H. gigas is one of famous creatures in the deepest abyss
There is 6 deepest trenches in the ocean. They are Japan Trench, Izu-Ogasawara Trench, Philippine Trench, Mariana Trench, Kermadec Trench, and Peru-Chile Trench (1). The depth of their bottom is over 8,000 m. The temperature of their bottom is around 2°C. Especially, the pressure of bottom is extremely high. Because of high pressure, the lives in the deepest bottom are only one or two species. One of the residents in the deepest bottom is an amphipod named Hirondellea gigas. A lot of researchers found H. gigas in the Challenger Deep of Mariana Trench, the deepest site in the world. James Cameron, a famous filmmaker, found some shrimp like animals in the Challenger Deep at the depth of over 10,000 m (2). They were just H. gigas.
Why is H. gigas mysterious?
H. gigas live in the deepest place of the ocean. The environment of the deepest place is very high pressure of 100 MPa! It's as much pressure as a jumbo jet is on your hand. The carbonate compounds are dissolved under such a high pressure. The calcium carbonate is principal component in skeleton of crustacean. So, In the case of ordinary crustaceans, the skeleton melts and disappears in the deep sea. To make matters worse, there is no food in the deep sea. Since it is 10,000 meters away from the sea surface, plankton are almost eaten by fish on the way. Also, the number of deep-sea fish is small, and there is almost no chance to eat their carcasses. H. gigas is a very mysterious animal that survives such extremely harsh environment.
H. gigas is one of the most studied deep-sea life.
There are great amount of lives in the ocean. Lots of researchers have studied the ecology of some commercial fishes, shrimps, and mussels for aquaculture. Researchers hardly studied the deep-sea animals. Because of the decompression, deep-sea animals cannot live around the surface of the sea. Almost all studies of animals require breeding to understand their ecology. Recent advances in molecular biology and genetic engineering have allowed researchers to investigate deep-sea animals from genomic and molecular biology data. H. gigas attracts many scientists due to the animal in the deepest bottom of the ocean. The scientists interested in the mechanisms of tolerance to high pressure. Also scientists interested in how to get nutrient and energy to sustain H. gigas’ life. Several scientific reports on H. gigas show that they eat wood fragments, get nutrients by digesting with cellulose, and survive in the deepest oligotrophic environments (3). Some environmental pollutants were found in their body (4). In addition, the body of H. gigas is covered with aluminum hydroxide gel to prevent the dissolution of calcium bicarbonate in exoskeleton under high pressure. Aluminum has a very low concentration in seawater. Therefore, H. gigas needs to obtain aluminum other than seawater. Aluminum, on the other hand, is contained in the minerals of seafloor sediments. The scientific report also showed that H. gigas extracts aluminum from the sediment of seafloor with gluconolactone (5). H. gigas is a unique deep-sea creature whose ecology is revealed.
Our specimen is a good exhibit.
The specimens of animals are usually pickled in formalin. Animals in formalin are very grotesque for decolorization. In most cases, formalin specimens will be the least popular on display. We created a resin-embedded specimen of H. gigas. Our specimens keeps its shape and color. In addition, the resin-embedded sample can be observed from all directions. Please note that sunlight will turn the resin yellow, so avoid it. The resin-embedded specimen of H. gigas has been adopted .in “DEEP OCEAN 2017” of National Museum of Nature and Science in Japan. The specimens of H. gigas are Research samples from public research institutes. Therefore, most people or museum do not have a chance to get this rare H. gigas specimen. Here, we sell this resin-embedded specimen of H. gigas for the first time in the world. We captured H. gigas from the Izu-Ogasawara or Japan Trench at the depth of over 7,000 m. If you would like to purchase, please contact us by e-mail (08shizen@gmail.com). The price of this item is $9,990 plus shipping fee. The numbers of items is limited to only twenty in the world. Shipping fee differs depending on the countries and areas. We also attach an A0 size poster about ecology of H. gigas. This poster greatly enhances the attractiveness of the exhibits and an educational effect.
Hideki Kobayashi, Ph. D.
Reference
(1) Kobayashi, Hideki, et al. "Polysaccharide hydrolase of the hadal zone amphipods Hirondellea gigas." Bioscience, biotechnology, and biochemistry 82.7 (2018): 1123-1133.
(3) Kobayashi, Hideki, et al. "The hadal amphipod Hirondellea gigas possessing a unique cellulase for digesting wooden debris buried in the deepest seafloor." (2012): e42727.
(4) Jamieson, Alan J., et al. "Bioaccumulation of persistent organic pollutants in the deepest ocean fauna." Nature ecology & evolution 1.3 (2017): 1-4.
(5) Kobayashi, Hideki, et al. "An aluminum shield enables the amphipod Hirondellea gigas to inhabit deep-sea environments." PloS one 14.4 (2019): e0206710.