Zhang B.,Shenzhen Museum |
Lin W.,Shenzhen Museum |
Wang Y.,Shenzhen Museum |
Xu R.,Sun Yat Sen University
Turkish Journal of Fisheries and Aquatic Sciences | Year: 2010
In order to investigate the effects of artificial substrates on shrimp growth, spatial distribution and non-specific immunity factors, such as phenoloxidase (PO), superoxide dismutase (SOD), peroxidase (POD), antibacterial activity (Ua), lysozyme (Ul) and hemolysin activity, 30-day old Litopenaeus vannamei post-larvae (PL30) were reared intensively for 60 days at a density of 500 shrimp m-2 of water surface area in each of 8 PVC aquaria (1.0×1.0×1.5m, water surface area 1 m-2, water volume 1000 L). Two aquaria containing no artificial substrate were a control group, and 1, 2 and 3 artificial substrates were present in other 6 aquaria. Shrimp growth (gain in weight), survival and yield increased significantly (P<0.05) when more artificial substrates were added. The percentage of shrimp on artificial substrates increased with increasing number of artificial substrates and rearing time. As for non-specific immunity factors, the activities of PO, Ua, Ul, POD, SOD and hemolysin of groups with artificial substrates were lower than those of control group significantly (P<0.05). With an increasing number of artificial substrates, the activities of PO, Ua, Ul, POD and hemolysin reduced, but SOD activity increased. It was suggested that artificial substrates could alleviate the negative effect of the high stocking density by providing well living environment for shrimp. © Published by Central Fisheries Research Institute (CFRI) Trabzon.
Ye Y.,Shenzhen Museum |
Zhang B.,Shenzhen Museum |
Zhang R.,Guangdong Ocean University |
Wang K.,Guangdong Ocean University
Turkiye Entomoloji Dergisi | Year: 2015
Fumigation with essential oils from plants is a popular, safe, and environment friendly alternative tool for pest control in stored products. To provide a range of choices and to reduce costs in a variety of contexts, more plantderived pest management control agents from local plant species should be identified and more effective fumigant methods must be developed. This paper describes the toxic effects of the essential oils from Perilla frutescens (L.) Britt. (Lamiaceae) as a fumigant, either alone or in combination with CO2-enriched modified atmospheres, for the control of Dermestes maculatus Degeer. The essential oils showed strong fumigant activities against this pest. After six hours of fumigation with the essential oils at a concentration of 0.10 μL/L, mortalities for each life stage was 73.0% (adult), 61.2% (larva), 39.6% (pupa) and 55.4% (egg). Furthermore, the effects were enhanced when CO2 levels were increased. At an essential oil concentration of 0.08 μL/L in the treatment group with 60% CO2, mortality rate for all life stages was 100%. We propose that CO2 concentration plays a direct role during joint fumigation, as atmospheres with high CO2 levels cause the permanent opening of insect spiracles, thereby increasing the uptake of plant essential oils.