Colonisers of the dark: biostalactite-associated metazoans from lu Lampiune submarine cave (Apulia, Mediterranean Sea)

Metazoan/microbial bioconstructions, or biostalactites (BSTs), discovered in submarine caves of Apulia c. 20 years ago-and later found in several shallow-water Mediterranean caves-are receiving increasing attention in the last years. Examination of a single BST from the lu Lampiune cave (Apulia), at the limit between the Adriatic and the Ionian seas, has been addressed for the first time in this paper. The BST started growing at c. 6,000 years ago with a rapid accretion of large-sized serpulids (Protula), slowing down since about 3,000-4,000 years ago with a shift in main bioconstructors, probably caused by environmental changes. The present-day community on the outer BST surface is dominated by skeletonised epibionts, mostly small-sized serpulids, bryozoans and foraminifers, which contribute carbonate to the BST growth, by encrusting sponges, and by a few endobionts, including boring bivalves and insinuating sponges. New data remarkably increase biodiversity known for the lu Lampiune cave and the cave habitat in the region. Thirty-five taxa (16 bryozoans, 10 serpulids, 3 brachiopods, 2 foraminifers, 2 sponges, 1 bivalve and 1 cirriped) are recorded for the first time from Apulian marine caves, highlighting the need for further research in the area. In addition, the BST-associated community seems to differ from those of individual BSTs from other Mediterranean caves, revealing the individuality of these communities.

Automated summary

The study examined the metazoan/microbial bioconstructions, or biostalactites (BSTs) found in submarine caves of Apulia, with a focus on one BST in the lu Lampiune cave. The BST started growing approximately 6,000 years ago and has shown a shift in main bioconstructors around 3,000-4,000 years ago. The present-day community on the BST surface is dominated by skeletonised epibionts, contributing to BST growth.