Male internal reproductive structures of european pea crabs (Crustacea, Decapoda, Brachyura, Pinnotheridae): Vas deferens morphology and spermatozoal ultrastructure

Abstract

Pea crabs of the subfamily Pinnotherinae (Pinnotheridae) have a high investment in reproduction and an outstanding reproductive output, probably as an adaptation to the required increase in reproductive rate due to the pinnotherids small size and their parasitic, host-dependant way of life. In the present study, we investigate the male internal reproductive structures and the ultrastructure of spermatozoa of Pinnotheres pisum and Nepinnotheres pinnotheres by histological methods and both scanning- and transmission electron microscopy. In the Brachyura, the male internal reproductive systems generally consist of paired testes and corresponding vasa deferentia where spermatozoa develop and mature. Spermatozoal ultrastructure of the investigated pinnotherids conforms to the thoracotreme type, however, N. pinnotheres has an accessory opercular ring and a periopercular rim, neither of which are present in spermatozoa of P. pisum. Spermatozoa are enclosed within spermatophores in the secretory proximal vas deferens. Two types of secretions were observed in P. pisum and N. pinnotheres: an electron dense substance secreted in the proximal vas deferens involved in spermatophore formation, and large electron-luscent vesicles constituting the seminal plasma in the medial and distal vas deferens. The medial vas deferens is strongly widened compared to other brachyurans to purpose storing spermatophores embedded in seminal plasma. Tubular appendices, which produce and store large amounts of seminal plasma, arise from the distal region of the vas deferens. The appendices extend into the ventral cephalothorax and also in the first pleomere. The latter being an exceptional location for reproductive structures among male brachyurans.

Reproductive traits of the symbiotic pea crab Austinotheres angelicus (Crustacea, Pinnotheridae) living in Saccostrea palmula (Bivalvia, Ostreidae), Pacific coast of Costa Rica

“…Detailed information about many aspects of the association between pinnotherid crabs and their host remain to be studied (McDermott 2006, Peiró et al 2011). Several studies addressed different reproductive aspects of these symbiotic crabs, including the morphology of the reproductive system (Becker et al 2011, 2012, 2013), mating system (Dos Santos-Alves and Pezzuto 1998, Baeza 1999, Peiró et al 2013), intraspecific latitudinal effects on different reproductive attributes (Lardies and Castilla 2001), as well as fecundity (Báez and Martínez 1976, Hines 1992, Cabrera Peña et al 2001, Lardies and Castilla 2001). Our knowledge about energy allocation in embryo production of pinnotherid crabs is scarce; however, results obtained from several species of pea crabs clearly demonstrated that brood masses of these crabs are extraordinarily large in relation to female body size when compared to free-living decapods (Hines 1992, Lardies and Castilla 2001).…”

Male internal reproductive tracts of Côte d’Ivoire brackishwaters crabs, <i>Callinectes amnicola</i>, (de Rochebrune; 1883; Decapoda: Portunidae)

“…Previous results about the testes (d 'Almeida, et al, 2007) are not presented. The male reproductive system in Callinectes amnicola is quite like that found in Callinectes sapidus (Cronin, 1947;Johnson and Otto, 1981), in the blue swimming crab, Portinus pelagicus (Stewart et al, 2010), in Paguristes eremita (Tirelli et al, 2010), in hermit crab Clibanarius sclopetarius, (Santos and Mantelatto, 2011), in Pea Crabs (Becker et al, 2013), in Callinectes ornatus (Do Nascimento and Zara, 2013). Soundarapandian et al (2013aSoundarapandian et al ( , 2013b indicate similar organs in the two species, Charybdis feriata and Portunus pelagicus.…”

“…The vasa deferentia of others adult crabs are divided into ducts or tubules. In Pinnotheres pisum and Nepinnotheres pinnotheres, the anterior vas deferens is composed of coiled tubules (Becker et al, 2013). In Charybdis feriata and Portunus pelagicus the vasa deferentia are pair coiled tubules (Soundarapandian et al., 2013a(Soundarapandian et al., , 2013b.…”

“…However the juveniles are not able to reproduce since they have abdomen attached to the cephalothoracic sternum. The vasa deferentia of adult crabs are most frequently divided into three sections (George, 1963 ;Hinsch and Walker, 1974 ;Hartnoll, 1975 ;Hinsch, 1988a ;Martin Garcia and Fietosa Silva, 2006 ;Erkan et al, 2009 ;Simeo et al, 2009 ;Amadio and Mantelatto, 2009 ;Becker et al, 2013 ;Soundarapandian et al, 2013aSoundarapandian et al, , 2013b. Cronin (1947), Johnson and Otto (1981) mentioned the regionalization of the vasa deferentia according to its tinctorial aspect in the adults of Callinectes sapidus.…”

The ontogeny of the female reproductive system in the parasitic castrator pea crab Calyptraeotheres garthi: Implications for its mating system

“…Later, both sexes moult into a well-calcified 'hard' stage that exhibits free-living adaptations facilitating to leave the host and move in the external environment (Hartnoll, 1972). Males reach sexual maturity in this stage (Becker, Klaus, & Tudge, 2013) but the ovary appears to be not yet developed in hard stage females (Becker, Brandis, & Storch, 2011). Hard-stage females recolonize the host and once inside they moult into the 'post-hard' stages (Atkins, 1926).…”