Gyrodactylus gasterosteia difficult meal to swallow for the three-spined sticklebacks,Gasterosteus aculeatusL.

Abstract

This study examines the transmission strategies employed by parasites in order to colonize new hosts. Three-spined sticklebacks, Gasterosteus aculeatus L., were challenged with Gyrodactylus gasterostei Gläser, 1974 in a chamber and the colonization of new hosts was observed. Live-video recording indicates that gyrodactylid transmission possibly maximizes the chances of contact with an alternatively feeding response from dead parasitized hosts to predatory stickleback. It is proposed that host scavenge feeding may comprise an additional route for gyrodactylid transmission, although its relative importance with respect to other recognized routes remains uncertain. Although it was clearly demonstrated that G. gasterostei can reside in the mouth of its host, the study revealed that scavenging-feeding upon dead parasitized hosts did not contribute significantly to the level of infection in 3 h and parasite transmission observed on the feeding fish. A series of experimental exposures and scanning electron microscope images suggest that once ingested, the parasites can attach to the lining of the buccal cavity and then migrate to their preferred colonization site on the outer surface of the fish. In addition to the direct contact infection pathway normally associated with many. This study highlights that diagnosticians should be aware of the fact that the oral cavity may act as temporary transmission location for gyrodactylid fauna.

Does the anaesthetic infl uence behavioural transmission of the monogenean Gyrodactylus gasterostei Gläser, 1974 off the host?

“…This suggests that gyrodactylids that have given birth at least once are more likely to leave the host following host death in order to colonise new hosts, as a MCO appears after gyrodactylids have given birth for the fi rst time (at an age of 24 -30 h at 13 °C for G. gasterostei according to Harris, 1985a). Grano-Maldonado (2014b), showed a signifi cantly higher probability of parasites transferring in the groups with an MCO (penis) than those lacking an MCO, being a key factor during oral route transmission from dead to live fi sh during scavenging activities. Young fl ukes, which have not given birth, have high life expectancy, and may remain on the fi sh until after they have given birth in order to maximise population numbers.…”

Development of a non‐lethal hydrogen peroxide treatment for surveillance of Gyrodactylus salaris on trout farms and its application to testing wild salmon populations

“…The chemical method achieved a 33% improvement in gyrodactylid recovery rate (84.6%) compared with that of whole‐body examination alone (51.9%), and the procedure historically conducted by the Cefas Fish Health Inspectorate for surveillance in England and Wales. The total parasite count estimated by the chemical method was 25% higher than that of whole‐body examination, and this may in part be explained by parasites that were attached within the buccal and gill cavities of fish (Grano‐Maldonado, ). These may be hidden to screeners conducting physical examinations but are detached and recovered following exposure to hydrogen peroxide (this may be influenced by the experience of the screener(s)).…”

Ultrastructure study of the stored lipid reserves in Gyrodactylus gasterostei (Monogenea) using confocal and transmission electron microscopy

“…This experiment follows a previous experiment's methods to evaluate the influence of the maturity of monogenean on host transfer using a parasite–host model. [ 8 9 10 11 12 ] Twenty individual sticklebacks were terminally euthanized with 0.01 M 2-phenoxyethanol (MERCK, Darmstadt, Germany) and placed in individual Petri dishes containing clean water at 10°C. Dead hosts were observed under an Olympus SZ30 stereomicroscope (Tokio, Japan) at different magnifications, with the time at which each gyrodactylid looped off the fish during 60 min being recorded.…”

“…The MCO was considered to be present only if the spines were clearly visible. [ 8 11 ] For taxonomical identification, each gyrodactylid was carefully mounted on triangular surgical needles (size 16, Barber of Sheffield, UK). Each specimen was then mounted on a glass slide in a drop of distilled water ensuring that the haptoral hooks were flat.…”

“…An experimental model with Gyrodactylus gasterostei and the host fish Gasterosteus aculeatus was used for the purposes of this study. This is a simple and successful system to examine the aspects of transmission of parasites from live to dead fish, since Harris[ 7 ] and recently Grano-Maldonado[ 8 9 10 11 12 ] employed this model on the biological and behavioral bases of host selection, gyrodactylid transfer during multiple fish transportation, influence of maturity in transmission routes; this information about parasite migration from the dead host has upgraded knowledge on the management of parasitic diseases.…”