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Giải quyết của Ấu trùng 4.1 Những lý do để thông qua CHO SỰ TỒN TẠI PERIPHYTONIC Sau khi đi qua giai đoạn phù du (kéo dài trong planktotrophic và ngắn ở ấu trùng lecithotrophic), ấu trùng của động vật không xương sống sẵn sàng để giải quyết và phát triển hơn nữa. Việc chuyển đổi từ sinh vật phù du (cá nổi) để tồn tại periphytonic (xem mục 1.1) là thời điểm quan trọng trong vòng đời của các sinh vật sống ở các bề mặt cứng có nguồn gốc tự nhiên và nhân tạo. Thật vậy, ở nhiều loài, biến. | 4 Settlement of Larvae 4.1 THE REASONS FOR PASSING TO PERIPHYTONIC EXISTENCE Having passed through the planktonic stage prolonged in planktotrophic and short in lecithotrophic larvae the larvae of invertebrates get ready for settlement and further development. The transition from planktonic pelagic to periphytonic existence see Section 1.1 is the key moment in the life cycle of organisms inhabiting hard surfaces of natural and artificial origins. Indeed in many species the metamorphosis into an adult is possible only on a hard surface. In some cases in the larvae of those species whose adults are attached metamorphosis may also end during the free-swimming stage according to laboratory observations Berrill 1931 Chia and Bickell 1978 Cloney 1978 . In these cases the organisms do not establish contact with the substrate and if they were in the sea milieu they surely would be quickly eliminated. The settlement of propagules larvae and spores is an active behavioral process however it is also influenced by environmental factors and depends on the properties of the hard surface. The larvae may settle repeatedly exploring different surfaces and becoming part of the plankton until they find a favorable substrate that is to say they actively choose their permanent habitat. Settlement may be considered as one of the colonization processes which include passing from the plankton to the hard surface settlement proper and crawling along it until the beginning of attachment in sessile species metamorphosis in motile species or returning to the plankton. As the propagules move along the surface they explore it and determine whether that surface should be chosen or rejected as a substrate. For individuals that have already passed through metamorphosis during their planktonic life settlement is considered to be only a sinking to the surface accompanied by the exploration and choice or rejection of a substrate. Some other workers e.g. Scheltema 1974 Chia 1978 Burke 1983 hold .
