Nhiều loài cá rạn san hô chuyển sang hình thức tập hợp tại các trang web dự đoán được và thời gian ngắn ngủi để đẻ trứng. Theo mục đích của tổng quan này, tập hợp sinh sản được định nghĩa là bất kỳ tập hợp tạm thời được hình thành bởi các loài cá đã chuyển đổi cho mục đích cụ thể của sinh sản. Tập hợp sinh sản được biết là được hình thành bởi 164 loài từ 26 gia đình của các loài cá rạn san hô, nhưng con số thực tế có thể cao hơn nhiều | SPAWNING AGGREGATIONS OF CORAL REEF FISHES CHARACTERISTICS HYPOTHESES THREATS AND MANAGEMENT JOHN CLAYDON Department of Marine Biology James Cook University Townsville Queensland 4811 Australia E-mail Abstract Many coral reef fishes migrate to form short-lived aggregations at predictable sites and times in order to spawn. For the purposes of this review such spawning aggregations are defined as any temporary aggregations formed by fishes that have migrated for the specific purpose of spawning. Spawning aggregations are known to be formed by 164 species from 26 families of coral reef fishes but the actual number is likely to be much higher. Aggregative spawners share a number of common features. 1 All except one species release pelagic eggs. 2 They tend to have large body sizes. 3 They are more abundant in some phylogenetic groups such as the Labridae Scaridae Serranidae Acanthuridae and Lutjanidae although they are relatively uncommon in all but the least speciose families of Albulidae Chanidae Gerreidae and Scombridae. 4 They are more likely to come from large populations with high densities. However these features are not independent and their relative importance is not easily assessed. Known spawning aggregations form at the same sites over successive predictable spawning seasons. However from the limited data presently available spawning aggregations do not appear to form consistently on predictable reef structures. The periodicity of spawning aggregations can differ greatly for the same species with relatively small degrees of spatial separation. A number of hypotheses have been proposed to explain why when and where spawning aggregations are formed. These include those that predict that the phenomenon of aggregative spawning 1 reduces predation on spawning adults and their eggs the predator satiation hypothesis 2 increases the degree of mate selectivity and 3 allows individuals to assess sex ratios of populations and make decisions on
