Morphological analysis of the female reproductive system of Stenorhynchus seticornis (Brachyura: Inachoididae) and comparisons with other Majoidea

Abstract

We examined the female reproductive system of the yellowline arrow crab Stenorhynchus seticornis by means of histological and histochemical techniques. Mature specimens obtained in the field were kept in the laboratory for mating experiments. After 24 h, newly mated females were dissected, and their reproductive trait routinely processed for embedding in historesin. The specimens examined each possessed a pair of kidney‐shaped seminal receptacles (SR), and these we classified as ventral type, based on the location of the oviduct opening. The mesodermal dorsal region (DR) of SR consisted of a stratified epithelium with scaly cells, while the ectodermal ventral region (VR) was composed of a simple epithelium covered by a cuticle. The oviduct opened at the transition region (TR) between DR and VR and had no velum. The simple epithelium of TR had more folds on the face of the oviduct opening. The vagina exhibited the same features as the TR epithelium and was contiguous to VR, anchored by muscles. In the lumen, from one to three strata of sperm packets were observed, the dorsal one containing free sperm, and the most ventral stratum, spermatophores. An acidophilic glycoprotein layer enclosed the strata. Spermatophores in the ventral stratum were enclosed in a voluminous secretion, composed by acid polysaccharides most likely from the last male mated. The ventral‐type receptacle, stratified sperm packets, and polyandry, usually observed in females of Majoidea, suggest the occurrence of sperm competition in S. seticornis, favoring the sperm of the last male mated, as its sperm mass is located near the opening of the female oviduct.

Male reproductive system of the arrow crab Stenorhynchus seticornis (Inachoididae)

“…The secreted material that surrounds sperm packages in the SR of females of S. seticornis (Antunes et al. ) has the same histochemical features as the secretions of the AG and PVD of males investigated in the present study. Such similarities observed in S. seticornis support the hypothesis that the secretions produced by the accessory glands in males delimit the sperm packets in layers, and are transferred together with the spermatophores at mating.…”

“…Although genetic analyses of broods from most Brachyura species demonstrate multiple paternity, the sperm stratification observed in the SR (attributed to dislodgement of the previous ejaculates to the dorsal region of the SR by the last male to mate) in females of S. seticornis (Antunes et al. ) can contribute to a single paternity of the brood, specifically in those species with ventral SR (Birkhead et al. ; Beninger et al.…”

The morphology of the reproductive system in the crab Percnon gibbesi (Decapoda: Brachyura: Grapsoidea) reveals a new combination of characters in Thoracotremata

“…The histological properties of the holocrine transfer tissue are consistent among thoracotremes (Lee & Yamazaki, ; Becker et al, ; de Souza et al, ) and very similar to the secretory tissues that line the seminal receptacles and contain the oviduct orifice in heterotremes (Beninger, Lanteigne, & Elner, ; Lanteigne, Beninger, & Gionet, ; Sal Moyano, Gavio, & Cuartas, ; Zara, Raggi Pereira, & Sant'anna, ; Antunes, Zara, López‐Greco, & Negreiros‐Fransozo, ). Due to the shared histological characters and their association with the oviduct orifice, both tissues are most likely homologous.…”

Morphology of the female reproductive system of three dorippid crabs (Crustacea: Decapoda: Brachyura: Dorippidae) and the role of accessory cuticle structures associated with seminal receptacles

“…; Antunes et al. ). This is also the case in the dorippid species we investigated, regardless of whether a cuticle lining of the spongious tissue is present.…”

“…During ovulation, the oviducts lead the mature oocytes from the ovaries into the SRs where they come in contact with the stored spermatozoa, and fertilization is initiated (Diesel 1989;Lee & Yamazaki 1990;Sainte-Marie & Sainte-Marie 1998). The SRs are equipped with glandular tissues, which usually line the dorsal area, while the ventral part and the adjoining vagina are cuticle-lined (e.g., Diesel 1989;Beninger et al 1993;Jensen et al 1996;Lanteigne et al 1996;Sant'Anna et al 2007;L opez-Greco et al 2009;Lautenschlager et al 2010;Becker et al 2011;de Souza et al 2013;Zara et al 2014;Vehof et al 2016;Antunes et al 2016;de Souza et al 2017). Diesel (1991) distinguished two types of SRs, a ventral and a dorsal type.…”