Liu Yue, Grier Harry J, Tiersch Terrence R
Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA, USA.
Fish and Wildlife Research Institute, St. Petersburg, FL, USA; Department of Vertebrate Zoology, Division of Fishes, National Museum of Natural History, MRC 159, Smithsonian Institution, Washington, DC, USA.
Anim Reprod Sci. 2018 Sep;196:77-90. doi: 10.1016/j.anireprosci.2018.06.021. Epub 2018 Jun 30.
Previous studies of sperm cryopreservation of livebearing fish have been limited to two genera within the family Poeciliidae. The goal of the present study was to investigate the feasibility to produce live young of livebearing goodeids (family Goodeidae) with cryopreserved sperm, using aquarium-trade populations of the endangered species Redtail Splitfin (Xenotoca eiseni, Rutter, 1896). Reproductive condition of females was evaluated by histological categorization of ovarian development. A total of 117 females were inseminated with cryopreserved sperm, 81 were inseminated with fresh sperm, 27 were mixed with males for natural breeding, and 30 were maintained without males or insemination. Histological images of 34 mature females indicated 68% of ovaries had primary- or secondary-growth oocytes, and 32% had ovulated eggs. Ovarian development had no significant relationship (P = 0.508) with body wet weight, but had a relationship (P < 0.001) with ovary weight and gonadosomatic index. Sperm cells were observed within ovaries that were fixed at 12 h after insemination with fresh sperm. A total of 29 live young were produced from two females inseminated with thawed sperm (8% post-thaw motility with HBSS300 as extender, 20 min incubation in 15% DMSO, cooling rate at 10 °C/min, and thawing at 40 °C for 7 s), 12 were produced from two females with fresh sperm (1%-20% motility), 41 were produced from five naturally spawned females, and no live young were produced from the female-only group. This study provides a foundation for establishment of germplasm repositories for endangered goodeids to assist conservation programs.
先前关于卵胎生鱼类精子冷冻保存的研究仅限于花鳉科中的两个属。本研究的目的是利用濒危物种红尾剑尾鱼（Xenotoca eiseni，鲁特，1896年）的水族贸易种群，探讨用冷冻保存的精子培育卵胎生古氏鱼科（Goodeidae）幼鱼的可行性。通过卵巢发育的组织学分类来评估雌鱼的生殖状况。总共117条雌鱼用冷冻保存的精子授精，81条用新鲜精子授精，27条与雄鱼混合进行自然繁殖，30条在没有雄鱼或未授精的情况下饲养。34条成熟雌鱼的组织学图像显示，68%的卵巢有初级或次级生长卵母细胞，32%有排卵的卵。卵巢发育与鱼体湿重无显著关系（P = 0.508），但与卵巢重量和性腺指数有关系（P < 0.001）。在用新鲜精子授精后12小时固定的卵巢中观察到精子细胞。用解冻精子授精的两条雌鱼共产出29条幼鱼（以HBSS300为稀释剂，解冻后活力为8%，在15%二甲基亚砜中孵育20分钟，降温速率为10℃/分钟，在40℃解冻7秒），用新鲜精子授精的两条雌鱼产出12条幼鱼（活力为1%-20%），五条自然产卵的雌鱼产出41条幼鱼，仅雌鱼组未产出幼鱼。本研究为建立濒危古氏鱼科种质库以协助保护计划奠定了基础。
