A pair of killer whales, nicknamed ‘Port and Starboard’, has been terrorizing great white sharks. In recent years as many as 8 sharks (possibly more) have succumbed to the pair. Many of the discovered sharks were missing their fatty liver and sometimes their heart. While orca hunting escapades are not particularly newsworthy, the antics of these orcas have attracted the attention of scientists as they are altering the ecosystem. Once […]
There we were minding our own business at a family picnic when fruit flies descended on our lunch like an invading army. Alas, our swatting resulted in very few casualties. I am sure they snuck off with bites of this and that, although we may have found a few victims in the lemonade. So, why is it so difficult to swat fruit flies? I had a sudden desire to know […]
Did you know that blood vessels come fully equipped with the ability to help regulate blood pressure? This is possible because of smooth muscle cells that wrap around blood vessels (see image above). Because they wrap around the inner layers of the blood vessel, when these cells contract, the lumen od the blood vessel becomes narrow and increases blood pressure. When they relax, the blood vessels widen thereby lowering blood […]
Did you know that rodents and rabbits are not able to vomit? This was certainly news to me. So, I had to find out more… First, let’s talk about the difference between retching and vomiting. During retching (or dry heaves), the diaphragm and abdominal muscles contract, which helps increase pressure within the stomach (and prepare the contents for expulsion). Vomiting also involves contractions of the diaphragm, abdominal as well as […]
Existing species of coelacanths (pictured above) are descendants of a group of fish that existed about 410 million years ago, during the early Devonian period. They can be found in the Western Indian Ocean off the coast of Indonesia. These fish are really interesting because they have very low metabolic rates. In fact, their metabolism is among the lowest of any other existing vertebrate. Even sloths are jealous of their […]
There are several ways to stay warm on a cold day. If you are human, you can turn up the heat in your home, put on a sweater, snuggle, and even produce body heat through shivering as well as non-shivering metabolic pathways – although the ability to produce heat metabolically typically declines with aging. If you are a small mammal, turning up the heat or putting on a sweater are […]
If you have ever had a fish tank, you may be familiar with monitoring ammonia levels in the water. Ammonia levels can rise due to overcrowding, overfeeding, as well as fish waste. Nitrite levels in the water also require monitoring as nitrite can bind to hemoglobin, which prevents oxygen from binding. In effect, by preventing oxygen from binding, the fish can succumb to hypoxia. Hannah Hughes, a graduate student working […]
Prolactin is an important pituitary hormone in mammals that works with oxytocin to provide milk for offspring. It also plays a role in promoting bonding between new mothers and their offspring. But did you know that non-mammalian vertebrates have prolactin too? Considering non-mammalian organisms do not have mammary glands, it must serve a different purpose in these animals. As it turns out, prolactin is very important in the ability […]
Jacob Pithan, a graduate student in the laboratory of Dr. Kendra Greenlee (North Dakota State University), presented their research examining how aging affects exercise performance as well as oxidative health at last month’s Experimental Biology conference in Philadelphia. The oxidative stress theory of aging postulates that aging results from an overproduction of free radicals along with a decrease in antioxidants that can scavenge them. The problem with free radicals is […]
In humans, pregnancy can be an uncomfortable time as the growing fetus makes it more difficult to breathe. It can also become more difficult for the expectant mother to get around. It may be surprising to find out that grasshoppers may develop similar issues when they are ‘expecting’. In fact, a gravid grasshopper can carry an egg mass that makes up as much as 40% of their weight! Could you […]
Life Lines by Dr. Dolittle 