clasper

n. 扣子, 抱茎卷须, 鳍脚
【医】 抱握器, 交接突起, 鳍脚

clasp.er

n.（名词）
One that clasps.
紧抱的人
Any of the appendages of the male of certain insects and crustaceans that are used during copulation to hold the female.
抱握器：一种雄性昆虫或雄性甲壳类动物的悬垂物，在交配中用来持住雌性
A posterior extension on each of the pelvic fins of male elasmobranch fishes that aids in the transmission of sperm during copulation.
交合突，鳍脚：雄性板腮亚纲鱼的每支腹鳍的前端延伸，在交配中辅助精子的传递