South Adam, Sota Teiji, Abe Norio, Yuma Masahide, Lewis Sara M
Department of Biology, Tufts University, Medford, MA 02155, USA.
J Insect Physiol. 2008 May;54(5):861-6. doi: 10.1016/j.jinsphys.2008.03.008. Epub 2008 Mar 26.
During mating, many male insects transfer sperm packaged within a spermatophore that is produced by reproductive accessory glands. While spermatophores have been documented in some North American fireflies (Coleoptera: Lampyridae), little is known concerning either production or transfer of spermatophores in the aquatic Luciola fireflies widespread throughout Asia. We investigated this process in Japanese Luciola lateralis and L. cruciata by feeding males rhodamine B, a fluorescent dye known to stain spermatophore precursors. We then mated males with virgin females, and dissected pairs at various timepoints after mating. In both of these Luciola species, spermatophores were produced by three pairs of male accessory glands and were transferred to females during the second stage of copulation. Male spermatophores were highly fluorescent, and were covered by a thin outer sheath; a narrow tube leading from an internal sperm-containing sac fit precisely into the female spermathecal duct, presumably for sperm delivery. Both L. lateralis and L. cruciata females have a spherical spermatheca as well as a highly extensible gland where spermatophore breakdown commences by 24h post-mating. Similar reproductive anatomy was observed for both sexes in Luciola ficta from Taiwan. These results suggest that nuptial gifts may play an important role in many firefly-mating systems.
在交配过程中，许多雄性昆虫会传递包裹在精荚中的精子，精荚由生殖附属腺产生。虽然在一些北美萤火虫（鞘翅目：萤科）中已记录到精荚，但对于广泛分布于亚洲的水生熠萤属萤火虫的精荚产生或传递情况却知之甚少。我们通过给雄性日本扁萤和条背萤喂食罗丹明B（一种已知可对精荚前体进行染色的荧光染料）来研究这一过程。然后让雄性与未交配过的雌性进行交配，并在交配后的不同时间点解剖配对的萤火虫。在这两种熠萤属萤火虫中，精荚均由三对雄性附属腺产生，并在交配的第二阶段传递给雌性。雄性精荚具有高度荧光性，且被一层薄薄的外层鞘所覆盖；一根从内部含精子囊引出的细管精确地插入雌性受精囊导管，大概用于输送精子。日本扁萤和条背萤的雌性都有一个球形受精囊以及一个高度可伸展的腺体，交配后24小时精荚开始在该腺体中分解。在台湾的拟熠萤中，两性均观察到类似的生殖解剖结构。这些结果表明，婚飞礼物可能在许多萤火虫交配系统中发挥重要作用。
