臺灣博碩士論文加值系統

本研究首次利用組織學的方式，除了確認鱗片重疊程度與鰻魚銀化體色呈現之關聯性，並獲得日本鰻皮膚中purine結晶的清楚結構，藉此判定鰻魚的銀色體色呈現是由iridophore所造成。
對降海洄游的鰻魚而言，銀化是其必經歷程，在銀化過程中，鰻魚在型態、生理及行為上皆發生改變，以適應即將面對的海水環境，是以銀化過程被視為變態。體側皮膚金屬光澤的出現是判斷銀化的一項重要特徵，亦是其最原始的定義，此色澤為一種結構色，會受到鱗片重疊及嘌呤結晶累積的影響。在鮭魚的研究，甲狀腺素在銀化過程中扮演著重要角色，雖然對於鮭魚及鰻魚的銀化目的相同，然而目前對於鰻魚銀化的判斷標準，則多與性成熟相關，性腺發育被當做判斷銀化標準的主要指標。本實驗聚焦於淡水養殖日本鰻鱗片排列及組織結構對於外部體色的關連。本實驗對淡水養殖之日本鰻皮膚進行採樣，藉由光學及穿透式電子顯微鏡觀察其結構與鱗片堆疊情況。鰻魚之鱗片包覆於真皮上層內，鱗片覆蓋之面積增加及鱗片間重疊情況已可在淡水銀鰻中觀察到，並伴隨著金屬光澤的出現。本研究首次對日本鰻皮膚中purine結晶的型態進行描述，更進一步辨認出下在鰻魚中purine結晶是以iridophore之形式存在。本實驗亦藉由外源性藥物的處理，觀察甲狀腺素及雄性素對日本鰻銀化過程所造成的影響，並發現以thiourea (TU)處理之魚隻腹部以及胸鰭有黑色素累積的情況出現。此結果顯示日本鰻的銀化，可能在降海前便近乎完成，與性成熟間的關聯並不明顯，且鱗片重疊伴隨著皮膚內嘌呤結晶的累積。甲狀腺素可能參與銀化的早期階段，但銀化的完成以及進入生殖洄游階段，必需在甲狀腺活性下降後才會發生。

These results for the first time provide the silvering color of Japanese eel is asso-ciation with scale arrangement increase and determine the existence of iridophores in eels by the ultrastructure of the purine crystals deposition in the skin of the Japanese eel.
Silvering is a required process in catadromous eels’ downstream migration. Dur-ing silvering, the morphology, physiology and behavior in eels are changed for adap-tation to the upcoming ocean life stage. The ventral skin exhibited metallic silvering is the original definition and important characteristic of silvering. Silvery body color of fish is a structural color, which is caused by overlapping of scales and purine accu-mulation in skin. In salmonids, thyroid hormones play an important role in smoltification. Although the salmonid smoltification the same as eel silvering, the sil-vering of eel are generally regarded association with sexual maturation, the silvering stage are determine by the status of gonad development.
This study focus on association between skin-scale complex and skin color of cultured freshwater Japanese eels. The skin was excised from flank region of Japanese eels which cultured in fresh water, and observed by light and transmission electron microscope. Iridophores under the outer chromatophore layer can be found. Scales were embedded in the upper of the dermis. In cultured freshwater Japanese eels, scales develop intercrossly and are overlapped in appearance accompany with metallic hue. This is the first time iridophores have been found in skin of eels. The effect of thyroid hormone and androgen on silvering process was preliminary studied by ex-ogenous drugs. In thiourea (TU) treated eels, melanization can be found in ventral skin and pectoral fins. The results suggest that the scale development in Japanese eel has been started or even finished in the fresh water, not directly induced by gonad maturation. Scale arrangement increase may be accompany with deposition of purine crystals during silvering process. Thyroid hormone may stimulate the onset of silvering, but a complete of silvering or spawning migration behavior express may start after the activity of thyroid gland was decrease.

