Lozano-Cobo Horacio, Gómez-Gutiérrez Jaime, Franco-Gordo Carmen, Prado-Rosas María Del Carmen Gómez Del
Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, Departamento de Plancton y Ecología Marina. Av. IPN s/n, CP 23096, La Paz, Baja California Sur.
Centro de Ecología Costera, Universidad de Guadalajara, Gómez Farías 82, CP 48980, San Patricio Melaque, Jalisco.
Acta Parasitol. 2017 Jun 1;62(2):401-411. doi: 10.1515/ap-2017-0048.
A comprehensive literature review shows that 12 types of pathogens, micropredators and parasites are reported to interact with chaetognaths, mostly digenean trematodes, cestodes and nematodes larval stages. Through analysis of 78,152 chaetognaths from a monthly zooplankton time series (Jan 1996-Dec 1998) collected in the Mexican Central Pacific twelve acanthocephalan larvae parasitizing chaetognaths were discovered. This is the first record of an acanthocephalan parasitizing chaetognaths, raising to 13 the types of symbionts known to interact with them (excluding predators). Cystacanth larval specimens of Corynosoma sp. (Polymorphidae) were observed parasitizing the head, trunk and caudal cavities of three of the eight chaetognath species inhabiting this tropical coastal region (Flaccisagitta enflata, Flaccisagitta hexaptera and Zonosagitta bedoti). Because Corynosoma sp. parasitized chaetognaths during different months and years (Jan-Feb 1996, Mar and Jul 1997, Jan, Jun, Aug-Sep 1998) and because the total length of these cystacanths varied between 165-480 µm, suggesting growth inside the hosts, we conclude that chaetognaths are intermediate hosts of Corynosoma sp. The twelve parasitized chaetognaths were juveniles (without gonads) or immature adults (none in reproductively mature stage IV); therefore Corynosoma may have a negative influence on host reproduction. Marine crustaceans (amphipods, decapods, copepods, mysids and euphausiids) and fishes are common intermediate or paratenic hosts of acanthocephalans. Fish, sea birds and marine mammals are definitive hosts for marine Corynosoma species. The present discovery implies that acanthocephalans are transmitted trophically through different intermediate hosts (crustaceans, chaetognaths and/or fish); thus chaetognaths can also be part of the marine acanthocephalan life cycle.
一项全面的文献综述表明，据报道有12种病原体、微捕食者和寄生虫与毛颚动物相互作用，其中大多数是复殖吸虫、绦虫和线虫的幼虫阶段。通过对1996年1月至1998年12月在墨西哥中部太平洋采集的月度浮游动物时间序列中的78152只毛颚动物进行分析，发现了12种寄生在毛颚动物体内的棘头虫幼虫。这是棘头虫寄生毛颚动物的首次记录，使已知与它们相互作用的共生体类型（不包括捕食者）增加到13种。观察到多形科的Corynosoma sp.的囊尾蚴幼虫标本寄生在栖息于该热带沿海地区的8种毛颚动物中的3种（扁平箭虫、六翼箭虫和贝氏箭虫）的头部、躯干和尾腔中。由于Corynosoma sp.在不同的月份和年份寄生毛颚动物（1996年1月至2月、1997年3月和7月、1998年1月、6月、8月至9月），并且这些囊尾蚴的总长度在165 - 480微米之间变化，表明它们在宿主体内生长，我们得出结论，毛颚动物是Corynosoma sp.的中间宿主。这12只被寄生的毛颚动物是幼体（无性腺）或未成熟成体（没有处于生殖成熟的IV期）；因此，Corynosoma可能对宿主繁殖有负面影响。海洋甲壳类动物（十足目、十足目、桡足类、糠虾类和磷虾类）和鱼类是棘头虫常见的中间宿主或转续宿主。鱼类、海鸟和海洋哺乳动物是海洋Corynosoma物种的终末宿主。目前的发现意味着棘头虫通过不同的中间宿主（甲壳类动物、毛颚动物和/或鱼类）进行营养传播；因此，毛颚动物也可以成为海洋棘头虫生命周期的一部分。
