Affiliations 

  • 1 School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
  • 2 School of Fisheries and Aquaculture Sciences, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia
  • 3 Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang Selangor, Malaysia
  • 4 School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. Electronic address: zdcc@ukm.edu.my
J. Invertebr. Pathol., 2018 02;152:17-24.
PMID: 29360442 DOI: 10.1016/j.jip.2018.01.005

Abstract

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.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.