Identification of juvenile abalone Haliotis diversicolor based on number of open and sealed respiratory pores

Abstract

Changes in the number of respiratory pores (open pores) and their imprints (sealed pores) in post-larvae and juveniles were observed and compared for four abalone species Haliotis diversicolor, H. discus discus, H. madaka, and H. gigantea. The first open pore was evident at a shell length (SL) of 1.5 mm in H. diversicolor, 1.9–2.0 mm Sl in H. discus discus, and 2.3–2.4 mm SL in H. madaka and H. gigantea. The number of open pores in H. diversicolor gradually increased with growth, with four to five pores at 2.5–18.0 mm SL and five to six pores at 18.0–27.0 mm SL. The other three species maintained four to five open pores after they reached 3.4–4.5 mm SL. The total number of open and sealed pores (TNP) was greater in H. diversicolor than in the other species at the same SL. Juvenile H. diversicolor were identified among field-caught abalone by the difference in the relationship between SL and TNP (SL-TNP relationship) and also by the monoclonal antibody reaction method. The results of the two methods were in perfect agreement, indicating that our method using the SL-TNP relationship is reliable for the identification of H. diversicolor.