Quantification and distribution ofAnisakis simplexsensu stricto in wild, one sea winter Atlantic salmon,Salmo salar, returning to Scottish rivers

Abstract

Quantification and distribution of Anisakis simplex sensu stricto in wild, one sea winter Atlantic salmon, Salmo salar, returning to Scottish rivers patricia noguera, campbell pert, catherine collins, nichola still and david bruno Red vent syndrome (RVS) has previously been reported in returning wild Atlantic salmon, Salmo salar from Canada, Iceland, Ireland, Norway and the UK. Affected fish show reddening and swelling in the perianal/vent area, with scale loss, ulceration and bleeding in severe cases. Studies in the UK and elsewhere report the condition to be induced by Anisakis simplex sensu stricto (s.s.) larvae. This parasite, commonly reported in several marine fish species, is typically found in the body cavity and the skeletal muscle, but has recently been reported within the vent tissues of salmon. This latter finding may reflect greater efforts in examining this body portion due to current awareness of the parasite presence in this atypical location. Based on clinical observations, affected fish are classified into three categories according to the severity of the external lesions, but quantification of the vent parasite numbers in relation to the categories, and assessment of the relative importance of this area as a site of infestation, are missing to date. This investigation aimed to provide data on parasite number and distribution in the viscera, skeletal muscle, peduncle and vent area and to confirm the identity of the larvae found in the vent and the viscera. The study showed the perianal/vent region harbours the highest total number of A. simplex larvae per fish and, proportionally to fish biomass, is the most heavily infested body location irrespective of external severity levels of RVS.

Increasing intensities of Anisakis simplex third-stage larvae (L3) in Atlantic salmon of coastal waters of Scotland

“…intensities in 1-sea winter Atlantic salmon between studies carried out in the late 1960's, 1970's [43,44] to those in 2008 and 2009 [5,9,45] revealed a tenfold increase in North Atlantic and North Sea populations of Atlantic salmon during the intervening 40-year period [9]. In comparison to a similar study of Atlantic salmon in Scottish coastal waters in 2009 (2.19 ± 0.53 kg) [3], the present study demonstrates that eight, three and four-fold increases in A. simplex (s.l.) intensity have occurred respectively in the musculature, viscera, and per fish.…”

“…Carcasses were removed from the freezer ~12 h before digestion. The enzymatic digestion followed the method described by Jackson et al [25], which was updated and modified by Noguera et al [3].…”

“…The Atlantic salmon, Salmo salar (L.), is a second intermediate host of A. simplex (s.s.) (L3) larvae. In addition to the musculature, visceral organs and tissues in the body cavity such as the gut, pyloric caeca, liver and mesenteries, are the most common sites of infection [3]. Following reports of a condition which, in 2005, became known as Red Vent Syndrome (RVS) [4], large numbers of unencapsulated A. simplex (s.l.)…”

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

“… 6 , 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 model 9 16 17 18 22 36 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 ...…”

Increasing intensities of Anisakissimplex (Rudolphi, 1809 det. Krabbe, 1878) larvae with weight and sea age in returning adult Atlantic salmon, Salmosalar L., of coastal waters of Norway

“…The presence of Anisakis larvae has been reported in Atlantic salmon caught in different geographical areas (Beverley‐Burton et al., 1977; Beverley‐Burton & Pippy, 1978; Kent et al., 2020; Noguera et al., 2015; Pippy, 1969; Senos et al., 2013; Wootten et al., 2010b). Most of these studies only reported the occurrence of Anisakis larvae associated with the viscera in the abdominal cavity of the fish, but some studies included the presence of Anisakis larvae also in the musculature (Beverley‐Burton & Pippy, 1978; Kent et al., 2020; Noguera et al., 2015) and one in the musculature only (Wootten et al., 2010b).…”