Behaviour

Scientists at the University of Exeter studying rockpool prawns (Palaemon elegant) have discovered that they exhibit different personalities, and those that are "shy" tend to fare better when competing for food.

The findings of their study was published in Volume 140 of the journal Animal Behaviour.

In the study, the prawns, all taken from the Gyllyngvase beach in Falmouth, were tagged and tested on their level of boldness by placing them in an unfamiliar tank and observing how much they explored and ventured to the centre.

Whereas the beaks of the common needlefish were needle-sized and shaped, this one's mouth was similarly pointed, but 15 cm long and lined with large, sharp, interlocking teeth. As I crumbled some bits of food for the ever present lagoon fish, it accelerated forward to take a morsel and the small fish shot away, creating a dazzling, submarine firework exploding in silence. When it opened its pointed mouth to take a morsel it revealed a throat nearly the same diameter as its body--it was well equipped to catch and swallow large prey. It had two parallel scars on its right side.

Working on Palmyra atoll, around 1,000 miles south of Hawaii, a team of researchers from the University of California Santa Barbara became aware of the fish's farming habit when they noticed many bite marks in specific areas of algae growing on dead coral.

They followed these patches through time and found parrotfish were feeding heavily in each patch for a short period of time. Then, the fish would allow that exact location to recover before returning to harvest the algae again.

Researchers at the University of British Columbia (UBC) discovered that some fish have learnt to stay within marine reserves where they are safe from fishing, demonstrating the importance of such facilities. They made the discovery after modelling the movements of skipjack and bluefin tuna and great white sharks in the ocean.

While many sharks are solitary predators, some are known to live in groups and are suspected of engaging in complex social behaviors. Meanwhile others simply aggregate due to similar habitat, food, or mating requirements.

Using a novel tagging procedure, scientists in the United States, have discovered that some shark species like to spend their time mixing and chilling out together.

So shark dive clubs usually bring some fishy scraps—in most cases the remains left over after big fish have been cut up for sale. The scent attracts the sharks into view and provides a bit of excitement as the animals investigate and try to get a piece. But little actual food or nourishment is given. The sharks circle far and wide through the vast volume of the visible ocean, in a memorable and dramatic display, as they look over the scene, zoom in for a closer look, try for a scrap, and socialize.

A difficulty in obtaining information about the natural behaviour of wild animals is that detailed observations of the activities of different individuals is necessary over long periods of time, and this is especially hard to achieve with sharks.

Bull shark diving is becoming a popular tourist activity in the waters around Cancun, Playa del Carmen and Cozumel.

Be quiet

Luis Lombardo Cifuentes, director of Saving Our Sharks, told the Riviera Maya News they have noticed the sharks displaying fearful behaviour this year and are asking divers to use extreme caution when approaching them by being very quiet and not make noise in the water.