliar to native Florida fish. However, Lionfish can have negative effects on the overall reef habitat as they can eliminate organisms which serve important ecological roles such as herbivorous fish which keep algae in-check on the reefs.
In fact, scientists report that this problem is so serious that virtually all seafood now contains plastic. We’re fast running out of space for landfills—especially near cities. Seaside cities have been dumping trash into their oceans for decades to circumvent the problem, but with widespread marine ecological collapse, this is no longer a viable option. Other things include air pollution from factories. B.
In one instance, the parent attacked a human who approached their babies. (fws.gov). The Northern Snakehead has made quite an economic impact on the areas it has invaded. Since it destroys ecosystems, money has to be spent on pesticides to attempt to wipe out the species. When the pesticide is placed in a pond, it kills every fish in that pond.
Sea anemones are anchored to the substrate by their muscular pedal disc ("Sea Anemones (Actiniaria) On The Shores Of Singapore"). Some types of sea anemone burrow into the sandy seabed instead of attaching to a stable substrate ("Sea Anemones (Actiniaria) On The Shores Of Singapore"). Feather stars use a claw-like appendage underneath the calyx called the cirri to anchor themselves when filter feeding ("Feather stars (Crinoidea) on the Shores of Singapore"). However, both animals are capable of locomotion. Some species of sea anemone are capable of moving slowly by sliding along the substrate on their pedal discs (Parker, 1916).
The blowhole of a sperm whale “is found far forward on the left side of the head with a spout that comes out at a sharp angle from the head and toward the left” (Brownell 682).Sperm whales have a wrinkled appearance (Brownell 682).“They has 18 to 25 peglike teeth one each side”(Wursig 258). The “adult male sperm whales measure up to 36 to 65 feet” while the “adult female sperm whales measure up to 28 to 41 feet” (Brownell 682).“Almost all sperm whales live only in tropical and mild water” (Wursig 258).Their daily intake of food consists of large squids, “certain fishes, such as cod, skate, barracuda, and shark”(Wursig 258). Another type of toothed whales is the beaked whales.Beaked whales “have a beaklike snout and only two or four teeth in the lower jaw” (Wursig 258) and “the upper teeth are absent or vestigial” (Brownell 682a). “Beaked whales are of medium size,” (Brownell 682a) “some kinds grow only about 12 feet long, but others reach 42 feet” (Wursig 258).“There are 18 known species of beaked whales” (Wursig 258). “Beaked whales live in all the oceans”(Wursig 258), but some of the beaked whales “species live in the deep waters” (Wursig 258).