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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of polycyclic musks and bisphenol A on the settlement and metamorphosis on sponge, Spongia ceylonensis

Chen, Shiang-Ting 05 September 2011 (has links)
Sponge population partly depends on larval recruitment. Environmental factors, e.g. light, salinity, pH and temperature, chemical factors and pollution may influence larval settlement and metamorphosis. In this study, the effects of galaxolide¡]HHCB¡^¡Btonalide¡]AHTN¡^and bisphenol A¡]BPA¡^on the settlement and metamorphosis of an intertidal sponge ¡]Spongia ceylonensis¡^ were examined. The experiments included LC50 test, effects of solvent, HHCB, AHTN and BPA on sponge settlement and metamorphosis. In the LC50 tests, the 96 hr¡VLC50 value of HHCB and AHTN all greater than 1.00 mg/L, and the 96 hr¡VLC50 of BPA was 0.58 mg/L. Acetone concentration (1.00 mg/L ) in this study didn¡¦t affect sponge settlement and metamorphosis. Effect of HHCB and AHTN on sponge settlement and metamorphosis concentrations of 0.13, 0.25, 0.50 and 1.00 mg/L was insignificant. In contrast, the settlement rate was decrease by 20 % at treatment of 1.00 mg/L BPA. The metamorphosis rates were also decrease by 20 % and 80 % at concentrations of 0.50 mg/L and 1.00 mg/L BPA. In conclusion, the toxicity of AHTN was greater than that of HHCB to sponge settlement and metamorphosis.
2

The study of filtration efficiency of two intertidal sponges to four algal powders

Tang, Mu-ting 16 February 2011 (has links)
The present study was undertaken to evaluate the filtration efficiency of the bath sponge Spongia ceylonensis (Spongiidae) and fire sponge Tedania klausi (Tedaniidae) collected from Penghu. In the feeding experiements, live and algal powder of Tetraselmis chui (8-16£gm), Chaetoceros muelleri (6-9£gm), Isochrysis galbana (3-7£gm) and Nannochloropsis oculata (2-5£gm) were used to determine the clearance rate of sponges. Sponges S. ceylonensis and T. klausi showed selective feeding under various algal species, concentrations and conditions (live algae or powders). After 90 minutes, the clearance rate of T. klausi fed on N. oculata powder was 71 ml h-1 gDW-1 at algal concentration of 107 cells ml-1, but S. ceylonensis didn¡¦t feed at the same concentration. At 106 cells ml-1 concentrations, the clearance rate of S. ceylonensis fed on live I. galbana was 538 ml h-1 gDW-1 which was higher than T. klausi, i.e. 11 ml h-1 gDW-1. At 105 cells ml-1 concentrations, the clearance rate of T. klausi fed on live T. chui was 431 ml h-1 gDW-1 which was higher than S. ceylonensis, i.e. 23 ml h-1 gDW-1. At 104 cells ml-1 concentrations, S. ceylonensis fed on live T. chui with clearance rate 532 ml h-1 gDW-1, and T. klausi was 315 ml h-1 gDW-1. The results showed differential clearance rates of sponges depend on sponge species, algal species, concentrations and conditions (live or powder). In gerneral, sponge clearance rate is higher when feeds on live algae than algal powders. Although the filtration efficiency of algal powders is low, the advantage of low cost and high accessibility still make algal powder highly competitive in sponge aquaculture industry.

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