Estrutura populacional do camarão dulcícola macrobrachium amazonicum (heller, 1862) no Paraná do Ramos, Boa Vista do Ramos/Am

Abstract

The present study analyze a population structure of the Macrobrachium amazonicum, in Paraná do Ramos, Boa Vista do Ramos - AM, based on the frequency distribution in size classes and sex ratio. Collections were carried out monthly in period of the August 2023 to July 2024. A total of 562 specimens of M. amazonicum were analyzed, 272 males and 290 females, of which 12 were ovate. For females, the smallest size (CC) found was 4.24 mm and the largest 15.92 mm. For males, the smallest value was 6.19 mm and the largest 16.18 mm of carapace. Males and females of the collected species showed no statistical differences between the average size, presenting 11.55 - CC mm and 11.52 - CC mm, respectively (p < 0.05). The frequency in the distribution by length class fluctuated around the annual pattern. Males were more frequent in larger size classes during the period of highest rainfall (January to April). Females showed greater variation in size classes during the months of September to December/2023, being frequent in classes that ranged from 4-5 mm to 15-16 mm, with juveniles, adults and ovigerous occurring in this period. For both sexes, the recruitment of juveniles showed peaks in different periods. Ovigerous females were not found in all months of collection, being found only in the months of October/23, March, June and July/24. The observed sex ratio was 1:1, showing proportionality between the sexes, with the exception of the months of January to April/24 where male individuals were more abundant.