What makes jellyfish unique?


This 4 October 2018 video says about itself:

Jellyfish 101 | Nat Geo Wild

How much do you really know about jellyfish? Given their diverse evolutionary history, jellies exhibit a fantastic range of shapes, sizes, and behaviors. Learn all about these squishy, brainless, beautiful creatures. Also make sure to read the full October 2018 National Geographic magazine feature story.

From the Okinawa Institute of Science and Technology (OIST) Graduate University in Japan:

What makes a jellyfish?

April 15, 2019

Summary: Genomic study reveals how jellyfish develop into floating beauties, rather than staying stationary like corals or sea anemones.

Translucent jellyfish, colorful corals and waving sea anemones have very different bodies but all fall on the same big branch in the animal family tree. Jellyfish actually start out anchored to the sea floor, just like corals and anemones. Researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) recently uncovered which genes allow jellyfish to graduate from this stationary stage and swim off into the sea.

Early in their life cycles, jellyfish develop from larvae into polyps — immobile, stalk-like structures rooted into the sediment. Anemones and coral live out their lives in this state, which earned them the name anthozoa or “flower animals” in Greek. Jellyfish set themselves apart from anthozoans by being able to develop from the polyp stage to the medusa stage, blossoming into the luminous, bell-like creatures we know and love.

The new study, published in April 16, 2019 in Nature Ecology & Evolution, reports the genomes of two jellyfish species and investigated why some creatures can enter the medusa stage while others remain frozen as polyps. The genomes can be browsed online and compared to other species on the OIST BLAST server.

Newly Decoded Jellyfish Genomes

OIST researchers and colleagues from Japan and Germany compared the genomes of a moon jellyfish (Aurelia aurita) and a giant box jellyfish (Morbakka virulenta). In Japanese, these species are known as the “water jellyfish” and “fire jellyfish”, respectively. The fire jellyfish is highly venomous and owes its name to its painful, burning sting.

“By comparing two different types of jellyfish we expected to identify some universal rules on how to make a medusa stage,” said Dr. Konstantin Khalturin, first author of the study and a scientist in the OIST Marine Genomics Unit led by Prof. Noriyuki Satoh. As a jellyfish exits its polyp stage and leaves the sandy sea floor, different genes switch on to drive its development. To identify these special genes, the researchers first had to catalogue all the genes present in their sample jellyfish species.

“We then looked at how these genes behaved in the polyp and jellyfish stages of their lifecycles,” Khalturin said.

The researchers sequenced the complete genome of a moon jellyfish from the Baltic Sea and giant box jellyfish from Japan. Genomes contain all the instructions to build and maintain an organism, encoded in individual building blocks known as genes. Along with a creature’s genetic composition, the order in which these building blocks are lain helps determine how a creature develops. The researchers compared their freshly decoded jellyfish genomes to those from corals and anemones, pinpointing which genes appeared in each animal and in what sequence.

“We expected that the genome organization in the two jellyfish would be more similar to each other than to the genomes of sea anemones or corals,” said Khalturin. Surprisingly, the gene order in the moon jelly genome resembled anthozoans much more closely than fire jellyfish. In contrast, the genetic composition of the two jellyfish hardly overlapped; their genomes differ as drastically as humans do from sea urchins.

What Makes the Difference

The results suggest that the giant box jellyfish genome must have been vigorously reshuffled at some point in its evolution. The dearth of similarities between moon and giant box jellies convinced the researchers that there is no universal region within jellyfish genomes responsible for orchestrating the medusa stage formation.

One question remained: why can’t corals and anemones enter the jellyfish stage?

To solve this mystery, the researchers assessed which genes were active in the polyp and medusa stages of both jellyfish. They compared these distinct patterns of gene expression to those observed in 11 different cnidarian species — the taxonomic group that encompasses medusozoans and anthozoans. Remarkably, they found that coral and anemones contain about two-thirds of the genes active in the moon jellyfish’s medusa stage.

But moon jellyfish have a special genetic toolkit: an elite arsenal of genes that activate during their medusa stage but are absent in anthozoans. Devoid of a jellyfish stage, corals and anemones lack the genes to grow certain organs and tissues, such as eyes and specialized swimming muscles. The researchers found that water and fire jellyfish share about 100 of these species-specific genes that only switch on in their jellyfish stages. A large proportion of these genes code for transcription factors, proteins that fine tune which genes are expressed, when and in what quantities.

Looking forward, the researchers plan to sequence the genome of a local box jellyfish called the Okinawan sea wasp (Chironex yamaguchii, “habu-kurage”), which will provide a closer comparison to the fire jellyfish. Future studies could advance our understanding of how jellyfish evolve and what sets them apart from their blobby brethren and other creatures of the deep.

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Japanese eels, new research


This 2015 video is called The Mystery of the Eel – Documentary Film.

