Crustacean symbionts of the sea anemone <i>Telmatactis cricoides</i> at Madeira and the Canary Islands*

Abstract

The crustacean symbionts of the club‐tipped sea anemone Telmatactis cricoides (Duchassaing, 1850) were studied at Madeira ( n = 81 anemones) and the Canary Islands ( n = 124 anemones). Of all anemones, 86% had crustacean symbionts. Nineteen species of crustaceans were encountered in association with Telmatactis cricoides. There were up to 18 individuals of up to four crustacean species associated with the same anemone. Anemone size and number of crustacean symbionts were positively correlated ( P &lt; 0.001) but only weakly so (r=+0.27). The most common crustacean symbiont was the shrimp Thor amboinensis , encountered with 65% of all anemones. Frequency and type of association with Telmatactis cricoides is described for each of the crustacean symbionts, Thor amboinensis, Lysmata grabhami, Lysmata seticaudata, Eualus occultus, Brachycarpus biunguiculatus, Stenorhynchus lanceolatus, Homola barbata, Pilumnus villosissimus, Gnathophyllum elegans, Inachus phalangium, Heteromysis sp. nuv. , Palaemonella atlantica, Herbstia condyliata, Stenopus spinosus, Athanas nitescens, Dromia personata Xantho incisus, Galathea sp., Liocarcinus sp. The shrimp Lysmata grabhami appears to live in stable pairs of two simultaneous hermaphrodites, a social structure not previously described for any crustacean species.