Patterns in prawn production across space and time - based on the data emanated from Penaeus monodon and Fenneropenaeus indicus inhabiting the brackish water Chilika lagoon in the Bay of Bengal

摘要

The Chilika lagoon is famous for its prawn fishery that includes commercially important species, namely Penaeus monodon and Fenneropenaeus indicus. A literature search in the Scopus database revealed that a spatiotemporal variability in the production has not yet been carried out microscopically for any species of the Chilika lagoon. We, therefore, examined the pattern of landing biomass of these two species across space and time. We obtained daily production data from each landing center over a period of two years continuously. Thereafter, we computed monthly averages of production using log-transformed data and performed Cosinor rhythmometry with a fixed time window (tau = 365.25 d). We obtained the circannual rhythm parameters, such as Mesor, amplitude, and the peak. The results revealed an interesting phenomenon in the pattern of locations of the peaks of the circannual rhythm in the production of the two sympatric prawn species. A peak partitioning was evident. This implies that the abundance of each species in the identical niche is timed significantly differently leading to the optimization of coexistence. Concluding, there is a necessity to identify the stimuli that influence the observed spatial and temporal heterogeneity in monthly and annual production patterns of the two prawn species.