From Kobe University in Japan:

Endangered eel located using DNA from one liter of water

March 1, 2019

Researchers have shed light on the distribution of Japanese eel by analyzing environmental DNA (eDNA) from small samples of river water. This could enable faster and more effective surveys of Japanese eel populations, and help to conserve this endangered species. The finding was published on February 27 in Aquatic Conservation: Marine and Freshwater Ecosystems.

Eels are migratory fish that spawn in the ocean and grow up along the coast and in rivers. There are 16 known species in the world, distributed in 150 countries. The Japanese eel (Anguilla japonica) is found across East Asia. Since ancient times it has been an important part of Japanese life: as a food source, a subject of traditional poems and art, and sometimes even as a target of worship. However, eel catches have fallen drastically since the 1970s, and in 2014 it was added to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

Most river surveys of Japanese eel use electrofishing. However, this method requires a lot of time and resources, and for widely distributed species it may not collect enough data. Surveys are usually carried out in the daytime, while the nocturnal eels hide among vegetation and dirt.

Rapidly-advancing eDNA technology can monitor aquatic lifeforms through extraction and analysis of DNA present in water, without capturing the organisms themselves. In this study, the team investigated whether eDNA analysis could be used to show the distribution of Japanese eel. They collected 1-liter samples from 125 locations upstream and downstream in 10 rivers in Japan, and analyzed the eDNA from these samples using a Real-Time PCR system. At the same time they carried out an electrofishing survey in the same locations, and compared this with the eDNA analysis results.

Japanese eel eDNA was found in 91.8% of the locations where eel had been confirmed using electrofishing (56 of 61 locations), and eDNA was also detected in an additional 35 areas (mainly upstream) where eel individuals were not found. This shows that eDNA analysis is more sensitive than conventional surveys for detecting the presence of Japanese eel in rivers. Electrofishing data for eel numbers and biomass also positively correlated with eDNA concentrations, showing that eDNA could help us estimate the abundance and biomass of Japanese eel.

In this study, electrofishing required three or more people for each river and took at least three days. Collecting water samples for eDNA analysis only needed two people, took half a day at the most, and data processing was finished by one person in one and a half days. When carrying out a large-scale distribution survey the eDNA analysis method is better in terms of human and time resources.

This method could potentially survey populations on an even wider scale. It is non-lethal, making it ideal for monitoring endangered species. The team is currently using eDNA analysis to monitor eels in Japan and overseas: it can be used as an international unified method for widely-distributed species. This could be a great help in the conservation and sustainable use of eel species worldwide.

The eDNA analysis method is also effective in dealing with the invasion of foreign eel species. For 20 years there have been reports of foreign eels (European eels and American eels) being released into Japanese waterways. These species look the same as Japanese eel, making them hard to detect. They are also long-lived so they may impact the ecosystem over long periods of time. By carrying out a wide-ranging investigation using eDNA analysis, we can swiftly identify foreign eel species and their distribution.

This study was carried out by Research Associate Hikaru Itakura (Kobe University Graduate School of Science), Assistant Professor Ryoshiro Wakiya (Chuo University), Assistant Professor Satoshi Yamamoto (Kyoto University), Associate Professor Kenzo Kaifu (Chuo University), Associate Professor Takuya Sato and Associate Professor Toshifumi Minamoto (both from Kobe University).

Itakura comments: “Concentration of eDNA in rivers is influenced by physical properties such as water depth and the speed of the current. Next we must increase the accuracy of eDNA analysis by clarifying the impact of these physical properties on eDNA concentration.”

Japanese man marries robot girl


This 21 December 2013 punk rock music video from Scotland says about itself:

The Valves – Robot Love

Live at Edinburgh Liquid Rooms

The Scottish band The Valves wrote this song much earlier, in 1977.

However, now something happens not in song lyrics, but in reality.

From the New York Times, 19 January 2019:

Do You Take This Robot …

When Akihiko Kondo, a 35-year-old school administrator in Tokyo, strolled down the aisle in a white tuxedo in November, his mother was not among the 40 well-wishers in attendance. For her, he said, “it was not something to celebrate.”

You might see why. The bride, a songstress with aquamarine twin tails named Hatsune Miku, is not only a world-famous recording artist who fills up arenas throughout Japan: She is also a hologram.

Mr. Kondo insists the wedding was not a stunt, but a triumph of true love after years of feeling ostracized by real-life women for being an anime otaku, or geek.

Japanese whalers kill whales for dog food


This 2017 video says about itself:

Illegal Japanese whaling filmed by the Australian Government in Antarctica

This is the footage that the Australian Government didn’t want you to see. Since 2012, Sea Shepherd has been a part of a joint fight to get the Australian Government to release rare whaling footage obtained on a 2008 Australian Customs mission to the Antarctic.

Here is the footage that the Australian Government filmed with tax payers’ money, of the Japanese whaling fleet illegally whaling in Antarctica, in Australian waters. The footage was filmed as part of gathering evidence for the International Court of Justice, which found Japan’s whaling to be illegal.

By Peter Frost in Britain:

Friday, January 11, 2019

Japan is still killing whales that they don’t even eat

This summer the Japanese will start killing whales again. PETER FROST wonders why

ON Boxing Day 2018 Japan announced that it is leaving the International Whaling Commission to resume commercial, rather than so-called scientific hunts for the animals for the first time in 30 years.

