Putative mating plugs of harvestmen (Opiliones, Laniatores)

VICTOR ROBERT TOWNSEND; ABEL PÉREZ GONZÁLEZ; PROUD, DANIEL N.

ZOOLOGISCHER ANZEIGER

ELSEVIER GMBH

Año: 2019

0044-5231

In many species of scorpions (Order Scorpiones) and spiders(Order Araneae), mating plugs (gel-like or sclerotized) are deposited inthe female reproductive tract, minimizing the possibilities of furthermatings. Although harvestmen (Order Opiliones) have direct sperm transfervia copulatory organs (penis or spermatopositor in the male andovipositor in the female), prior studies of the reproductive anatomy ofthese arachnids have not reported the occurrence of these structures.With the aid of scanning electron microscopy, we observed distinct massesof amorphous, gel-like material in the distal openings of the ovipositorsof six different specimens including representatives of the familiesCosmetidae (Cynorta marginalis and Flirtea picta), Gonyleptidae(Discocyrtulus bresslaui and Geraeocormobius sylvarum), Kimulidae (Kimulasp.) and Metasarcidae (Metasarcus clavifemur). Dissection of one of thesestructures from a specimen of the cosmetid harvestman C. marginalisrevealed a detailed endocast of the internal surfaces of the femalereproductive tract. Considerable interspecific variation in the relativesizes and shapes (smooth and rough) of the amorphous gel-like structureswere observed, but evidence of sclerotized components (i.e., parts of themale genitalia) was not found. The location and morphology of the gellikestructures are consistent with observations of mating plugs in otherarachnids. The composition, source (male, female or both) and functionof these amorphous gel-like structures (i.e. effective matting plug) requires additional study.