致謝 I
中文摘要 II
英文摘要 III
前言 1
材料與方法 3
一. 實驗動物 3
二. 實驗設計 3
1.淡水養殖鰻鱗片與皮膚組織結構觀察 3
2.甲狀腺素對於鰻魚銀化的影響 4
三.形態特徵觀察 5
四. 犧牲採樣 5
五. 組織學處理 5
1. 組織切片 5
2. HE(Gill’s Hematoxyline and Eosin)染色 6
3. 鱗片染色 7
4. 穿透式電子顯微鏡觀察 8
六. 統計分析 9
實驗結果 10
一. 淡水養殖鰻鱗片與皮膚組織結構觀測 10
1. 銀化程度檢視 10
2. 體表鱗片堆疊狀態 10
3. 皮膚結構與鱗片發育 10
4. 穿透式電子顯微鏡觀察 11
二. 甲狀腺素對於鰻魚銀化的影響 12
1. 銀化程度檢視 12
2. 體表鱗片堆疊狀態 13
3. 皮膚厚度 13
4. 性腺發育狀態 13
5. 甲狀腺組織活性 13
討論 14
結論 21
參考文獻 22
表 33
圖 35
附錄 58

日比谷 京，(1982)。魚類組織図說-正常組織と病理組織。講談社。
吳煥成，(2003)。人工誘導日本鰻自然產卵排精之研究。國立臺灣大學漁業科學研究所碩士論文。
Allen, B. M. (1916). Extirpation experiments in Rana piplens larvae. Science, 44, 212-221,.
Aroua, S., Schmitz, M., Baloche, S., Vidal, B., Rousseau, K. and Dufour, S. (2005). Endocrine evidence that silvering, a secondary metamorphosis in the eel, is a pubertal rather than a metamorphic event. Neuroendocrinology, 82, 221-232.
Beddard, F. E. (1892). Animal coloration: an account of the principal facts and theories relating to the colours and markings of animals: S. Sonnenschein and Co.
Birks, E., Ewing, R. and Hemmingsen, A. (1985). Migration tendency in juvenile steelhead trout, Salmo gairdneri Richardson, injected with thyroxine and thiourea. Journal of Fish Biology, 26, 291-300.
Bishop C., Erezyilmaz D., Flatt T., Georgiou C., Hadfield M., Heyland A., Hodin J., Jacobs M., Maslakova S., and Pires A. (2006). What is metamorphosis? Integrative and Comparative Biology, 46, 655-661.
Bjornsson, B. T., Einarsdottir, I. E. and Power, D. (2012). Is salmon smoltification an example of vertebrate metamorphosis? Lessons learnt from work on flatfish larval development. Aquaculture, 362,264-272.
Boetius, I. and Larsen, L. O. (1991). Effects of testosterone on eye size and spermiation in silver eels, Anguilla anguilla. General and Comparative Endocrinology, 82:238.
Boetius, J., Boetius, I., Hemmingsen, A. M., Bruun, A. F. and Moller-Christensen, E. (1962). Studies of ovarial growth induced by hormone injections in the European and American eel (Anguilla anguilla L. and Anguilla rostrata LeSueur). Medd. Dan. Fisk.-Havunders. (Ny Ser.), 3, 183-198.
Boeuf, G. (1992). Salmonid smolting: a pre-adaptation to the oceanic environment Fish ecophysiology (pp. 105-135): Springer.
Bruun, A. F., hemmingsen, A. M. and moller-christensen, E. (1949). Attempts to induce experimentally maturation of the gonads of the European eel, Anguilla anguilla L. Acta Endocrinologica, 2, 212-226.
Callamand, O. and Fontaine, M. (1942). L''activite thyroidienne de l''anguille au cours de son developpement. Archives de Zoologie Experimentale et Generale, 82, 129-136.
Chakraborti, P., Rakshit, D. K. and Bhattacharya, S. (1983). Influence of season, gonadotropins, and gonadal hormones on the thyroid activity of freshwater perch, Anabas testudineus (Bloch). Canadian Journal of Zoology, 61, 359-364.
Chow, S., Kurogi, H., Mochioka, N., Kaji, S., Okazaki, M. and Tsukamoto, K. (2009). Discovery of mature freshwater eels in the open ocean. Fisheries Science:, 75, 257.
Cott, H. B. (1940). Adaptive coloration in animals. Oxford University Press.
