Biochemical properties of anemone fish mucous to understand its adaptation to sea anemone

Abstract

The study of anemone fish mucous to understand anemone fish adaptation to sea anemone was aimed to identify the biochemical composition in the fish mucous that enabled the protection of anemone fish against the stinging tentacles of sea anemones. Upon sampling, one species of sea anemone, Heteractis magnifica was identified with its resident anemone fish, the false clownfish, Amphiprion ocellaris, along with 2 other non-symbiont coral reef fish species, the scissor-tailed sergeant, Abudefduf sexfasciatus (Family Pomacentridae) and the moon wrasse, Thalassoma lunare (Family Labridae) to provide comparison and knowledge insight into anemone fish ability to live unharmed along the tentacles of sea anemone, H. magnifica. The scissor-tailed sergeant and the moon wrasse are among many other coral reef fishes that are observed to be stung upon contact with the sea anemone tentacles that elicit nematocyst discharge. Mucous of false clownfish, A. ocellaris was extracted and investigated for its glycoprotein by studying the protein and sialic acid content and compared against the mucous content of sea anemone, H. magnifica, and other fish species, the scissor-tailed sergeant, A. sexfasciatus and the moon wrasse, T. lunare. Protein identification was done by SDS-PAGE and MALDI-TOF analysis while thiobarbituric acid assay followed by HPLC detection were performed to assess sialic acid content in the mucous. Results indicated that the false clownfish had keratin and actin glycoproteins mucous with 1.636 mg/ml sialic acid content while for non-symbiont fish, the scissor-tailed sergeant presented collagen glycoprotein with 50.433 mg/ml concentration of sialic acid and moon wrasse had high molecular weight proteins with 71.893 mg/ml sialic acid content. The higher concentration of sialic acid was involved in causing the tentacles of sea anemone to discharge toxin. Hence, it is concluded that the false clownfish could afford protection from the stinging toxins of sea anemone by having glycoproteins with very low content of sialic acid which was not adequate to trigger sea anemone response for toxin discharge.