title: First Record of Paratenic Hosts of the Swimbladder Nematode Anguillicola crassus in North America.
abstract: Anguillicola crassus is a non-native parasite of the American eel, Anguilla rostrata. Since being introduced into North America, the nematode has spread rapidly across the range of A. rostrata, but paratenic hosts, which may facilitate parasite dispersion, have yet to be identified in the region. We investigated infection of larval A. crassus in 261 fish specimens belonging to 23 species and 12 orders collected from estuarine habitats in South Carolina (salinities 0-9 ppt) and Nova Scotia (10-18 ppt). A total of 35 fish belonging to 5 species and 3 orders were infected with the third-stage larvae (L3) of A. crassus, providing the first record of paratenic hosts for the parasite in North America. In South Carolina, high prevalence and abundance of the worm were found in spot (Leiostomus xanthurus), silver perch (Bairdiella chrysoura), and highfin goby (Gobionellus oceanicus), and a high prevalence but lower abundance was found in mummichog (Fundulus heteroclitus). In Nova Scotia, 2 nematodes were found in a single specimen of tomcod (Microgadus tomcod). All of the infected species are associated with a benthic lifestyle, and some of them are known to move between estuaries along the coastline. Lower infection rates in Nova Scotia may be associated with lower water temperatures and/or higher salinity of the sampling site. Most of the L3 were found encapsulated in mesenteric tissue around the intestine and stomach. No L4 or pre-adult worms were found. Mean body length of the L3 was smaller than L3 stages found in American eels from Cape Breton. This suggests that development of A. crassus is arrested at the L3 in the 5 fish species reported here, supporting their status as paratenic hosts.
authors.affiliation: Aquatic Biodiversity Section, Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 105 McGill Street, Montreal, Quebec H2Y 2E7, Canada. Correspondence should be sent to: david.marcogliese@ec.gc.ca.
authors.forename: WenXiang
authors.initials: W
authors.lastname: Li
authors.affiliation: Aquatic Biodiversity Section, Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 105 McGill Street, Montreal, Quebec H2Y 2E7, Canada. Correspondence should be sent to: david.marcogliese@ec.gc.ca.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Arnott
authors.affiliation: Aquatic Biodiversity Section, Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 105 McGill Street, Montreal, Quebec H2Y 2E7, Canada. Correspondence should be sent to: david.marcogliese@ec.gc.ca.
authors.forename: Katherine M M
authors.initials: KM
authors.lastname: Jones
authors.affiliation: Aquatic Biodiversity Section, Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 105 McGill Street, Montreal, Quebec H2Y 2E7, Canada. Correspondence should be sent to: david.marcogliese@ec.gc.ca.
authors.forename: Paola E
authors.initials: PE
authors.lastname: Braicovich
authors.affiliation: Aquatic Biodiversity Section, Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 105 McGill Street, Montreal, Quebec H2Y 2E7, Canada. Correspondence should be sent to: david.marcogliese@ec.gc.ca.
authors.forename: Isaure
authors.initials: I
authors.lastname: de Buron
authors.affiliation: Aquatic Biodiversity Section, Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 105 McGill Street, Montreal, Quebec H2Y 2E7, Canada. Correspondence should be sent to: david.marcogliese@ec.gc.ca.
authors.forename: GuiTang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Aquatic Biodiversity Section, Watershed Hydrology and Ecology Research Division, Water Science and Technology Directorate, Science and Technology Branch, Environment Canada, 105 McGill Street, Montreal, Quebec H2Y 2E7, Canada. Correspondence should be sent to: david.marcogliese@ec.gc.ca.
authors.forename: David J
authors.initials: DJ
authors.lastname: Marcogliese
mesh_terms: D000400:Air Sacs / Q000469:parasitology*; D000811:Anguilla / Q000469:parasitology*; D000818:Animals; D017176:Dracunculoidea / Q000502:physiology*; D005393:Fish Diseases / Q000469:parasitology* / Q000635:transmission; D005399:Fishes; D009656:North America; D045483:Rivers; D017205:Spirurida Infections / Q000469:parasitology / Q000635:transmission / Q000662:veterinary*