Potential hosts were dissected fresh aboard the ship or frozen at -80°C immediately upon arrival at the surface. Each potential host was thoroughly examined following standard methods for detecting metazoan parasites (Kuris et al. 2008, Morton et al. 2021, McLaughlin 2018).

Before dissection, hosts were identified to species using reference guides (Desbruyères et al. 2006). When species ID was uncertain, hosts were given a morphogroup ID or grouped at a higher taxonomic level (i.e., Family or Genus). In some cases, host identification was based on COI barcoding using universal metazoan primers (Folmer et al. 1994).

Host length was measured along the maximum dimension using standard protocol for each taxon: gastropods were measured from the base of the column to the apex; crabs were measured at the maximum carapace width; and shrimp were measured by carapace length along the midline, including the rostrum. Standard length and total length were recorded for fish. Additional host information, such as weight, sex, gut contents, and condition, were recorded when possible.

The exterior of each specimen and the wash from its storage bag or compartment were carefully inspected for ectoparasites. Internal parasites were detected visually by pressing host tissues between two glass plates, shining transmitted light from beneath and carefully scanning the entire slide in a grid pattern under a dissecting scope at 10-50x magnification. For large animals, each organ was examined individually to record the site of infection. Small animals were squashed and examined whole.

All symbionts detected by our methods (including metazoan parasites, commensals, protozoan parasites, and microbial pathologies) were assigned a species or morphogroup name and counted. When a species or morphogroup was first encountered or found in a new host species, several individuals were measured, photographed, and preserved for further morphological and molecular description.

Photos were taken using an eyepiece camera or a camera attached to a microscope photo tube and C-mount. Parasites were measured with a micrometer installed in the microscope eyepiece. Parasite specimens were preserved in 80% ethanol for morphological description and 95% ethanol for genetic analysis. Specialist taxonomists were consulted to ensure morphogroups were distinct to the species level. Parasite morphogroups were classified to the lowest possible taxonomic level based on morphological description and/or 18S and 28S barcoding (Bray et al. 2014). Barcoding was used as the primary method for classification of juvenile and cyst stages.

This dataset includes true parasites (macroparasites, castrators, and trophically-transmitted parasites) as well as other symbionts such as commensals and egg predators.

BCO-DMO Processing Notes:
* Added data file in Data File section to comply with data base requirements
* Dataset version 1 primary data file (version data 2022-08-24) replaced with version 2 (2023-05-11). The change is due to "Two parasite morphospecies names were updated based on new genetic information."
* File "PARASITES_VENT_DISSECTION.xlsx" (submitted to bcodmo on 2023-05-10) loaded as a data table into the BCO-DMO data system. Values "NO" "NR" and "NA" were identified as missing data values but preserved as strings within the data table instead of becoming blank (null) values to indicate no data. No modifications were made to the column names or values.

parasites_vent_dissection.csv