博士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 101 / We measured concentrations of Ca2+ in various tissues, including hemolymph, hepatopancreas, cuticle, and muscle, of whiteleg shrimp Litopenaeus vannamei in control, lead and copper environment. We also recorded the changes of tissue calcium levels at different molting stages and various salinities.
Calcium in tissues varied significantly with molting stage (p &;lt; 0.05). Salinity also affected Ca2+ concentrations in tissues (p &;lt; 0.05). The highest Ca2+concentrations were found in the cuticle, followed by the hepatopancreas. Ratios of Ca2+/Na+ in tissues (except for muscle) varied with molting stage, whereas higher in 4‰ than in the other salinities. The highest tissue accumulation was found at stage B in lower salinity when L. vannamei exposed to waterborn Cu2+ and Pb2+ environment at the concentration of 1 mg/L and 5 mg/L respectively, and hepatopancreas was the principle accumulating tissue. But the effects on the tissue Ca2+ distribution of Cu2+ and Pb2+ were different. Ca2+ and Ca2+/Na+ in hemolymph, hepatopancreas and cuticle, and cuticlar protein were higher when L. vannamei exposed to Cu2+ than the control and Pb2+; Ca2+ and Ca2+/Na+ in muscle and cuticlar chtosan were lower than control. However, Ca2+ and Ca2+/Na+ in hemolymph, hepatopancreas and muscle, and cuticlar chitosan were lower when L. vannamei exposed to Pb2+ then control and Cu2+; Ca2+ and Ca2+/Na+ in cuticle was not different to normal (p &;lt; 0.05), and cuticlar protein was higher when L. vannamei exposed to Pb2+ then normal and Cu2+.
In control, calcium entering the shrimp may initially be mineralized in the cuticle or stored in the hemolymph and hepatopancreas, after which it is released to support mineralization in the post-molt period. Muscles may take part in the growth of L. vannamei by storing calcium during the molting cycle. Lead and copper would both affect the calcium distribution among tissue in the body of L. vannamei, and they could be accumulation in the cuticle. But the effect is different between lead and copper. It might stimulate L. vannamei to absorb calcium from outsides to the body, and calcium is transported by hemolymph to save in hepatopancreas and deposit in cuticle when L. vannamei exposes to copper in the short time. However, the calcium transportation in hemolymph and the calcium saving in hepatopancreas are lower when L.vannamei exposes to lead in the short time. But it does not affect the deposition in cuticle. Summarizing above, lead and copper do not enter cuticle by competing the channel with calcium. Copper might enter cuticle with other ion channel. Lead-connecting protein brings lead into cuticle, and lead restrains chitin entering and synthesizing cuticle.
| Identifer | oai:union.ndltd.org:TW/101NTOU5451001 |
| Date | January 2013 |
| Creators | Chun-Huei Li, 李純慧 |
| Contributors | Sha-Yen Cheng, 鄭學淵 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 128 |
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