Hungry shrimp innovate more
Both size and hunger drove the prawns to innovate to get food, but only under certain circumstances

Hungry shrimps get smarter

Behavioural innovation is thought to play an important role in enabling animals to cope with environmental change. Research on animal innovation has focused on terrestrial and freshwater vertebrates, but few animals face environmental variation as extreme as those living in littoral zones, where physical and social conditions change dramatically from moment to moment.

Sex and violence amongst lobsters

The aim of this thesis was to study the chemical communication involved in aggressive and reproductive behaviours in the European lobster (Homarus gammarus). Both male and female H. gammarus established and maintained dominance, but the sexes used different strategies for dominance maintenance.

Male losers recognised individual fight opponents and avoided them but fought actively against unfamiliar dominants. In contrast, female losers avoided both familiar and unfamiliar dominants, indicating that they react to the dominance status of the opponent.

Common littoral crab (Carcinus maenas)

Crab shell compound makes wounds heal faster

In ancient China crabs were smashed open and thrust into wounds in battles because chitosan is antimicrobial, meaning it heals and kills bacteria.

Chitosan's properties allow it to rapidly clot blood and promote hemostasis (stops bleeding). Chitosan bonds with platelets and red blood cells to form a gel-like clot which seals a bleeding vessel.

Blue crab
Atlantic blue crab, or regionally as the Chesapeake blue crab, is a species of crab native to the waters of the western Atlantic Ocean and the Gulf of Mexico, and introduced internationally.

Blue crabs attack at low tide

Last September, ecologist David Johnson and his colleagues were at a Virginia salt marsh at low tide. There, they observed some unexpected behaviour by an aquatic predator.

They witnessed blue crabs waiting in shallow, water-filled pits, stalking and ambushing fiddler crabs above land, at low tide.

After capturing their prey, they would carry it back to the pit to consume it, then discard the large claws of the fiddler crab at the edge of the pit.

DAN Encourages Safe Diving During Florida Lobster Mini Season

While it’s a fun, challenging and tasty experience for most, more than 20 divers have lost their lives during mini season in the last decade.

Through analysis of these tragic deaths, researchers at Divers Alert Network (DAN) have identified the most relevant contributing factors and most important safety practices for divers participating in the annual event.

These tips probably won’t surprise you, but sometimes the most basic precautions are the most likely to save a life.

The two hermit crab species (Coenobita rugosus on the top left and C. perlatus on the top right), with the four shell types used in the research

Why two hermit crab species on same beach don't fight over shells

Researchers from the University of Bayreuth, Germany discovered how two hermit crab species co-exist on the same beach without fighting over limited resources like food or shelter.

Sebastian Steibl and Prof Dr. Christian Laforsch sought to investigate how resource partitioning occurs and whether it may be a driver of coexistence between competing species. (Resource partitioning involves similar species in the same environment utilising different subsets of the same resource (or using it in a different way), so they are not in direct competition with one another.)

The maze that the crabs in the study had to get through.

Study reveals crabs' spatial learning skills

Many studies about spatial learning in animals have focused on land animals, and less so in marine animals, possibly due to the difficulty in following them around.

This new study, led by Swansea University marine biologist Ed Pope and master’s student Ross Davies, gives a glimpse into the European shore crab’s level of spatial learning ability.

First, the team constructed a special maze that measured 75cm by 50cm. A single crushed mussel was placed at the end of it.

Some rockpool prawns prefer to stick with the food they found while others tend to forage for more choices.

Shy prawns fare better than bolder ones

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.

King crab in the Barents sea

King crabs threaten Antarctic ecosystem

Rising temperature of the ocean west of the Antarctic Peninsula - one of the most rapidly warming places on the planet - should make it possible for king crab populations to move to the shallow continental shelf from their current deep-sea habitat within the next several decades, researchers from Florida Institute of Technology find