Sperm morphology, ATP content, and analysis of motility in Atlantic halibut (Hippoglossus hippoglossus)

Abstract

Spermatozoon of Atlantic halibut (Hippoglossus hippoglossus (L., 1758)) is uniflagellated, lacks an acrosome, and is differentiated into a head, midpiece, and flagellum. There are two to five mitochondria in the midpiece, as well as proximal and distal centrioles. The flagellum consisted of 9 + 2 microtubules surrounded by plasma membrane, which is extended at the proximal part of the flagellum owing to the presence of vacuoles. After sperm activation in seawater, sperm motility and velocity decreased from 98.4% ± 3.4% and 170.3 ± 8.9 mmÁs -1 at 15 s after sperm activation to 4.8% ± 4.7% and 9.2 ± 8.9 mmÁs -1 at 120 s after sperm activation, respectively. ATP content (nmolÁL -1 ATP per 10 8 spermatozoa) significantly decreased at 60 s after sperm activation (5.9 ± 1.5) compared with at 0 and 30 s after sperm activation (14.9 ± 1.5 and 14.5 ± 1.5, respectively). Beating waves propagated along the full length of the flagellum after sperm activation, whereas waves were restricted to the proximal section during the latter motility period. Wave amplitude significantly decreased at 45 s after sperm activation, but wavelength did not differ. The present study showed associations among sperm morphology, ATP content, flagellar wave parameters, and sperm velocity, which could be used in comparative spermatology.Résumé : Le spermatozoïde du flétan atlantique (Hippoglossus hippoglossus (L., 1758)) est uniflagellé, sans acrosome et différencié en tête, corps médian et flagelle. Il y a deux à cinq mitochondries dans le corps médian, ainsi que des centrioles proximaux et distaux. Le flagelle consiste en 9 + 2 microtubules entourés d'une membrane plasmatique qui se prolonge dans la partie proximale du flagelle à cause de la présence de vacuoles. Après l'activation des spermatozoïdes dans l'eau de mer, la motilité et la vitesse des spermatozoïdes diminuent respectivement de 98,4 % ± 3,4 % et de 170,3 ± 8,9 mmÁs -1 à 15 s après l'activation à 4,8 % ± 4,7 % et 9,2 ± 8,9 mmÁs -1 à 120 s après l'activation. Le contenu en ATP (nmolÁL -1 ATP par 10 8 spermatozoïdes) diminue significativement 60 s après l'activation (5,9 ± 1,5) par comparaison à 0 et 30 s après l'activation (respectivement 14,9 ± 1,5 et 14,5 ± 1,5). Les ondulations de battement se propagent sur toute la longueur du flagelle après l'activation, mais sont restreintes à la partie proximale durant la période de motilité subséquente. L'amplitude des ondulations diminue significativement à 45 s après l'activation, mais leur longueur d'onde ne change pas. Notre étude met en lumière des associations entre la morphologie des spermatozoïdes, leur contenu en ATP, les variables ondulatoires des flagelles et la vitesse des spermatozoïdes qui pourraient servir en spermatologie comparée.[Traduit par la Rédaction]

Fins improve the swimming performance of fish sperm: A hydrodynamic analysis of the Siberian sturgeon Acipenser baerii

“…It has been noted previously that the sperm velocity in species with fin‐like structures on the flagellum is significantly higher than in species that have no fin structures [Lahnsteiner and Patzner, 1998; Alavi et al, 2011]. Alavi et al [2011] have noted, by collating data from several sources (see their work for references), that finned sperm in general swim faster than nonfinned sperm, although in their analysis no hydrodynamic analysis was done and the effects of beat frequency, flagellar length, and head size were not taken into account. Their analysis discusses the swimming speed of Barbus barbus (95–105 μm/s), Perca fluviatilis (105–125 μm/s), both sperm with no fins, and of Esox lucius (175–185 μm/s) and Acipenser ruthenus (160–180 μm/s), with one fin and two fins respectively.…”

“… Swimming speed of the sperm of several fish species, Barbus barbus, Perca fluviatilis, Trachurus mediterraneus, D. Sargus, Esox Lucius, Mullus barbatus, Acipenser ruthenus . Data are from Alavi et al [2011] and Lahnsteiner and Patzner [1998]. An apparent increase in swimming speed is seen from species without finned flagella, to those with single and paired fins.…”

“…Single, or paired, fin structures similar to those of the sturgeon sperm are found in many other fish species, and there is some evidence to suggest that these finned sperm are relatively fast swimmers, compared to unfinned sperm [Alavi et al, 2011]. Several authors have studied these fin structures in fish sperm and conjectured on their purpose, although there remains a debate [DiLauro et al, 1999; Cosson et al, 2000; Wei et al, 2007; Psenicka et al, 2011].…”

Morphology and fine structure of the Russian sturgeon, Acipenser gueldenstaedtii (Acipenseridae, Chondrostei) spermatozoa

“…The function of fin is probably enhancing flagellar beating of spermatozoa during movement. In sturgeon and teleosts with similar fin‐like structure such as pike and halibut (Alavi et al., , ), the velocity of spermatozoa is very high (about 170–200 μm s −1 ), while in most teleosts without this structure the spermatozoa velocity was reported between 90 and 150 μm s −1 (Cosson, ).…”

“…Immediately after arrival, the quality of sperm was checked by evaluation of the motility after activation in tap water under a dark‐field microscope according to Alavi et al. (). The samples with motility higher than 50–60% were fixed in 0.1 m phosphate buffer containing 2.5% glutaraldehyde and stored at 4°C until transfer to the Electron Microscopy lab, University of South Bohemia in České Budějovice, Czech Republic.…”