Abstract
In order to obtain the basic knowledges concerned to the semen preservation of aquacultural fishes, studies on the physical and chemical properties of semen, and sperm motility with the different osmotic pressures making by adding $Na^+,\;K^+,\; Mg^{++},\;and\;Ca^{++}$ to artificial seawater (ASW) were conducted in black seabream, Acanthopagrus schlegeli. Average semen volume per fish in one strip was 1.97ml and sperm concentration was $2.33\pm1.30\times10^{10}$ sperm/ml. Spermatocrit and pH of semen were $90.6\pm5.0\;and\;8.3\pm0.1$, respectively, Osmotic pressures of rearing seawater, seminal fluid and plasma were $939\pm24,382\pm70\;and\;342\pm77$ mOsm/l, and $Na^+,\;K^+$ and $Cl^-$ concentrations of seminal fluid were $169.5\pm4.5,\;4.9\pm2.2,\;156.0\pm2.0\;mM/l$, respectively. When semen were diluted by using $Na^+,\;K^+,\;Mg^{++}\;and\;Ca^{++}$ free ASW, only $Na^+$ free ASW had no sperm motility. As raising osmotic pressure graduary by addition of 1M NaCl to the $Na^+$ free ASW, spermatozoa showed the high motilities in 457-1128 mOsm/l, but the low motilities in 1398-1736 mOsm/l. In the case of same treatments with 1M of KCl, $MgC1_2\;and\;CaC1_2$ to the $K^+,\;Mg^{++}\;and\;Ca^{++}$ free ASW, spermatozoa revealed the high motilities in $904\~1434,\;818\~1175\;and\;956\~1343$ mOsm/l, respectively.
양식어류의 정자보존을 위한 기초자료를 얻고자, 순환여과 사육시스템에서 사육한 전장 $21.8\pm2.8cm$, 체중 $173.8\pm67.5g$의 감성돔, Acanthopagus schlegeli을 재료로 하여, 정액의 물리$\cdot$화학적 특성과 $Na^+,\;K^+,\;Mg^{++},\;Ca^{++}$ 농도별 삼투압에 따른 정자의 운동성을 평가하였다. 개체당 1회 착출시 정액량은 평균 1.97ml였으며, 정자의 농도는 $2.33\pm1.30\times10^{10}$ sperm/ml, spermatocrit는 $90.6\pm5.0$이었다. 정액의 pH는 $8.3\pm0.1$이었으며, 사육해수와 정장 및 혈장의 삼투압은 각각 $939\times24,\;382\pm70,\;342\pm77$ mOsm/l, 정장의 $Na^+,\;K^+,\;Cl^-$ 농도는 각각 $169.5\pm4.5,\;4.9\pm2.2,\;156\pm2.0$ mM/l였다. $Na^+,\;K^+,\; Mg^{++}$ 및$Ca^{++}$결여 인공해수에 정액을 희석시켰을 경우, $Na^+$ 결여 인공해수에서만 정자의 운동이 개시되지 않았다. $Na^+$결여 인공해수에 1M NaCl을 서서히 첨가하여 삼투압을 상승시켰을 때, 삼투압 $1398\~1736$mOsm/l에서는 정자의 운동성이 낮았으나, $457\~l128$ mOsm/l에서는 높은 운동성을 보였다. NaCl 첨가시와 같은 방법으로 $K^+,\;Mg^{++}$ 및 $Ca^{++}$ 결여 인공해수에 1M의 KCl, $MgCl_2$및$CaCl_2$ 처리를 한 경우, 각각의 삼투압 범위 $904\~1434,\;818\~l175$ 및 $956\~1343$ mOsm/l에서 정자의 운동성이 높았다.
(Department of Aquaculture, National Fisheries University of Pusan)
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