椰子蟹

椰子蟹（學名：Birgus latro）又稱八卦蟹，屬於陸寄居蟹科，是一種十足目的節肢動物，它是世界上最大的陸生節肢動物，也是現存最大型的陸生甲殼綱。它分佈在印度洋、太平洋的島嶼，從甘比爾群島、皮特肯群島直至桑給巴爾海岸。
椰子蟹體重最高可達6公斤，椰子蟹善於爬樹，能爬到樹頂覓食。有人稱椰子蟹為強盜蟹，傳言牠們會從民居和帳篷中偷竊罐和銀器之類的東西。隨著棲息地破壞及人類捕食影響，及椰子蟹在世界上的族群在近年急速減少 ，1981年，椰子蟹被IUCN紅色名錄列為易危物種，但由於缺乏生物學數據導致1996年被修正為「數據不足」，2018年，IUCN更新其評估為「易危」。臺灣已將椰子蟹列入臺灣保育物種列表中。

**特性**
椰子蟹是一種寄居蟹，能用螯弄破椰子的外殼，以吃其中的椰子果肉，並因以為其名。多數出現於熱帶地區海岸與部分亞熱帶群島海岸，通常在日本南方的伊豆群島與琉球群島中可發現到。而臺灣如東海岸、綠島、蘭嶼及恆春半島等地分佈最多。另外世界上其他地方如印度洋和太平洋的熱帶島嶼亦有分佈。
喜愛在海中潤濕鰓或繁殖，白天常躲藏於海邊陰涼的樹林、石頭及珊瑚礁之下，晚間才出沒覓食。食地瓜、椰子、木瓜和花生以及動物屍體為食等，但因為人類也會取用椰子來食用的關係，導致椰子的數量缺乏，使得有些椰子蟹因為食物不足而突然開始轉變成獵食者捕殺紅腳鰹鳥、玻里尼西亞鼠和一些小型蟹類。椰子蟹會爬樹，用鰓呼吸(但不能在水中呼吸)。椰子蟹是卵生動物，於海水中孵化。
它們體重最高可達6公斤，是現存最大型的陸生節肢動物，被認為是島嶼巨型化實例之一。因為善於爬樹，可以到樹頂覓食。它們通常會會用鉗子弄破椰子的外殼，以食用其中的椰子果肉。

**參考文獻**

**書目**
cite book |editor1=I. W. Brown |editor2=D. R. Fielder |year=1991 |title=The Coconut Crab: Aspects of the Biology and Ecology of Birgus latro in the Republic of Vanuatu |series=ACIAR Monograph |volume=8 |publisher=Australian Centre for International Agricultural Research |location=Canberra, Australia |isbn=978-1-86320-054-7 |ref=refBrownFielder Available as PDF:  pp. i–x, 1–35 date=20110409084502 ,  pp. 36–82,  pp. 83–128
*cite journal |author1=M. M. Drew |author2=S. Harzsch |author3=M. Stensmyr |author4=S. Erland |author5=B. S. Hansson |year=2010 |title=A review of the biology and ecology of the Robber Crab, Birgus latro (Linnaeus, 1767) (Anomura: Coenobitidae) |journal=Zoologischer Anzeiger |volume=249 |issue=1 |pages=45–67 |doi=10.1016/j.jcz.2010.03.001 |ref=refDrew
*cite book |author=Warwick J. Fletcher |chapter=Coconut crabs |editor1=Andrew Wright |editor2=Lance Hill |year=1993 |title=Nearshore Marine Resources of the South Pacific: Information for Fisheries Development and Management |publisher=International Centre for Ocean Development |location=Suva, Fiji |pages=643–681 |isbn=978-982-02-0082-1 |chapter-url=https://books.google.com/books?id=JHlBw5rYuF0C&pg=PA643 |ref=Fletcher |access-date=2019-09-15 |archive-date=2019-12-26 |archive-url=https://web.archive.org/web/20191226072018/https://books.google.com/books?id=JHlBw5rYuF0C&pg=PA643 |dead-url=no 
*cite book |editor1=Warren W. Burggren |editor2=Brian Robert McMahon |year=1988 |title=Biology of the Land Crabs |publisher=Cambridge University Press |location=Cambridge, United Kingdom |isbn=978-0-521-30690-4 |author=Richard Hartnoll |chapter=Evolution, systematics, and geographical distribution |pages=6–54 |ref=refHartnoll |chapter-url=https://books.google.com/books?id=RR09AAAAIAAJ&pg=PA6 |access-date=2019-09-15 |archive-date=2020-01-02 |archive-url=https://web.archive.org/web/20200102032152/https://books.google.com/books?id=RR09AAAAIAAJ&pg=PA6 |dead-url=no 
*cite book |editor1=Warren W. Burggren |editor2=Brian Robert McMahon |year=1988 |title=Biology of the Land Crabs |publisher=Cambridge University Press |location=Cambridge, United Kingdom |isbn=978-0-521-30690-4 |author=Thomas G. Wolcott |chapter=Ecology |pages=55–96 |ref=refWolcott |chapter-url=https://books.google.com/books?id=RR09AAAAIAAJ&pg=PA55 |access-date=2019-09-15 |archive-date=2019-12-29 |archive-url=https://web.archive.org/web/20191229075101/https://books.google.com/books?id=RR09AAAAIAAJ&pg=PA55 |dead-url=no 

