The basis of the diet of young white sharks migrating off the East coast of Australia, were large pelagic fish. However, the researchers found, these predators often prey on benthic prey, such as stingrays. This means that environmental preferences and hunting behaviour of white sharks is much wider than previously thought, say the authors of the article for the journal Frontiers in Marine Science.
White shark (Carcharodon carcharias) is widely recognized as the Supreme predators of marine ecosystems. However, information about their diet, especially at a young age, are very incomplete, and without them, academics find it difficult to understand the ecological characteristics of this species and to establish its effective conservation.
To understand the power of white sharks decided team of specialists, headed by Richard Granger (Richard Grainger) from the University of Sydney. They focus on the populations that migrate along the East coast of Australia. Adult sharks are relatively rare, and the majority are immature individuals with a length less than three meters.
The researchers analyzed the contents of the intestine 52 young white sharks, most of whom were killed in nets set for the protection of beaches in the state of New South Wales. Food residues were detected in 40 of them.
It turned out that in the early stages of life the most important place in the diet of the East Australian white shark is a bony fish (Teleostei). The most popular prey was a large arrip (Arripis trutta), a major fish species of coastal pelagic waters. It is often called the Australian salmon, although salmon to this, he has nothing. Other bony fishes in the diet of sharks was presented to the seafloor and reef shapes.
Cartilaginous fish was in the diet of young great whites a smaller share. Mostly it was various rays, which are often hunted males. Cephalopods and mammals (in this case dolphins) had eaten even less. However, the older and bigger were sharks, the more likely they hunted marine mammals.
Comparing the obtained results with data from South Africa, researchers found that young sharks of the two populations adhere to a similar diet. However, the South African specimens is Aripov ate mostly Peruvian sardines (Sardinops sagax) and less hunted rays.
According to the authors, their study shows that food preferences and hunting strategies of young white sharks more diverse than previously thought. Although this species is considered a typical hunter from the upper layers of the ocean, the presence in its diet of benthic production type of rays indicates the ability to hunt in deeper waters.
White sharks are born and spend the first years of life in the so-called nursery — shallow areas of the ocean in the Mediterranean sea and off the coast of South Africa, South-Eastern Australia, California and Western North America. And recently, paleontologists were able to detect a manger fossil white sharks. They are located off the coast of Central Chile during the Pliocene epoch from five to two and a half million years ago.
Sergey Knee High