Apparent kleptoparasitism in fish—parasitic gnathiid isopods
Gnathiid isopods are common external parasites/micropredators that feed on the blood of marine fishes. During the course of processing samples of gnathiid isopods collected from light traps in the central Philippines, we observed a gnathiid attached to and apparently feeding from the abdomen of another gnathiid. Because the abdomens of both gnathiids were enlarged, it was unclear whether one actually fed on the blood meal of the other. Introduction of unfed gnathiids with fed gnathiids revealed that one gnathiid could and did feed on the blood meal of another. This is the first observation of apparent conspecific kleptoparasitism reported for gnathiid isopods.
KeywordsMicropredator Hematophagous Coral reef Philippines
We thank the municipality of San Juan, Siquijor, Philippines, for permission to conduct this study. We also thank Dr. Hilconida P. Calumpong, Dr. Janet S. Estacion, Dr. Rene A. Abesamis, and the staff of the Silliman University Institute for Environmental and Marine Sciences for logistic support.
Funding was generously provided by grants from the National Geographic Society and the US National Science Foundation (OCE-1536794, PC Sikkel, PI). Financial assistance for RL Welicky from the Claude Leon Foundation of South Africa for this research is also acknowledged. This is contribution number 268 from the NWU-Water Research Group.
Compliance with ethical standards
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. All procedures performed in studies involving animals were in accordance with the ethical standards of Silliman University, Arkansas State University, North-West University, and the Government of the Philippines.
Conflict of interest
The authors declare that they have no conflict of interest.
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