Discovery of a deep-sea coral garden of Crypthelia vascomarquesi (Hydrozoa: Hydroidolina) in the Menez Gwen marine protected area (Mid-Atlantic ridge).

Abstract

Crypthelia Milne-Edwards & Haime, 1849 is the most diverse genus of lace corals inhabiting the Azores. During the 2012 DEEPFUN cruise, the first coral garden structured by this genus was recorded in the Menez Gwen Marine Protected Area (MPA). Identification of the species was based on morphology of specimens collected in situ and characterized using scanning electron microscopy (SEM). Imagery acquired by the remotely operated vehicle (ROV) Victor 6000 was used to document the species density as well as seabed geomorphology. The stylasterid Crypthelia vascomarquesi Zibrowius & Cairns, 1992 is described for the first time based on entire specimens, including female representatives. To date, this is the only Crypthelia species with female efferent pores located on dactylostomes, adding a new category to the feminine ampullar formula developed for the genus. The dense coral garden formed by C. vascomarquesi was recorded between 832 and 856 m depth at 37°48.896'N; 31°33.774'W. This vulnerable marine ecosystem (VME) represents a rare record of fragile and highly endemic corals that reinforces the value of natural heritage protected within a mid-Atlantic ridge MPA. We suggest that the C. vascomarquesi coral garden is included at level 5 of the deep-sea section of the European habitat classification system (EUNIS), as a means to emphasize its conservation value and the monitoring of MPAs.