Anisakis pegreffii (Nematoda: Anisakidae) in European anchovy Engraulis encrasicolus from the Mediterranean Sea: Fishing ground as a predictor of parasite distribution

The Mediterranean European hake, Merluccius merluccius : Detecting drivers influencing the Anisakis spp. larvae distribution

“…This statement is supported by data recorded for other fish species, like Engraulis engraulis and Sardina pilchardus (Levsen et al, in press), showing the highest levels of infection in this western part of the Mediterranean Sea (Table 2). This finding could be related to ecological characteristics of the Adriatic Sea, with both abiotic and biotic conditions favourable to maintain the life cycle of A. pegreffii at high population size (see Cipriani et al, 2017). Some favourable abiotic conditions of the central Adriatic Sea, which favour the presence of a stable food web, may result in enhancing the overlapped and abundant distribution of hosts belonging to different trophic levels of the life cycle of A. pegreffii, and could thus explain its pattern of distribution and high levels of infection in different fish species, such as hakes, anchovies (present issue Cipriani et al, 2017), and sardines (Levsen et al, in press), in this semi-enclosed and narrow basin.…”

“…This finding could be related to ecological characteristics of the Adriatic Sea, with both abiotic and biotic conditions favourable to maintain the life cycle of A. pegreffii at high population size (see Cipriani et al, 2017). Some favourable abiotic conditions of the central Adriatic Sea, which favour the presence of a stable food web, may result in enhancing the overlapped and abundant distribution of hosts belonging to different trophic levels of the life cycle of A. pegreffii, and could thus explain its pattern of distribution and high levels of infection in different fish species, such as hakes, anchovies (present issue Cipriani et al, 2017), and sardines (Levsen et al, in press), in this semi-enclosed and narrow basin. Abiotic and biotic factors, such as mean sea surface temperature, depth, salinity, sea surface temperature range, as well as primary production, were identified as most important abiotic variables impacting the distribution of Anisakis spp.…”

“…The geographical areas too, with their ecological conditions and the presence of suitable hosts for the life cycle of the Anisakis spp., seem to represent a determinant driver of A. pegreffii rate of infection. Previous authors (Valero et al, 2006;Mattiucci et al, 2004Mattiucci et al, , 2014bSuzuki et al, 2010;Cipriani et al, 2017) noted that levels of infection by different species of Anisakis vary depending on the geographical origin of the fish host. In fact, remarkably higher levels of infection for A. pegreffii were recorded in hakes of the Adriatic Sea/Ionian Sea areas compared to the fish of the same size range obtained from the western Mediterranean fishing grounds.…”

“…A further hypothesis to explain the high densities of A. pegreffii recorded in this basin could be the presence of an "anthropogenic shortcut" in the life cycle of the parasite (see Cipriani et al, 2017). There is a widely used routine, followed by local fishermen, who eviscerate fish (above all hakes and scabbard fish) directly on board of the vessels, then discard the viscera at sea, together with bycatches.…”

Gene expression profiles of antigenic proteins of third stage larvae of the zoonotic nematode Anisakis pegreffii in response to temperature conditions

“…larvae were collected from Engraulis encrasicolus anchovies caught in the Adriatic Sea (off the S. Benedetto del Tronto coast), where high rates of infection with the target parasite species, i.e. A. pegreffii, have previously been recorded [15]. After the capture, the fish were maintained at 2°C, using a data logger, until the parasitological examination.…”