Pattern of hemipenis use in the male lizard Anolis sagrei after unilateral castration

This study investigated whether sensory feedback from the testis and sperm duct determines the pattern of hemipenis use in male A. sagrei. Males were unilaterally castrated and observed in copulations that began 2 wk after surgery. Independent of whether the left or right testis had been removed, unilaterally castrated males showed no significant difference in the frequency of use of either the left or right hemipenis in either of two copulations separated by 1–3 h or in a series of 16 copulations over 16 days. Thus, males did not preferentially use the hemipenis leading to the intact testis. Moreover, unilaterally castrated males showed significant alternation in the use of the hemipenes, not only in the two successive copulations, but also in the series of 16 copulations. The mass of the sperm ducts differed significantly after the last of the copulations. The mass of ducts that led to a testis was significantly greater than that of ducts not leading to a testis. These findings suggest that the pattern of alternation of hemipenis use in male A. sagrei is not determined by sensory input from either the testis or the sperm duct.