Damselfish energetics from multiple shallow reef sites in the Caribbean between June 2016-2019

Food webs are a complex array of trophic interactions. With a heavy emphasis on \"classic\" predator-prey interactions, most studies of trophic dynamics completely omitted parasitic interactions. However, recent work has shown that parasites contribute significantly to many aspects of trophic structure. In the current study, I have estimated the biomass transfer by parasites and predators from members of the genus Stegastes from multiple sites in the Caribbean. These results show that most of the parasite-driven biomass transfer comes from ectoparasitic gnathiid isopods. Moreover, I have found that predation rates are high for juveniles and decrease as they become adults, while the opposite is true for parasitism. Despite this, more biomass is being transferred from adults than younger stages via both predation and parasitism. I also show that in coral reef ecosystems, parasitism can transfer more biomass than predation for adult Stegastes. These results highlight the contribution of parasites to energy flow in coral reef environments and suggest that they must be considered in future food web studies.

食物网是由各类营养级交互作用构成的复杂网络。过往研究大多侧重‘经典’的捕食者-猎物互作，绝大多数营养动态相关研究完全忽略了寄生互作。然而，近期研究表明，寄生生物对营养结构的诸多方面均具有显著贡献。在本研究中，笔者针对加勒比海多个采样点的眶锯雀鲷属（Stegastes）物种，估算了寄生生物与捕食者介导的生物量传递量。研究结果显示，由寄生生物介导的生物量传递，绝大多数来自外寄生性颚虱等足类（gnathiid isopods）。此外，笔者发现，眶锯雀鲷幼体的捕食压力较高，且随个体发育为成体后捕食压力逐渐降低；而寄生压力则呈现相反的变化趋势。尽管如此，通过捕食与寄生两条途径，成体个体所介导的生物量传递量仍高于幼体阶段。本研究还证实，在珊瑚礁生态系统中，对于成体眶锯雀鲷而言，寄生途径介导的生物量传递量高于捕食途径。上述研究结果凸显了寄生生物在珊瑚礁生态系统能量流动中的重要贡献，并指出未来食物网相关研究必须将寄生生物纳入考量范畴。