Host reaction in paratenic fish hosts against 3rd stage larvae of Anguillicola crassus

Abstract

Many fish species of Lake Balaton (Hungary) serve as paratenic hosts for the 3rd stage larvae of the eel parasite Anguillicola crassus. The incidence of different phases of the host reaction varies with paratenic fish host but its nature is basically the same. The appearance of mononuclear cells around the larvae migrating in the tissues or in the abdominal cavity is regarded as a sign of cellular host reaction. The cells adhering to the surface of the larvae gradually assume an epithelioid shape and form a granuloma. With the advancement of the process the larvae and the epithelioid cells surrounding them undergo necrosis, and the granuloma becomes surrounded by a connective tissue capsule. In more chronic cases, the inside of the parasitic nodule surrounded by several layers of connective tissue is filled out by amorphous tissue and parasite debris. In the 'suitable paratenic hosts' Anguillicola sp.larvae not affected by the host's cellular reaction outnumber those affected by it, whereas in the 'less suitable paratenic hosts' the cellular reaction very rapidly forces the larvae into foci and destroys them.

Morphological and morphometric features of nematode-cysts in Gymnotus inaequilabiatus liver in the Brazilian Pantanal

“…The largest cysts harbor a thicker collagen-layer, which might indicate a chronic reaction in older larvae with higher deposition time. These findings suggest that the vascular via was not used by these nematodes in G. inaequilabiatus, since vascular alterations such as perivascular inflammatory reaction, coagulative necrosis, and edematous areas, as well as obstructive thrombosis, were not observed, in contrast to other studies (SZÉKELY et al, 1996;VENTURA et al, 2016). Based on the amount of cyst structures found after the macroscopic and microscopic assessment, we inferred that this organ is a critical site of nematode infection.…”

“…Based on the amount of cyst structures found after the macroscopic and microscopic assessment, we inferred that this organ is a critical site of nematode infection. The deposition of encysted forms did not affect the liver function, since degenerated hepatocytes or extensive granulomatous reactions were not observed, in contrast to what has been reported on other species of fish affected by parasites (SZÉKELY et al, 1996;FERGUSON, 2006;FEIST & LONGSHAW, 2008). Furthermore, the condition factor Kn was not associated with the liver cyst-nematode number, suggesting that G. inaequilabiatus might not be sensitive to liver nematode infracommunities.…”

Parasitic Helminths and Freshwater Fish Introduction in Europe: A Systematic Review of Dynamic Interactions

“…The most diversified native hosts are cyprinids, leuciscids and percids. A few examples of non-native paratenic hosts are the North American Centrarchidae L. gibbosus [94,112,[115][116][117], the Central American cichlid Amatitlania nigrofasciata (Günther, 1867) [118], the Asian cyprinid P. parva [112,116,117] and a total of five well-studied Ponto-Caspian gobids [119][120][121][122]. The majority of these paratenic hosts are species living in close association with the substrate (benthopelagic and demersal species), as was previously pointed out in both Belgium and Sweden [94,123].…”

“…The presence of the co-introduced P. laevis could thus be another factor facilitating the spread of A. crassus through invasional meltdown [125,128,129]. [112,116,117] Carassius carassius Native Benthopelagic Nekton, Zoobenthos, Zooplankton, Detritus Hungary [116,117] Carassius gibelio Unclear Benthopelagic Zoobenthos, Detritus Hungary [112,116,117] Cyprinus carpio Native Benthopelagic Nekton, Zoobenthos, Zooplankton, Detritus, Plants Hungary [112,[115][116][117] Leuciscus aspius Native Benthopelagic Zooplankton, Nekton Hungary [112,116,117] Phoxinus phoxinus Native Demersal Nekton, Zoobenthos, Zooplankton, Detritus, Plants…”

“…France [130] Pseudorasbora parva Non-native Benthopelagic Nekton, Zoobenthos, Zooplankton, Plants Hungary [112,[115][116][117] Rhodeus amarus Native Benthopelagic Zoobenthos, Plants Hungary [112,116,117] Romanogobio albipinnatus Native Benthopelagic Zoobenthos Hungary [116,117] Scardinius erythrophthalmus Native Benthopelagic Nekton, Zoobenthos, Zooplankton, Detritus, Plants Belgium [94], Hungary [112,116,117] Tinca tinca Native Demersal Nekton, Zoobenthos, Zooplankton, Detritus Belgium [94], Hungary [112,116,117] Esocidae Esox lucius Native Pelagic Nekton, Zoobenthos, Zooplankton Hungary [112,116] Gasterosteidae Gasterosteus aculeatus Native Benthopelagic Nekton, Zoobenthos, Zooplankton, Plants Belgium [94], France [130] Pungitius pungitius Native Benthopelagic Nekton, Zoobenthos, Zooplankton France [130] Gobiidae Babka gymnotrachelus Non-native Benthopelagic Nekton, Zoobenthos Poland [119] Neogobius fluviatilis Non-native Benthopelagic Nekton, Zoobenthos, Zooplankton Germany [119,120], Hungary [112,116,117]…”