Jump to content

Japanese rice fish

From Wikipedia, the free encyclopedia
(Redirected from Himedaka)
"Medaka" redirects here. For the manga and anime series, see Medaka Box.

Japanese rice fish
Oryzias latipes
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Beloniformes
Family: Adrianichthyidae
Genus: Oryzias
Species:
O. latipes
Binomial name
Oryzias latipes
Synonyms[2]
  • Poecilia latipes Temminck & Schlegel, 1846
  • Aplocheilus latipes (Temminck & Schlegel, 1846)

The Japanese rice fish (Oryzias latipes), also known as the medaka,[2] is a member of genus Oryzias (ricefish), the only genus in the subfamily Oryziinae. This small (up to about 3.6 cm or 1.4 in) native of Japan is a denizen of rice paddies, marshes, ponds, slow-moving streams and tide pools.[3][4] It is euryhaline, occurring in both brackish and freshwater.[3] It became popular as an aquarium fish because of its hardiness and pleasant coloration: its coloration varies from creamy-white to yellowish in the wild to white, creamy-yellow, or orange in aquarium-bred individuals. Bright yellow, red or green transgenic populations, similar to GloFish, have also been developed, but are banned from sale in the EU.[5] The medaka has been a popular pet since the 17th century in Japan.[6] After fertilization, the female carries her eggs attached anterior to the anal fin for a period before depositing them on plants or similar things.[5]

Ecology

[edit]

Medaka live in small ponds, shallow rivers, and rice fields.[7] They can survive in a wide range of water temperatures (0–42 °C or 32–108 °F), but they prefer a water temperature of 15–28 °C (59–82 °F).[8] Since they eat juvenile mosquitoes and small plankton, they are known as a beneficial organism for humans. They produce 10–20 eggs per birth, and they can produce eggs every day in laboratory conditions. They are seasonal breeding animals and usually lay eggs between spring and summer.[9] They prefer to lay eggs around water grass and often prefer living in rice fields.[7] The egg usually requires 4–10 days to hatch.[10] They have an advanced renal function, which enables them to live in saltwater and brackish water.[11] The average life span of this species in the wild is estimated to be 2 years, though in laboratory conditions they can survive 3–5 years. They live in schools, and they can recognize the faces of other individual medaka.[12]

Taxonomy and range

[edit]
A group in a shallow ditch, a typical habitat of the species (Katori, Japan)

As originally defined, O. latipes was native to much of east and mainland southeast Asia, but in recent decades most of these populations have been split off as separate species based on morphological (morphometrics and meristics) and genetic evidence.[4][13] This limits the native range of definite O. latipes to Japan: eastern and southern Honshu, Shikoku, Kyushu, and smaller southern islands in the country.[13] Formerly included in this species but now regarded as separate are O. sakaizumii in northwestern Honshu in Japan (locally, it hybridizes with O. latipes), and O. sinensis (Chinese rice fish) in much of China, west Korea and parts of mainland southeast Asia.[4][13][14] The taxonomic position of certain populations, including some in China, Laos and east Korea, is unclear and require further study.[4][13] It is possible that all these Chinese populations are part of O. sinensis, but the Laos specimens are relatively large, similar to O. latipes rather than the tiny O. sinensis.[4] The east Korean population is part of a clade with O. sakaizumii and O. latipes. Based on morphology it is closer to O. sakaizumii than O. latipes, but it may be an undescribed species.[13]

O. latipes has been introduced to Hokkaido in northern Japan (where ricefish are not native).[15] There are other reports of introductions around the world, but at least most of those in mainland Asia and Europe involve O. sinensis (Chinese rice fish).[15][16]

Origin of Southern and Northern Japanese populations

[edit]

Phylogenetic analysis shows that the southern Japanese population was derived from that of the northern Kyushu area and spread into Honshu. On the other hand, the northern population was derived from a population from the Tajima-Tango region and spread alongside the Sea of Japan coast.[17] O. latipes is known to have nine sub-populations: East Japanese type, East Setouchi type, West Setouchi type, San'in type, Northern Kyushu type, Osumi Type, Ariake type, Satsuma type and Ryukyu type. These sub-populations have been mixed with each other due to artificial releasing and decreasing local genetic diversity.[citation needed]

Use in science

[edit]
An orange aquarium variant (himedaka) achieved through selective breeding, photographed from above. Not to be confused with the brightly colored transgenic aquarium variants.

