ROV imaging of deep-sea echinoderms from the Brazilian continental margin, Southwest Atlantic

摘要

ROV images were registered from the Brazilian continental margin, Southwestern Atlantic (700-1100 m) in 2004 through the 'Campos Basin Deep-Sea Coral Assessment Project' conducted by CENPES-PETROBRAS. An area of 0.105 km~2 was covered by coral banks and their associated fauna, and images from this were taken from nested 8 areas over 50 m long parallel transects in each area: 0.080 km~2 (n = 4); 0.160 km~2 (n = 1); and 0.225 km~2 (n = 3). A total of 368 echinoderms were viewed and identified to the lowest possible level. All classes of echinoderms were represented in the videos: Crinoidea (1 order); Asteroidea (5 orders, 5 families, 4 species); Ophiuroidea (2 orders, 3 families); Holothuroidea (1 order, 1 family); Echinoidea (1 cohort). Asteroidea was the most diverse group in terms of species richness; however Ophiuroidea, also common especially on Anthozoa and Porifera, was most likely underestimated. The following echinoderm species were identified: Novodinia antillensis (n = 94), Nymphaster arenatus (n = 3), Plutonaster bifrons (n = 2), Zoroaster fulgens (n = 1) (Asteroidea); and Mesothuria verrilli (n = 4) (Holothuroidea). Except for N antillensis, the other asteroids were found in soft sediments. Most comatulids (n = 35) were viewed on biological substrates, and fewer were found in the mud at the edges of the banks (n = 16). Even though the ROV may have underestimated quantitative sampling properties, its images provided a general overview of the environment and reasonable qualitative estimates of the larger echinoderms.