Ultrastructure and functional morphology of spermatozoa of Rossia pacifica (Cephalopoda, Decapoda)

Abstract

FIELDS, W. G., and K. A. THOMPSON. 1976. Ultrastructure and functional morphology of spermatozoa of Rossia pacifica (Cephalopoda, Decapoda). Can. J. Zool. 54: 908-932. The mature spermatozoan of Rossia pacifica consists of acrosome, nucleus, mitochondrial spur, and tail. Anteriorly, the complex acrosome has a cup-shaped depression containing membrane-bound vacuoles. The acrosome is enclosed by a meshwork of longitudinal and circumferential filaments; its invaginated posterior end surrounds juxtanuclear periacrosomal material. The elongated nucleus, of condensed chromatin filaments, encloses lateroposteriorly the proximal and distal centrioles withina centriolar fossa. Mitochondria lie in a separate, spurlike appendage; proximally its lateral margins are continuous with a collarlike annulus. Nine coarse outer fibres surround the 9 + 2 axoneme. They originate from a centriolar ring and diminish in diameter distally, Staining with periodic acid -Schiff demonstrates some glycogen in the mitochondrial spur near its junction with the nucleus.Structural significance and possible functional roles of the various elements are discussed relevant to fertilization. Although this sperm appears intermediate between the more primitive invertebrate sperm type and highly specialized vertebrate sperm, its morphology seems more related to fertilization biology than to phylogenetic position. The singular separateness of areas of energy production and use in R . pacifica sperm and the lengthy energy-transport path may provide unique opportunities for analysis of metabolic processes common to but indecipherable in other sperm. FIELDS, W. G., et K. A. THOMPSON. 1976. Ultrastructure and functional morphology of spermatozoa of Rossia pacifica (Cephalopoda, Decapoda). Can. J. Zool. 54: 908-932.Le spermatozoIde a maturiti, chez Rossia pacifica, contient I'acrosome, le noyau, l'eperon mitochondrial et la queue. Vers I'avant, I'acrosome complexe porte une depression en forme de coupe ou se trouvent les vacuoles reliees i la membrane. L'acrosome est retenu par un rtseau de filaments longitudinaux et circulaires; son extrtmite posterieure invaginee entoure la substance periacrosomienne juxtanuclCaire. Le noyau allonge, constitue de filaments compacts de chromatine, contient, en position posterieure laterale, les centrioles proximal et distal, ainsi qu'une fosse centriolaire. Les mitochondries occupent un appendice sipare, en forme d'eperon; dans la partie proximale de cet appendice, les bordures laterales sont en continuit6 avec un annulus formant une sorte de col. Neuf grosses fibres externes entourent les 9 + 2 axonkmes.Elles prennent leur origine dans un anneau centriolaire et elles s'amenuisent en direction distale. La coloration au I'acide periodique -Schiff revele la presence de glycogene dans l'eperon des mitonchondries, au voisinage de sa jonction avec le noyau.On discute de l'importance structurale et des r6les fonctionnels possibles de ces divers elements dans la fecondation. Bien que ce spermatozo~de apparaisse comme un intermediaire...

Ultrastructure of spermiogenesis inVampyroteuthis infernalis Chun — a relict cephalopod mollusc

“…In other cephalopods only a single triplet centriole is usually observed (Maxwell, 1974(Maxwell, , 1975, though Fields & Thompson (1976) identify two centrioles in spermatozoa of the sepiohd Rossia pacifica, and two centrioles initially occur in spermatids of Octopus spp. (Galangau, 1969;Healy, 1989}.…”

Ultrastructure of spermatozoa and spermiogenesis inSpirula spirula (L.): systematic importance and comparison with other cephalopods

“…(see Fig. 6), but at present no information is available on its formation during spermiogenesis (in other investigated sepiolids -Sepietta oweniana and Rossia pacifica, a mitochondrial spur of the Sepiida/Teuthida type is present - Franz~n, 1955;Fields & Thompson, 1976). Although the microtubular sheath in spermatids of Spirula encloses the developing nucleus @nd mitochondrial sleeve, in other cephalopods this sheath appears to be confined to the nuclear region (Maxwell, 1974(Maxwell, , 1975Healy, 1990).…”

“…Mature spermatozoa: comparison with other cephalopods Figure 6 summarizes, in semi-diagrammatic form, sperm morphology in Spirula and other studied coleoid taxa (based on data of Franz~n, 1955Franz~n, , 1967Galangau, 1969; Galangau & Tuzet, 1968a, b;Longo & Anderson, 1970;Maxwell, 1974Maxwell, , 1975Fields & Thompson, 1976;Olson & Linck, 1980;Healy, 1989, 1990 andunpublished data). It can be seen from this comparative figure that sperm of the Sepiidae, Loliginidae and Sepiolidae (exception Heteroteuthis) all share a curved nucleus, eccentrically positioned flagellum and mitochondrial spur and a plasma membrane skirt.…”

“…6). Acrosomal vesicles of all decapod coleoids (including Spirula) show variously developed rods or plates -usually angularly oriented in relation to the longitudinal axis (see also Fields &Thompson, 1976 andOlson &Linck, 1980). Olson & Linck (1980) found that each internal "fibre" (= rod) of the acrosomal vesicle of Spermatozoa of Vampyroteuthis exhibit several characters commonly noted in spermatozoa of externally fertilizing (often primitive) molluscs such as the Archaeogastropoda, Bivalvia and Scaphopoda (relatively undifferentiated acrosomal vesicle; two triplet substructure centrioles; short nucleus; pericentriolar mitochondria) ( Fig.…”

Ultrastructure of spermatozoa and spermatogenesis inOctopus minor(Sasaki, 1920) (Cephalopoda: Octopoda)

“…The morphology and formation of cephalopod spermatozoa have considerable potential in systematics (Healy 1989), and much research has been conducted on sperm morphology and spermiogenesis of cephalopods (Franzén 1955(Franzén , 1967Maxwell 1974Maxwell , 1975Maxwell , 1983Fields and Thompson 1976;Arnold and Williams 1978;Healy 1990aHealy , 1990bHealy , 1993Selmi 1996;Giménez-Bonafé et al 2002;Ribes et al 2002;Martínez et Roura et al 2009Roura et al , 2010aRoura et al , 2010b. However, only a few Octopus species have been investigated regarding sperm ultrastructure (e.g.…”