Host‐parasite interface of Neoechinorhynchus rutili (Eoacanthocephala) in naturally infected salmonids*

Abstract

The fine structure of the presomal tegument of Neoechinorhynchu,s rutili is described from worms attached to the intestinal wall of salmonid fishes. The host's cellular reaction at the worms' point of attachment is described from the same hosts. The acanthocephalans' presomal surface coat had a liquid hpid appearance. It seemed to be fed by droplets of lipid from necrotic host cells, by the contents of the granules of the hosts' coarsely granulated granulocytes and by excretions of the parasite. The crypts of the worms' presomal outer limiting membrane were unbranched while those of the metasoma branched up in the striped layer. The striped layer of the proboscis hooks was more sclerotized than that of the surrounding (presomal) tegument-Inward from the hooks' striped layer the crypts formed a mesh. The contents of the crypts were usually continuous with the presomal surface coat. The host's intestinal tissue in the region ofthe worms' proboscides was heavily inflamed, especially around the hooks, where numerous granulocytes accumulated and degranulated. The acanthocephalans did not seem to be adversely affected by the inflammation and survived for at least 6 months in fish kept in the laboratory. The inflammator>' tissue around the proboscides of worms exceeding a length of about 5 mm was enriched with fibroblasts and collagen fibres forming a capsule. Generally, the worms showed a shallow attachment. They were never found in extra-intestinal positions.

Levamisole hydrochloride as an anthelmintic against Neoechinorhynchus buttnerae in juvenile Colossoma macropomum

“…exposure from 300 mg L −1 . Satisfactory in vitro results were also reported by Taraschewski et al, (1990) whoused LVC to control other acanthocephalan species (N. rutili and Echinorhynchus truttae), after 4 h of exposure.…”

Cellular responses of goldfish, Carassius auratus (L.), to metacercariae of Ribeiroia marini (Faust & Hoffman, 1934)

“…Ellis (1982Ellis ( , 1985 proposed that the eosinophilic granular cell of rainbow trout has a histaminogenic function similar to the mast cells of mammals. The eosinophilic granular cell has been shown to be present as an antiparasitic cell (Sharp, Pike & Secombes 1989;Taraschweski 1989;Hoole & Nissan 1994;Richards, Hoole, Lewis, Ewens & Arme 1994). We propose that the eosinophilic granular cell of the goldfish functions as an antiparasitic cell by releasing bioactive granules that alter the physiological environment of the epidermis and facilitate the expulsion of metacercariae from the lateral line canal.…”

Histological patterns of the intestinal attachment of Corynosoma australe (Acanthocephala: Polymorphidae) in Arctocephalus australis (Mammalia: Pinnipedia)

“…Several ecologic pressures influenced many aspects of the functional morphology of the Acanthocephala species and selected these parasites to an effective attachment mechanism (Petrochenko 1971), but there are scarce studies investigating the relationship between Acanthocephala morphology and attachment performance (Petrochenko 1971;Taraschewski et al 1989;Taraschewski 1990;Aznar et al 1999). The histopathological pattern from BDINA-1 to CLCH may represents a parasite attachment progressive mechanism (APM).…”