Chinese Academy of Fishery SciencesPearl River Fisheries Research Institute’s Fishery Resources Ecology Research Team has made new progress in the intra-species competition of river fish. Related results”Individual dietary specialization reduces intraspecific competition, rather than feeding activity, in black amur bream (Megalobrama terminalis)” were published on”Scientific Reports”. The first author and corresponding author of the article are Assistant Researcher Xia Huguo and Researcher Li Xinhui (Director) ). Article link https://doi.org/10.1038/s41598-020-74997-8.
The competitive process in population ecology affects the spatial and temporal distribution pattern of individuals, and its operation process has always been an issue of great concern to ecologists. Due to the same growth and reproduction requirements among individuals, intraspecific competition is generally more intense than intermediate competition. Individual specialization refers to the use of a small part of the basic resources of the population by some members of the population, which are widely present in wild animal populations, even in different genders or age classes. Intraspecies and interspecies competition, the diversity of available resources, predation, etc. will all affect the intensity of individual population specialization. The individual specialization and high plasticity of the feeding rhythm are common in natural populations. However, the role of these two in intraspecific competition remains unclear. The study used continuous day and night sampling, microscopic examination and stable isotope methods to study the feeding rhythm, food composition, niche width, niche overlap, and individual specialization of Guangdong bream. The results showed that Guangdong bream was in the process of individual development. There are changes in food preference and individual specialization, and the niche width of adult fish is significantly higher than that of juvenile fish. There is no significant difference in eating rhythm between different size groups, and the eating activity is only significantly related to time. There is strong food competition between different individuals of Guangdong bream, and the individual specialization of small individuals is significantly higher than that of large individuals. There is a positive correlation between the degree of individual specialization and the similarity of eating habits. The above results indicate that Guangdong bream reduces intraspecies competition through individual specialization, rather than through changes in feeding rhythm.