Sperm morphology, ATP content, and analysis of motility in Atlantic halibut (Hippoglossus hippoglossus) Sayyed Mohammad Hadi Alavi, Ian A.E. Butts, Azadeh Hatef, Maren Mommens, Edward A. Trippel, Matthew K. Litvak, and Igor Babiak 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 acti- vation, whereas waves were restricted to the proximal section during the latter motility period. Wave amplitude signifi- cantly 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 compara- tive spermatology. Re ´sume ´: Le spermatozoı ¨de du fle ´tan atlantique (Hippoglossus hippoglossus (L., 1758)) est uniflagelle ´, sans acrosome et diffe ´rencie ´ en te ˆte, corps me ´dian et flagelle. Il y a deux a ` cinq mitochondries dans le corps me ´dian, ainsi que des centrio- les proximaux et distaux. Le flagelle consiste en 9 + 2 microtubules entoure ´s d’une membrane plasmatique qui se prolonge dans la partie proximale du flagelle a ` cause de la pre ´sence de vacuoles. Apre `s l’activation des spermatozoı ¨des dans l’eau de mer, la motilite ´ et la vitesse des spermatozoı ¨des diminuent respectivement de 98,4 % ± 3,4 % et de 170,3 ± 8,9 mmÁs –1 a ` 15 s apre `s l’activation a ` 4,8 % ± 4,7 % et 9,2 ± 8,9 mmÁs –1 a ` 120 s apre `s l’activation. Le contenu en ATP (nmolÁL –1 ATP par 10 8 spermatozoı ¨des) diminue significativement 60 s apre `s l’activation (5,9 ± 1,5) par comparaison a ` 0 et 30 s apre `s l’activation (respectivement 14,9 ± 1,5 et 14,5 ± 1,5). Les ondulations de battement se propagent sur toute la lon- gueur du flagelle apre `s l’activation, mais sont restreintes a ` la partie proximale durant la pe ´riode de motilite ´ subse ´quente. L’amplitude des ondulations diminue significativement a ` 45 s apre `s l’activation, mais leur longueur d’onde ne change pas. Notre e ´tude met en lumie `re des associations entre la morphologie des spermatozoı ¨des, leur contenu en ATP, les variables ondulatoires des flagelles et la vitesse des spermatozoı ¨des qui pourraient servir en spermatologie compare ´e. [Traduit par la Re ´daction] Introduction Morphology, motility, and seminal plasma composition are considered major elements in the study of comparative fish spermatology (Jamieson 1991; Ishijima et al. 1998; Alavi et al. 2008a). Fish spermatozoa are differentiated into a head, a midpiece, and a flagellum with the typical 9 + 2 pairs of microtubules (Jamieson 1991; Lahnsteiner and Patz- ner 2008). Spermatozoa of most fish species are immotile in the testis or sperm duct prior to spawning (Morisawa and Suzuki 1980). Activation of sperm occurs after release from the genital papilla into an aquatic environment (Billard et al. 1995). The mechanism of sperm motility initiation differs between freshwater and marine fishes with the former re- Received 30 June 2010. Accepted 21 December 2010. Published on the NRC Research Press Web site at cjz.nrc.ca on 12 February 2011. S.M.H. Alavi 1 and A. Hatef. 2 South Bohemia Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in C ˇ eske ´ Bude ˇjovice, 389 25 Vodn ˇany, Czech Republic. I.A.E. Butts. 2 Fisheries and Oceans Canada, Biological Station, 531 Brandy Cove Road, St. Andrews, NB E5B 2L9, Canada; Department of Biology, University of New Brunswick (Saint John), Ganong Hall, P.O. Box 5050, Saint John, NB E2L 4L5, Canada. M. Mommens and I. Babiak. 3 Reproductive Biology Research Group, Faculty of Biosciences and Aquaculture, University of Nordland, Bodø, 8049, Norway. E.A. Trippel. Fisheries and Oceans Canada, Biological Station, 531 Brandy Cove Road, St. Andrews, NB E5B 2L9, Canada. M.K. Litvak. Department of Biology, Mount Allison University, 63B York Street, Sackville, NB E4L 1G7, Canada. 1 Corresponding author (e-mail: alavi@vurh.jcu.cz). 2 Both authors contributed equally to this work as second author. 3 Corresponding author (e-mail: Igor.Babiak@uin.no). 219 Can. J. Zool. 89: 219–228 (2011) doi:10.1139/Z10-113 Published by NRC Research Press Can. J. Zool. Downloaded from www.nrcresearchpress.com by "Institute of Vertebrate Paleontology and Paleoanthropology,CAS" on 06/03/13 For personal use only.