Labeo rohita and Argulus siamensis infection: Host size, local inflammatory reaction and immunity modulate ectoparasite load on fish. (22nd September 2017)

• Record Type: Journal Article
• Authors: Parida, Sonali; Mohapatra, Amruta; Mohanty, Jyotirmaya; Sahoo, Pramoda K
• Is Part Of: Aquaculture research. Volume 49:Number 2(2018)
• Page Start: 757
• Page End: 766
• Publication Date: 2017-09-22
• Subjects: Argulus siamensis -- fingerling -- inflammation -- juvenile -- Labeo rohita -- pre‐adult; Aquaculture -- Periodicals; Fishery management -- Periodicals; 639.8
• DOI: 10.1111/are.13506
• Languages: English
• ISSNs: 1355-557X

Abstract

Abstract: Parasite species often show a heterogeneous, highly dispersed pattern of infestation within hosts. Varieties of factors including morphological, physiological, immunological and nutritional characteristics affect the infestation level of a specific parasite in homogenous pray. Limited attempts, however, have been made to explore such underlying drivers of infestation pattern. Here, three stages of Labeo rohita (fingerling, juvenile and pre‐adult) were challenged with ectoparasite, Argulus siamensis in same aquaria. The parasite load on individuals was determined at 5‐day interval for 1 month. The load was found to be highest in pre‐adult stage followed by juveniles and fingerlings. On day 20 post infection, the load of parasite on pre‐adult fish was high along with detectable skin damages. Skin tissues were collected for immune gene expression analysis and histopathology. Histological studies showed increased melanization in the dermis and mild inflammatory cellular reactions in pre‐adult fish whereas, massive subcutaneous myositis with engorged blood vessels were observed in fingerlings. The expression levels of various inflammation and innate immune‐related genes viz ., interleukin (IL)‐8, IL‐10, IL‐11, IL‐15, natural killer enhancing factor, toll‐like receptor 4, apolipoprotein A–I and immunoglobulin Z were significantly high in skin samples of infected fingerlings as compared to other two growth stages or controls of each stage. On the other hand, the expression of immunoglobulin M was down‐regulated in all infected samples as compared to their respective controls. The results thus depict that local immuno‐inflammatory response plays a significant role in determining susceptibility of host in intra‐specific group, and has important implications for ecology and aquaculture.