**論文**
 Altevogt, R., Davis., T.A. (1975) Birgus latro: India's monstrous crab. A study and an appeal. Bulletin of the Department of Marine Sciences, University of Cochin.- Barnett, L.K., Emms, C. and Clarke, D. (1999). The coconut or robber crab (Birgus latro) in the Chagos Archipelago and its captive culture at London Zoo, pp. 273–284: in Sheppard, C.R.C. and Seaward, M.R.D. (Eds). Ecology of the Chagos Archipelago. Linnean Society Occasional Publications, 2. Westbury Publishing. pp. 351. - Combs, C. A. N., Alford, A., Boynton, M. and Henry, R. P (1992). Behavioural regulation of haemolymph osmolarity through selective drinking in land crabs, Birgus latro and Gecarcoidea lalandii. Biol. Bull. 182, 416-.- Greenaway, P. and Morris, S (1989). Adaptations to a terrestrial existence by the robber crab Birgus latro. III. Nitrogenous excretion. J. Exp. Biol. 143: 333-.- Greenaway, P., Taylor, H. H. and Morris, S (1990). Adaptations to a terrestrial existence by the robber crab Birgus latro. VI. The role of the excretory system in fluid balance. J. Exp. Biol. 152: 505-.- Grubb, P. (1971) Ecology of terrestrial decapod crustaceans on Aldabra. Philosophical Transactions of the Royal Society: Biological Sciences. 260: 411–416.- Held, E.E. (1963) Moulting behaviour of Birgus latro. Nature, 200: 799–800.- Lavery S Moritz C & Fielder DR (1996) Indo-Pacific population structure and evolutionary history of the Coconut Crab Birgus latro. Mol Ecol 5: 557–570.- Morris, S., Taylor, H. H. and Greenaway, P (1991). Adaptations to a terrestrial existence in the robber crab Birgus latro L. VII. The branchial chamber and its role in urine reprocessing. J. Exp. Biol. 161: 315-.- Stensmyr, M. C., Erland S., Hallberg E., Wallén R., Greenaway P., Hansson B. S. (2005). Insect-Like Olfactory Adaptations in the Terrestrial Giant Robber Crab. Current Biology 15: 116–121.- Taylor, H. H., Greenaway, P. and Morris, S (1993). Adaptations to a terrestrial existence in the robber crab Birgus latro L. VIII. Osmotic and ionic regulation on freshwater and saline drinking regimens. J. Exp. Biol. 179: 93–113（ PDF download date=20080411042905 ）

**外部連結**
  椰子蟹簡介-  完全資訊 - ARKive -  椰子蟹（Birgus latro）圖片及影片-  椰子蟹（Birgus latro）