Instituto Tecnolóxico para o Control do Medio Mariño de Galicia (INTECMAR), Consellería do Mar, Xunta de Galicia, Peirao de Vilaxoán s/n, 36611 Vilagarcía de Arousa, Spain.
Centro de Investigacións Mariñas (CIMA), Consellería do Mar, Xunta de Galícia, Pedras de Corón s/n, 36620 Vilanova de Arousa, Spain.
J Invertebr Pathol. 2020 May;172:107364. doi: 10.1016/j.jip.2020.107364. Epub 2020 Mar 19.
Outbreaks of Marteilia cochillia have caused massive mortalities of common cockle, Cerastoderma edule, in some natural beds in Galicia (NW Spain) since 2012. The life cycle of Marteilia spp. is still unresolved and the most accepted hypothesis suggests that an additional host is involved. Researchers have assumed that sporangia are shed into the environment in the faeces, but details about this process have not been reported previously. Here, we report the massive liberation of Marteilia cochillia sporangia through the exhalant siphon into the environment, packaged as faeces. Using light microscopy observations on fresh samples, imprints and histology, we also describe a thick (ca. 5 µm) transparent envelope covering the sporangia that has not been reported previously. The massive release of encapsulated sporangia reported here ensures that millions of infective stages of M. cochillia cycle through the environment and become available for infection. The elucidation of the role played by the sporangia envelope would be of utmost importance for the understanding M. cochillia life cycle.
自 2012 年以来，在西班牙西北部加利西亚（Galicia）的一些天然养殖场中，副肌蛤 Marteilia cochillia 的爆发已导致普通贻贝 Cerastoderma edule 大量死亡。Marteilia spp. 的生命周期仍未得到解决，最被接受的假设是涉及到额外的宿主。研究人员假设，在粪便中，游动孢子囊被释放到环境中，但此前尚未报道过有关此过程的详细信息。在这里，我们报告了大量的 Marteilia cochillia 游动孢子囊通过呼气管被释放到环境中，被包裹在粪便中。通过对新鲜样本进行的光学显微镜观察、印痕和组织学研究，我们还描述了以前未报道过的覆盖游动孢子囊的厚（约 5µm）透明包膜。这里报道的大量封装游动孢子囊的释放，确保了数以百万计的 M. cochillia 感染阶段循环通过环境并可供感染。阐明游动孢子囊包膜所起的作用对于了解 M. cochillia 的生命周期至关重要。
