title: The quality of great scallop (Pecten maximus) sperm after thawing.
abstract: Most publications devoted to the cryopreservation of mollusc sperm have focused on the definition of technical protocols, avoiding the description of sperm quality after thawing. The present study investigated the effects of cryopreservation on sperm quality in the great scallop. Wild scallop were fished during the natural spawning period and conditioned in the hatchery before use. Sperm samples were obtained after intragonadal injection of serotonin and cryopreserved using a previously published protocol. Sperm quality was assessed using a panel of four parameters: sperm motility characteristics, using a computer assisted sperm analysis plugin with Image J, intracellular ATP content using an ATP-Lite kit, sperm integrity, using flow cytometry and sperm morphology, using transmission electron microscopy. For each parameter, fresh (control) and thawed spermatozoa were compared. A significant decrease of both the percentage of motile spermatozoa (reduction: 75%) and sperm swimming speed (86%) were observed for thawed sperm compared with fresh sperm. The percentage of living spermatozoa, as assessed using flow cytometry, was significantly lower for thawed sperm (72.4±2.5%) compared with fresh sperm (86.4±1.1). However, no significant difference of intracellular sperm ATP content was observed between fresh and thawed sperm. Post thawing, while some spermatozoa showed little or no morphological differences compared with fresh sperm, others had undergone drastic changes, including swelling of the plasma membrane, structural alterations of the chromatin and damage to mitochondria. In conclusion, the descriptive parameters studied in the present work showed that the quality of thawed great scallop sperm was lower than that of fresh cells but was still sufficient for use in aquaculture programs and sperm cryobanking for this species.
authors.affiliation: Ifremer, UMR 6539, PFOM Department, Station Expérimentale d'Argenton, Argenton, France. Electronic address: msuquet@ifremer.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Suquet
authors.affiliation: Ifremer, UMR 6539, PFOM Department, Station Expérimentale d'Argenton, Argenton, France.
authors.forename: Clémence
authors.initials: C
authors.lastname: Gourtay
authors.affiliation: IUEM, UMR 6539, Lemar, Technopole Brest Iroise, Plouzané, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Donval
authors.affiliation: IUEM, UMR 6539, Lemar, Technopole Brest Iroise, Plouzané, France.
authors.forename: Nelly
authors.initials: N
authors.lastname: Le Goïc
authors.affiliation: Ifremer, UMR 6539, PFOM Department, Technopole Brest-Iroise, Plouzané, France.
authors.forename: Claudie
authors.initials: C
authors.lastname: Quere
authors.affiliation: Ifremer, UMR 6539, PFOM Department, Station Expérimentale d'Argenton, Argenton, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Malo
authors.affiliation: Ifremer, UMR 6539, PFOM Department, Station Expérimentale d'Argenton, Argenton, France.
authors.forename: Jaqueline
authors.initials: J
authors.lastname: Le Grand
authors.affiliation: Ifremer, UMR 6539, PFOM Department, Station Expérimentale d'Argenton, Argenton, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Ratiskol
authors.affiliation: Ifremer, UMR 6539, PFOM Department, Station Expérimentale d'Argenton, Argenton, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Mingant
authors.affiliation: Ifremer, UMR 248, Marbec, Station Ifremer, Palavas, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Fauvel
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D008297:Male; D049910:Pecten / Q000378:metabolism*; D055101:Semen Analysis / Q000379:methods*; D012758:Shellfish / Q000032:analysis*; D013094:Spermatozoa / Q000378:metabolism*
keywords: Cryopreservation; Gamete; Pecten maximus; Reproduction; Sperm