Habitat Suitability and Glacial Refugia of the Turbid-Water Coral Turbinaria peltata Across the Indo-West Pacific Ocean Based on MaxEnt Modeling

As a typical turbid-water reef coral, Turbinaria peltata shows strong tolerance to high temperature and sediment disturbance, yet its basin-scale niche drivers and glacial distribution dynamics across the Indo-West Pacific remain unclear. Here we constructed optimized MaxEnt models using 322 independent distribution points and 21 non-collinear marine environmental variables for modern and Last Glacial Maximum (LGM) scenarios. The model average test AUC reached 0.9874, showing excellent predictive performance. Water depth acted as the most influential predictor in the model (contribution = 44.76%), followed by distance to land and warm-season sea temperature; habitat suitability had an extremely weak linear correlation with depth (R2 = 0.05), consistent with a strongly nonlinear response along the depth gradient. Modern suitable habitats are mainly concentrated in Southeast Asia and northern Australia, with the South China Sea at the species’ northern margin. Massive shelf exposure during the LGM severely shrank its range, and three potential glacial refugia (northeastern Australia, Madagascar coast, Red Sea–Gulf of Aden) were identified. These refugia may have maintained coral populations through glaciation and contributed to the present-day biogeographic patterns of this species. Our findings provide quantitative spatial evidence for targeted conservation of nearshore stress-resistant corals under climate warming.