Thursday, February 24, 2011
Up to 4 cm. in length, Australia's Bulldog Ants are the biggest ants in the world and can be found in any part of Australia. They killed a farmer in Victoria in 1988 but this is one of only three deaths by this species.
Authorities are more worried about the South American fire ant that has made it into Australia and has been found around Brisbane. Being very aggressive and having a powerful bite they are considered quite able to kill people and authorities have gone to considerable trouble to try and eradicate this ant.
The quagga was originally classified as an individual species, Equus quagga, in 1788. Over the next fifty years or so, many other zebras were described by naturalists and explorers. Because of the great variation in coat patterns (no two zebras are alike), taxonomists were left with a great number of described "species", and no easy way to tell which of these were true species, which were subspecies, and which were simply natural variants. Long before this confusion was sorted out, the quagga had been hunted to extinction for meat, hides, and to preserve feed for domesticated stock. The last wild quagga was probably shot in the late 1870s, and the last specimen in captivity died on August 12, 1883 at the Artis Magistra zoo in Amsterdam.
Because of the great confusion between different zebra species, particularly among the general public, the quagga had become extinct before it was realized that it appeared to be a separate species. The quagga was the first extinct creature to have its DNA studied. Recent genetic research at the Smithsonian Institution has demonstrated that the quagga was in fact not a separate species at all, but diverged from the extremely variable plains zebra.
Tuesday, February 22, 2011
The platypus or duck-billed platypus is an egg laying mammal of Eastern Australia. It has a duck-like bill, and wide, flat tail. It is about 61 cm. (24 in.) long and weighs about 1.8 kg. (4 lbs.). It has dark brown or yellow fur and its webbed feet and tail help it to swim. Males have poison spurs on their hind feet that kill small animals and wound larger ones. Using plates on its bill it crushes and eats worms, mollusks, crustaceans, and plants.
Mating takes place in early spring. The female digs a hole about 4.5-18 m (15-60 ft.) deep. There she builds a nest and usually lays two eggs. They hatch in about eight to ten days and nurse for about 5 months. The average life span is about 10 years.
They usually live by a river bank. They are able to move around on land, but they have to walk on their knuckles because their webbing gets in the way.
Friday, February 18, 2011
The largest bird in the Galapagos Islands, the waved albatross, is getting ready to depart, as it follows the cool waters back to lower southern latitudes. Albatrosses nest only on Española (Hood) Island, and live here from late March through early January.
The sole purpose of coming here is to reproduce, and so all their mating efforts must succeed before the arrival of the warm waters. This also brings the first rains, and their inland habitat is just impossible for them to cope with, as grasses particularly turn the dessert-like environment into a thick green lush jungle. Their offspring must be ready to leave too, as subaldults (adults with no previous mating experience), and so from October through December the most amazing flying lessons and wing exercises are witnessed on those brand new individuals.
Lots of downy feathers are seen being swept by the wind; the newer feathers are just coming out, and albatrosses must be ready to take off. Because of their big size, the young adults cannot have a second chance to take off. Once they jump off the cliffs near Punta Suárez, they will start their long journey until the nutrient-rich waters start heading back to the islands. Our ships have reported as of December 30th, a total of just 12 albatrosses left on the island. The latest they have stayed is the end of the second week in January. Bon Voyage!
Tuesday, February 15, 2011
Like other members of its class, the sand dollar is radically symmetrical. It also shows evidence of a secondary bilateral symmetry, i.e., the mouth is centered on the oral (under) surface, but the anus lies near the rear edge of the test. Tube feet are similar to those in other echinoderms and are used for locomotion and to convey small food particles, mostly organic matter found in sand, to the mouth. Tube feet on the upper surface are used for respiration.
Sand dollars differ from the closely related heart urchins by their shorter spines and more flattened shape. More convex, short-spined sand dollars are called sea biscuits. Sand dollars are abundant on the sandy bottom of deeper waters on both the Atlantic and Pacific coasts. They are classified in the phylum Echinodermata , class Echinoidea, order Clypeastroida.
