Reply to the letter to the editor referencing to “Apparent kleptoparasitism in fish-parasitic gnathiid isopods” (https://doi.org/10.1007/s00436-018-6152-8)

Abstract

We greatly appreciate the interest in our paper. We were indeed quite surprised by our observations. We also appreciate the discussion on terminology. We have always struggled with how gnathiid isopods appear to straddle the line between "parasite" as traditionally used and "micropredator" as used to describe organisms such as mosquitoes. Indeed, that lack of fit has resulted in gnathiids being excluded from much of the parasitology literature (including textbooks) and from the broader literature and discussions on micropredation. Therefore, we are not firmly "attached" to either term with regard to gnathiids and welcome the suggestion of "temporary parasite." We are also not strongly attached to the term "kleptoparasitism" (another form of temporary parasitism) with respect to our observations and are certainly open to the use of the term "hyperparasitism." As with any terminology, these terms either need to be revised to be more inclusive, or we will require new terms as new discoveries are made that do not fit neatly into existing terms. Our work may indeed represent the later scenario. To add further to the discussion, we point out in our paper that the observed behavior could be a bi-product of the detection of host (fish) blood such that the "intent" is to attach to a host and feed on blood and that the attachment to and feeding from another gnathiid is a "mistake." If so, this type of accidental or incidental parasitism may warrant yet another term