Oryzias latipes is a model organism and is extensively used in many areas of biological research, most notably in toxicology. Medaka have a short gestation period, and are reproductively prolific—characteristics that make them easy to rear in the laboratory. They can withstand cold and can be shipped easily. Nearly all aspects of the life cycle of medaka have been analyzed by researchers including sexual behavior, genetic inheritance of coloration, spawning habits, feeding, pathology, embryological development, ecology, etc.[18][19] It has a relatively small genome (~800 mega base pairs, half the size of the genome of another popular model fish, the zebrafish) as well as a generation time of 7 weeks (rather than 9 weeks for zebrafish) and hardier growth in a broad temperature range (6–40 °C or 43–104 °F).[20][21]

Transgenic medaka are relatively easy to produce. They have been genetically modified to secrete various human hormones, express promoter sequences from other fish, and to make antimicrobial proteins and a protein that makes the medaka glow fluorescent green, yellow or red.[5][22] There are also many mutations that show up in medaka at random, for example, a mutant strain that lacks scales, and one with extra-long fins. Haploid embryonic stem cell lines have been established.[23]

In space

[edit]
O. latipes mating in space

O. latipes carries the distinction of having been the first vertebrate to mate in orbit.[24] The result of the mating was a brood of healthy fry, hatched on the Space Shuttle Columbia in 1994. O. latipes returned to space in 2012, launched aboard a Soyuz spacecraft Soyuz TMA-06M and housed in an aquarium aboard the International Space Station.[citation needed]

Inbreeding lines

[edit]

The possibility of serial inbreeding facilitates genetic research due to reduction of heterozygous sites in the genome. In medaka it is relatively easy to establish inbred lines, unlike other model species like zebrafish and mice.[25] By 1979, researchers had generated 10 inbred strains.[26] These inbred lines made medaka a model species for scientific research in genetics.[27][28] In 2014, work began on generating 111 different inbred lines derived from a single population collected in the wild.[29]

Sex and reproduction

[edit]

Medaka reproduce on a daily basis, which is an optimal trait for studying their reproductive biology. Researchers have studied HPG axis activities intensively in this species.[30][31] Moreover, the medaka is the first non-mammalian vertebrate species for which a sex-determination gene (DMY) has been identified,[32] their sex is reversible by sex steroid manipulation,[33] and they exhibit morphological sexual dimorphism between males and females. Furthermore, some methods such as ovariectomy[34] and altered light-dark cycles[35] have been developed to study the mechanism of reproduction in medaka.[citation needed]

Immunology

[edit]

The discovery that T-lymphocytes home to the thymus in medaka has led to an understanding that this is not specific to mammalians but can be found in other vertebrates.[citation needed]

Skeletal Research

[edit]

This species is increasingly used as a model in research relating to skeletal diseases in humans,[36] such as osteoporosis.

Conservation

[edit]

Status

[edit]

The medaka is listed as a least-concern species in the IUCN red list. The justification of this categorization is that this species is living in widespread habitat (755,000 km2) and is relatively abundant in its various habitats.[1] However, it is considered an endangered species by Japan's Ministry of the Environment.[37] Many local communities try to preserve wild medaka in Japan.[38][39][40]

Concerns

[edit]

There are two major concerns about medaka conservation: habitat degradation and hybridization with domesticated medaka (himedaka). Due to modernization of rice fields and irrigation canals, optimal places for medaka reproduction are massively decreasing.[7] In addition, recent studies confirmed that himedaka have been introduced into many local regions by artificial release.[41] This will eliminate local genetic adaptations of each sub-population of medaka.[41][42] Furthermore, since himedaka have vivid orange body color, the hybrids will attract more predators and thus decrease the total medaka population.[43] In 2011, researchers discovered that almost 15% of wild-caught medaka in Nara had a himedaka-specific gene marker.[44] In addition to these concerns, invasive species like mosquitofish compete with medaka by sharing the same habitat. A study reported that over 70% of medaka had their tail fins injured by attacks from mosquitofish.[45] The damage at the anal fin will decrease medaka offspring by preventing courtship behavior.[46] In 2006, it was found that a transgenic line of medaka was brought to Japan from Taiwan for commercial purposes. This transgenic line had an introduced gene which expresses green fluorescence, making the body glow. Now, this transgenic line has been released into the wild and is causing genetic pollution.[47] There is no comprehensive study of population size of medaka, but the genomic analysis of one medaka sub-population indicates that their effective population size is around 25000–70000.[48]   

