UK
CRISIS CAPITALISM: OCTOPUS ENERGY


INVESTIGATION
28 November 2022

In the third installment of Heat the Rich – an investigative series on energy firms profiting from the cost of living crisis – Corporate Watch takes a critical look at the UK’s fourth-biggest energy supplier, Octopus Energy.
Image description: A remote-controlled light switch is operated on by a nearby smartphone.
Credit: Green energy futures/Flickr

Octopus Energy Ltd is the fourth biggest energy supplier in the UK currently controlling around 11% of the energy supply market. It is the newest supplier in the big six, trendy enough to be reviewed by Vogue and posed as a ‘solution’ to “a broken, inefficient market”.

Originally launched in the UK in 2016, Octopus Energy Group Ltd now operates in 13 other countries with 23 million customer accounts. Its model is supposedly a “cheap green energy system” funded by “high sums of investment”.

But the Octopus name is not limited to the energy market. In 2018, it was listed as managing over £7 billion in assets with over 50,000 investors, Since then, it’s continued to grow, Octopus now operates eight distinct businesses: Octopus Energy, Octopus Investments, Octopus Healthcare, Octopus Ventures, Octopus Real Estate, Octopus Moneycoach, Octopus Renewables, Seccl and Octopus Wealth.

According to co-founder Christopher Hulatt, the group takes a holistic approach: “by building companies with one purpose – the relentless pursuit of ‘better’.” But better for who? Better for the pockets of Hulatt and wealth investors or for energy customers…Suffice to say, this isn’t covered in the Octopus Energy Ltd podcast on the Energy Crisis.

HOW MANY UK ENERGY CUSTOMERS DOES OCTOPUS ENERGY HAVE?

Electricity (excluding pre-payment): 3.1 million

Gas (excluding pre-payment): 2.7 million

WHO OWNS IT?

Touted as an “independent supplier” by Forbes. Octopus Energy is in fact part of a group, that is ultimately owned by OE Holdco Ltd.

At the start of the tax year in April 2022, OE Holdco Ltd, a UK-based holding company, was owned by the co-founder of Octopus Energy, Christopher Hulatt. But mysteriously, since the end of September OE Holdco Ltd has no listed owner. Hulatt and Octopus co founder Simon Rogers remains two of the three directors of OE Holdco Ltd, the third directorship is held by Octopus Company Secretarial Services Ltd.

OE Holdco Ltd was formed back in March, at the same time as families around the UK were plunged further into the cost of living crisis. Already by September, it has become the ultimate parent company of the Octopus Group. It’s certainly one to keep eye on when annual accounts are due.

IS OCTOPUS ENERGY SUFFERING AS A RESULT OF THE COST OF LIVING CRISIS?

It doesn’t seem so, in fact, Octopus Energy appears to be going from strength to strength. According to the company’s accounts from 2021, it recorded record revenues of £1.9 billion in 2021 with profits at £25 million. Bouncing back from a loss of £47 million in 2020.

The Octopus Group, with its fingers in many pies, celebrated a revenue of £2 billion in 2021, £800 million more than in 2020, a 62% increase.


Whilst the ultimate parent company OE Holdco Ltd is too new to file accounts, the Octopus Capital Ltd’s accounts for 2021 show that energy supply is the key moneymaker for the group, accounting for 85% of the total turnover. The group is also expanding internationally through acquisitions in Japan and the USA. The cherry on the cake is that the Group paid dividends of £17.7 million in 2021 in comparison to £3 million in 2020 highlighting that right now business is booming for the Octopus Group, despite the ongoing cost of living crisis.

WHO RUNS IT?

Legend has it that Octopus was started in Chris Hulatt’s bedroom, when Hulatt, Simon Rogerson, and Guy Myles founded the company in 2000. Hulatt and Rogerson remain at the top, while Myles left in 2014 to set up a financial investment company.