Cottrill, R. A., McKinley, R. S. and Van Der Kraak, G. (2002). An examination of utilizing external measures to identify sexually maturing female American eels, Anguilla rostrata, in the St. Lawrence River. Environmental Biology of Fishes, 65, 271-287.
Cyr, D., Bromage, N., Duston, J. and Eales, J. (1988). Seasonal patterns in serum levels of thyroid hormones and sex steroids in relation to photoperiod-induced changes in spawning time in rainbow trout, Salmo gairdneri. General and Comparative Endocrinology, 69, 217-225.
D''Ancona, U. (1960). The life cycle of the Atlantic eel. Symposia of the Zoological Society of London. 1, 61-75
Dales, S.,and Hoar, W. S. (1954). Effects of thyroxine and thiourea on the early development of chum salmon (Oncorhynchus keta). Canadian Journal of Zoology, 32, 244-251.
Denton, E. J. and Saunders, R. L. (1972). On the organization of silvery layers in the skin of the Atlantic salmon (Salmo salar) during smoltification and on the regeneration of these layers under abnormal lighting conditions. Journal of the Marine Biological Association of the United Kingdom, 52, 889-898.
Dickhoff, W. W., Folmar, L. C. and Gorbman, A. (1978). Changes in Plasma Thyroxine during Smoltification of Coho Salmon, Oncorhynchus Kisutch. General and Comparative Endocrinology, 36, 229-232.
Dufour, S. and Rousseau, K. (2007). Neuroendocrinology of fish metamorphosis and puberty: Evolutionary and ecophysiological perspectives. Journal of Marine Science and Technology-Taiwan, 15, 55-68.
Durif, C., Dufour, S. and Elie, P. (2005). The silvering process of Anguilla anguilla: a new classification from the yellow resident to the silver migrating stage. Journal of Fish Biology, 66, 1025-1043.
Durif, C., Elie, P., Dufour, S., Marchelidon, J. and Vidal, B. (2000). Analysis of morphological and physiological parameters during the silvering process of the European eel (Anguilla anguilla) in the lake of Grand-Lieu (France). Cybium, 24, 63-74.
Edel, R. (1975). The induction of maturation of female American eels through hormone injections. Helgolander wissenschaftliche Meeresuntersuchungen, 27, 131-138.
Ege, V. (1939). A revision of the genus Auguilla SHAW, a systematic, phylogenetic and geographical study. Dana Report., 16, 1-256.
Egginton, S. (1987). Metamorphosis of the American eel, Anguilla rostrata LeSeur: III. Contractile characteristics of skeletal muscle. Journal of Experimental Zoology, 243, 39-50.
Fok, P. and Eales, J. G. (1984). Regulation of plasma T3 levels in T4-challenged rainbow trout, Salmo gairdneri. General and Comparative Endocrinology, 53, 197-202.
Fournie, J. W., Wolfe, M. J., Wolf, J. C., Courtney, L. A., Johnson, R. D., and Hawkins, W. E. (2005). Diagnostic criteria for proliferative thyroid lesions in bony fishes. Toxicologic pathology, 33, 540-551.
Fox, D. L. (1976). Animal biochromes and structural colours: physical, chemical, distributional and physiological features of coloured bodies in the animal world: Univ of California Press.
Hornyold, A. G. (1922). The age and growth of some eels from a small Worcestershire pond. Journal of the Royal microscopical society, 9-26.
Fujii, R. and Oshima, N. (1986). Control of Chronatophore Movements in Teleost Fishes. Zooloicalg Scencei, 3, 13-47.
Fujita, H., Suemasa, H. and Honma, Y. (1966). An electron microscopic study of the thyroid gland of the silver eel, Anguilla japonica.(A part of phylogenic studies of the fine structure of the thyroid). Archivum histologicum Japonicum, 27, 153.
Fukuda, N., Miller, M. J., Aoyama, J., Shinoda, A. and Tsukamoto, K. (2013). Evaluation of the pigmentation stages and body proportions from the glass eel to yellow eel in Anguilla japonica. Fisheries Science, 1-14.
