School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
School of Fisheries and Aquaculture Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia.
J Invertebr Pathol. 2018 Feb;152:17-24. doi: 10.1016/j.jip.2018.01.005. Epub 2018 Jan 31.
The tropical conch, Laevistrombus canarium (Linnaeus, 1758) and Canarium urceus (Linneaus, 1758) are ecologically and economically important shellfish species in Malaysia and neighboring region. Their populations, however are currently declining and this histopathological study investigates the aspect of parasitism and diseases that may affect their well-being. Conch samples were randomly collected from their natural habitat and histological sections (4-5 µm) of various organs and tissues were examined under light microscope. This was followed by ultrastructure analysis on infected tissues using transmission electron microscope (TEM). Based on the histological analysis, large numbers of gamonts, sporocysts and trophozoites of Apicomplexa-like parasites were observed in the vacuolated cells and pyramidal crypt cells of the digestive tubules, and in the digestive ducts. Furthermore, coccidian and oocysts-like Pseudoklossia sp. stages were also observed in the cells of the kidney. Apart from that, spores with cyst-like structure were observed in the digestive gland and kidney. Although the parasites were present in most of the organs analyzed, there was no obvious symptom, inflammatory response or mortality incurred on both species, which implies the possibility of a non-virulent relationship like commensalisms or mutualism. However, more investigations, including molecular studies, are needed to confirm the parasite identification and dynamics, and to further evaluate the nature of relationship between Apicomplexa parasites and their host.
热带宝贝螺，Laevistrombus canarium（Linnaeus，1758）和Canarium urceus（Linneaus，1758）是马来西亚和周边地区生态和经济上重要的贝类物种。然而，它们的数量正在减少，本组织病理学研究调查了可能影响它们健康的寄生虫和疾病方面。从其自然栖息地随机采集宝贝螺样本，并在光显微镜下检查各种器官和组织的组织学切片（4-5 µm）。然后，使用透射电子显微镜（TEM）对感染组织进行超微结构分析。根据组织学分析，在消化管的空泡细胞和金字塔状隐窝细胞以及消化管中观察到大量似 Apicomplexa 的配子体、孢子囊和滋养体。此外，还在肾脏的细胞中观察到似球虫和卵囊样 Pseudoklossia sp. 阶段。除此之外，在消化腺和肾脏中观察到具有囊状结构的孢子。尽管寄生虫存在于大多数分析的器官中，但两种物种均未出现明显的症状、炎症反应或死亡率，这表明它们之间可能存在非致病关系，如共生或互利共生。然而，需要进行更多的调查，包括分子研究，以确认寄生虫的鉴定和动态，并进一步评估 Apicomplexa 寄生虫与其宿主之间的关系性质。