At the same time it said it would no longer go to the Antarctic for its much-criticised annual killings.

Chief Japanese Cabinet Secretary Yoshihide Suga said his country would resume commercial whaling in July 2019 “in line with Japan’s basic policy of promoting sustainable use of aquatic living resources based on scientific evidence.”

He added that Japan is disappointed that the IWC — which he claims is dominated by conservationists — focuses on the protection of whale stocks even though the commission has a mandate for both whale conservation and the development of the whaling industry.

“Regrettably, we have reached a decision that it is impossible in the IWC to seek the coexistence of states with different views,” he said at a news conference.

Japan faced much criticism earlier last year when its so-called scientific research whaling fleet slaughtered 122 pregnant whales.

In 2014, the international court of justice ruled against the annual Japanese slaughter of whales in the Southern Ocean, after concluding that the hunts were not, as Japanese officials had claimed, conducted for scientific research but for the commercial whale meat market.

Japan resumed whaling in the Southern Ocean in 2016 under a programme that reduced its kill by about two-thirds.

Australia and New Zealand, as well as several anti-whaling campaigning groups, have done what they can to stop the Japanese whaling in the Southern Ocean and they seem to have been successful – the Japanese now say that whaling this summer will only be in Japanese waters.

However the Japanese whaling fleet will again flaunt international opinion and start hunting whales later this year.

Japan will also continue to campaign to end the international ban on commercial whaling, claiming that populations of some whale species have recovered sufficiently to allow the resumption of what Japan claims is sustainable hunting.

Japan sent no fewer than 70 delegates to last autumn’s IWC meeting in Brazil. They argued that the 1986 moratorium on commercial whaling was intended to be a temporary measure, and accused the IWC of abandoning its original purpose — managing the sustainable use of global whale stocks.

The Japanese said: “Japan proposes to establish a committee dedicated to sustainable whaling (including commercial whaling and aboriginal subsistence whaling).”

The Japanese proposals would have allowed IWC’s members to decide on quotas with a simple majority rather than the current two-thirds majority from 2020 onwards. This would have made it easier for Japan to buy enough votes to end the ban on commercial whaling.

Votes in favour of whaling come from those nations still involved in the grisly business. Only Norway and Iceland still have commercial whaling fleets and they both support Japan.

In addition a number of small island communities also carry out limited aboriginal whale hunting as part of what are usually claimed to be ancient cultural traditions.

Japan, however, has often bought additional votes supporting whaling from countries by offering advantageous trading terms and other close relationships.

Does Japan need to eat whale meat? No. In fact very little whale meat is actually consumed by Japanese people today.

Much is made into expensive edible dog treats for the small lap-dogs that are so fashionable among affluent Japanese.

When it comes to human consumption a recent poll commissioned by Greenpeace and conducted by the independent Nippon Research Centre found that 95 per cent of Japanese people very rarely or never eat whale meat.

Given how Japan has leant over backwards to justify its whaling, and how much international criticism its getting, you might conclude whale meat is a hugely important part of the Japanese diet.

In fact the amount of uneaten frozen whale meat stockpiled in Japan doubled to 4,600 tons in the 10 years between 2002 and 2012, the last dates for which figures have been published.

It isn’t as if there is a long Japanese tradition of eating whale meat going back centuries. In fact the widespread eating of whale was only introduced directly after World War II by the US General Douglas MacArthur, who effectively ruled Japan during the post-war allied occupation.

World War II shattered Japan’s economy, food was scarce and meat especially so. MacArthur and his occupying administrators decided Japan could and should get much of their protein from sea mammal meat.

In 1946, MacArthur converted two US military tankers to become giant industrial whaling factory ships. A generation of Japanese children grew up eating whale meat as part of their school dinners.

Today for most Japanese, whale meat is little more than a novel culinary curiosity. For those few Japanese old enough to remember eating whale in immediate post-war school dinners it provides an occasional nostalgic trip down memory lane.

Japan’s former top international whaling negotiator Komatsu Masayuki for instance, told the world’s press he had never tried whale meat before he took on the whaling propagandist’s job.

This was the top man putting Japan’s argument for continuing to kill and eat whales saying he had never even tasted whale meat.

Why is it then that Japan is prepared to make itself such a pariah in world opinion? One popular view, and it is certainly the one I subscribe to, is that it is Japanese pride that will not accept other countries defining just what the Japanese nation can and cannot do.

Pride and humiliation are two sides of the way that Japanese people see their position in society and their nation’s place in the world.

If the world in general thinks it can tell the Japanese to stop killing whales, then that might be all the argument the Japanese need to keep up the bloody slaughter.

Some better whale news

Back in last September I wrote about a beluga whale that was spotted in the River Thames.

According to experts the 11-foot (3.5m) whale is still alive and well, and has been spotted regularly almost every week off the Kent coast in the Thames estuary.