**Conflict of interest**

the tropical marine sponge were tested for series of bioassays antibacterial, antiphotosynthetic, antifouling, antialgal, antifouling, antialgal, antiphotosynthetic, antifungal, and antitubercular. The results showed majority of the tested compounds were active against at least two of the applied test systems [152]. Recently, sponge-derived actinomycetes and sediments isolated from marine sponge were tested for bioactive constituents with antifungal and antimicrobial activity. Out of 15 prepared active extract nine were found active against *Enterococcus fascism* (vancomycin-resistant) and *Candida albicans* multidrug-resistant [132], including strains resistant to conventional antibiotics. Thus the bacterial actinomycetes from marine sponges and other marine organisms have been proved prolific producers of pharmacologically active compounds. Literature studies revealed that 70% of naturally derived antibiotics which are currently in clinical use have been derived from actinomycetes. In the recent study, *Streptomyces* sp. strains from Mediterranean sponges and secondary metabolite namely, cyclic depsipeptide valinomycin, indolocarbazole alkaloid staurosporine and butenolide, were screened for anti-infective activities. All the isolated compounds along with *Streptomyces* sp. exhibited antiparasitic activities. Researchers also claim the anti-infective potential of marine actinomycetes is very promising.

**11. Marine sponges-derived antifouling and antibiofilm compounds**

**12. Conclusion**

214 Biological Resources of Water

Bacterial biofilms are surface-attached microorganism's communities that are protected by an extracellular matrix of biomolecules. Continuous use of chemical antifoulants resulted in increased tributyltin concentration and created extensive pollution problems in marine organisms. Natural antifouling molecules from marine have been recently reviewed and researches hope that will provide more specific and less toxic antifouling activity in future. Antifouling compounds derived from sponges were found to be very effective, environmentally friendly biocides and less toxic [205]. In the last few years several studies were directed to find the most promising alternative technologies to antifouling in marine organisms, especially from sponges. In a recent study structurally different compounds containing 3-alkylpyridine moiety were evaluated for antifouling potential. The compounds, namely haminols, saraine and 3-alkylpyridinium salts extracted from *Reniera sarai, Haliclona* sp. and the mollusk *Haminoea fusar* is obtained by synthesis, showed very good antifouling potential larvae of the barnacle *Amphibalanus amphitrite*. Bromopyrrole or diterpene alkaloids derivatives isolated from *Agelas linnaei* and *Ageles nakamurai* Indonesian marine sponges exhibited cytotoxic activity. Moreover, agelasine derivatives inhibited settling of larvae of *Balanus improvisus* in an antifouling bioassay as well as the growth of planktonic forms of biofilm forming bacteria *S. epidermidis* [206].

Marine invertebrates (Porifera, Cnidaria, Mollusca, Arthropoda, Echinodermata, etc.) are considered as one of the major groups of biological organisms which gave huge number of natural products and secondary metabolites with interesting pharmacological properties and led in the formation of novel drugs. Among marine invertebrates, marine sponges (phylum: Porifera) is the most dominant responsible group for discovering significant number of natural components, which has been used as template to develop therapeutic drugs. These natural products The authors declare that they have no conflict of interest.
