Shrimps remove ectoparasites from fishes in temperate waters

Abstract

We have found that two very common species of North Atlantic shallow water shrimp, Palaemon adspersus and Palaemon elegans, remove and feed on ectoparasites on plaice (Pleuronectes platessa L.). The relationship could be mutualistic, as we did not observe any attempts by the fishes to feed on the shrimps. The ectoparasites removed included monogenean worms (Gyrodactylus sp.) and sea lice (Lepeophtheirus pectoralis). An experiment showed that there were 65% more Gyrodactylus parasites on the fishes that had been apart from compared with those that had been together with shrimps for 48 h. Shrimps on coral reefs are known for cleaning fishes, but that shrimps in temperate waters show parasite-cleaning behaviour is, to our knowledge, a new observation.

Cleaner fishes and shrimp diversity and a re‐evaluation of cleaning symbioses

“…If we were to consider the view of Spotte () to the exclusion of all observations of cleaning interactions in the literature, there would only be six shrimp considered as cleaners, notably Ancylomenes holthuisi (Palaemonidae) and Urocaridella sp. c. (Becker & Grutter, ), A. pedersoni (Bunkley‐Williams & Williams, ; McCammon et al ., ), Lysmata amboinensis (Militz & Hutson, ), and Palaemon adspersus (Palaemonidae) and Palaemon elegans (Palaemonidae) (Östlund‐Nilsson, Becker, & Nilsson, ). The view of Spotte () is probably premature.…”

“…Cleaner shrimp vary considerably in size between species and genera. Their size may influence the ability to remove and consume certain ectoparasites, for which they use their chelae (Karplus, ; Östlund‐Nilsson et al ., ; Yaldwyn, ), but small size also facilitates access into areas of the mouth and gill chamber of client fishes (Karplus, ). An increase in the robustness of the mandibles, as well as the morphological intricacy of the gastric mill reflects a carnivorous feeding habit in crustaceans (Kunze & Anderson, ).…”

Refuge size, group living and symbiosis: testing the “resource economic monopolization” hypothesis with the shrimp Betaeus lilianae and description of its partnership with the crab Platyxanthus crenulatus

“…Nonetheless a recent study has demonstrated cleaning of large hosts (e.g. fish) by shrimp from temperate environments (Östlund-Nilsson et al, 2005;Jensen 2006). Most interestingly, we rarely observed crabs with their carapace covered by barnacles or any other fouling organism commonly found among rocks and mollusk shells at the study site.…”

Palaemon elegans Rathke, 1837 in the food of Baltic cod (Gadus morhua callarias L., 1758) from the Gulf of Gdańsk

“…Palaemon elegans is essentially omnivorous, feeding on foraminiferans, small invertebrates such as other crustaceans, molluscs, polychaetes, and insect larvae, but also on fish fry as well as algae and detritus (Kö hn & Gosselck 1989;Smaldon et al 1993;Jephson et al 2008;Persson et al 2008). In addition, the prawn was observed to feed on dermal ectoparasites of flatfish (Ö stlund-Nilsson et al 2005). On the other hand, the prawn may be a significant component of the food web as prey of predatory fishes, as suggested by Janas et al (2004) and Persson et al (2008).…”