The Study of Crawling Behavior, Oxygen Consumption and Oxygen Stress in Earthworm Amynthas gracilis after UV-B Exposure

紫外線B(UV-B)對纖細遠環蚓(A. gracilis)爬行行為、呼吸及造成體表氧化壓力之研究

莊淑君(Shu-Chun Chuang) ； 陳俊宏(Jiun-Hong Chen)

《Acta Zoologica Taiwanica》 14卷2期 (2004/10) Pp. 97-98

https://doi.org/10.6576/AZT.2004.14.(2).4

摘要

在大雨過後的清晨常可看見蚯蚓陳屍水漥中，為何在爬出地表後不爬回土壤而死於水漥中呢？本實驗以會呈現此行為的Amynthas gracilis為實驗動物，發現紫外線是一關鍵因素。特別是UV-B會影響其爬行能力並造成死亡率的增加。由照射時立即的行為反應及之後發生的體表病變，可分為急性及慢性反應，急性為蚯蚓照射時會立即出現肌肉強烈收縮，有不正常S型爬行行為及跳動；慢性反應則會造成表皮和肌肉細胞的破損及個體的死亡。在測量蚯蚓泡過水再加以UV-B照射後的耗氧量發現，其耗氧會明顯降低，推測是由於紫外線造成肌肉無法正常收縮，而蚯蚓氧氣的取得是藉由濕潤的體表讓氧氣滲透，再經由肌肉的收縮使血液中的氧氣帶至身體各處，因此當紫外線照射後，體表的傷害會阻擋部份的氧氣進入血管中，肌肉無法正常運動造成蚯蚓血液循環變緩，造成缺氧（耗氧降低）而死。在測量與氧化壓力有關的物質及酵素發現，蚯蚓體表在照射UV-B後，體表的脂質過氧化現象會增加，抗氧化酵素（catalase及GPx）活性會降低，並且直接測量其中的H2O2發現含量會增加，顯示氧化壓力是造成蚯蚓體表傷害及死亡的原因之一。

關鍵字

蚯蚓 ； Amynthas gracilis ； 爬行 ； 紫外線UV ； 耗氧 ； 氧化壓力

並列摘要

After a heavy raining day, it is possible to see earthworms wandering on the soil surface at the next day morning. They might die in few hours. Why did they not crawl back to soil but die in water? By using earthworms, Amynthas gracilis which presents the described behavior, ultraviolet (UV) was suspected as the main factor to kill the earthworms. The damage of ultraviolet radiation on earthworms could refer to two responses, acute response and chronic response. The acute response is that the appearance of strong muscle contraction such as abnormal S-shape movement and jumping behavior. The phenomenon might be caused by bad muscle coordination. The chronic response showed the damage of skin and muscle cells and high mortality after UV-B exposure. The oxygen consumption of A. gracilis was significantly decreased after UV-B exposure. Because the circulation of earthworms is mediated by muscle contraction, earthworms maybe stifle when their muscles didn't contract normally. Meanwhile, the chronic response, seriously A. gracilis cause epithelial necrosis that affect the oxygen diffused into the blood vessel of the earthworms. UV also increased oxidative stress on cells. I found that the lipid peroxidation, antioxidant enzyme (catalase, GPx, SOD) of earthworms was increased after UV-B expose. It inferred that oxygen stress was another reason that caused earthworms died after UV-B exposure.

並列關鍵字

earthworm ； Amynthas gracilis ； crawling ； ultraviolet UV ； oxygen consumption ； oxygen stress