Life Lines by Dr. Dolittle

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Ocean Life

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 […]

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Limb regeneration in brittle stars

A new study published in Frontiers in Zoology examined the developmental process involved in regulating limb regeneration in brittle stars (Amphiura filiformis) following amputation of an arm. Limb regeneration is a multi-stage process involving initial healing and repair of the wounded site, initial growth of the limb followed by development of more complex layers of cells until ultimately the limb has been fully regenerated. Understanding this process in brittle stars may lead to […]

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Experimental Biology – Day 5

Today was the final day of the meeting. Dr. Joe Thompson (Franklin and Marshall College) spoke about oblique striated muscles, which get their name from the diagonal pattern formed by the location of the Z-lines. This type of muscle is common among cephalopods, nematodes, tunicates, molluscs, etc. Dr. John Whiteman (University of Wyoming) gave a fascinating talk about polar bears and whether hunting on the shore as compared to the sea […]

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Experimental Biology 2016 – Day 2

Today was a great day for trainees in comparative physiology! Here are some of the highlights from their sessions: Poster presentations: Alexis MacDonald et al., (Union College – Mentor Dr. Scott Kirkton) presented research showing that grasshopper skeletal muscles may use lactate for energy! Similarly, Dongying Wang et al., (Saint Louis University – Mentor Dr. Daniel Warren) also showed that skeletal muscle from painted turtles may use lactate. I guess it […]

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Why so many of us sleep

A special thank you to reader Dr. Barbara Goodman, Professor of Physiology at Sanford School of Medicine of the University of South Dakota who sent me a story from The Scientist about sleep in animals complete with footage of a dolphin that was seen apparently “sleeping” (video posted on YouTube): Why do animals sleep? This is a question with many potential answers. It is known that birds and mammals experience slow-wave and rapid eye movement (REM) […]

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The seal of enigma!

I am excited to present this guest blog from Bridget Martinez, graduate student from the University of California, Merced. She has been studying elephant seals in the laboratory of Dr. Rudy Ortiz. She had presented her research at the 2015 Experimental Biology conference in Boston, MA which was mentioned in a prior blog . Here is her description of her research: Bridget Martinez, Graduate Student, University of California – Merced […]

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Great white shark longevity

Scientists have discovered that great white sharks (Carcharodon carcharias) actually live longer than previously thought (up to 23 years or so). Using radiocarbon age estimates, Dr. Hamady and colleagues at Woods Hole Oceanographic Institution determined the animals can live to the ripe-old-age of 70+ years. These findings mean that great white sharks, like humans, may take longer to mature. It also means that overfishing may pose more of a threat […]

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100-year old manuscript talks about the sexual “crimes” of penguins

According to the report on the Discover Magazine website, George Levick, a surgeon and zoologist, went on an Antarctic expedition with Captain Robert Scott (the Terra Nova Expedition) where he spent time observing and documenting the largest colony of Adélie penguins at Cape Adare (image above). Following his trip he published a story about the penguins for the general public as well as a scientific account. It was in this second document that he wrote […]

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