Day to day, Hulatt specialises in two things: hunting for investments for Octopus worldwide and cosying up to the UK government through meetings with politicians and ministers. A Cambridge graduate, Hulatt owns over 75% shares of Octopus Group Holdings Ltd and is the director of 30 companies on Companies House including Octopus Energy Ltd. With no official position apart from ‘co-founder’ Hulatt’s salary from Octopus businesses is difficult to measure. But what remains certain, is that Hulatt is not feeling the bite from the energy crisis: with a net worth of £276 million. Outside of the Octopus business, Hulatt is the Chairperson of Enthuse, a digital donation tech company, and the non-executive director of ClearlySo an investment bank.

Simon Rogerson is the chairperson of Octopus Investments, the CEO of both the Octopus Group and OE Holdco Ltd. He is listed as the director of 26 companies and was educated at the University of St Andrews. Rogerson is likely to have taken home at least £663,000 in 2021 as the highest-paid director of Octopus Capital Ltd. But Rogerson’s pockets go a lot deeper than one remuneration. According to business information databases, Rogerson owns 11% of shares at his workplace, making him the biggest single shareholder of the Octopus Group. Rogerson’s net worth is as high as £229 million.

Greg Jackson is the CEO and founder of Octopus Energy Group. Jackson is likely to be earning a salary upward of £169,000 as the highest-paid director of Octopus Energy Group Ltd. Celebrated in iNews, Jackson was seen as a bit of an angel after he gave up £150,000 in autumn 2021 “when the energy crisis began to bite”. But despite a relatively low salary he’s well-placed to make such a “selfless act” because Jackson’s 6% stake in the renewables branch of Octopus means he’s estimated to be worth around $300 million (over £265m).

Aside from Octopus, Jackson is the chairperson of Consultant Connect UK, a private tech business profiting from NHS privatisation through referral management.

THE OCTOPUS ADD-ON? KRAKEN TECHNOLOGY

In addition to cashing in on supplying energy, the Octopus Energy Group has another trick up its sleeve: Kraken Technology – which is part of the Octopus Energy Group

Kraken Technology provides data services to manage energy usage. Kraken’s platform manages “billing, payments, meter data management, CRM, customer communications, digital self-service, contact centre telephony, industry and market connections (and more)”. It appears that through Kraken Technology services Octopus has made a name for itself in the playground of the Big Six, even convincing its competitors like EDF and e.on to buy up its license. Now, 40% of the British market is licensed to Kraken.

DOES THE COMPANY AVOID PAYING TAXES?

Octopus Energy seems to be in the clear. But it’s one to look out for, as OE Holdco is yet to publish its first set of accounts, and has no publicly registered owner.

Moreover, the majority of companies owned by Octopus Investments Ltd are registered as LLPs, which fall under a different tax system in that the LLP itself is not taxable, untaxed profits are distributed to members who then pay tax through a self-assessment tax return.

The Octopus Group certainly doesn’t shy away from speaking about business tax to the government. In May 2022, Octopus Group attended a meeting on business taxation at the HM Treasury with Lucy Frazer MP alongside Uber and BP amongst others.

POLITICAL DONATIONS IN THE UK

In 2018 Octopus Investments Ltd donated £12,500 to the central Conservative party. Co-founder, Christopher Hulatt, donated a further £2,500 to the party’s local branch Hitchin & Harpenden (Hulatt’s home constituency) in 2019.

Hulatt’s donation fuelled controversy after Open Democracy revealed it had preceded former chancellor – and now Prime Minister – Rishi Sunak’s, selection of Octopus Investments to manage the government’s £100m “sustainable infrastructure fund”, the UK Infrastructure Bank (UKIB).

DOES THE COMPANY HAVE CLOSE RELATIONSHIPS WITH THE GOVERNMENT?

Yes. As Octopus co-founder Christopher Hulatt put it: “I spend most of my time focusing on…maintaining strong relationships with the UK government and MPs”.