Medaka in Tokyo, Japan

Social importance in Japan

[edit]

The medaka has been kept as a domesticated pet in Japan for centuries. In recent years the fish has gained further popularity, with some rarer breeds valued at over 1 million yen (approximately US$10,000)—though the most common varieties (like himedaka) can be purchased for around 50 yen per fish.[49] Currently, 456 commercial strains are documented and available for fishkeeping.[50] Medaka are not only kept as pets but also widely utilized in education; Japanese elementary school classes often raise medaka in order to give the students firsthand experience with caring for live organisms, as well as to foster more broad appreciation for animals' life cycles.[citation needed]

See also

[edit]
  • Mummichog (Fundulus heteroclitus), first fish sent to space in 1973

References

[edit]
  1. ^ a b Kanao, S.; Taniguchi, Y.; Watanabe, K. (2019). "Oryzias latipes". IUCN Red List of Threatened Species. 2019: e.T166979A1159322. doi:10.2305/IUCN.UK.2019-2.RLTS.T166979A1159322.en. Retrieved 1 July 2024.
  2. ^ a b Froese, Rainer; Pauly, Daniel (eds.). "Oryzias latipes". FishBase. April 2019 version.
  3. ^ a b Froese, Rainer; Pauly, Daniel, eds. (2014). "Oryzias latipes". FishBase.
  4. ^ a b c d e Parenti, L.R. (2008). "A phylogenetic analysis and taxonomic revision of ricefishes, Oryzias and relatives (Beloniformes, Adrianichthyidae)". Zoological Journal of the Linnean Society. 154 (3): 494–610. doi:10.1111/j.1096-3642.2008.00417.x.
  5. ^ a b c "Oryzias latipes". SeriouslyFish. Retrieved 21 February 2017.
  6. ^ Hellweg, M (August 2013). "The Ricefish: An Odd and Interesting Group". TFH Magazine. Retrieved 21 February 2017.
  7. ^ a b c 牧人, 小林; 知尚, 頼経; 翔平, 鈴木; 彩美, 清水; 美香, 小井土; 優太郎, 川口; 洋一, 早川; さやか, 江口; 弘文, 横田; 義和, 山本 (2012). "屋外池における野生メダカ Oryzias latipes の繁殖行動". 日本水産学会誌. 78 (5): 922–933. doi:10.2331/suisan.78.922.
  8. ^ Shima, Akihiro; Mitani, Hiroshi (2004-07-01). "Medaka as a research organism: past, present and future". Mechanisms of Development. 121 (7): 599–604. doi:10.1016/j.mod.2004.03.011. ISSN 0925-4773. PMID 15210169. S2CID 397672.
  9. ^ Hirshfield, Michael F. (1980). "An Experimental Analysis of Reproductive Effort and Cost in the Japanese Medaka, Oryzias Latipes". Ecology. 61 (2): 282–292. Bibcode:1980Ecol...61..282H. doi:10.2307/1935187. ISSN 1939-9170. JSTOR 1935187.
  10. ^ Iwamatsu, Takashi (2004-07-01). "Stages of normal development in the medaka Oryzias latipes". Mechanisms of Development. 121 (7): 605–618. doi:10.1016/j.mod.2004.03.012. ISSN 0925-4773. PMID 15210170. S2CID 16570978.
  11. ^ Sakamoto, Tatsuya; Kozaka, Tomohiro; Takahashi, Akiyoshi; Kawauchi, Hiroshi; Ando, Masaaki (2001-02-15). "Medaka (Oryzias latipes) as a model for hypoosmoregulation of euryhaline fishes". Aquaculture. 193 (3): 347–354. Bibcode:2001Aquac.193..347S. doi:10.1016/S0044-8486(00)00471-3. ISSN 0044-8486.
