Life Lines by Dr. Dolittle

Ocean Life

Leave a comment

The ultimate desalination plant: the eel esophagus

I love fish. The diversity of these aquatic creatures is so vast, I find them fascinating. Take the eel for example: In a study published this month in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers wanted to link information they learned from sequencing the RNA of eels with understanding how the animals adapt to saline environments. During acclimation to saltwater, fish have no choice but […]

Continue Reading →

Leave a comment

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 in the environment could be for the cuttlefish to still mimic it quickly enough while moving. What […]

Continue Reading →

Leave a comment

First known case of zebra shark switching to asexual reproduction

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 mate was removed from the tank to prevent further breeding, she has shared the tank with […]

Continue Reading →

Leave a comment

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 about the costs of reproduction in orcas. Older mothers tend to spend more time taking care […]

Continue Reading →

Leave a comment

What is that purple blob?

By now you have probably seen the video showing the discovery of a strange purple blob during an exploration off the coast of California. As a scientist what do you do when you find something new? You bring it back to the lab of course. Although it may take years to identify what it is, the researchers have speculated it might be some new species of soft-bodied mollusk. Check out […]

Continue Reading →

Leave a comment

How the rectum helps prevent dehydration in saltwater

Teleost fish living in saltwater environments are constantly compensating for water loss. This happens because their surroundings have higher concentrations of salts than their plasma and the rule of thumb in Biology is: water follows salt.  Thus these fish must somehow compensate for water loss in order to prevent dehydration. One way they do this is by drinking a lot of water. Ions are then removed from the water in the intestines which […]

Continue Reading →

Leave a comment

Cartilaginous fish need to regulate sulfate too

Seawater contains sulfate concentrations that are nearly 40 times those measured in plasma. Therefore, it is easy to see why fish would need to develop mechanisms to keep sulfate within a physiologically normal range. The kidneys of teleost fish have been known to excrete excess sulfate in the urine. However until now, it was not known whether the kidneys of cartilaginous fish do the same thing as their kidneys are rather complex. In a new […]

Continue Reading →