In October 2020, Rishi Sunak alongside Boris Johnson appear to have done PR for Octopus Energy, promoting the company in an official 10 Downing Street video at the Octopus Energy HQ. Between 2020-2022 Octopus had four meetings with former UK prime minister Boris Johnson. This included one solo meeting to discuss energy technology and sustainability in October 2020 as well as a further 125 meetings with ministers to discuss energy: retail, innovation, efficiency and security.

In 2018, Hulatt spoke at the Conservative party conference as part of an event on ‘Boosting Consumer Capitalism’ organised by the right-wing Adam Smith Institute. Fellow speakers included Hulatt’s local Conservative MP, Bim Afolami, and Conservative MP John Penrose.

In 2020, Hulatt was part of the Unlock Britain Commission set up by the aforementioned Bim Afolami to produce a report for the Social Market Foundation to design “10 transformative policies for Britain after the Coronavirus crisis”. Other advisors included top figures from ASOS Plc and PwC.

In 2021, Hulatt led a training on “How to build a nation of entrepreneurs” with Conservative MP and Minister of State for Local Government and Building Safety, Paul Scully as part of The Entrepreneurs Network (TEN).

Last but by no means least, at the end of September when Octopus changed things up, Stuart Quickenden was brought on board as a director for the Octopus Group. Quickenden was a board member for the Department for Business, Energy and Industrial Strategy (BEIS) between 2017 to 2020. So no doubt he will have some useful contacts to make Octopus Energy’s relationship with government even cosier.

NEW INTERNATIONALIST

 

Octopus Moms Nest at Thermal Springs to Improve Odds of Survival

Courtesy MBARI

PUBLISHED AUG 24, 2023 4:34 PM BY THE CONVERSATION

 

[By Amanda Kahn and Jim Barry]

Two miles below the ocean surface off Monterey, California, warm water percolates from the seafloor at the base of an underwater mountain. It’s a magical place, especially if you’re an octopus.

In 2018, one of us, Amanda Kahn, was aboard the research vessel E/V Nautilus when scientists discovered the “Octopus Garden.” Thousands of pearl octopuses (Muusoctopus robustus) were curled up into individual balls in lines and clumps. As Nautilus Live streamed the expedition online, the world got to share the excitement of the discovery.

We now know why these amazing creatures gather at this and other underwater warm springs.

Scientists with the Monterey Bay Aquarium Research Institute take viewers on a journey to Davidson Seamount in a video narrated by Jim Barry, an author of this article. Credit: © MBARI.

In a new study involving scientists from several fields, we explain why octopuses migrate to the Octopus Garden. It’s both a mating site and a nursery where newborn octopuses develop faster than expected, giving them the best shot at survival in the deep, cold sea.

Life in the Octopus Garden

Female octopuses seek out rocky cracks and crevices where warm water seeps from the rocks. There, they vigilantly guard their broods. Subsisting off their energy reserves alone, these mothers will never eat again. Like most cephalopods, they make the ultimate sacrifice for their offspring and die after their eggs hatch.

The Octopus Garden, at the base of Davidson Seamount about 80 miles (130 kilometers) southwest of Monterey, California, is the largest of a handful of octopus nurseries recently discovered in the Eastern Pacific. Many have been found near hydrothermal springs where warm water seeps from the seafloor.

The Octopus Garden is about 2 miles deep near Davidson Seamount, an inactive volcano off the Central California coast. It is inside the Monterey Bay National Marine Sanctuary. Illustration by Madeline Go/MBARI, basemap created via ArcGIS Online, sources: Esri, USGS | Esri, GEBCO, DeLorme, NaturalVue | California State Parks, Esri, HERE, Garmin, SafeGraph, FAO, METI/NASA, USGS, Bureau of Land Management, EPA, NPS

We wanted to know what makes these environments so appealing for nesting octopuses.

