SHARKS - ORECTOLOBIFORMES
The Orectolobiformes are an extremely diverse group of sharks, made up of individual species of many shapes, sizes, habitats, diets and remarkable physical characteristics. In general, they are identified by their two dorsal fins and a very short, transverse mouth. Below each eye is a spiracle, the size of which depends on the species, which is used for breathing. The exception to this rule is the Whale Shark, which has a spiracle behind its eye as opposed to below it. The nostrils are recognised by their evident barbels as well as grooves, known as nasoral grooves, which usually connect the nostrils to the mouth.
In addition to the dorsal fins, Orectolobiformes have a tail, or caudal fin, with a fairly well developed upper lobe in line with its body and a lower lobe that is not quite as developed. The Whale Shark is again the exception and displays a well developed lower lobe.
Some Orectolobiformes are oviparous, while others are ovoviviparous. In both cases, the male fertilises the female internally. Then, oviparous species lay the eggs, often in a protective leathery case, where they will hatch after a variable gestation period. In the case of the eggs being protected in a ‘purse’, the mother has been known to wedge them in rocks and crevices for added safety. Ovoviviparous sharks are those that actually form eggs internally, feeding the young off the nutrient-rich egg yolk. The pups then hatch into the internal oviduct (similar to a uterus in humans) in the mother and continue to be nurtured there until they are developed enough to look after themselves. At this stage, they are born alive into the ocean where they will immediately begin their life of independence.
Orectolobiformes only dwell in the saltwater environments of the world’s oceans and seas. They prefer the Whale shark - Rhincodon typus - with snorkeler
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