Distribution and abundance of the species Holothuria tubulosa GMELIN, 1788 and Holothuria forskali DELLE CHIAJE, 1823 (Holothuria Echinodermata) in the Adriatic Sea

Abstract

      The data on the qualitative and quantitative distribution of the species Holothuria tubulosa and Holothuria forskali as affected by bottom types and depth are presented. The material originates from the continental shelf of the Adriatic Sea collected during PIPETA research cruises.
     Biological material was collected with bottom trawl from the Italian commercial trawler PIPETA in the 1982-1995 period. For the estimation of the abundance of the species Holothuria tubulosa and Holothuria forskali standard "swept area" method was used.
     The total mass and the number of individuals of these species were obtained from 833 hauls (21 cruises) of the bottom trawl over a surface area of 39808.191 km² of the Adriatic bottom.
     Obtained results are indicative regarding the fact that there are some differences in the horizontal and vertical distribution between the species Holothuria tubulosa and Holothuria forskali and that the abundance is affected by sediment type.