First report of the parasitic copepod Lernaea cyprinacea (Copepoda: Lernaeidae) on gobioid fishes (Teleostei: Gobonellidae) in southern Europe

Abstract

Lernaea cyprinacea is a non host-specific parasitic copepod known to infest many freshwater fish species. Outbreaks of infestations by this ectoparasite may cause mass mortality of parasitized fishes. L. cyprinacea has been found mostly on pelagic species. Records on small benthic fish species are less common. Especially rare are infestations of Gobioidei adapted to a benthic life style, with reports restricted to Asia and, in Europe, to the Ponto-Caspian region. Although it is cosmopolitan, L. cyprinacea has rarely been found in Italy. One of the few Italian localities with documented infestations is Lake Trasimeno, a lake with an economically important fishery. Although endoparasites of commercially interesting fish species in this lake are well documented, information about ectoparasites is rare. In May 2015, specimens of two gobioids − Knipowitschia panizzae and Pomatoschistus canestrinii − infested with L. cyprinacea were sampled at the south shore of Lake Trasimeno. Both gobies are not native to the lake. This is the first documentation of gobioid fishes as hosts of L. cyprinacea in Italy and in Europe (outside of the Ponto-Caspian region). Although both gobies are not optimal hosts (small size, short life expectancy) they have the potential to carry and to transmit the parasite in freshwater habitats, e.g. by unintentional introduction with fry of other fish species.

Ecological Status Assessment of Transitional Waters

“…In the Venice lagoon, trophic levels indeed show marked changes along the salinity gradients, with higher nutrient and chlorophyll concentrations recorded in the more confined portions of the basin [91,92]. Common estuarine species, integrating complex ecological processes such as trophic interactions in transitional water ecosystems, could therefore play a key role as indicators of such changes in the inner areas of the lagoon [41,[93][94][95].…”

“…Such input could result in positive, negative, or no effect on the equilibrium magnitude or carrying capacity (N i * ) of a species. The inverse of the negative community matrix (−A ij −1 ) provides an estimate of change in the equilibrium level of variable N i * carrying capacity due to change in parameter C h [95].…”

Lagoon Resident Fish Species of Conservation Interest According to the Habitat Directive (92/43/CEE): A Review on Their Potential Use as Ecological Indicator Species

“…As an oligohaline species, N. canestrinii can be common also in freshwater habitats, where other factors could threat its local population survival. For Trasimeno Lake, for example, it has been hypothesized that the Eurasian copepod Lernaea cyprinacea could infest the host, generally belonging to the Gobionellidae family, causing its death [95]. At present, there is no evidence of parasitism on N. canestrinii and it is established that in brackish waters this risk is remote because L. cyprinacea does not tolerate even low salinity [95].…”

Prevalence and Histopathological Effects of Parasitic Copepod Lernaea Cyprinacea in Estuarine Fishes From Mediterranean Region of Turkey, With a New Host Record

“…One of the most important enemies of fishes, the parasitic copepods could damage their hosts by the attachment mechanisms and feeding activities (Alaş et al 2015). So far as known, it was determined that the non-host specific copepod Lernaea cyprinacea Linnaeus, 1758 or anchor worm can infect native and introduced fish in Turkey, being recorded on freshwater species more in lakes and ponds rather than in river creek and streams (Ahnelt et al 2018;Koyun and Atici 2018).…”