Structure and seasonal dynamics of penaeid shrimp post-larvae and juvenile assemblage in Alamparai estuary, Southeast coast of India
Volume 65 Issue 1
K. Silambarasan, P. Senthilkumaar, A. Sundaramanickam and E. Rajalakshmi
doi:10.6024/jmbai.2023.65.1.2288-04
Abstract
The structure and seasonal dynamics of penaeid shrimp post-larvae and juvenile assemblage in the Alamparai estuary were studied for two years from April 2012 to March 2014 concerning environmental characteristics such as rainfall, water temperature, salinity, pH, dissolved oxygen, nitrite, phosphate and silicate. A total of six commercially important species of penaeid shrimps viz., Penaeus indicus, P. monodon, P. semisulcatus, Metapenaeus dobsoni, M. monoceros and M. brevicornis were recorded. The post-larvae and juveniles of P. indicus were the most abundant throughout the year, with two peaks post-monsoon (226.3±154.4 N/m2 ) and pre-monsoon (136.7 ± 93.1 N/m2 ) at all stations. M. brevicornis post-larvae and juveniles were dominant in post-monsoon (140.7±89.7 N/m2 ) at all stations. Both P. monodon (120.0±102.2 N/m2 ) and P. semisulcatus (29.3±17.2 N/m2 ) were predominant in monsoon season. The peak abundance of M. monoceros post-larvae and juveniles was recorded in pre-monsoon (40.7±33.6 N/m2), whereas that of M. dobsoni was predominant in summer (40.3±45.1 N/m2). Moreover, canonical correspondence analysis indicated that nitrite, phosphate and silicate, along with water temperature, pH, salinity and dissolved oxygen, were the main driving forces for these temporal variations in species distribution and community composition of penaeid shrimp post-larvae and juveniles. Finally, correlation analysis showed a significant correlation with water temperature, dissolved oxygen, salinity and silicate.
