Archives for January, 2017

Camouflage in motion

Cuttlefish (Sepia officinalis) are masters of camouflage. Being able to mimic their surroundings helps them hide from predators. But how do they maintain their camouflage while moving through complex environments, such as coral reefs, sea grass, and varying light patterns? A new study published in Frontiers in Physiology examined this question. They wanted to know how small an object…

The cause of stomach rumbling

The stomach and small intestine of many species moves rhythmically during fasting, something called the rhythmic ‘migrating motor complex’, or MMC. The MMC has 3 phases: no contraction, intermittent small contractions followed by regular large contractions. These contractions are thought to help clean the GI tract by moving along debris and bacteria as well as preparing our guts for the…

The story begins in 1999 when Leonie, a zebra shark (aka a leopard shark in Australia), was captured from the wild. In 2006 she was transferred to Reef HQ Aquarium in Queensland, Australia where she met her mate. By 2008, she had started laying eggs and the pair had multiple litters of offspring through sexual reproduction. After her…

Ammonia tolerance of goldfish

Liver failure or congenital defects can lead to a build-up of ammonia in the brain of mammals resulting in life-threatening swelling, convulsions and comas. For goldfish (Carassius auratus), environmental exposure to ammonia causes reversible swelling of the brain. In a new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers wanted…

Why orcas go through menopause

Orcas are one of only three species of mammals that go through menopause, including humans of course. A new study published in Current Biology may have discovered why this happens in killer whales. Examination of 43 years worth of data collected by the Center for Whale Research and Fisheries and Oceans Canada, revealed a remarkable finding…

The obese marathon mouse

As the name implies, Dummerstorf marathon mice are bred to run. If allowed to be sedentary, these animals can build up quite a bit of fat within their peripheral tissues even if they do not overeat. If given an exercise wheel, however, they burn fat very quickly. In a new study published in the Journal of Comparative Physiology – B,…