Parasites as biological tags to track an ontogenetic shift in the feeding behaviour of Gadus morhua off West and East Greenland

Abstract

Parasites, being an integral part of every ecosystem and trophically transmitted along the food webs, can provide detailed insights into the structure of food webs and can close the information gap between short-term stomach content analyses and long-term fish otolith analyses. They are useful for tracking ontogenetic shifts in the host's diet, the occurrence of specific organisms or migratory behaviour of their hosts, even in inaccessible environments. In the present study, stomach content analyses and parasitological examinations were performed on 70 Atlantic cod Gadus morhua, one of the most important high-level predators of small fish in the North Atlantic, caught during one research vessel cruise from West and East Greenlandic waters. Analyses revealed significant differences in fish size with higher values for East Greenland (average total length (TL) of 50.5 cm) compared to West Greenland (average TL of 33.3 cm). Clear differences were also present in prey and parasite composition. Crustacea was the main food source for all fish (IRI = 10082.70), while the importance of teleosts increased with fish size. With a prevalence of 85 % in West Greenland and 100 % in East Greenland, Nematoda were the most abundant parasite group. The results indicate an ontogenetic shift in the diet, which are discussed in the context of the common distribution theory, stock dynamics and migratory behaviour.

Host size-dependent anisakid infection in Baltic cod Gadus morhua associated with differential food preferences

“…It may be hypothesized that Baltic cod in SD25 obtain infection with C. osculatum when cod (reaching a TL of 30 cm) physically become able to ingest sprat. Corresponding dynamic associations between cod size, diet and parasites have been recorded previously in Atlantic cod (Münster et al 2015). It may be speculated that the sprat become infected when feeding on infected copepods and/or cladocerans, although we did not document infection in these planktonic organisms.…”

Parasite fauna of the Antarctic dragonfish Parachaenichthys charcoti (Perciformes: Bathydraconidae) and closely related Bathydraconidae from the Antarctic Peninsula, Southern Ocean

“…Bathydraconidae), feeding mostly on small crustaceans (this study). The same applies to infection patterns within one species; size-dependent differences in parasite infection rates as well as parasite fauna composition can be observed [11, 42]. However, another reason is that the known parasite fauna is most often directly linked to sampling effort [19]; therefore a more diverse parasite fauna is common for intensively studied fish species such as many of the economically important fishes (e.g.…”

Environmental variables and definitive host distribution: a habitat suitability modelling for endohelminth parasites in the marine realm

“…the ISI Web of Knowledge online database was searched according to a set of search terms ( Anisakis , Anisakid) to assess the novel research articles in the field that have been published since 2011 and extract specific locality records. In total, 101 publications were considered in the present model916171822364748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135…”