To solve this mystery, we assembled geologists, biologists and engineers. Using Monterey Bay Aquarium Research Institute’s deep-sea robots and sensors, we studied and mapped the Octopus Garden during several visits over three years to examine the links between thermal springs and breeding success for pearl octopuses. We found nearly 6,000 nests in a 6-acre (2.5-hectare) area, suggesting more than 20,000 octopuses occupy this site.

A female pearl octopus brooding her eggs at the Octopus Garden. Credit: © 2020 MBARI

We witnessed male octopuses approaching and mating with females. We cheered for the successful emergence of hatchlings, which looked like translucent miniatures of their parents. And we mourned the deaths of mothers and their broods.

When a nest became empty, it was quickly filled by a different octopus mother. We saw that nothing went to waste at the Octopus Garden. Dead octopesus provided a vital food source for a host of scavengers, like sea anemones and snails.

Warmer water speeds up embryo development

A new generation of octopuses must overcome at least two hurdles before hatching.

First, they must develop from egg to hatchling. They start as opaque, sausage-shaped eggs cemented to the rocks. Over time, tiny black eyes, then eight little arms grow visible through the egg capsule. Second, crucially, they must not succumb to external threats, including predators, injuries and infections. The longer the incubation period, the greater the risk that an embryo might not survive to hatch.

A portion of a photomosaic produced following surveys of the Octopus Garden with MBARI’s remotely operated vehicle Doc Ricketts and the Low-Altitude Survey System sensor suite from the Seafloor Mapping Lab at Monterey Bay Aquarium Research Institute, or MBARI. The photo allowed researchers to count nests and estimate the total. Credit: © 2022 MBARI

For octopus species living in warm, shallow waters, brood periods are only days to weeks long. But a very different scenario plays out in the abyss. Near-freezing temperatures dramatically slow metabolic processes in coldblooded animals like octopuses. The longest-known brood period for any animal actually comes from another deep-sea octopus species, Graneledone pacifica, with a mother tending her nest for a remarkable 4½ years. An octopus nursery for this species was recently discovered off the west coast of Canada.

At Davidson Seamount, where ambient water temperatures are 35 degrees Fahrenheit (1.6 degrees Celsius), we would expect pearl octopus embryos to take five to 10 years, or possibly longer, to develop. Such an extended brooding period would be the longest known for any animal, exposing an embryo to exceptional risks.

Instead, temperature and oxygen sensors we were able to slip inside octopus nests documented a much warmer microenvironment around the eggs. On average, the temperature inside octopus nests was about 41 F (5.1 C), considerably warmer than the surrounding waters. We predicted that octopus embryos would develop faster in this warmer water.

Each octopus has distinctive markings that scientists quickly learned to identify. Credit: © 2022 MBARI

Distinctive marks and scars helped us identify individual mothers. Over repeat visits we tracked the development of their brood. Although we did expect faster growth in the warm water, we were stunned to find that eggs hatched in less than two years. Nesting in thermal springs clearly gives pearl octopuses a boost.

But nesting in thermal springs is a potentially risky strategy. Once eggs are laid, they’re cemented to the rock. We know little of the thermal tolerance of pearl octopuses or their embryos, but even a short exposure to overly warm waters could be lethal to developing embryos, wiping out any hope of successful reproduction for that mother. Indeed, one of the first recorded deep-sea octopus nurseries may have experienced unpredictable fluid flow.

Nurseries highlight risks to seafloor habitat

The thermal springs at the Octopus Garden are part of a ridge flank hydrothermal system. Here, water percolating beneath the seafloor picks up heat from Earth’s mantle before it’s channeled out from volcanic rock outcrops like Davidson Seamount. These systems have become an emerging focus in seafloor geology, though only a few have been discovered so far.

Unlike hydrothermal vents, which form at ridge crests and belch plumes of hot water that are detectable hundreds of meters above the bottom, thermal springs on ridge flanks are cryptic. These springs seep warm water that dissipates only meters above the bottom, making them exceedingly difficult to find and only visible by a slight shimmer in the water.

Our yearlong recordings from thermal springs at the Octopus Garden demonstrate these may be stable environments, with the potential to release warm fluids for thousands of years. Such stability benefits not only pearl octopus, but also the community of life that thrives alongside the nesting mothers.

A male octopus walks through the Octopus Garden. Credit: © 2019 MBARI

The recent discoveries of octopus nurseries off the Pacific coast of Costa Rica, also near hydrothermal springs, suggests these areas may be more common than previously thought. It also highlights that hydrothermal springs may be vital biological hot spots.

The deep sea is the largest living space on Earth, and that expansive size can hide the importance of localized hot spots like these. Davidson Seamount and its Octopus Garden are protected as part of Monterey Bay National Marine Sanctuary, but many more biological treasures like thermal springs may be at risk, especially as deep-seabed mining proposes to scrape large understudied swaths of seafloor. We hope the octopus mothers we’ve met at this nursery inspire everyone to rethink stewardship for the yet-undiscovered hidden gems that may be lost.

Amanda Kahn is Assistant Professor of Invertebrate Ecology at Moss Landing Marine Laboratories, San José State University

Jim Barry is a Marine Ecologist at MBARI, San José State University.

This article appears courtesy of The Conversation and may be found in its original form here. 

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.

CTHULHU STUDIES

Oldest known sex chromosome emerged 248 million years ago in an octopus ancestor

The oldest-known sex chromosome emerged in octopus and squid between 455 million and 248 million years ago — 180 million years earlier than the previous record-holder, scientists have discovered.

Octopus and squid appear to have evolved sex chromosomes at least 248 million years ago.

 (Image credit: Olga Visavi/Shutterstock)


The oldest known sex chromosome in animals has been discovered, pushing back the date for the evolution of sex chromosomes to between 248 million and 455 million years ago.

The ancient chromosome was found in octopus and squid, suggesting that these may have been among the first animals to determine their sex via genetic blueprint, instead of environmental cues.

Sex chromosomes are standard in mammals. In humans, the sex chromosomes are X and Y. Males usually have an X and a Y chromosome, while females have two Xs, although there are some variations, such as XXX or XXY, which can have a wide range of impacts from no effect at all to certain learning disabilities or neurological differences.

For a long time, researchers weren't sure whether cephalopods, the soft-bodied mollusks that include squid and octopuses, determined their sex with chromosomes. Mollusks have a variety of ways to handle reproduction, including hermaphroditism or sequential hermaphroditism, in which individuals swap sexes over time.

Octopuses stick to one sex, but it wasn't clear whether genes or environmental cues determined what sex that would be. In some reptiles and fish, factors like temperature decide the sex of offspring.

Related: Octopuses torture and eat themselves after mating. Science finally knows why.

In 2015, researchers completed the first full gene sequence of a cephalopod, the California two-spot octopus (Octopus bimaculoides). That sequence still included gaps, though, so a team led by Andrew Kern, a biologist at the University of Oregon, set about filling them in with high-fidelity sequencing.


Researchers discovered the chromosome after completing the full gene sequence of the California two-spot octopus. (Image credit: Brent Durand/Getty Images)

They soon noticed that one chromosome, chromosome 17, seemed less filled-out with genes than the other chromosomes in their sequence. Because they had sequenced a female octopus, they compared their results to the earlier individual, a male. In the case of the male, chromosome 17 looked no less populated than other chromosomes in the octopus.

This was a clue that chromosome 17 might have something to do with sex differences. To confirm, the team sequenced four more octopuses, two male and two female, and confirmed that females have just one copy of chromosome 17, while males have two. Thus, they represent the octopus sex chromosomes not as XY and XX as in humans, but as ZZ and Z0.

The researchers then compared their octopus genomes to the genomes of three other octopus species, three species of squid, and the chambered nautilus (Nautilus pompilius).

They found the ZZ/Z0 pattern in the squid and the octopus, but not in the nautilus, a more distantly related species. This showed that the sex chromosomes evolved after the split between the nautilus line and the line leading to modern squid and octopus, which occurred between 455 million and 248 million years ago.

"This is an astoundingly long time for a sex chromosome to be preserved," the researchers wrote in their paper, which is now available pre-peer review on the preprint website BioArxiv.

Prior to this research, the oldest confirmed sex chromosome was in sturgeon fish, according to Nature News, with an age of about 180 million years.

Octopuses Might Have The Oldest Sex Chromosomes in The Animal Kingdom

NATURE09 March 2024

ByCARLY CASSELLA

(Judit Pungor/CC By 4.0)

Cephalopods may have the oldest sex chromosomes of any animal, according to a recent discovery in the octopus genome.

That's a big deal given that scientists didn't know until now that these oddball creatures even had a form of sex determination written into their genes. To determine if an octopus is male or female, biologists have relied purely on observation, differentiating between which individuals lay eggs versus which produce sperm.

Searching the octopus genome had shown no clear sign of a sex chromosome system. Scientists were beginning to wonder if perhaps cephalopods were like some fish and reptiles, with sex determined through environmental factors such as the temperature at which eggs are kept rather than the inheritance of distinct chromosome.

At last, researchers at the University of Oregon claim to have solved the mystery.

Their pre-print study, which is currently under peer review, provides the first evidence of genetic sex determination among octopuses.

Examining the genes of the California two-spot octopus (Octopus bimaculoides) – the first cephalopod to have its whole genome sequenced – researchers have finally found a unique chromosome pair.

They discovered it on chromosome number 17, and it only stood out to researchers when they compared the male octopus genome that had been fully sequenced to a female one. The female octopus seemed to be missing one of their two copies.

Digging further, researchers say they found clear signatures of a ZW sex-determination system, which is seen in birds, crustaceans, and some insects,

We humans rely on an XY system, wherein two X chromosomes create the default female body plan, while the presence of a Y chromosome generally triggers the development of male characteristics.

Octopuses have an opposite system. It is the males that typically have a double-Z pair and females that have only one Z chromosome.

To see if this system was present in other cephalopods, researchers compared the genomes of three octopus species, three squid species, and a nautilus.

They concluded that the Z chromosome is an "evolutionary outlier" that stands apart from similar chromosomes in close relatives.

Only the genomes of the bobtail squid (Euprymna scolopes) and the East Asian common octopus (Octopus sinensis) had similar outlier signatures, but because these creatures are from different lineages, it suggests the Z chromosome originated before their split.

As such, researchers at the University of Oregon argue that the Z chromosome is "of an ancient, unique origin" that probably arose between 455 and 248 million years ago. If the chromosome appeared towards the earlier end of that timeline, the octopus could have the oldest animal chromosome yet found, beating even some insects which are thought to have sex chromosomes that date back 450 million years.

Compared to those of octopuses, however, these arthropod sex chromosomes are poorly conserved across species.

For comparisons, the oldest accepted vertebrate chromosome is that of a sturgeon fish, which is thought to be about 180 million years old. Sturgeon fish females have a ZW sex chromosome set pair as opposed to the female octopus's 'hemizygous' Z chromosome. It's possible the octopus's corresponding W chromosome may have been lost over time in a manner similar to the ill-fated trajectory of the Y chromosome in humans.

The story behind sex chromosomes has changed a lot in recent years. Once, they were thought to be intrinsic features of sex determination in animals. But biological research tends to be biased towards mammals. As it turns out, some fish and reptiles, like crocodiles, don't have sex chromosomes at all. The sex of their offspring is instead determined by other, external factors through epigenetic regulations.

Clearly, there is still much to be learned about how sex chromosome evolved, and why. Octopuses, with their deep evolutionary roots could be fascinating models for future research.

"The data presented in this paper definitely suggests that cephalopods have among the oldest sex chromosomes in both animals and plants," independent evolutionary scientist, Sarah Carey, told Carissa Wong at Nature.

"This is such a cool time to be working on the genetics of sex chromosomes."

The preprint was published in bioRxiv.

Oldest known animal sex chromosome

evolved in octopuses 380 million years ago


Result reveals for the first time how some cephalopods determine sex.

By Carissa Wong
04 March 2024

The California two-spot octopus (Octopus bimaculoides) has one or two copies of chromosome 17, depending on its sex.Credit: Norbert Wu/Minden Pictures via Alamy

Researchers have found the oldest known sex chromosome in animals — the octopus Z chromosome — which first evolved in an ancient ancestor of octopuses around 380 million years ago. The findings1 answer a long-standing question about how sexual development is directed in the group of sea creatures that includes octopuses and squid.

“We stumbled upon probably the oldest animal sex chromosome known to date,” says evolutionary geneticist Andrew Kern at the University of Oregon in Eugene. “Sex determination in cephalopods, such as squids and octopi, was a mystery — we found the first evidence that genes are in any way involved.”

How does it feel to have an octopus arm? This robo-tentacle lets people find out

In many animals, including most mammals and some insects, sex chromosomes determine whether an individual becomes male or female. In humans, females usually have two X sex chromosomes, and males typically have one X and one Y sex chromosome. But for some animal groups, such as cephalopods — which include soft-bodied animals such as squids and octopuses, as well as hard-shelled creatures called nautiluses — researchers have been unsure about how individuals become male or female. Scientists generally thought that environmental factors such as temperature play a part — as they do for some reptiles and fish.

Catching Zs

In 2015, researchers reported2 sequencing a cephalopod genome for the first time — that of a male California two-spot octopus, Octopus bimaculoides. In the latest study1, Kern and his colleagues mapped the genome of a female California two-spot octopus. They discovered 29 pairs of chromosomes and one single chromosome, called chromosome 17. By contrast, the male octopus genome had two copies of chromosome 17. That difference led the researchers to hypothesize that chromosome 17 was a sex chromosome.

Sequencing the DNA of other O. bimaculoides octopuses confirmed the idea. Males always had two copies of chromosome 17, whereas females had one copy. Chromosome 17 also contained several genes similar to those that encode proteins in human reproductive tissues, including a protein found in sperm. In animals including birds and butterflies, males similarly have two Z sex chromosomes, whereas females have one Z and one W sex chromosome.

“It very much looked like we were looking at a Z chromosome in O. bimaculoides,” says Kern. But the researchers failed to find a W chromosome in the female octopuses. That suggested that males have ZZ sex chromosomes, whereas females are ZO, with the O denoting the lack of a W chromosome.

Well conserved

The team also found Z chromosomes in some other octopus and squid species — but not in a nautilus.

“This pattern suggests that the Z chromosome evolved once in the lineage that led to modern squid and octopuses — after this lineage split off from hard-shelled nautiloids,” says Kern. This means the Z chromosome first appeared between 450 million and 250 million years ago and has been retained to the present day, he says. Previously, the oldest known animal sex chromosome was thought to have evolved in sturgeon fish about 180 million years ago3.

This chromosome is profoundly evolutionarily conserved, says Matthias Stöck, an evolutionary geneticist at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin.

“The data presented in this paper definitely suggests that cephalopods have among the oldest sex chromosomes in both animals and plants,” says Sarah Carey, who studies the evolution of sex chromosomes at the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama. “This is such a cool time to be working on the genetics of sex chromosomes.”

doi: https://doi.org/10.1038/d41586-024-00637-0

References

1. Coffing., G. C. et al. Preprint at bioRxiv https://doi.org/10.1101/2024.02.21.581452 (2024).

2. Albertin, C. B. et al. Nature 524, 220–224 (2015).

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3. Kuhl, H. et al. Phil. Trans. R. Soc. B 376, 20200089 (2021).