Sperm density, seminal plasma composition and their physiological relationship in the endangered Caspian brown trout (Salmo trutta caspius)

Abstract

Sperm density, mineral and organic composition of the seminal plasma and their physiological relationship were investigated in the Caspian brown trout (Salmo trutta caspius). To establish a rapid and accurate method for assessment of sperm density, three di¡erent techniques were used: sperm counting, spectrophotometry (at 480 nm) and determination of the spermatocrit. The seminal plasma contained 159.26 AE 8.84 mM sodium (Na), 33.72 AE 2.01mM potassium (K), 133.04 AE 5.96 mM chlorine (Cl), 1.68 AE 0.2 mM calcium (Ca) and 0.988 AE 0.13 mM magnesium (Mg). The following organic components were found: total protein 0.75 AE 0.14 mg100 mL À 1 , cholesterol 2.86 AE 0.58 mg L À 1 and glucose 3.81 AE 1.04 mM L À 1 . The mean sperm density was estimated to be 3.3 Â 10 9 spermatozoa mL À 1 . The spermatocrit (%) ranged from 25 to 52 in sperm samples. Highly signi¢cant linear relationships were found between sperm density and spermatocrit (R 2 5 0.703, Po0.001) and sperm density and optical density (R 2 50.909, Po0.001), indicating that optical density can be used as a quick and accurate method of estimating sperm density. Signi¢cant relationships were also found between sperm density and Ca, Mg and total protein of seminal plasma. A signi¢cant correlation was also observed between the Ca and Mg concentrations (R 2 50.774, Po0.01). The following correlations were observed between mineral and organic components: total protein and Ca (R 2 50.462, Po0.05), total protein and Mg (R 2 50.518, Po0.05) and glucose and Cl (R 2 50.374, Po0.05). These parameters should be considered when developing procedures for either arti¢cial fertilization or for cryopreservation of sperm. Sperm density and seminal plasma composition in Salmo trutta caspius A Hatef et al.

Evaluation of semen quality of endangered Caspian brown trout (Salmo trutta caspius) in different times of spermiation during the spawning season

“…In many previous researches, similar relationships were observed between sperm density vs Na + , K + , Ca 2+ , Mg 2+ in landlock salmon, Salmo salar M. Sebago Girard (Piirenen, 1985), sperm density vs total protein in Siberian sturgeon, Acipenser baeri (Piros et al, 2002) and in a previous study in Caspian brown trout, sperm density vs Ca 2+ , Mg 2+ and total protein (Hatef et al, 2007). Similarly, the close correlations between the concentration of Na + , Cl -, K + , Ca 2+ , Mg 2+ and sperm density reveal a regulatory role of these minerals during spermiation of Caspian brown trout (Piirenen, 1985;Hatef et al, 2007). Lahnsteiner et al (2004) reported that some proteins of seminal plasma were shown to have a key role in the motility of sperm cells.…”

“…Lahnsteiner et al (2004) reported that some proteins of seminal plasma were shown to have a key role in the motility of sperm cells. It is possible that in dense semen, higher concentrations of these types of proteins are required for the stimulation of sperm motility than in semen with low sperm density (Hatef et al, 2007). Similarly like in some teleost fish (Takashima et al, 1984;Aas et al, 1991;Ciereszko and Dabrowski, 1993;Hatef et al, 2007), a positive relationship between sperm density and spermatocrit was found in Caspian brown trout.…”

“…It is possible that in dense semen, higher concentrations of these types of proteins are required for the stimulation of sperm motility than in semen with low sperm density (Hatef et al, 2007). Similarly like in some teleost fish (Takashima et al, 1984;Aas et al, 1991;Ciereszko and Dabrowski, 1993;Hatef et al, 2007), a positive relationship between sperm density and spermatocrit was found in Caspian brown trout. Thus, such a relationship suggests that the evaluation of sperm quantity by spermatocrit determination is better than the spermatozoa counting method from facility and time saving aspects.…”

“…in hatchery and subsequently, an increase in the glucose concentration of body fluids (such as seminal and blood plasma) follows because of the constant activity of glycolysis pathway in liver in response to stress conditions (Portz et al, 2006). In general, differences in the organic and inorganic composition of seminal plasma in fish probably represent species-specific characteristics among fish species Alavi et al, 2004;Hatef et al, 2007) that should be considered when procedures for artificial insemination or storage of sperm (both short-term storage and cryopreservation) are envisaged (Billard et al, 1995;Rurangwa et al, 2004;Alavi and Cosson, 2006). In the present study, inorganic and some organic components of seminal plasma showed different values in different times of spermiation.…”

Relationships between seminal plasma composition and sperm quality parameters of the Salmo trutta macrostigma (Dumeril, 1858) semen: with emphasis on sperm motility

“…The composition of seminal plasma in other salmonid species has been examined scarcely so far (Cruea, 1969;Morisawa et al, 1979;Piironen and Hyvarinen, 1983;Hatef et al, 2007). It is well known that the composition of seminal plasma can differ even among related species.…”