BOLETÍN DEL MUSEO NACIONAL DE HISTORIA NATURAL 138 Generally most PSP cases resolved within 10 days after first detection. However, those located along the longitudinal line below either side of the dorsal fin (basidorsal) tended to persist for a longer time, up to two months in the second stage. Perhaps due to this longer span, the basidorsal area was the most frequent location for PSP stage 2. Table 2 shows the approximate duration for 22 cases of PSP in 13 L. australis, the stage at the first record of the event and their location relative to the basidorsal area. Due to the short duration of PSP syndrome (days) it was not possible to assess its daily growth rate. TABLE 2. Approximate duration of pale skin patches, their development stage at first sight and relative location to the basidorsal area, for 13 L. australis ranging in waters of Añihué Reserve ID code Approximate duration Stage Basidorsal RA1_27 1) N/A (several months before resighted) 1 no 2) < 5 days 1 no 3) N/A (several months before resighted) 2 yes 4) Almost 2 months 2 yes 1) About 9 days 1 no 2) < 4 days 1 no RA1_36 1) 3 months 2 yes RA1_41 1) 19 days 2 no 2) 2 days 2 no 3) 66 days 2 yes 1) N/A (several months before resighted) 1 no 2) < 50 days 2 no 3) < 7 days 2 no RA1_47 1) N/A (several months before resighted) 3 yes RA1_51 1) < 13 days 1 no RA1_58 1) < 7 days 2 no RA2_14 1) < 7 days 3 yes RA2_20 1) < 2 months 1 no RA2_23 1) < 3 days 3 no 2) one month 2 yes RA3_4 1) < 6 days 1 no RA3_5 1) < 7 days 1 no RA1_32 RA1_43 Epidemiology of PSP Among the 115 photo-identified L. australis in Añihué Reserve, 86 (74.8 %) individuals presented at least one event of PSP. Prevalence was highly variable between pods and differences remained stable over time. For instance, we found the same pods with most of their members affected by large PSP during this study. PSP was documented on all individuals independent of their sex or age class. Thus, neonate RA5_1 had its back and flank covered with PSP (see Figure 10). Recurrence of PSP was identified. After clearing initial PSP patches on its dorsal fin, RA1_32 was resighted with new patches at different stages of development on its flanks eight days later. The dolphin had again cleared the condition after four days. Subsequently, it was seen with stage 2 PSP 17 days later. Direct observation revealed several individuals presenting multiple events of PSP over time, simultaneously on