  12. ^ Wang, Mu-Yun; Takeuchi, Hideaki (2017-07-11). Tsao, Doris Y (ed.). "Individual recognition and the 'face inversion effect' in medaka fish (Oryzias latipes)". eLife. 6: e24728. doi:10.7554/eLife.24728. ISSN 2050-084X. PMC 5505697. PMID 28693720.
  13. ^ a b c d e Asai, T.; Senou, H.; Hosoya, K. (2011). "Oryzias sakaizumii, a new ricefish from northern Japan (Teleostei: Adrianichthyidae)". Ichthyol. Explor. Freshwaters. 22 (4): 289–299. ISSN 0936-9902.
  14. ^ Parenti, L. (2012). "Oryzias sinensis". IUCN Red List of Threatened Species. 2012: e.T181312A1720540. doi:10.2305/IUCN.UK.2012-1.RLTS.T181312A1720540.en.
  15. ^ a b "Oryzias latipes". Invasive species of Japan. National Institute for Environmental Studies (Japan). Retrieved 20 February 2017.
  16. ^ Kottelat, M.; Freyhof, J. (2007). Handbook of European freshwater fishes. Publications Kottelat, Cornol, Switzerland. ISBN 978-2-8399-0298-4.
  17. ^ Katsumura, Takafumi; Oda, Shoji; Mitani, Hiroshi; Oota, Hiroki (2019-01-01). "Medaka Population Genome Structure and Demographic History Described via Genotyping-by-Sequencing". G3: Genes, Genomes, Genetics. 9 (1): 217–228. doi:10.1534/g3.118.200779. ISSN 2160-1836. PMC 6325896. PMID 30482798.
  18. ^ Leroi, Armand Marie. (2003). Mutants: On Genetic Variety and the Human Body. New York: Viking. Penguin Publishing. ISBN 0-670-03110-0.
  19. ^ "Major topic "Oryzias": free full-text articles in National Library of Medicine".
  20. ^ "Oryzias latipes, medaka as a model organism: taxonomy, facts, development stages, bibliography at GeoChemBio".
  21. ^ "Medaka (Oryzias latipes) Genome Browser Gateway".
  22. ^ Tanaka M, Kinoshita M, Kobayashi D, Nagahama Y (2001). "Establishment of medaka (Oryzias latipes) transgenic lines with the expression of green fluorescent protein fluorescence exclusively in germ cells: a useful model to monitor germ cells in a live vertebrate". Proc Natl Acad Sci USA. 98 (5): 2544–9. Bibcode:2001PNAS...98.2544T. doi:10.1073/pnas.041315498. PMC 30174. PMID 11226275.
  23. ^ Yi, Meisheng; Hong, Ni; Hong, Yunhan (2009). "Generation of Medaka Fish Haploid Embryonic Stem Cells". Science. 326 (5951): 430–433. Bibcode:2009Sci...326..430Y. doi:10.1126/science.1175151. PMID 19833967. S2CID 7505131.
  24. ^ "Medaka aboard Columbia". Archived from the original on 2009-03-26. Retrieved 2006-07-16.
  25. ^ Hilgers, Leon; Schwarzer, Julia (2019). "The untapped potential of medaka and its wild relatives". eLife. 8. doi:10.7554/eLife.46994. ISSN 2050-084X. PMC 6615862. PMID 31287418.
  26. ^ "NBRP Medaka". shigen.nig.ac.jp. Retrieved 2019-10-07.
  27. ^ Kasahara, Masahiro; Naruse, Kiyoshi; Sasaki, Shin; Nakatani, Yoichiro; Qu, Wei; Ahsan, Budrul; Yamada, Tomoyuki; Nagayasu, Yukinobu; Doi, Koichiro; Kasai, Yasuhiro; Jindo, Tomoko (June 2007). "The medaka draft genome and insights into vertebrate genome evolution". Nature. 447 (7145): 714–719. Bibcode:2007Natur.447..714K. doi:10.1038/nature05846. ISSN 1476-4687. PMID 17554307.
