Characterization of pink pigmented lesions and its associated inflammatory-like responses that influence resilience in a scleractinian coral
Abstract
The reef-building Scleractinian coral Porites lutea is widely affected by abnormal pink inflammations including Pink line syndrome (PLS) and Pink spot (PS). However, the immune responses of these non-normal pink pigmented tissue lesions in P. lutea are poorly understood. This study aimed to investigate the histopathological changes, innate immune responses, and microbial community shifts associated with pink-pigmented lesions in P. lutea in order to better understand disease severity and recovery. Healthy and pigmented tissues were analyzed using comparative histopathology, microscopy, enzymatic assays, protease profiling, and genome-level screening of microbial communities and functional response genes. Histopathology revealed fragmentation, degradation, and disintegration of the polyp gastrodermal architecture and mesoglea in pigmented tissues. Bacterial colonizers occurred in both healthy and pigmented tissues, whereas ciliates were detected only in the lesions. Pigmented tissues also showed reduced numbers and surface area of symbiotic algae, ova, and mesenterial filaments, indicating compromised survival and fecundity. Increased melanin deposition and mucus secretion, together with elevated phenol oxidase, peroxidase, superoxide dismutase, catalase, and protease activities, indicated strong innate immune and oxidative stress responses in inflamed tissues. Genome-level screening further revealed shifts in microbial communities and stress-related functions between healthy and pigmented tissues. These findings show that pink inflammatory lesions in P. lutea are associated with major tissue damage, immune activation, and microbial reorganization, and provide insight into the resilience of this massive coral under biotic and abiotic stress.
URI
https://www.sciencedirect.com/science/article/pii/S0022201126001059http://drs.nio.res.in/drs/handle/2264/9653
Collections
- Scholarly literature [9297]

