Maternal Traits Are Associated With Hemolytic Capacity in Sea Turtle Hatchlings, Independently of Systemic Immune Stimuli

Infectious diseases represent a major threat to the survival of endangered sea turtles. The immune response in these animals is configured early in development and is heavily influenced by the incubation environment. While maternal traits are known to influence offspring immune function in some reptiles, their role in shaping immune responses in sea turtle hatchlings remains poorly understood. The hemolytic capacity, a key component of the innate immune system, shows stability across incubation environments, suggesting that it might be shaped by maternal factors rather than by environmental variation. Herein, the relationship between the hemolytic capacity of hatchlings challenged with lipopolysaccharide (LPS) and maternal characteristics, including hemolytic response and body size, was studied. Blood samples and morphologic measurements were collected from nesting females over 2 years. Each clutch was entirely relocated to individual shaded nests for incubation. Upon emergence, one hatchling per nest was injected intraperitoneally with phosphate-buffered saline (PBS) and another hatchling with LPS. 4 h later, hatchlings were euthanized and blood samples were collected. The results showed that hatchling's hemolytic capacity was positively associated with maternal hemolysis and body mass, but negatively linked to maternal straight carapace length. Lipopolysaccharide challenge did not significantly modify the hemolytic capacity of hatchlings. Although based on a limited sample size due to the species' protected status and technical constraints of ecoimmunological research in wild animals, these findings suggest a possible influence of maternal attributes on offspring immune function. They also suggest that hemolytic capacity is a robust early-life immune defense in hatchlings.