This paper is a first detailed contribution to the knowledge of serpulid diversity from marine caves of the eastern Mediterranean Sea. A total of 27 taxa were recorded in two submerged caves of Lesvos Island, in the Aegean Sea. A clear trend of variability was observed with serpulid abundance, specifically that of sciaphilic and deep-sea species, increasing inwards while the number of taxa and species diversity did not change significantly across the two caves. In the innermost sectors of the studied caves two types of bioconstructions were observed: (a) ‘coiled doughnuts’ of Protula, recorded for the first time in Mediterranean caves; and (b) ‘biostalactites’ mainly consisting of skeletal metazoans recorded for the first time from the eastern Mediterranean. The results of the present study revealed new faunal elements and type of bioconstructions for the Mediterranean marine caves, showing that several aspects of their communities are still poorly known and deserve to be further investigated.

Aggregates of the Polychaeta Phyllochaetopterus socialis were recorded for the first time off Gemlik Bay in the Sea of Marmara, in August 2008. These were found at about 53 m depth, on the soft sediments around the sub-sea part of the North Anatoly Earthquake Fault. Samples were landed by beam trawl. Total wet weight of the mats was 58 kg. Forty-three species belonging to 10 phyla associated with P. socialis were recorded from the whole landing materials. Echinodermata and Gastropoda were the most abundant (12 and 8 species, respectively). Shannon–Wiener diversity and Margalef species richness indices were applied to analyse the structure of benthic communities. Presence and abundance lognormal distribution of the species and communities in mat habitat are shown. The hydrographic environment of the water mass is also discussed.

The coral reef inhabiting tubeworms from the Marshall Islands have been studied by few authors mainly by samplings in Enewetak Atoll. We report several new records of serpuline and spirorbine tubeworms from Enewetak Atoll as well as from Kwajalein, Utirik and Rongelap Atolls. Twenty-one species of Serpulinae and seven species of Spirorbinae are described and illustrated with line drawings, colour and/or scanning electron microscopy photographs. Neodexiospira turrita nom. nov. is proposed to replace Neodexiospira preacuta. Enewetak Atoll still represents the most species-rich atoll in the Marshall Islands but this is most likely the result of a greater sampling effort in this atoll for the last few decades.

Settlement of the fouling community is generally influenced by the physical, chemical and biological properties of the settling surface. The colour of the substratum may also exert an influence on larval settlement. In the present study, the influence of surface colour on the recruitment of fouling communities was investigated by suspending acrylic panels (red, green, blue, white and yellow) in coastal waters. Results showed that the colour of the substratum plays an important role in the recruitment of sessile species. Recruitment was comparatively high on red and blue coloured surfaces. Barnacle and tubeworm recruitment showed significant variation (Tukey test, P < 0.05) between different coloured surfaces. The significant conclusion of this study is that the colour of the artificial substrata should be taken into consideration when interpreting results from short-term biofouling studies.