Gill, G. W., Frost, J. K. and Miller, K. A. (1974). A new formula for a half-oxidized hematoxylin solution that neither overstains nor requires differentiation. Acta Cytologica, 18, 300-311.
Gorbman, A., Dickhoff, W. W., Mighell, J. L., Prentice, E. F. and Waknitz, F. W. (1982). Morphological Indexes of Developmental Progress in the Parr-Smolt Coho Salmon, Oncorhynchus Kisutch. Aquaculture, 28, 1-19.
Gudernatsch, J. (1912). Feeding experiments on tadpoles. I. The influence of specific organs given as food, on growth and differentiation. Wilhelm Roux Arch. Entwicklungsmech. Organismen, 13, 1913-1914.
Hagihara, S., Aoyama, J., Limbong, D. and Tsukamoto, K. (2012). Morphological and physiological changes of female tropical eels, Anguilla celebesensis and Anguilla marmorata, in relation to downstream migration. Journal of Fish Biology, 81, 408-426.
Han, Y.-S., Liao, I., Tzeng, W.-N., Huang, Y.-S. and Yu, J. Y.-L. (2003). Serum estradiol-17β and testosterone levels during silvering in wild Japanese eel Anguilla japonica . Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 136, 913-920.
Han, Y. S., Liao, I. C., Tzeng, W. N. and Yu, J. Y. (2004). Cloning of the cDNA for thyroid stimulating hormone beta subunit and changes in activity of the pituitary -thyroid axis during silvering of the Japanese eel, Anguilla japonica. General and comparative endocrinology, 32, 179-194.
Hoar, W. S. (1939). The thyroid gland of the Atlantic salmon. Journal of morphology, 65, 257-295.
Hoar, W. S. (1963). The endocrine regulation of migratory behavior in anadromous teleosts. Paper presented at the Procedure Sixteenth International Congress of Zoology.
Ikuta, K., Aida, K., Okumoto, N. and Hanyu, I. (1985). Effects of thyroxine and methyltestosterone on smoltification of masu salmon (Oncorhynchus masou). Aquaculture, 45, 289-303.
Ikuta, K., Aida, K., Okumoto, N. and Hanyu, I. (1987). Effects of sex steroids on the smoltification of masu salmon, Oncorhynchus masou. General and Comparative Endocrinology, 65, 99-110.
Inui, Y. and Miwa, S. (1985). Thyroid hormone induces metamorphosis of flounder larvae. General and comparative endocrinology, 60, 450-454.
Jellyman, D. J. (1979). Scale development and age determination in New Zealand freshwater eels (Anguilla spp.). New Zealand Journal of Marine and Freshwater Research, 13, 23-30.
Jellyman, D. J. and Todd, P. R. (1982). New Zealand Ministry of Agriculture and Fisheries, Fisheries Research Division Information Leaflet 11, Christchurch, New Zealand.
Klaren, P. H., Geven, E. J. and Flik, G. (2007). The involvement of the thyroid gland in teleost osmoregulation. In: Baldisserotto B, Mancera JM, Kapoor BG (eds) Fish osmoregulation. Science Publishers, Enfield, pp 35–65
Kleckner, R. C. (1980a). Swim bladder volume maintenance related to initial oceanic migratory depth in silver-phase Anguilla rostrata. Science, 208, 1481-1482.
Kleckner, R. C. (1980b). Swimbladder wall guanine enhancement related to migratory depth in silver phase Anguilla rostrata. Comparative Biochemistry and Physiology Part A: Physiology, 65, 351-354.
Land, M. (1972). The physics and biology of animal reflectors. Progress in Biophysics and Molecular Biology, 24, 75.
Landgrebe, F. W. (1941). The role of the pituitary and the thyroid in the development of teleosts. Journal of Experimental Biology, 18, 162-169.
Leatherland, J., Copeland, P., Sumpter, J. and Sonstegard, R. (1982). Hormonal control of gonadal maturation and development of secondary sexual characteristics in coho salmon, Oncorhynchus kisutch, from Lakes Ontario, Erie, and Michigan. General and Comparative Endocrinology, 48, 196-204.
Leonard, J. B., and Summers, R. G. (1976). The ultrastructure of the integument of the American eel, Anguilla rostrata. Cell and Tissue Research, 171, 1-30.
