The Amphipod Gammarus fossarum as a Natural True Intermediate Host of the Nematode Raphidascaris acus

Abstract

A single third-stage larva of the fish nematode Raphidascaris acus (Bloch, 1779) (body length 1.77 mm) was found in 1 of 775 gammarids Gammarus fossarum Koch examined from the Jihlava River, Czech Republic. This is the first confirmed record of the advanced L, of this species from an invertebrate host, showing that an invertebrate may serve as true intermediate host of this nematode, in addition to lower aquatic vertebrates. Until now, invertebrates have generally been considered as paratenic hosts of the second-stage larvae of R. acus.

Complex interaction between proliferative kidney disease, water temperature and concurrent nematode infection in brown trout

“…Fish are capable of regenerating renal tissue by repopulation of injured nephrons and, unlike mammals, by the de novo production of nephrons. Renal regeneration by nephron neogenesis has been reported in catfish, rainbow trout, tomcod, zebrafish, tilapia, aglomerular toadfish and medaka (Reimschuessel et al 1990, 1996, Reimschuessel 2001, Salice et al 2001, Watanabe et al 2009, Diep et al 2011. In contrast to fish from the tributaries, 38 to 69% of brown trout originating from the Lyssbach still showed chronic renal changes in March 2009 as age 1+ fish, together with, mainly degenerated, intralesional T. bryosalmonae.…”

“…Definitive hosts are most frequently pike and brown trout, but other salmonids and occasionally other fish species can also be affected (Smith 1984). The life cycle involves obligate intermediate hosts: various fish species, cyclostomes and gammarids, and rarely also amphibians (Moravec 1970a, 1996, 2004, Smith 1984. In the brown trout, nematodes usually mature in the gut (Smith 1984).…”

Role of Leptodora kindti (Cladocera:Leptodoridae) in the life cycle of Raphidascaris biwakoensis (Nematoda:Anisakidae), a fish parasite in Lake Biwa, Japan

“…Whereas the largest third-stage larva of R. acus recorded from an invertebrate (Gammarus fossarum) was only 1.77 mm long, with only a small, ovalshaped genital primordium (Moravec 1996), some larvae of R. biwakoensis from L. kindti attained a body length of more than 5 mm and their genital primordia were highly advanced, even in the snlallest larvae (1.74 to 2.38 mm long) reported by Kataoka & Momma (1932). Such advanced genital primordia are usually typical of fourth-stage larvae, but the presence of the ventral cephalic tooth and the absence of a vulva in female larvae as well as their poorly developed lip anlages clearly show that they are third-stage larvae.…”

“…That of the congeneric species Raphidascans acus involves obligate intermediate hosts, various species of fish and cyclostomes, and, less often, amphibians, whereas various invertebrates (oligochaetes, snails, plankton and benthic crustaceans and aquatic insects) have generally been considered as pre-intermediate paratenic hosts of second-stage larvae (Moravec 1970, 1994, Smith 1984b, Torres & Alvarez-Pellitero 1988. Only recently has Moravec (1996) proved that an invertebrate (Gammarus) may serve, in addition to some lower aquatic vertebrates, as a true intermediate host of R. acus.…”

Experimental infection in Notodiaptomus sp. (Crustacea: Calanoida) with larvae of Camallanus sp. (Nematoda: Camallanidae)

“…Their life cycle has been studied in copepods (Stromberg and Crites, 1974;Bashirullah and Ahmed, 1976;De et al, 1986), amphipods (Moravec, 1996) and cladocerans (Moravec et al, 1998). In laboratory conditions, Campana-Rouget (1961), Stromberg and Crites (1974), Bashirullah and Ahmed (1976) and De et al (1986) studied the infection rate and the life cycle evolution of camallanid larvae in microcrustaceans.…”