ENZYME-LINKED IMMUNOSORBENT ASSAYS AND BILLFISH GENDER: TESTING MUSCLE TISSUE AND SURFACE MUCUS IN TAGGING STUDIES

摘要

Recent advances in enzyme-linked immunosorbent assay (ELISA) technology (Crowther, 2001) have facilitated studies of the gender factors of billfishes (Tan et al., 2006). In this paper, appropriate methodologies and ELISAs were investigated for non-lethal sex identification in billfish tagging studies, where gender is typically unknown (Wilson et al., 1991). Tan et al. (2006) developed an ELISA to quantify vitellogenin-derived yolk proteins (VDYP) in muscle tissue biopsy samples from Atlantic blue marlin, Makaira nigricans Lacepede, 1802, and also used a commercially-available ELISA for 11-ketotestosterone (11-KT). Here, we show that the same assays can be applied to three other istiophorid billfish species: white marlin, Tetrapturus albidus Poey, 1860, longbill spearfish, Tetrapturus pfluegeri Robins and de Sylva, 1963, and sailfish, Istiophorus platypterus (Shaw in Shaw and Nodder, 1792). Samples from two different groups of sailfish were tested by ELISA: the first with extracts of muscle tissue, the second, with surface mucus. Use of surface mucus represents a less invasive and more practical alternative than either muscle biopsy or blood serum collection (Gordon et al., 1984; Kishida et al., 1992; Moncaut et al., 2003; Schultz et al., in press), especially when dealing with large, live animals at boatside (Graves et al., 2002).