Monday, February 14, 2011
The front legs of a hyena are longer than the hind ones, giving the back a sloping appearance. Despite their reputation as scavengers, hyenas are also skillful hunters; they can crush bones with their strong teeth and jaws. They sleep by day, in caves or burrows. Hyenas range over most of Africa and SW Asia. Three species are generally recognized.
The spotted hyena, Crocuta crocuta, of Africa S of the Sahara, is the largest and boldest species; it stands 2 1/2 ft (76 cm) high at the shoulder and has a gray coat with irregular patches. It is also known as the laughing hyena, because of its cry, which resembles maniacal laughter. Often abroad in the day as well as at night, it pursues game in packs and even invades camps and villages in search of food. The females are dominant and more aggressive, outranking the males in the pack. The smaller striped hyena, Hyaena hyaena, of Asia and N Africa and the brown hyena, or strand wolf, H. brunnea, of S Africa are shyer and more nocturnal and solitary in their habits. The former is grayish brown with darker stripes; the latter is dark brown over most of the body.
The aardwolf is the fourth member of the hyena family. Hyenas are classified in the phylum Chordata , subphylum Vertebrata, class Mammalia, order Carnivora, family Hyaenidae.
Wednesday, February 9, 2011
One of the most amazing things about the Horseshoe Crab is just how long they have been around in pretty much the same shape and form. I know you are curious so I will fill you in on their age. It is estimated that the Horseshoe Crab has pretty much remained unchanged for about 455 million years. Believe it or not some scientists believe they can trace it back even further to about 490 million years. Surprisingly, this little creature has survived 5 mass extinctions in which it saw a large number of their co-inhabitants disappear. Talk about being built to survive!
So lets learn a little more about the anatomy and physiology of these unique animals, shall we? For starters, these long-living animals breathe through “book gills” which are little plates found along the abdomen of the Horseshoe Crab. As well, they have that hard, armour plating which apparently protects them from everything. Well, I guess that isn’t true since sharks, sea turtles, some birds and humans have been known to successfully hunt these imitation crabs.
If you are hoping to catch a glimpse of these ancient animals on your next tropical vacation then you are best to do some night diving. Yep, the Horseshoe Crab is nocturnal. They wait for the night to fall before they head out in search of a yummy supper consisting of sea worms, mollusks and crustaceans. I wonder if they ever get tired of seafood?
Horseshoe Crab Fast Fact – The Horseshoe Crab uses their long, thin tail to help change their direction while swimming. Similarly, this tail can also help flip them over if they accidentally land on their back. As a result Horseshoe Crabs with a broken tail are more susceptible to predation and dessication.
Tuesday, February 8, 2011
Things are not always what they seem when it comes to fishï something researchers at the Smithsonian Institution and the Ocean Science Foundation are finding out. Using current hereditary psychoanalysis, combined with traditional examination of morphology, the researchers discovered that what were once believed to be three species of blenny in the genus Starksia are actually 10 distinct species.
Starksia blennies, small (less than 2 inches) fish with stretched out bodies, generally native to shallow to moderately deep rock and coral reefs in the western Atlantic and eastern Pacific oceans, have been well-studied for more than 100 years. It would have been reasonable to assume that there was little about the group left to discover. Modern DNA bar-coding techniques, however, suggested otherwise. While trying to match larval stages of coral reef fish to adults through DNA, the team of researchers noticed contradictions between the preliminary genetic data and the current species classification. Further investigation revealed that the team was dealing with a number of species new to science, including the new Starksia blennies.
"DNA analysis has offered science a great new resource to examine old questions," said Carole Baldwin, a zoologist at Smithsonian's National Museum of Natural History and main author of the paper. "This discovery is a perfect example of how DNA barcoding is illuminating species that we've missed before, especially small cryptic reef fishes like Starksia blennies. We don't know where we stand in terms of understanding species diversity, and our work suggests that current concepts appears to be surprisingly incomplete".........
Thursday, February 3, 2011
Linhenykus monodactylus is a member of the theropod dinosaurs.
Most theropods had three fingers on each hand. But Linhenykus belongs to a family known as the alvarezsauroids: small, long-legged dinosaurs that had one big finger alongside two barely functional nub fingers