Antifouling activities of marine sedentary invertebrates .on some macrofoulers

Abstract

Antifouling activities of alcohol extracts from four gorgonian species <i>(Melitodes </i>sp., <i>Gorgonella sanguinolenta, Echinogorgia complexa, Acanthogorgia turgida), </i>five soft corals <i>[Dendronephthya </i>sp. 1, <i>Dendronephthya </i>sp. 2,<i> Dendronephthya (Roxasia) </i>sp., <i>Dendronephthya (Morchellana) </i>sp., <i>Dendronephthya (Spongodes) </i>sp], three unidentified

<span style="font-size:14.0pt;line-height:115%;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";color:black;mso-ansi-language:en-in;="" mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">antipatharian species (coded as antipatharian sp. 1, antipatharian sp.2, antipatharian sp.3) and five sponges <i>[Plakortis simplex, Axinella </i>sp., <i>Fasciospongia cavernosa, Azorica pfeifferae </i>, <i>Dercitopsis </i>sp.] against cyprids of the barnacle <i>Balanus amphitrite </i>and green mussel <i>Perna viridis </i>are reported here. All the extracts examined inhibited the settlement of cyprids of<i> B.amphitrite. </i>The EC₅₀values of the extracts ranged from 16 ± 3 μg/ml (antipatharian sp.2) to 150 ± 8 μg/ml (antipatharian sp. 3). The LC₅₀ values of the extracts varied from 38 ± 3.8 μg/ml [<i>Dendronephthya (Roxasia) </i>sp.] to 218 ± 30.6 μg/ml<i>(Fasciospongia cavernosa). </i>A comparison of the EC₅₀ and LC₅₀ values reveal that most of the extracts are non toxic to the cyprids of <i>B. amphitrite </i>. In the case of <i>P. viridis </i>only 7 out of 17 extracts (41%) inhibited byssal production and attachment. Gorgonian coral extracts displayed highest incidence of attachment inhibitory activity (75%) followed by soft corals (40%), antipatharians (33%) and sponges (20%), when tested against <i>P. viridis. </i>The EC₅₀ values of the extracts ranged from 164 ± 12μg/ml <i>(A. pfeifferae) </i>to 898 ± 11μg/ml [<i>Dendronephthya (Morchellana) </i>sp.]. Toxicity revival studies indicate that the transient presence of active extracts did not cause irreversible damage to <i>P. viridis. </i>The results indicate the possible potentialities of these extracts as natural non toxic antifouling agents.</span>