Lokman, P. M., Vermeulen, G. J., Lambert, J. G. and Young, G. (1998). Gonad histology and plasma steroid profiles in wild New Zealand freshwater eels (Anguilla dieffenbachii and A. australis) before and at the onset of the natural spawning migration. I. Females. Fish Physiology and Biochemistry, 19, 325-338.
Lokman, P. M., Rohr, D. H., Davie, P. S. and Young, G. (2003). The physiology of silvering in anguillid eels: androgens and control of metamorphosis from the yellow to silver stage. In: Aida K, Tsukamoto K, Yamauchi K (eds) Eel biology. Springer, Tokyo, pp 331–350
Madsen, S. S. and Korsgaard, B. (1989). Time-course effects of repetitive oestradiol-17β and thyroxine injections on the natural spring smolting of Atlantic salmon, Salmo salar L. Journal of Fish Biology, 35, 119-128.
Matsui, I. (1952). Studies on the morphology, ecology and pond-culture of the Japanese eel (Anguilla japonica Temminok and Schlegel). Shimonoseki College of Fisheries. l). Journal of the Shimonoseki College of Fisheries, 2, 1–245
Matty, A. and Sheltaway, M. (1967). Thyroxine and skin purines in trout. General and Comparative Endocrinology, 9, 473-482.
McCormick, S. D. (2001). Endocrine control of osmoregulation in teleost fish. American Zoologist, 41, 781-794.
Nagaishi, H., and Oshima, N. (1992). Ultrastructure of the motile iridophores of the neon tetra. Zoological science, 9, 65-75.
Nair R.V., Dorairaj K. (1975) Observations on scales of short-finned eel, Anguilla bicolor McClelland and their utility in age-determination. Current Science, 44,53-55.
Ojima, D. and Iwata, M. (2010). Central administration of growth hormone-releasing hormone and corticotropin-releasing hormone stimulate downstream movement and thyroxine secretion in fall-smolting coho salmon (Oncorhynchus kisutch). General and Comparative Endocrinology, 168, 82-87.
Okamura A., Oka H.P., Horie N., Utoh T., Yamada Y., Mikawa N., Tanaka S., and Tsukamoto K. (2009). Assessing sexual maturity of feminized Japanese eel Anguilla japonica by measuring eye size. Aquaculture International, 17, 91-99.
Okamura, A., Yamada, Y., Horie, N., Utoh, T., Mikawa, N., Tanaka, S. and Tsukamoto, K. (2008). Effects of silvering state on induced maturation and spawning in wild female Japanese eel Anguilla japonica. Fisheries Science, 74, 642-648.
Okamura A., Yamada Y., Yokouchi K., Horie N., Mikawa N., Utoh T., Tanaka S., and Tsukamoto K. (2007). A silvering index for the Japanese eel Anguilla japonica. Environmental Biology of Fishes, 80, 77-89.
Olivereau, M. and Olivereau, J. (1979). Effect of estradiol-17 β on the cytology of the liver, gonads and pituitary, and on plasma electrolytes in the female freshwater eel. Cell and tissue research, 199, 431-454.
Opuszynski, K. (1965). Obserwacje nad wiekiem biologia mlodego Wegorza (Anguilla anguilla L.).(Observation on young eel, Anguilla anguilla L. age and biology). Roczniki Nauk Rolniczych. 86-B-2, 393-411.
Pankhurst, N. and Sorensen, P. (1984). Degeneration of the alimentary tract in sexually maturing European Anguilla anguilla (L.) and American eels Anguilla rostrata (LeSueur). Canadian Journal of Zoology, 62, 1143-1149.
Pankhurst, N. W. (1982). Changes in the skin-scale complex with sexual maturation in the European eel, Anguilla anguilla (L.). Journal of Fish Biology, 21, 549-561.
Pankhurst, N. W. and Lythgoe, J. N. (1982). Structure and colour of the integument of the European eel Anguilla anguilla (L.). Journal of Fish Biology, 21, 279-296.