  28. ^ Kimura, Tetsuaki; Shimada, Atsuko; Sakai, Noriyoshi; Mitani, Hiroshi; Naruse, Kiyoshi; Takeda, Hiroyuki; Inoko, Hidetoshi; Tamiya, Gen; Shinya, Minori (2007-12-01). "Genetic Analysis of Craniofacial Traits in the Medaka". Genetics. 177 (4): 2379–2388. doi:10.1534/genetics.106.068460. ISSN 0016-6731. PMC 2219511. PMID 18073435.
  29. ^ Kirchmaier, Stephan; Naruse, Kiyoshi; Wittbrodt, Joachim; Loosli, Felix (2015-04-01). "The Genomic and Genetic Toolbox of the Teleost Medaka (Oryzias latipes)". Genetics. 199 (4): 905–918. doi:10.1534/genetics.114.173849. ISSN 0016-6731. PMC 4391551. PMID 25855651.
  30. ^ Karigo, Tomomi; Kanda, Shinji; Takahashi, Akiko; Abe, Hideki; Okubo, Kataaki; Oka, Yoshitaka (2012-07-01). "Time-of-Day-Dependent Changes in GnRH1 Neuronal Activities and Gonadotropin mRNA Expression in a Daily Spawning Fish, Medaka". Endocrinology. 153 (7): 3394–3404. doi:10.1210/en.2011-2022. ISSN 0013-7227. PMID 22544888.
  31. ^ Kanda, Shinji (2018-11-27). "Evolution of the regulatory mechanisms for the hypothalamic-pituitary-gonadal axis in vertebrates–hypothesis from a comparative view". General and Comparative Endocrinology. 284: 113075. doi:10.1016/j.ygcen.2018.11.014. ISSN 0016-6480. PMID 30500374. S2CID 54468539.
  32. ^ Matsuda, Masaru; Nagahama, Yoshitaka; Shinomiya, Ai; Sato, Tadashi; Matsuda, Chika; Kobayashi, Tohru; Morrey, Craig E.; Shibata, Naoki; Asakawa, Shuichi; Shimizu, Nobuyoshi; Hori, Hiroshi (May 2002). "DMY is a Y-specific DM-domain gene required for male development in the medaka fish". Nature. 417 (6888): 559–563. Bibcode:2002Natur.417..559M. doi:10.1038/nature751. ISSN 1476-4687. PMID 12037570. S2CID 4363239.
  33. ^ Scholz, S; Gutzeit, H. O (2000-10-01). "17-α-ethinylestradiol affects reproduction, sexual differentiation and aromatase gene expression of the medaka (Oryzias latipes)". Aquatic Toxicology. 50 (4): 363–373. Bibcode:2000AqTox..50..363S. doi:10.1016/S0166-445X(00)00090-4. ISSN 0166-445X. PMID 10967398.
  34. ^ Kanda, Shinji; Akazome, Yasuhisa; Matsunaga, Takuya; Yamamoto, Naoyuki; Yamada, Shunji; Tsukamura, Hiroko; Maeda, Kei-ichiro; Oka, Yoshitaka (2008-05-01). "Identification of KiSS-1 Product Kisspeptin and Steroid-Sensitive Sexually Dimorphic Kisspeptin Neurons in Medaka (Oryzias latipes)". Endocrinology. 149 (5): 2467–2476. doi:10.1210/en.2007-1503. ISSN 0013-7227. PMID 18202129.
  35. ^ Weber, D. N.; Spieler, R. E. (1987-06-01). "Effects of the light-dark cycle and scheduled feeding on behavioral and reproductive rhythms of the cyprinodont fish, Medaka,Oryzias latipes". Experientia. 43 (6): 621–624. doi:10.1007/BF02126355. ISSN 1420-9071. PMID 3595795. S2CID 11727260.
  36. ^ Di Biagio, Claudia; Dellacqua, Zachary; Martini, Arianna; Huysseune, Ann; Scardi, Michele; Witten, Paul Eckhard; Boglione, Clara (2022-06-30). "A Baseline for Skeletal Investigations in Medaka (Oryzias latipes): The Effects of Rearing Density on the Postcranial Phenotype". Frontiers in Endocrinology. 13. doi:10.3389/fendo.2022.893699. ISSN 1664-2392. PMC 9281570. PMID 35846331.
