Greenland deep-sea shark, the longest living vertebrate on the planet, can live for around 400 years

Amazing stuff!

"... But in April 2026, a group of researchers and volunteers stood on the cloudy shoreline of County Sligo, Ireland, and marvelled at the sight of a species that had never been stranded here before – a dead Greenland shark. 

Judging by its size – around 3m (10ft) long – the grey-beige animal lying on the tidal flats was over 150 years old. ... 

The Greenland shark, the longest living vertebrate on the planet, can live for around 400 years. ..."

"... The [recovered dead] shark is now undergoing detailed scientific postmortem examination, contributing valuable data to the understanding of this elusive deep-water species. Tissue samples and selected anatomical components are being preserved as part of the National Museum’s scientific collections, ensuring a permanent record of this exceptional specimen. ..."

'We were all just in awe': A stranding in Ireland sheds new light on the long, slow, ice-cold life of a deep-sea shark "Some Greenland sharks alive today may have been contemporaries of Shakespeare. With a scarred heart that beats for centuries and eyesight that doesn't fade, this deep-sea shark defies age-related decline."

Remains of a rare Greenland shark recovered (original news release) "The remains of a rare 3-metre-long Greenland shark (Somniosus microcephalus) has been successfully recovered from the shoreline in County Sligo, marking the first recorded stranding of this species on the Irish coast."

Source

Recovery of the remains of the dead shark

Watching a lifetime of a small vertebrate reveals the process of aging

Amazing stuff!

"In brief

• Stanford researchers studied African killifish to explore links between behavior and aging, revealing varied aging paths in similar environments.
• Findings show early behavioral differences, like sleep patterns, can predict lifespan potential in individuals, suggesting insights for human aging.
• The study’s implications extend to developing interventions for healthier aging, leveraging technology to track behavioral changes in real-time.

By midlife, an animal’s everyday behaviors can signal how long it is likely to live. ...

One of the team’s most surprising findings was how early individual aging paths begin to diverge. After following each fish through its entire lifespan, the researchers grouped animals based on how long they ultimately lived and then looked back to see when behavioral differences first emerged. They found that by early midlife (70 to 100 days of age), fish that would go on to live shorter or longer lives were already behaving differently. ...

Aging unfolds in steps [stages?]

The team’s observations also revealed that aging – in killifish, at least – does not progress as a smooth, gradual drift. Most of the fish underwent two to six rapid behavioral transitions, each lasting just a few days, followed by longer, stable stages that lasted weeks. Importantly, fish tended to progress through these stages in sequence, rather than switching back and forth between them. ...

The African turquoise killifish made that question experimentally possible. With a typical lifespan of just four to eight months, it is one of the shortest-lived vertebrates studied in the lab, yet it shares key biological features with longer-lived species like humans, including a complex brain. ..."

From the abstract:

"Mapping behavior of individual vertebrate animals across lifespan is challenging, but if achieved, could provide an unprecedented view into the life-long process of aging.

We created the first platform for high-resolution continuous behavioral tracking of a vertebrate animal across natural lifespan from adolescence to death—here, of the African killifish. This behavioral screen revealed that animals follow distinct individual aging trajectories.
The behaviors of long-lived animals differed markedly from those of short-lived animals, even relatively early in life, and were linked to organ-specific transcriptomic shifts.

Machine learning models accurately predicted age and even forecasted an individual’s future lifespan, given only behavior at a young age. Finally, we found that animals progressed through adulthood in a sequence of stable and stereotyped behavioral stages with abrupt transitions suggesting a novel structure for the architecture of vertebrate aging."

Watching a lifetime in motion reveals the architecture of aging | Stanford Report "Scientists tracking the entire life of the African turquoise killifish have discovered that behavior alone can predict whether an animal will live a long or short life."

Life-long behavioral screen reveals an architecture of vertebrate aging (preprint, open access)

Fig. 1 System enables continuous behavioral tracking from adolescence to death.

How specialized intestinal cells help pythons completely digest the bones of their prey

Amazing stuff!

"... When researchers peered into the intestines of Burmese pythons, they saw cells with narrow, crypt-like structures, which contained particles ... not seen previously in other vertebrates.

To find out how the cells worked ... analyzed intestinal cells from 14 year-old Burmese pythons that had fasted for three weeks before being fed one of three diets: a normal diet of whole rodents, a low-calcium diet of de-boned prey, or deboned rodents that had been injected with calcium.

When the pythons were fasting or fed a boneless meal, the crypts in their intestinal cells were narrow and empty;

snakes that ate whole rodents or boneless rodents with added calcium had crypts chock-full of large calcium, phosphorus, and iron particles.

These crypts, the researchers say, may help the snakes deal with excess calcium after eating large animals with many bones. Surprisingly, pythons that ate whole rodents did not have any bone fragments in their droppings, suggesting that they had all been completely dissolved. ..."

From the abstract:

"Burmese pythons, Python molurus bivittatus, digest the skeleton of their prey; this must result in a high amount of calcium and phosphorus passing through the intestinal lining. To determine how Burmese pythons can process this ion influx, the effects of different nutritional diets were examined in juveniles reared in captivity using three different diets: 

a normal diet with calcium and phosphorus provided from entire rodents;

a low-calcium and phosphorus diet using rodents with no bones (‘boneless prey’); and a calcium-rich diet composed of boneless rodents supplemented with calcium carbonate (CaCO3) through intraperitoneal injections inside the prey.

