Fungal Infection in Green Sea turtle, Chelonia mydas, Eggs and nest soil at Setiu and Chagar Hutang, Malaysia

Green turtles Chelonia mydas is a breeding species of sea turtles in Malaysia. Fungal infections pose serious threat to eggs and nest productivity. Limited surveys were conducted in Malaysia to study the relationship... [ view full abstract ]

Green turtles Chelonia mydas is a breeding species of sea turtles in Malaysia. Fungal infections pose serious threat to eggs and nest productivity. Limited surveys were conducted in Malaysia to study the relationship between fungal infection and types of incubation practices. This research was conducted at both Penarik Turtle Hatchery, Setiu (ex-situ incubation site) and Chagar Hutang, Redang Island (in-situ incubation site) to identify and compare number of fungal species present in green turtle nests (egg shells and soil), and to relate infection to hatching success. Fungi from both eggshell and sand samples were cultured separately in Potato Dextrose Agar (PDA). Once pure fungal colonies were obtained, slides were prepared for microscopic morphological analysis. Four species of fungi were isolated from both sites which were, Aspergillus niger, Fusarium sp., Aspergillus sp., and Penicillium sp. An additional unidentified species was also found among slides of Aspergillus niger. The most dominant species of fungi in both sites were Aspergillus niger. A Spearman correlation test between number of fungal species and hatching success showed negative correlation between these variables in Setiu but not at Chagar Hutang. This shows that in an in-situ incubation site (Chagar Hutang), the number of isolated fungal species had no effect on hatching success, while at an ex-situ incubation site (Setiu) a higher number of isolated fungi resulted in lower hatching success. Handling of eggs by rangers in Setiu may contribute to additional fungal species there.