THE ROLE OF CHELA MORPHOLOGY IN FEMALE MATE CHOICE IN THE RED SWAMP CRAYFISH (PROCAMBARUS CLARKII)

Reproductive behavior is a core component of animal patterns, and mate choice is a key field in behavioral ecology. Mate selection relies on conspecific recognition and is regulated by physiological status and social experience. Females generally invest considerably more in reproductive resources than males, making mate choice a female-dominated behavior with strong preferences. As a typical invasive alien species, the red swamp crayfish (Procambarus clarkii) has drawn wide attention for its reproductive strategies and sexual selection mechanisms. Using sexually mature individuals, we performed binary choice tests to examine the effects of chela size, integrity, and symmetry on female mate choice. A female-female control treatment was set up to separate sexual selection from general social preference. Results showed that females significantly preferred males with larger chela area and intact chelae, while single-chelaed females displayed no obvious preference for chela symmetry in males. In addition, the number of visits and duration of stays in the choice area by female crayfish were not correlated with the chelae area, length, or height of preferred male crayfish. Our findings indicate that chela morphological traits are critical cues for mate choice in P. clarkii, offering empirical support for clarifying its sexual selection and reproductive ecological strategies.