Chromis

Photo: Robert Ulph · © all rights reserved

Chromis form dense aggregations above the Secca delle Fumose's crest, using the bubble streams and thermocline eddies created by the vents as reference points for their schooling behaviour. Males turn a dramatically darker brown during breeding season and vigorously defend small nesting patches scraped clean on the rock surface near vent openings. Their density here exceeds most comparable Mediterranean seamounts, likely because the suppressed urchin population allows the algal turf that chromis graze to grow unchecked.