![]() ![]() However, Gilbert Percy Whitley, a celebrated ichthyologist who worked at the Australian Museum from 1925 to 1964, wrote that the only true ‘mermaid purse’ is the skates’ egg. Today, the term ‘mermaid purse’ is broadly applied to the egg case of any shark or ray. The zebra shark egg ( Stegostoma fasciatum), on the other hand, looks a bit like a jacaranda pod: ‘Mermaid purses’ Then there’s the egg of the Australian ghost shark ( Callorhinchus milii) which would pass as a prop from the movie Alien, with its metallic blue-black colour, and ribbed edges: ![]() It’s an orange-yellow colour, with bright tendrils that look a lot like cake decorations: One of the most bizarre-looking shark eggs is that of the draughtboard shark ( Cephaloscyllium laticeps). I think they are able to smell them because later in development the eggs split open a little to allow water to circulate to help respiration.” Other-worldly “There is some work that suggests embryos in shark eggs reduce their activity when predators are present to reduce chances of predation. “When they emerge they have to be ready to go, able to feed, able to look after themselves because we haven’t seen any evidence that the parents provide care post laying eggs.”Īnd life isn’t easy inside the egg, either. Safe and sound?Īccording to Colin, once the sharks lay their eggs, the pups are completely on their own, subject to the weather and other predators. The purpose of the tendrils, he says, is to become tangled in seaweed or glued to the algae as another way to anchor the egg. “When the Port Jackson shark lays an egg, she’ll pick it up in her mouth and screw it into rocks and crevices to anchor it, so that they don’t wash away and that’s what gives them that shape,” explains Mark. And there’s practical reasons for its bizarre shape. Without the black tendrils, it looks identical to the Port Jackson shark egg – the one you’re most likely to see at the beach. His favourite is the egg of the crested-horn shark ( Heterodontus galeatus), which is cone-shaped, black matte in colour and has spiralling tendrils hanging off the bottom. Mark McGrouther has been the ichthyology (fish science) collection manager at the Australian Museum since the late 1980s and has seen his fair share of shark eggs. Download and use 1,000+ Zebra Shark stock photos for free. These often palm-sized eggs come in various colours, shapes and textures, depending on the species of shark. Oviparity – the laying of eggs – is harnessed by a small number of shark species, as most sharks are viviparous, meaning the eggs develop inside the mother. This method is known as ‘intrauterine cannibalism’. “The grey nurse shark pups eat each other within the uterus and then you end up with just one surviving animal,” he says. Professor Colin Simpfendorfer, a shark expert from James Cook University in Queensland has spent a lot of his time studying the reproductive lives of Australian sharks and rays and he continues to be fascinated by the different ways they nourish their young.Īccording to Colin, by far the most bizarre strategy is that of the grey nurse shark ( Carcharias taurus). Please get involved, spread the word and contribute your photographs.The reproductive organs of sharks are a lot like human reproductive organs, in that the male sharks have a pair of external claspers that they insert into the cloaca – the female’s reproductive organs. Shark Guardian is pleased to help promote this project in Thailand. Christine Dudgeon, The University of Queensland ) and the diving community of Thailand. ![]() Spot the Leopard Shark Thailand is a joint venture between Thai researchers (Phuket Marine Biological Center) and Australian researchers ( Dr. Browse our collection to find stock imagery of zebra shark adults and juveniles close-ups of zebra sharks in their natural habitats and photos of zebra sharks facing the camera. Leopard sharks are classified as Endangered to Extinction on the IUCN Red List. The iStock image library contains more than 1600 zebra shark stock photos in its image library. Stegostoma fasciatum Zebra shark, the common name of these slow-swimming, non-aggressive, bottom-dwelling sharks, is derived from their juvenile coloration: narrow bars reminiscent of a zebra’s stripes. So every time you take a photo, you are also being a marine biologist and collecting data! T aking pictures of the Leopard (Zebra) sharks may seem pretty simple but these questions are important and timely for this species. Submitted photos and information will be used to address questions of how many leopard sharks there are in Thailand, which areas they use, how this changes over time, how long they live, etc. Spot the Leopard Shark Thailand was launched on Koh Phi Phi Island, Thailand, in August 2013. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |