Researchers Discover Sea Slug’s ‘Disposable’ Male Organs

Researchers Discover Sea Slug's 'Disposable' Male OrgansJapanese researchers observed the bizarre mating behaviour in a species called Chromodoris reticulata, a sea slug, which is found in the Pacific Ocean. They believe this is the first creature known that can repeatedly copulate with what they describe as a “disposable penis”. The study is published in the Royal Society’s journal Biology Letters.

‘Simultaneous hermaphrodites’

The sex life of the sea slug is complicated even before detachable organs come into play. Almost all of these creatures, which are also known as nudibranchs, are thought to be “simultaneous hermaphrodites”. This means they have both male and female sexual organs and can use them both at the same time.

The Japanese team observed sea slugs that they had collected from shallow coral reefs around Japan. They saw the animals mate 31 times. The act took between a few seconds and a few minutes, after which the creatures would push away and shed their penises, leaving them on the floor of the tank. However, the researchers were surprised to discover that just 24-hours later, the sea slugs had regenerated their male organs and were able to mate again.

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‘Disposable penis’

Closer examination of the animals’ anatomy revealed that the sea slugs had a large part of their penis coiled up in a spiral inside their bodies, which they would then use to replenish their missing part. The scientists also noted that the penis was equipped with spines. At most, the animals were able to copulate three times in succession, with each bout separated by about 24 hours.

Sea slugs are not the only animals who abandon their penis. Orb weaving spiders are known to lose their male organs after sex, as does a sea creature called the periwinkle and land slugs belonging to the genus Ariolimax. However the researchers believe that Chromodoris reticulata is the first creature known that can re-grow its appendage – and its disposable penis gives it a sexual advantage.

Do you find this creature’s disposable body part fascinating? What other bizarrely-structured creatures have you encountered?

Source: BBC News

Image: National Geographic

$1 Billion Mission Underway To Drill Into Earth’s Mantle

Humans have reached the moon and are planning to return samples from Mars, but when it comes to exploring the land deep beneath our feet, we have only scratched the surface of our planet. This may be about to change with a $1 billion mission to drill 6 km (3.7 miles) beneath the seafloor to reach the Earth’s mantle and bring back the first ever fresh samples.

Geologists involved in the project are already comparing it to the Apollo Moon missions in terms of the value of the samples it could yield. However, in order to reach those samples, the team of international scientists must first find a way to grind their way through ultra-hard rocks with 10 km-long (6.2 miles) drill pipes — a technical challenge that one of the project co-leaders Damon Teagle, from the UK’s University of Southampton calls, “the most challenging endeavor in the history of Earth science.”


Their task will be all the more difficult for being conducted out in the middle of the ocean. It is here that the Earth´s crust is at its thinnest at around 6 km compared to as much as 60 km (37.3 miles) on land. They have already identified three possible locations — all in the Pacific Ocean — where the ocean floor was formed at relatively fast spreading mid-ocean ridges, says Teagle. The hole they will drill will be just 30 cm in width all the way from the ocean floor to inside the mantle — a monumental engineering feat.

To get to the mantle scientists will be relying on a purpose-built Japanese deep-sea drilling vessel called Chikyu, first launched in 2002 and capable of carrying 10 km of drilling pipes.

For Teagle, reaching the Earth’s mantle would provide a “legacy of fundamental scientific knowledge” and “inspire” future generations. If Japanese support can be combined with other funding, Teagle says they could start drilling before the end of the decade, making it possible for humans to finally reach the Earth’s mantle by the early 2020s.

Are you excited about this new project aimed to reach the earth’s mantle? What are your questions about the origins and evolution of the Earth?

Source: CNN

Image: Business Insider