The effect of these diets was analysed along the intestinal mucosa using light and electron microscopy techniques ... Blood calcium and hormone levels [parathyroid hormone (PTH) and calcitonin] were also analysed from fasting pythons and snakes repeatedly fed with either a normal prey diet or a low-calcium and -phosphorus diet (boneless rats).

The results revealed the presence of specialised cells in the intestinal epithelium that are involved in the production of calcium and phosphorus particles in fed snakes. These cells have an apical crypt possessing a multi-layered particle made of calcium, phosphorus and iron-rich nucleation elements in the centre.

In fasting snakes, this cell type has empty crypts.

When snakes are fed with boneless prey, particles are not produced by this cell type, although iron elements are located within the crypts.

When calcium supplements are added to a boneless meal, large particles fill the crypts.

When snakes are fed repeatedly with a low-calcium diet, blood calcium level drops while levels of calcitonin, and particularly of those of PTH, increase.

Therefore, Burmese pythons possess a specialised intestinal cell type involved in excreting excess dissolved calcium and phosphorus that originate from the prey and are precipitated as particles that must accumulate in the faeces.

This cell type is also found in other snake species that eat vertebrates (some Boidae and a colubrid) along with a lizard, the Gila monster, Heloderma suspectum. A broader analysis among vertebrates that ingest their prey whole and dissolve the prey skeleton would allow a thorough evolutionary analysis."

ScienceAdviser

New “bone-digesting” cell type discovered in pythons

Diet-dependent production of calcium- and phosphorus-rich ‘spheroids’ along the intestine of Burmese pythons: identification of a new cell type? (no public access)

A Burmese python devouring an alligator

How ribs might have been vital in the evolution of walking

Amazing stuff! Does the Bible not say Eve was made from one of Adam's ribs? (just kidding)

"An analysis of a fossil found 20 years ago has revealed new details which might explain how vertebrates evolved to walk on land nearly 400 million years ago.

Tiktaalik, a 375-million-year-old fish,  discovered in Canada, is a “fishapod” – a missing link between fish and the first four-legged tetrapods to walk the Earth. All land animals with a backbone (and those which evolved to be water dwellers again, like whales) can trace their ancestry back to pioneering fish like Tiktaalik – from dinosaurs, frogs and birds to humans. ...
“These new high-resolution micro-CT scans show us the vertebrae and ribs of Tiktaalik and allow us to make a full reconstruction of its skeleton, which is vital to understanding how it moved through the world.” ...

Most fish have vertebrae and ribs that are the same length along their spine. But limbed vertebrates have vastly differently sized ribs. This allowed specialised functions in different parts of the trunk including a mechanical link between ribs and the pelvis and hind limbs that support the body. ..."

From the significance and abstract:

"Significance

The origin of terrestrial vertebrates is marked by changes to the entire post-cranial skeleton. To date, information on the vertebrae and ribs of the closest relatives to limbed vertebrates has been limited, making it difficult to reconstruct how the axial skeleton was evolving. This paper describes the axial column of Tiktaalik roseae, a close relative of limbed vertebrates. The holotype specimen was µCT (micro-computed tomography) scanned, which revealed its vertebrae and posterior ribs. These data show how specialization for head mobility, body support, and pelvic fin buttressing arose in stem tetrapods, allowing for a three-dimensional reconstruction of Tiktaalik and shedding light on the antecedents to the terrestrial walking behaviors.

Abstract

The axial columns of the earliest limbed vertebrates show distinct patterns of regionalization as compared to early tetrapodomorphs. Included among their novel features are sacral ribs, which provide linkage between the vertebral column and pelvis, contributing to body support and propulsion by the hindlimb. Data on the axial skeletons of the closest relatives of limbed vertebrates are sparce, with key features of specimens potentially covered by matrix. Therefore, it is unclear in what sequence and under what functional context specializations in the axial skeletons of tetrapods arose. Here, we describe the axial skeleton of the elpistostegalian Tiktaalik roseae and show that transformations to the axial column for head mobility, body support, and pelvic fin buttressing evolved in finned vertebrates prior to the origin of limbs. No atlas–axis complex is observed; however, an independent basioccipital–exoccipital complex suggests increased mobility at the occipital vertebral junction. While the construction of vertebrae in Tiktaalik is similar to early tetrapodomorphs, its ribs possess a specialized sacral domain. Sacral ribs are expanded and ventrally curved, indicating likely attachment to the expanded iliac blade of the pelvis by ligamentous connection. Thus, the origin of novel rib types preceded major alterations to trunk vertebrae, and linkage between pelvic fins and axial column preceded the origin of limbs. These data reveal an unexpected combination of post-cranial skeletal characters, informing hypotheses of body posture and movement in the closest relatives of limbed vertebrates."

How ribs might have been vital in the evolution of walking

The axial skeleton of Tiktaalik roseae (open access)

Fig. 1 Volumetric rendering of µCT scans of Tiktaalik roseae