The marine eels and other members of the superorder Elopomorpha have a leptocephalus larval stage, which are flat and transparent. This group is quite diverse, containing 801 species in 24 orders, 24 families and 156 genera (super diverse).
Leptocephali have compressed bodies that contain jelly-like substances on the inside, with a thin layer of muscle with visible myomeres on the outside, a simple tube as a gut, dorsal and anal fins, but they lack pelvic fins. They also don’t have any red blood cells (most likely is respiration by passive diffusion), which they only begin produce when the change into the juvenile glass eel stage. Appears to feed on marine snow, tiny free-floating particles in the ocean.
This large size leptocephalus must be a species of Muraenidae (moray eels), and probably the larva of a long thin ribbon eel, which is metamorphosing, and is entering shallow water to finish metamorphosis into a young eel, in Bali, Indonesia.
Scientists said Tuesday a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic.
U.S. Pacific Blue Whales Seen Rebounding Close To Historic Levels
Decades after the threat of extinction led to them being protected from whalers, there are now about 2,200 blue whales off the West Coast, according to a new study. That’s roughly 97 percent of historical levels, say researchers at the University of Washington who call their findings a conservation success story.
"This is the only population of blue whales known to have recovered from whaling," according to a university news release, “blue whales as a species having been hunted nearly to extinction.”
The scientists say the population of California blue whales was never as large as many of those elsewhere on Earth, citing research that shows that whales in the eastern Pacific Ocean are distinct from those in the western Pacific. California blue whales swim in waters from the equator up to Alaska.
The new report is coming out months after the same research team studied the damage done to the same blue whale population from 1905-1971. They say the gains off the U.S. coast show that blue whales, the huge animals that have often been used to promote wildlife and environmental protections, can rebound elsewhere, as well.
“The recovery of California blue whales from whaling demonstrates the ability of blue whale populations to rebuild under careful management and conservation measures,” said study lead author Cole Monnahan, a doctoral student in quantitative ecology and resource management.
The researchers believe that a rebound close to historic levels might explain the whales’ recently slowing population growth better than theories that blame deadly strikes by large ships. They suggest that the animals’ large size — they can reach nearly 100 feet in length, and can weigh nearly 200 tons — might limit their population density.
"Our analysis suggests that while current levels of ship strikes are likely above legal limits, they do not immediately threaten the status of the ENP blue whale. This conclusion is based on the log-linear model which suggested the population has likely increased since 1993 (despite ship strikes), and from the theta-logistic model, which found this growth has slowed due to density dependence, not ship strikes."
But even if the study’s new data are confirmed by further research, “there is still going to be ongoing concern that we don’t want these whales killed by ships,” says study co-author Trevor Branch, assistant professor of aquatic and fishery sciences.
The University of Washington study was funded in part by the National Oceanic and Atmospheric Administration, through the Joint Institute for the Study of the Atmosphere and Ocean.
let throw my 2 cents in there but actually the whole “fish do (or do not) feel pain” is still an ongoing debate among scientists. A study published in 2012 showed that fish do not have the neuro-physiological capacity for a conscious awareness of pain.
So pain is a twofold experience. First, you have the neurobiological process of our nerves communicating with the brain. Second, there’s the emotional response to pain that varies from person to person. Pain research distinguishes between a conscious awareness of pain and an unconscious processing of impulses through nociception, the latter of which can also lead to complex hormonal reactions, behavioural responses as well as to learning avoidance reactions.
Nociceptor nerve cells in our bodies deliver that initial pain-related communiqué along a route through the central nervous system to the brain. Research has shown that other mammals, birds and fish also have nociceptors. The presence of those nerve cells implies that fish have the sensory capability to recognize when something is harming their bodies. Hence, fish can experience the neurological pain process.
Overall, the scientific consensus is that fish have the anatomical requirements to demonstrate neurophysiologic and behavioral reactions to pain as a means of survival.
One of the primary arguments against fish having a sense of pain is that their brains lack the structural elements, namely the neocortex, necessary for it. Without that, they cannot be aware of the pain as they are experiencing it. There islittle evidence exists to suggest that the fish also react emotionally to pain like humans. The physiological prerequisites for a conscious experience of pain are hardly developed in fish.
So basically fish can sense the pain and remember not to get caught in nets later on for example (study here) but they do not experience it emotionally like we humans do. It’s tricky though because basically, it is very difficult to deduct underlying emotional states based on behavioral responses, especially based on human standards of pain.
So really the on-going dilemma right now is that fish either have absolutely no awareness of pain in human terms or they react completely different to pain. By and large, it is absolutely not advisable to interpret the behaviour of fish from a human perspective.
The massively plump predator, estimated to measure at least 16 feet and weigh 1.6 tons, was captured on March 30 off King George Sound, and fitted with an internal tag in a process biologists described as groundbreaking.
But the photo atop this post, revealing the incredible girth of the shark as it was turned over for the tagging process, was released Tuesday. That sent websites scrambling to post the photo and update the story.
The female shark’s nickname: Joan of Shark.
Joan is among many sharks that are tagged as part of an alternative to culling, to let biologists know their whereabouts, in part so swimmers and surfers can be warned.
Since Joan was tagged she has been detected near Albany beaches several times, including nine times last Saturday. (Albany is in the extreme south of Western Australia, and is not in the region in which culling is occurring.)
The wild Chinese sturgeon is at risk of extinction, state media reported, after none of the rare fish were detected reproducing naturally in the polluted and crowded Yangtze river last year.
One of the world’s oldest living species, the wild Chinese sturgeon are thought to have existed for more than 140 million years but have seen their numbers crash as China’s economic boom brings with it pollution, dams and boat traffic along the world’s third-longest river.
For the first time since researchers began keeping records 32 years ago, there was no natural reproduction of wild Chinese sturgeon in 2013, according to a report published by the Chinese Academy of Fishery Sciences.
No eggs were found to have been laid by wild sturgeons in an area in central China’s Hubei province, and no young sturgeons were found swimming along the Yangtze toward the sea in August, the month when they typically do so.
"No natural reproduction means that the sturgeons would not expand its population and without protection, they might risk extinction," Wei Qiwei, an investigator with the academy, told China’s official Xinhua news agency on Saturday.
The fish is classed as “critically endangered” on the International Union for the Conservation of Nature’s “Red List” of threatened species, just one level ahead of “extinct in the wild”.
Only around 100 of the sturgeon remain, Wei said, compared with several thousand in the 1980s.
Chinese authorities have built dozens of dams—including the world’s largest, the Three Gorges—along the Yangtze river, which campaigners say have led to environmental degradation and disrupted the habitats of a range of endangered species.
Many sturgeon have also been killed, injured by ship propellers or after becoming tangled in fishermen’s nets.
Animal populations in many of China’s ecosystems have plummeted during the country’s decades of development and urbanisation, the World Wildlife Fund (WWF) said in a 2012 study.
According to findings compiled by WWF from various sources, the Yangtze river dolphin population crashed by 99.4 percent from 1980 to 2006, while that of the Chinese alligator fell by 97 percent from 1955 to 2010.
SO CAN WE PLEASE DISCUSS THAT OCEAN RESEVOIR POST THING BECAUSE ?????? I CAN'T IF THAT'S TRUE