The macrofauna associated to the bamboo coral Isidella elongata: to what extent the impact on isideidae affects diversification of deep-sea fauna

Abstract Macrofauna associated with the bamboo coral Isidella elongata was analysed in Balearic Basin at depths of 697–1308 m. The diversity macrofauna and specific associations identified depended on different morphological characteristics colonies, such as height or density rami. Species consisted mainly sessile fauna, cnidarians (the actinian Amphianthus dornhii solitary Desmophyllum dianthus ) cirripeds ( Gibossaverruca sp.). strongest relationship (commensalism) occurred for Pontogeneiidae amphipod Dautzenbergia megacheir , living attached to colonies represented by all population stages from adult (oostegal) females males juveniles. Species-coral relationships between corals (Isididae) are plausible. spp. showed differences Atlantic (described Walker 1897 “eyes wanting”) Mediterranean (with well-developed reddish eyes) specimens. This would suggest diversification this genus, has been recently suggested Pleustidae deep gorgonians. macrofaunal community I. higher most mature (larger density) fields found NW Mallorca, than other parts Mediterranean. only site where sp. (a first faunal record) D. were collected. These complex deep-water may provide arguments protect these fragile ecosystems a source diversification.