Antifouling activities of marine sedentary invertebrates on some macrofoulers

Antifouling activities of alcohol extracts from four gorgonian species (Mel itodes sp., Gorgonella sanguinolenta, Echinogorgia complexa, Acanthogorgia turgida), five soft corals [Dendronephthya sp. 1, Dendronephthya sp. 2, Den dronephthya (Roxasia) sp., Dendronephthya (Morchellana) sp., Dendronephthya (Spongodes) sp]. three unidentified antipatharian species (coded as antipa tharian sp.1, antipatharian sp.2, antipatharian sp.3) and Five sponges [Pla kortis simplex, Axinella sp., Fasciospongia cavernosa, Azorica pfeifferae. Dercitopsis sp.] against cyprids of the barnacle Balanus amphitrite and gre en mussel Perna viridis are reported here. An the extracts examined inhibit ed the settlement of cyprids of B. amphitrite. The EC50 values of the extra cts ranged from 16 +/- 3 mu g/ml (antipatharian sp.2) to 150 +/- 8 mu g/ml (antipatharian sp. 3). The LC50 values of the: extracts varied from 38 +/- 3.8 mu g/ml [Dendronephthya (Roxasia) sp.] to 218 +/- 30.6 mu g/ml (Fascios pongia cavernosa). A comparison of the EC50 and LC50 values reveal that mos t of the extracts are non toxic to the cyprids of B. amphitrite. In the cas e of P. viridis only 7 out of 17 extracts (41 %) inhibited byssal productio n and attachment. Gorgonian coral extracts displayed highest incidence of a ttachment inhibitory activity (75%) Followed by soft corals (40%), antipath arians (33%) and sponges (20%), when tested against P. viridis The EC50 val ues of the extracts ranged from 164 +/- 12 mu g/ml (A. pfeifferae) to 898 /- 11 mu g/ml [Dendronephthya (Morchellana) sp.]. Toxicity revival studies indicate that the transient presence of active extracts did not cause irrev ersible damage to P. viridis The results indicate the possible potentialiti es of these extracts as natural non toxic antifouling agents.