Studies on prevention of fouling by barnacles

在盐度27左右、水温21~25℃、自然光照条件下，可实现无节幼体的日孵化。每周至少需要交换一次海水。一天几个小时让成虫的幼虫干涸是很重要的。一天内，八百多只孵化出来的卤虫应该被赠送给一个藤壶。孵化的藤壶无节幼体可在22~25℃内被钙化角毛藻作为食物变质为鲤鱼。用于生物测定的鲤鱼是在5℃下变质后保存2~10天的。化验容器采用聚苯乙烯或玻璃培养皿。在测试批的容器内涂上溶解的测试物，让溶剂挥发。20条鲤鱼和5毫升海水被引入到容器中。海水是盐度在20以上，用玻璃纤维过滤器(GF/C)过滤，紫外线照射。在连续黑暗和25℃下孵化3~4天，孵化结束时计数附着的鲤鱼和幼虫的数量。各种防污剂的筛选(1)通过在底物上应用防污剂来防止污垢。在所测试的各种物质中，猪肝脂肪酸(FAPL)和海藻酸钙被发现具有较高的防污活性，而不会杀死幼虫。由于后者抑制了80%以上的鲤鱼的沉降，因此目前正在木苏湾进行海洋防污活性的测试。(2)将防污剂溶解到海洋中防止污垢。通过向海水中充气碳酸气体，试验期间海水的pH值降至6.6以下，对鲤鱼的沉降至少有4天的完全抑制作用。

1. Reproductive condition for Balanus amphitrite.It became possible to get hatched nauplii every day under the following rearing conditions : Salinity is about 27, water temperature between 21 to 25 C, and natural light condition. Exchange of seawater is needed once a week at least. It is essential to dry up of brood adults for several hours a day. More than eight hundred of hatched Artemia should be given for a barnacle in a day.2. Methods of bioassay using B. amphitrite cyprids.Hatched barnacle nauplii could be metamorphosed to cyprids by Chaetoceros calcitrans as food in 22 to 25 C. The cyprids for bioassay are those kept in 5 C for 2 to 10 days after the metamorphose. Assay vessel is used polystyrene or glass petri dishes. Inside the vessels of test lot are coated with solubilized test substance, and let solvent volatilize. Twenty cyprids and 5 ml seawater are introduced to the vessel. The seawater is that the salinity is above 20, filtered with glass filter (GF/C) and UV radiated. The vessels are incubated for 3 to 4 days under continuous dark and 25 C. Number of attached cyprid and juvenile are counted at the end of incubation.3. Screening of various substances as antifoulants(1) Prevention of fouling by applying antifoulant to the substratum.Among the various substances tested, fatty acid from porcine liver (FAPL) and calcium alginate were noticed to have high antifouling activity without killing the larvae. Since the latter inhibited settlement of cyprids more than 80 %, the antifouling activity in the sea is now testing in Mutsu Bay.(2) Prevention of fouling by dissolving antifoulant to the sea.Carbonic acid was tested instead of chlorine used as dissolving antifoulant before. By aerating carbonic acid gas into seawater, pH of the seawater during test period decreased below 6.6, as a result, settlement of cyprids was perfectly inhibited for at least four days.