Cyprid Assay

Metamorphosed barnacle attached to the surface


Barnacle cyprid assay. The barnacle, Balanus amphitrite Darwin, is the most ubiquitous hard fouling organism found in all marine ecosystems, particularly in ports visited by commercial shipping. The standard assay to measure the biological potential of any antifouling compound against B. amphitrite utilizes the method developed initially at Duke University Marine Laboratory (North Carolina, USA) and now in routine use at SHMRC research facility in Tuticorin, India. Briefly, the barnacle adults are cultured in the laboratory and allowed to spawn naturally. The larvae are harvested and grown in artificial culture systems until they reach the cyprid stage at which time the larvae become competent to attach to surfaces. Once attached, the cyprids transform into a pinhead barnacle, thus becoming permanently attached to the surface

This assay accomplishes the following objectives:
1.1.1 Establish the inherent barnacle inhibitory effects against barnacle settlement
1.1.2 Establish an EC50 or minimum effective concentration necessary to inhibit this attachment.
1.1.3 Establish the toxic or nontoxic effects on the larvae by measuring the LD50 and observe any behavioral effects on larval development.
1.1.4 Upon completion of the above tests, Poseidon proposes the following tests to clarify the relationship with other known antifouling agents.

1.1.4a. Comparison of the EC50 against SeaNine 211, Arch’s Zinc and Copper Omadine, Frescalin, and other algaecides and anti-barnacle agents.
1.1.4b. Study the effects of combining the experimental compound with other known antifouling agents described in barnacle settlement assays.

Cyprid Settlement Assay on Coated Dishes
The test compound is incorporated on VYHH Resin and coated on the bottom of Falcon petri dish. The active agent is therefore trapped in the resin and the anti-settlement effect is comes from the surface and as the agent migrates out of the resin. (EC50 determined).