The genus Siganus, or Rabbitfish, is comprised of 26 or 27 species of fish and a couple of hybrids, depending on who you ask, all of which are commonly known as rabbitfishes also called spinefoots by some people. Rabbitfish, found in shallow lagoons, have small, hare-like mouths, large dark eyes, and a peaceful temperament. They are colorful, and have well developed, venomous dorsal and anal fin spines. Use caution when handling these fish, as the spines will inflict a painful sting. Also, while these fish are sometimes eaten, you can have hallucinations if not properly prepared. The largest rabbitfish grows to about 53 cm (21 in), but most species only reach between 25 and 35 cm (9.8 and 13.8 in). All have large, dark eyes and small, somewhat rabbit-like mouths, which gives them their name. Most species have either bright colors or a complex pattern. I decided to give them their own post because they are attractive and to keep the other posts a little shorter.
Evidence for the existence of sharks dates from 450–420 million years ago, before land vertebrates existed and before many plants had colonized the continents. Only scales have been recovered from the first sharks and not all paleontologists agree that these are from true sharks. The oldest generally accepted shark scales are from about 420 million years ago. The first sharks looked very different from modern sharks. The majority of modern sharks can be traced back to around 100 million years ago. Most fossils are of teeth, often in large numbers. Partial skeletons and even complete fossilized remains have been discovered. Estimates suggest that sharks grow tens of thousands of teeth over a lifetime, which explains the abundant fossils. The oldest white shark teeth date from 60 to 66 million years ago, around the time of the extinction of the dinosaurs. These sharks attained gigantic proportions and include the extinct megatoothed shark, Carcharias megalodon. This giant shark reached a total length of more than 16 meters (52 ft). It may have approached a maximum of 20.3 meters (67 ft) in total length and 103 metric tons (114 short tons) in mass.
When we were at the Sydney Aquarium we had a chance to see one of their star attractions, the dugong. Sirenia (commonly referred to as sea cows) are an order of aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. Four species are living, in two families and genera. These are the dugong (one species, Dugong dugong) and manatees (three species; Amazonian manatee (Trichechus inunguis), West Indian manatee (Trichechus manatus), and West African manatee (Trichechus senegalensis)). Sirenia, commonly sirenians, are also referred to by the common name sirens, deriving from the sirens of Greek mythology. This comes from a legend about their discovery, involving lonely sailors mistaking them for mermaids. “Sea cow” (seekoei) is also the name for a hippopotamus in Afrikaans. In Germanic languages, the word Sea can mean either a body of fresh or salt water, so this follows from the hippopotamus inhabiting lakes in southern Africa rather than the sea itself. Australia is home to the largest population of dugongs, stretching from Shark Bay in Western Australia to Moreton Bay in Queensland. The population of Shark Bay is thought to be stable with over 10,000 dugongs.
When we visited the Sea Life Sydney Aquarium we got to see not only small tropica fish but also large schools of the much larger fish due to the grand scale of the facility. Approximately half of the aquarium’s visitors come from overseas, and they’ve been flooding in since the complex opened in 1988. Many visitors come to see creatures that they have never seen before, such a platypuses and dugongs. In general, the exhibits that can be found at the Sydney Aquarium revolve around Australian themes, and the exhibit areas mostly pertain to different Australian regions and habitats. Some of the displays are housed in the main exhibit hall and others are housed in floating oceanariums. The Seal Sanctuary and Open Ocean exhibits comprise two massive oceanariums, amongst the largest in the world, and have underwater tunnels allowing visitors to examine marine life at close quarters. If you make it to Sydney, this should be on your “must do” list.
Since we did not visit the Great Barrier Reef, we were particularly happy to visit the Barrier Reef exhibit at Sea Life Sydney Aquarium. One of Australia’s most remarkable natural gifts, the Great Barrier Reef is blessed with the breathtaking beauty of the world’s largest coral reef. The reef contains an abundance of marine life and comprises of over 3000 individual reef systems and coral cays and literally hundreds of picturesque tropical islands with some of the worlds most beautiful sun-soaked, golden beaches. They have a beautiful collection of coral and fish at the Sydney Aquarium.
Since we were in Australia and surrounded by water we decided to visit the Sea Life Sydney Aquarium. The aquarium contains a large variety of Australian aquatic life, displaying more than 700 species comprising more than 13,000 individual fish and other sea and water creatures from most of Australia’s water habitats. Additionally, the aquarium features 14 themed zones including a Bay of Rays, Discovery Rockpool, Shark Walk, and the world’s largest Great Barrier Reef display. The aquarium was designed by Australian architects to resemble a large wave, to complement the underwater theme of an aquarium and the maritime theme of Darling Harbour, and took nearly two years to build. The Great Barrier Reef complex which opened in October 1998 continues this same theme. The Sydney Aquarium was opened in 1988, during Australia’s bicentenary celebrations, and is one of the largest aquariums in the world. I plan to separate the visit into several posts.