Boa constrictor constrictor reproductive biology aspects: the testes histological study in the reproductive periods of quiescence and maximal activity

ABSTRACT These snakes belong to the second largest group within the reptiles, being able to present seasonality regarding spermatogenesis, with discontinuous or continuous production. The present study aims to characterize Boa constrictor constrictor reproductive biology aspects from histological findings in testicles during periods of maximum activity (period of gametogenesis) and quiescence. The testicles of two specimens of Boa c. constrictor (7767 and 11752) were cut to a thickness of 3μm in microtome, stained with 1% toluidine blue, photodocumented and described. The spermatozoa presence in the seminiferous tubule lumen in individual 7767 indicates a period of maximum gametogenesis, whereas the seminiferous tubules lumen is not very evident without spermatozoa and the absence of dividing gametic cells characterizes individual 11752 in the quiescent period. Through the histological findings we concluded that Boa c. constrictor presents seasonality in relation to gametogenesis, and the pattern of reproductive seasonality observed along with the period of copulas reported in the literature resembles the pre-nuptial pattern.

摘要 此类蛇隶属于爬行类第二大类群，其精子发生存在季节节律，可表现为间断式或连续式的精子生成。本研究旨在通过红尾蚺指名亚种（Boa constrictor constrictor）睾丸组织在最大活性期（配子发生期）与静止期的组织学特征，阐明其繁殖生物学特性。研究对两份红尾蚺指名亚种（Boa c. constrictor）标本（编号7767与11752）的睾丸进行切片处理：使用切片机将组织切成3μm厚的切片，以1%甲苯胺蓝染色，随后进行拍照记录并开展形态描述。编号7767的标本其生精小管管腔内存在精子，表明该个体处于配子发生最大活性期；而编号11752的标本生精小管管腔不明显且无精子存在，同时未观察到正在分裂的生殖细胞，这标志其处于静止期。基于上述组织学观察结果，本研究得出结论：红尾蚺指名亚种的配子发生存在季节节律；结合文献中报道的交配期来看，其观测到的繁殖季节节律模式属于婚前期模式。