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Phylum Cycliophora Symbion Pandora Lyrics: Shin Kubota Music, Arrangement and Vocal: Sillty |
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The Cycliophora is the newest animal phylum on the planet. This phylum was officially proposed in 1955. Since then, only three species, for example Symbion pandora, have been described, and thus, they are rare animals. At a glance, the Cycliophora looks similar to the solitary Entoprocta having a bilaterally symmetric body. The Cycliophora is a small animal which attaches to the mouth of crustaceans, such as clawed lobsters and spiny lobsters. Symbion pandora has a wheel-like ingestion apparatus around the mouth, which looks like a trochial disk of the Rotifera. Movement of the cilia on this apparatus creates water flow from the top to the bottom, and they filter small organic debris for food. Thus, S. pandora is a gentle animal. Similar to other sessile animals which looks like S. pandora, the digestive tract of S. pandora is U-shaped. Unlike the Entoprocta which has the mouth and anus openings close to each other within the ingestion apparatus, S. pandora has the anus on the trunk far from and outside of the ingestion apparatus. The molecular phylogenetics indicates that the Cycliophora is not closely related to the Entoprocta. No one actually has ever seen the complicated whole life history of Symbion pandora, and scientists put together the pieces of observational results and make up a story of the whole life of S. pandora. A maternal body in an asexual generation attaches to a host animal and buds its clones in the body first. The clones are immature, and the outer shape looks like female. They move out from the maternal body and swim in the sea to live a planktonic life. The maternal body loses the ingestion apparatus when the asexual generation is produced. However, in due course, the apparatus may be regenerated many times as new buds are produced. Thus, they have potential of strong regenerative force. Afterwards, the female produce female larval buds and the male produce male larval buds in their respective bodies. The larvae are, therefore, in a sexual generation. Except in the male body, the next generation larvae already develop in the larvae like a nested box. Female Symbion pandora is less than 0.4 mm in length, and the male is even smaller than the female, about 0.1 mm long. They are so-called dwarf males and the body is like a capsule filled with sperms. The male has a pair of penises and copulate with the female to produce offspring. Copulation takes place when the female is in the maternal body during the asexual generation by the male attaching to the maternal body. Because they are protected in the maternal body, the copulation can be completed safely and securely. The female with fertilized eggs swim out of the maternal body into the sea, and she eventually attaches to a host organism. Then the larvae grow further and further in the female body, and the brain and the primitive kidney, which have not developed in any developmental stage, start to grow. Such a complexly structured notochordal larva (not the same notochord as that of the higher animals) swims in the sea and attaches to a new host and becomes an asexual generation maternal body. This completes the complex life history of S. pandora. They are like a Russian matryoshka doll which contains a smaller figure of itself inside, which has, in turn, another figure inside of it and so on. Therefore, the reproduction of S. pandora remind the image of opening the Pandora’s box, and thus, the animal is named S. pandora. Also, the body is covered with cuticles for protection at any developmental stage. It is possible that S. pandora molt to grow because remnants of what appeared to be repeated molting may be observed on the base of the body. |
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We all live around the lobster`s mustache |
I am sorry.
A song is only Japanese.
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Copyright (C); 2007, Shin Kubota.All Rights Reserved.