Characterization and distribution of undersulfated chondroitin sulfate and chondroitin in leptocephalous larvae of elopomorph fishes.

Undersulfated chondroitin sulfate (i.e., chondroitin sulfate with sulfate: hexosamine molar ratios ranging from 0.06-0.17) has been identified as a principal glycosaminoglycan (GAG) in whole-body extracts of leptocephalous larvae of four species of marine teleost fishes, representing two orders and three families. These include the eels (Anguilliformes)Ariosoma balearicum (Congridae),Rhechias dubia (Congridae) and Ophichthus sp. (Ophichthidae) and the ladyfish (Elopiformes: Elopidae: Elops saurus). A second GAG found in relatively large amounts in A. balearicum has been identified as chondroitin. Chondroitin and undersulfated chondroitin sulfate formed distinctive precipitates during extraction and were easily separated. Undersulfated chondroitin sulfate also was extracted and purified from early metamorphosing bonefish (Albuliformes: Albulidae: Albula sp.) leptocephali, where it is a minor GAG component, and was shown to be similar in composition to the compounds obtained from eels and ladyfish.