  37. ^ Takehana, Yusuke; Nagai, Naoko; Matsuda, Masaru; Tsuchiya, Kimiyuki; Sakaizumi, Mitsuru (October 2003). "Geographic Variation and Diversity of the Cytochrome b Gene in Japanese Wild Populations of Medaka, Oryzias latipes". Zoological Science. 20 (10): 1279–1291. doi:10.2108/zsj.20.1279. ISSN 0289-0003. PMID 14569151. S2CID 22958328.
  38. ^ "「東京めだか」を守っています ｜ 東京ズーネット". www.tokyo-zoo.net. Retrieved 2019-11-29.
  39. ^ "追跡取材！ 進行中の「三浦メダカ」保全活動をレポート！ - はまれぽ.com 神奈川県の地域情報サイト". はまれぽ.com. Retrieved 2019-11-29.
  40. ^ "和歌山市におけるのメダカの現在の生息状況". kodomo123.jp. Retrieved 2019-11-29.
  41. ^ a b Nakao, Ryohei; Iguchi, Yuka; Koyama, Naoto; Nakai, Koji; Kitagawa, Tadao (2017-01-01). "Current status of genetic disturbances in wild medaka populations (Oryzias latipes species complex) in Japan". Ichthyological Research. 64 (1): 116–119. Bibcode:2017IchtR..64..116N. doi:10.1007/s10228-016-0528-5. ISSN 1616-3915. S2CID 44688469.
  42. ^ 直人, 小山; 幹大, 森; 宏施, 中井; 忠生, 北川 (2011). "市販されているメダカのミトコンドリアdna 遺伝子構成". 魚類学雑誌. 58 (1): 81–86. doi:10.11369/jji.58.81.
  43. ^ Nakao, Ryohei; Kitagawa, Tadao (2015). "Differences in the behavior and ecology of wild type medaka (Oryzias latipes complex) and an orange commercial variety (himedaka)". Journal of Experimental Zoology Part A: Ecological Genetics and Physiology. 323 (6): 349–358. Bibcode:2015JEZA..323..349N. doi:10.1002/jez.1916. ISSN 1932-5231. PMID 26054930.
  44. ^ 宏施, 中井; 遼平, 中尾; 昌司, 深町; 直人, 小山; 忠生, 北川 (2011). "ヒメダカ体色原因遺伝子マーカーによる奈良県大和川水系のメダカ集団の解析". 魚類学雑誌. 58 (2): 189–193. doi:10.11369/jji.58.189.
  45. ^ 優秋, 田代; 康則, 上月; 陽一, 佐藤; 仁士, 村上 (2005). "外来種カダヤシによるメダカへの影響と保全策に関する一考察". 日本生態学会大会講演要旨集. ESJ52: 814. doi:10.14848/esj.ESJ52.0.814.0.
  46. ^ 珠央, 伊藤; 右介, 小関; 靖章, 新妻 (2006). "メダカOryzias latipesにおける雄の鰭の損傷による産卵数および受精率の低下". 野生生物保護. 10 (1–2): 1–7. doi:10.20798/wildlifeconsjp.10.1-2_1.
  47. ^ "環境省_未承認の遺伝子組換えメダカの回収のお願いについて". www.env.go.jp. Retrieved 2019-11-29.
  48. ^ Spivakov, Mikhail; Auer, Thomas O.; Peravali, Ravindra; Dunham, Ian; Dolle, Dirk; Fujiyama, Asao; Toyoda, Atsushi; Aizu, Tomoyuki; Minakuchi, Yohei; Loosli, Felix; Naruse, Kiyoshi (2014-03-01). "Genomic and Phenotypic Characterization of a Wild Medaka Population: Towards the Establishment of an Isogenic Population Genetic Resource in Fish". G3: Genes, Genomes, Genetics. 4 (3): 433–445. doi:10.1534/g3.113.008722. ISSN 2160-1836. PMC 3962483. PMID 24408034.
  49. ^ "100万円の値がついた「高級メダカ」とは！？人気急上昇中、希少なメダカを一挙公開". ラグジュアリー体験の入り口メディア (in Japanese). Retrieved 2019-11-29.
  50. ^ "改良メダカ年表 - めだかの館". 改良メダカ年表 - めだかの館 (in Japanese). Retrieved 2019-11-29.
[edit]
Look up Medaka in Wiktionary, the free dictionary.
Wikimedia Commons has media related to:
Oryzias latipes (category)
Wikispecies has information related to Oryzias latipes.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Japanese_rice_fish&oldid=1242558624"