Settlement patterns of molluscs, with particular reference on Great Mediterranean scallop (Pecten jacobaeus, Linnaeus) and biofouling organisms on different type of collectors and locations in Boka Kotorska Bay

Abstract

The settlement of molluscs’ larvae of and other biofouling organisms on experimental collectors was studied, with particular reference Great Mediterranean scallop, Pecten jacobaeus. Three types of experimental collector made from vegetable sacks, modelled based on the collectors used in Japan, were placed in four existing fish and shellfish farms located in the Boka Kotorska Bay. The experimental collectors were placed in the periods June–October and June–December 2017 and the period August 2017–February 2018 and monitored after immersion of four to six months, respectively. In total, 18 species of molluscs and also 28 species of biofouling organisms were determined. The most abundant ones found on the collectors were the following shellfish species (68 %) Talohlamys multistriata, Mytilus galloprovincialis, Modiolarca sp., Anomia ephippium and Limaria hians. The most abundant group of biofouling organisms were crustaceans (18 percent) with a species of porcelain crab, Pisidia longicornis, and tunicates (5 percent) with the species Phallusia mammillataand Ascidia mentula. The main target species, Great Mediterranean scallop, was most abundant on collector Type II,with 28 individuals. From three types of experimental collectors used in the process of collecting larvae of shellfish and biofouling species, collector type-I and type-II proved to be a more suitable basis for receiving larvae of shellfish due to the unimpeded flow of sea water that allows their successful growth and development. Species Talochlamys multistriata, were found in great abundance and it could be good candidate to diversify the aquaculture production, thus potentially offering farmers an additional source of income.