Department of Pond Fisheries, The Stanisław Sakowicz Inland Fisheries Institute in Olsztyn, Żabieniec, 05-500 Piaseczno, Poland.
J Fish Biol. 2014 Sep;85(3):736-51. doi: 10.1111/jfb.12455. Epub 2014 Jul 18.
Preservation in 30% ethanol and freezing to a temperature of -20 ± 2° C is an appropriate method for measurement of fish eggs, larvae and juveniles. Egg diameter of the common carp Cyprinus carpio increased insignificantly by 1·32% after preservation compared with live size. The total length (LT ) of 1 day post-hatching (dph) larvae as well as the standard length (LS) of 16 dph larvae of C. carpio increased significantly (2·95 and 1·50%, respectively) after preservation. Egg diameter as well as the LT of 1 dph larvae of barbel Barbus barbus increased significantly after preservation, by 1·74 and 1·96%, respectively over their original size. The standard length (LS ) of 14 dph larvae of B. barbus as well as juveniles of B. barbus, crucian carp Carassius carassius, common nase Chondrostoma nasus and tench Tinca tinca decreased significantly after preservation (-0·56 to -5·54%), whereas their body mass increased significantly (11·46-18·57%). Preserved eggs of C. carpio and B. barbus were hard, round and transparent. The larvae and juveniles of examined fishes, preserved in frozen ethanol, were straight, flexible and easily measurable after 60 days. Integrity of body surface and fins, as well as preservation of colours were much better in larvae or juveniles frozen and thawed only once than in specimens frozen and thawed thrice. Cooling in 30% ethanol to a temperature of 6 ± 2° C and freezing in water to a temperature of -20 ± 2° C are not appropriate preservation methods for eggs and larvae of C. carpio (1 and 16 dph).
30%乙醇保存和-20±2°C 冷冻是测量鱼类卵、仔鱼和幼鱼的合适方法。鲤鱼卵的卵径经保存后比活鱼尺寸仅增加了 1.32%，增加不显著。1 日龄仔鱼的全长（LT）和 16 日龄仔鱼的标准长（LS）经保存后分别显著增加（2.95%和 1.50%）。厚唇裂腹鱼的卵径和 1 日龄仔鱼的 LT 经保存后分别增加了 1.74%和 1.96%，超过了原始大小。14 日龄仔鱼的 LS 和厚唇裂腹鱼、鲫鱼、泥鳅和丁鱥的幼鱼经保存后显著减少（-0.56 至-5.54%），但其体重显著增加（11.46-18.57%）。保存的鲤鱼和厚唇裂腹鱼的卵坚硬、圆形且透明。在冷冻乙醇中保存的仔鱼和幼鱼在 60 天后是直的、有弹性的，并且易于测量。与冷冻和解冻三次的标本相比，仅冷冻和解冻一次的鱼类幼虫或幼鱼的体表和鳍的完整性以及颜色保存更好。将鱼卵和仔鱼在 30%乙醇中冷却至 6±2°C，然后在水中冷冻至-20±2°C 不是鲤鱼（1 日龄和 16 日龄）卵和仔鱼的合适保存方法。
