Biology

Origins of vertebrates may be pushed back by 500-million-year-old sea squirt fossil

In 2019, paleontologist Karma Nanglu from Harvard University received a finger-sized fossil. The specimen had originated from a fossil-rich stratum of Cambrian limestone in western Utah, and had been kept in a drawer at a Salt Lake City museum for years.

Upon hearing that there could be a very old tunicate, Nanglu expressed excitement interlaced with caution: "That's a group for which there is essentially no fossil record for the entire 500 million years of recorded history."

How corals are surviving climate change

For more than two years, researchers on board the French expedition ship Tara sailed through the Pacific, stopping at almost 100 coral reefs to take thousands of water and coral samples. The expedition ended in 2018, and the analysis of the massive amount of data collected has taken five years.

Now, the initial results of the data analysis have been published. The findings should help us to better understand the living conditions of corals, to check their health status and to open up new possibilities for nature conservation. 

Sorting out the Stingrays

The bluespotted ribbontail ray is easy to distinguish from other small rays with blue spots by its oval shape. This one was found sheltering under a wreck in the Red Sea. Photo by Nigel Marsh.

Gliding slowly over the rocky reef, I was mesmerised, watching all the colourful reef fishes going about their daily activities. I was so entranced that I was startled to look up and find I was on a collision course with a massive stingray. This was the first stingray I had ever seen, and the giant creature terrified me. In the second it took my panicking brain to work out what to do, the stingray suddenly saw me and also got a shock.

Cetaceans have developed mechanisms against diseases such as cancer

Why whales don't seem to get cancer

Cetaceans were not limited by gravity in the buoyant marine environment and evolved multiple giant forms, exemplified today by the largest animal that has ever lived: the blue whale (Balaenoptera musculus).

There are tradeoffs, however, associated with large body size, including a higher lifetime risk of cancer due to a greater number of somatic cell divisions over time.  The largest whales can have ∼1,000 times more cells than a human, with long lifespans, leaving them theoretically susceptible to cancer. 

Clam lived to be over 500 years old

This makes the otherwise unassuming Arctica islandica clam the longest lived animal species on record, though some corals are probably much older. The clam was initially named Ming by Sunday Times journalists, in reference to the Ming dynasty, during which it was born.

Researchers from Bangor University in North Wales – unaware of the animal’s impressive age – determined the age by drilling through and counting rings on its shell (a technique known as sclerochronology). In the process the clam died.

Staghorn coral
The staghorn coral (Acropora cervicornis) is a branching, stony coral with cylindrical branches ranging from a few centimetres to over two metres in length and height.

Coral restoration projects show promise in Florida Keys

Reef-building staghorn coral (Acropora cervicornis) was abundant and widespread throughout the Caribbean and Florida until the late 1970s.  The fast-growing coral formed dense thickets in forereef, backreef, and patch-reef environments to depths over 20 m. 

The ridged cactus coral, relatively uncommon but striking in its beauty, had reproduced in a lab for what the aquarium says is the first time.

Scientific breakthrough could save Florida’s Reefs

The corals were rescued by the Florida Fish and Wildlife Conservation Commission and NOAA Fisheries after an outbreak of Stony Coral Tissue Loss disease commenced 2014. Previously, little was known about ridged cactus coral reproduction, as no photos, videos, or published studies were ever done on the species' reproductive biology.

Researchers find deep-sea coral gardens off Western Australia

Widely known as a biodiversity hotspot for marine animals, Australia’s Bremer Canyon Marine Park has been found to also host rich, diverse ecosystems within the canyon’s cold waters.

This discovery was made during a scientific expedition after researchers used a deep-sea remotely operated vehicle (ROV) to collect samples of deep-sea corals, associated fauna, seawater and geological samples from the abyssal depths to the continental shelf.

Many species of whales and dolphins have supersensitive hearing because they use sound to navigate

Whales and dolphins naturally muffle loud sounds

Instead of wearing earplugs at a rock concert, imagine you could simply tune a dial inside your ears to lower the volume and protect your hearing. In a new report published in Integrative Zoology, researchers have discovered four whale species and dolphins can do just that. This could potentially shield the animals from navy sonar and oil drilling, linked to at least 500 marine mammal deaths since 1963.