New records of crustose seaweeds associated with subtidal maerl beds and gravel bottoms in Galicia (NW Spain)

We studied crustose seaweeds associated with subtidal maerl beds and gravel bottoms in the Galician rias (NW Iberian Peninsula). Each species is described as well as its habitat and occurrence in maerl beds and gravel bottoms. We confirmed the great crustose species richness associated with European Atlantic maerl beds. We report a new species for the Atlantic Ocean (Contarinia peyssonneliaeformis) and six new records for the Iberian Peninsula (Atractophora hypnoides stage Rhododiscus pulcherrimus'', Peyssonnelia immersa, Scytosiphon lomentaria stage Microspongium gelatinosum'', Petroderma maculiforme, Pseudolithoderma roscoffense and Phycocelis foecunda). Peyssonnelia armorica is a new record for the Atlantic Iberian Peninsula and Peyssonnelia harveyana is a new record for the Galician coast. We provide for the first time observations on spermatangial structures in Cruoria cruoriaeformis occurring on the Atlantic Iberian Peninsula. The Galician crustose algal flora of subtidal maerl beds and gravel bottoms is increased up to 23 species (15 Rhodophyta and 8 Ochrophyta). Peyssonnelia rubra is excluded from the Galician flora.