Spermiogenesis and sperm structure in the shrimp Parapenaeus longirostris (Crustacea: Dendrobranchiata): comparative aspects among decapods

Abstract

Early spermatids of the dendrobranchiate shrimp Parapenaeus longirostris (Lucas, 1846) have a spherical nucleus with large patches of heterochromatin, surrounded by a cytoplasmic mass that contains the conspicuous proacrosomal vesicle. The highly polarized mid spermatid mainly consists of the nuclear region, displaying a discontinuous nuclear envelope, and a large proacrosomal vesicle located at the opposite side of the cell. The most recent spermiogenic transformations primarily concern elongation of the proacrosomal vesicle to form a tapering spike. This results in the typically tack-shaped sperm of natantian decapods. The initial steps of spermiogenesis in the two studied dendrobranchiates prove to be parallel to reptant spermiogenesis in some respects, namely rupture of the nuclear envelope, chromatin decondensation and differentiation of electron-dense regions within the proacrosomal vesicle content. Specifically, whereas the anteriormost condensation gives rise to the operculum in brachyurans, in dendrobranchiates it becomes the apical portion of the spike. Despite an unquestionable morphological similarity between the sperm of carideans and dendrobranchiates, spermiogenesis in both groups displays meaningful differences. Spermatids of caridean shrimps lack a distinct proacrosomal vesicle. In the course of spermiogenesis, the spike arises from aggregated cytosolic materials; hence it is not membrane-bound. Unlike in other decapods, caridean sperm do not undergo a conventional acrosome reaction, since exocytotic events are not involved in this process. The above arguments suggest that, in the Decapoda, separation into three sperm classes is more suitable than the two traditionally accepted classes. The dendrobranchiate and reptant sperm types share a humCommunicated by S. M. P6r6s, Marseille A. Medina

A transmission electron microscopy investigation: the membrane complex in spermatogenesis of Fenneropenaeus chinensis

“…Membrane complex originated from cytoplasm occurs during the spermiogenesis of F. chinensis, and it is comprised derivative of endoplasmic reticulum, mitochondria and nuclear membrane which is similar to that reported in most species (Langreth 1969;Reger 1970;McKnight and Hinsch 1986;Du et al 1988;Medina 1994;Li 1995;Tudge et al 2001;Zhu et al 2002;Medina et al 2006). The only difference lies in the typical annular lamina bodies wound from the endocytoplasmic reticulum in the membrane complex of F. chinensis.…”

“…The morphology and structures of such sperms vary from species to species, although they all share the same characteristics, such as without flagella, unmovable and without condensed nucleus. In the past, several research groups have studied the morphology of the sperm and spermatiation, including the membrane complex in spermatogenesis (Moses 1961;Kaye et al 1961;Langreth 1969;Reger 1970;Arsenault et al 1979;Arsenault 1984;Haley 1986;Mcknight and Hinsch 1986;Shigekawa and Clark 1986;Du et al 1988;Medina and Rodrfguez 1992;Medina 1994;Li 1995;Yang et al 1998;Wang et el. 1999;Tudge et al 2001;Zhu et al 2002;Medina et el.…”

Descripción histológica de la oogénesis y espermatogénesis del camarón de cultivo, Litopenaeus vannamei

“…La estructura de lóbulos con túbulos seminíferos es similar en L. setiferus, L. vannamei, P. indicus, P. longirostris y M. monoceros (Chow et al 1991, Mohamed & Diwan 1993, Medina 1994, Abraham et al 2007. Sin embargo, los estudios de Medina (1994), Abraham et al (2007) y Kang et al (2008) refieren el desarrollo de espermatozoides con espinas completas en los túbulos del testículo de P. longirostris, M. monoceros y Fenneropenaeus chinensis (Osbeck, 1765), respectivamente.…”

“…En Parapenaeus longirostris (Lucas, 1846) se evaluó la ultraestructura de la espermatogénesis (Medina 1994).…”

Different aspects of reproduction strategies in crayfish: A review

“…Spermatozoal cell ultrastructure has been successfully studied in taxonomic and phylogenetic studies across many animal taxa, including crustaceans (Felgenhauer, 1991;Medina, 1994;Tudge, 1995;Jamieson et al, 1995a, b;Jamieson and Tudge, 2000;Martin and Davis, 2001;Tirelli et al, 2008;Tudge, 2009;Niksirat et al, 2013b). Apart from its taxonomic and phylogenetic importance, knowledge of spermatozoal morphology can contribute to understanding the complex mechanisms of acrosome reaction and gamete fertilization (Simeo et al, 2010).…”