The contribution of different food sources to the diet of Parasesarma persicum Naderloo and Schubart 2010 in the mangrove ecosystem of Hara Biosphere Reserve; a stable isotope approach

The current study aimed to determine the isotopic composition of different food sources and their contribution to the diet of Parasesarma persicum inhibiting a mangrove ecosystem in the Persian Gulf. The potential food sources, i.e., Avicennia marina green and yellow leaves, Particulate Organic Matter (POM), Microphytobenthos (MPB), and Sediment Organic Matter (SOM) were collected for stable isotope analysis. The most 13C-depleted values were observed for mangroves with mean δ13C values of -28.31‰ and -28.05‰ for green and yellow leaves, respectively. The mean δ15N values of mangrove leaves were 3.79‰ and 5.08‰ for green and yellow leaves, respectively. The crab P. persicum had an average value of carbon and nitrogen isotopes of -19.48‰, and 4.18, respectively. The results showed that the A. marina yellow leaves (28.1%) and SOM (13.3%) had the highest and lowest contribution to the diet of P. persicum in the mangrove ecosystem, respectively. The results emphasize the role of mangroves in supporting estuarine food webs. This also further confirms the ecological role of sesarmid crabs as ecosystem engineers in mangrove ecosystems.