Rubio-Godoy Miguel, Montiel-Leyva Adriana, Martínez-Hernández J Antonio
Instituto de Ecología, A.C., Red de Biología Evolutiva, km 2.5 ant carretera a Coatepec, Xalapa, Veracruz 91070, México.
Dis Aquat Organ. 2011 Jan 21;93(2):171-7. doi: 10.3354/dao02287.
Two different genetic types of tilapia, Mozambique tilapia Oreochromis mossambicus (MT), and Pargo-UNAM (PU; a synthetic hybrid whose genetic composition is 50% Florida red tilapia, 25% Rocky Mountain tilapia, and 25% red variant Oreochromis niloticus), were acclimatized to salinity and exposed to seawater from the Gulf of Mexico off the port of Veracruz, Mexico. Both fish types were infected by the monogenean ectoparasite Neobenedenia sp. and were killed within 2 to 3 wk. A crude worm extract was prepared from whole specimens collected during the original outbreak and used to immunize naive hosts of the same 2 types of tilapia. Immunized fish were then exposed to seawater, which resulted in Neobenedenia sp. infection. Immunization did not confer any protection against Neobenedenia sp. infection. However, the experiment enabled detailed analysis of the dynamics of infection and comparison of the effects of the parasite on the 2 host types. Although both tilapia types exhibited similar resistance to infection (as they harbored similar parasite burdens in the early phase of infection), PU is less tolerant to Neobenedenia sp., as a mean parasite abundance of ca. 50 worms fish-' killed all hosts within a fortnight, while 22% of MT survived up to 3 wk, harboring a mean parasite abundance of ca. 900 worms fish-'. Our results suggest that, as reported elsewhere, Neobenedenia sp. could negatively affect mariculture off the Mexican coast of the Gulf of Mexico.
两种不同遗传类型的罗非鱼，即莫桑比克罗非鱼（Oreochromis mossambicus，MT）和帕尔戈 - 国立自治大学罗非鱼（PU；一种合成杂交品种，其遗传组成为50%佛罗里达红罗非鱼、25%落基山罗非鱼和25%尼罗罗非鱼红色变种），被驯化适应盐度，并暴露于墨西哥韦拉克鲁斯港附近墨西哥湾的海水中。这两种鱼类均被单殖吸虫外寄生虫新贝尼登虫属（Neobenedenia sp.）感染，并在2至3周内死亡。从最初疫情爆发期间收集的完整标本中制备了粗制虫体提取物，并用于免疫相同两种罗非鱼类型的未感染宿主。然后将免疫后的鱼暴露于海水中，结果导致新贝尼登虫属感染。免疫并未对新贝尼登虫属感染提供任何保护。然而，该实验使得能够详细分析感染动态，并比较寄生虫对两种宿主类型的影响。尽管两种罗非鱼类型对感染表现出相似的抵抗力（因为它们在感染早期携带相似的寄生虫负荷），但PU对新贝尼登虫属的耐受性较低，因为平均每条鱼约50条虫的寄生虫丰度在两周内杀死了所有宿主，而22%的MT存活至3周，平均每条鱼携带约900条虫。我们的结果表明，正如其他地方所报道的，新贝尼登虫属可能会对墨西哥湾墨西哥海岸的海水养殖产生负面影响。