Petersen, C. (1894). The common eel (Anguilla vulgaris (Turton)) gets a particular breeding dress before its migration to the sea. Report of the Danish Biological Station, 5, 5-35.
Qu, X. C., Shin, D. H., Nagae, M., Todo, T., Adachi, S. and Yamauchi, K. (2006). Changes in serum thyroid hormone levels and thyroid gland activity in artificially maturing female Japanese eel (Anguilla japonica). Aquaculture Science, 54, 283-292.
Rohr, D. H., Lokman, P. M., Davie, P. S. and Young, G. (2001). 11-Ketotestosterone induces silvering-related changes in immature female short-finned eels, Anguilla australis. Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology, 130, 701-714. doi:
Rousseau, K. and Dufour, S. (2012). Introduction to fish first and secondary metamorphoses. In: Dufour, S., Rousseau, K., & Kapoor, B. G. (Eds.) Metamorphosis in Fish. CRC Press, pp 1-11
Silva, S. S. D., Gunasekera, R. M. and Collins, R. O. (2002). Some morphometric and biochemical features of ready-to-migrate silver and pre-migratory yellow stages of the shortfin eel of south-eastern Australian waters. Journal of Fish Biology, 61, 915-928.
Sklower, A. (1930). Die Bedeutung der Schilddruse fur die Metamorphose des Aales und der Plattfische. Forschung und Fortschritte der Dtutsche Wissenshaftliche, 6, 435-436.
Slater, C. H., Schreck, C. B. and Swanson, P. (1994). Plasma profiles of the sex steroids and gonadotropins in maturing female spring chinook salmon (Oncorhynchus tshawytscha). Comparative Biochemistry and Physiology Part A: Physiology, 109, 167-175.
Soma, K. K., Francis, R. C., Wingfield, J. C. and Fernald, R. D. (1996). Androgen regulation of hypothalamic neurons containing gonadotropin-releasing hormone in a cichlid fish: integration with social cues. Hormones and Behavior, 30, 216-226.
Staley, K. and Ewing, R. (1992). Purine levels in the skin of juvenile coho salmon (Oncorhynchus kisutch) during Parr-smolt transformation and adaptation to seawater. Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 101, 447-452.
Suzuki, S. (1992). Thyroid Gland. In Atlas of Endocrine Organs (pp. 63-71):Springer Berlin Heidelberg.
Tesch, F. (1977). The eel: biology and management of anguillid eels. Translated from German by J. Greenwood. Chapman and Hall/John Wiley and Sons, New York, USA
Todd, P. R. (1981). Morphometric changes, gonad histology, and fecundity estimates in migrating New Zealand freshwater eels (Anguilla spp.). New Zealand Journal of Marine and Freshwater Research, 15, 155-170.
Tsukamoto, K. (1992). Discovery of the Spawning Area for Japanese Eel. Nature, 356, 789-791.
Tsukamoto, K., Chow S., Otake T., Kurogi H., Mochioka N., Miller J.M., Aoyama J., Kimura S., Watanabe S., Yoshinaga T., Shinoda A., Kuroki M., Oya M., Watanabe T., Hata K., Ijiri S., Kazeto Y., Nomura K. and Tanaka H. (2011). Oceanic spawning ecology of freshwater eels in the western North Pacific. Nature communications, 2, 179.
van Ginneken, V., Durif, C., Dufour, S., Sbaihi, M., Boot, R., Noorlander, K., Doornbos, J., Murk, A.J. and van den Thillart, G. (2007). Endocrine profiles during silvering of the European eel (Anguilla anguilla L.) living in saltwater. Animal Biology, 57, 453-465.
Wallace, A.R. (1889). Darwinism. An exposition of the theory of natural selection with some of its applications. London: Macmillan.
Yamauchi, K. and Yamamoto, K. (1982). Experiments of artificial maturation and fertilization of the Japanese eel (Anguilla japonica). In: Richter CJ, Goos GJTh (eds)
Reproductive physiology of fish. Pudoc Press, Wargeningen, pp 185– 189
Youngson, A. F. and Simpson, T. H. (1984). Changes in serum thyroxine levels during smolting in captive and wild Atlantic salmon, Salmo salar L. Journal of Fish Biology, 24, 29-39.