Molluscs

A giant sea snail may turn out to be another line of defense against the destructive crown-of-thorn starfish that is currently plaguing Australia’s Great Barrier Reef.

Called the Pacific triton sea snail (Charonia tritonis), it can grow up to about 50 to 60cm and is indigenous to Australian waters. More importantly, the crown-of-thorn starfish happens to be part of its natural diet. However, the sea snail is currently endangered due to the consumer demand for their shells.

Sharks home in on faint bioelectric fields generated by the bodies of their prey which they pick up using sensitive detectors on their snouts.

When researchers from Duke University showed captive cuttlefish held in a tank videos depicting the menacing silhouettes of a shark or predatory grouper fish they reacted by lowering the electric field dramatically. Being shown the shadow of a harmless crab produced no reaction.

Researchers from Jerusalem’s Hebrew University have filmed crawling octopuses to learn how the animals utilized their flexible arms when they move. Until now, scientists have struggled to understand how their elaborate crawling movements are coordinated. The answer proved remarkably simple: they just choose which arm to use to push themselves along without a trace of rhythm.

New research by Lindsey Dougherty of the University of California, Berkeley, suggests that scaring off predators or luring prey may be the primary motivations for the disco clam’s flashy behavior.

Dougherty first became fascinated with disco clams when she was shocked by their display during a dive in Indonesia. “It was on that trip I first saw the disco clam, and immediately fell in love,” reminisced Dougherty.

A project conducted by researchers from Denmark's Technical University showed that 18 hectares of blue mussels in Skive Fjord reduced the levels of algae low enough to prevent oxygen depletion.

The main issue with fertilization of coastal waters causing algae bloom stems from the massive amounts of dead algae sinking to the bottom in thick layers. As they rot, they consume and deplete oxygen, choking huge swathes of the seabed, leading to widespread bottom death. This is a big issue along coasts of agricultural areas.