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2021.03.24
A world’s first! Successful rearing and artificial birth through artificial uterus apparatus of a Mollers lantern shark, a luminescent deep-sea shark!
The Okinawa Churaumi Aquarium and Okinawa Churashima Foundation Research Center developed an artificial uterus apparatus for sharks. Using the apparatus, they successfully reared a fetus of a Mollers lantern shark, a luminescent deep-sea shark, and it was successfully artificially delivered.
≪Mollers lantern shark≫
Scientific name：Etmopterus molleri
The Mollers lantern shark reaches just 40 cm in length. It lives at depths from 260 to 860 meters. It is widely distributed in the Pacific Ocean from Japan to Australia and New Zealand. There are very small luminous organs on the surface of its body which emit a faint blue light. Until now, there had been no record of long-term rearing.
The Mollers lantern shark is ovoviviparous (eggs form and hatch in the mother, then born live). There are around 6 fetuses in each pregnancy between the left and right uterus. The mechanisms of how the fetuses receive nutrients and oxygen is still unknown, however research has suggested that they are yoke dependent＊.
＊It refers to the type of reproduction where the yolk is its main source of nutrition during gestation. (Receiving little nutrient supply from the mother)
Adult Moller lantern shark
Moller lantern shark producing light
On October 29th, 2020, a pregnant female specimen was collected from the sea floor, at a depth of around 500 meters, off the west coast of the Okinawa Main Island. The pregnant female died shortly after being collected, however a 10 cm fetus was extracted from the mother’s body and was reared in an artificial uterus apparatus at the Okinawa Churaumi Aquarium for 146 days.
This artificial uterus apparatus was developed by Okinawa Churaumi Aquarium and Okinawa Churashima Foundation Research Center in preparation for the premature delivery of sharks and rays with various reproduction modes. It replicates the environment of a shark’s womb.
Fetus reared in an artificial uterus
Pup after birth
【Key points of this research】
1）Artificial uterus apparatus for sharks was developed. These are very rare.
2）The world’s first successful long-term rearing and artificial birth of a lantern shark.
3）Artificial rearing can match the reproduction modes of shark species with the goal of contributing to the understanding and conservation of rare shark species.
Okinawa Churaumi Aquarium is working to conserve Okinawa’s biodiversity. The artificial uterus apparatus that was developed 4 years ago can contribute to sustainable research and conservation of rare shark species that have declining populations. Our goal is to continue to improve the apparatus and use it to reveal the reproduction modes of rare shark species, and contribute toward their conservation.
This project was supported by JSPS KAKENHI Grant Number JP17K19334（supported to Keiichi Sato）. An international patent is currently pending for the artificial uterus apparatus and rearing methods developed in this study.
Inquiries
Okinawa Churaumi Aquarium
905-0206
424 Ishikawa, Motobu-cho, Kunigami-gun, Okinawa Prefecture
TEL:+81-980-48-3748
FAX:+81-980-48-4444
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