ABSTRACT
In deep-sea sampling undertaken by the SMBA over the past 10 years much further information has been obtained on the distribution of echinoderms in the Rockall Trough. Study of the more abundant species has defined bathymetric distributions which reflect vertical zonation in the overall distribution of the echinoderm fauna. The most clearly expressed pattern was a transition zone around 1000 m depth. A further increase in the rate of first and last occurrences of species seems to occur around 2000 m for ophiuroids and holothurians. Another trend was a considerably broader bathymetric range shown by post-larval and juvenile stages compared to the adults of certain species that are thought to have indirect larval development.
