. Bulletin. Science; Natural history; Natural history. 1 84 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES. -'0246 Age of Girella nigricans (years) Fig. 1. Simple linear regression correlating size (standard length) with age of Girella nigricans (r = ,/*< ). to be a minimum age when fish become parasitized. This occurs at approximately 200 mm SL (a minimum age of 5 yrs). Girella nigricans below this threshold are not parasitized. In the older adult size class, 7 of 8 specimens () of five years of age or older were parasitized (with 2, 4, 6, 8, 10, 15, and 18 A^. girellae). A signifi
. Bulletin. Science; Natural history; Natural history. 1 84 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES. -'0246 Age of Girella nigricans (years) Fig. 1. Simple linear regression correlating size (standard length) with age of Girella nigricans (r = ,/*< ). to be a minimum age when fish become parasitized. This occurs at approximately 200 mm SL (a minimum age of 5 yrs). Girella nigricans below this threshold are not parasitized. In the older adult size class, 7 of 8 specimens () of five years of age or older were parasitized (with 2, 4, 6, 8, 10, 15, and 18 A^. girellae). A significant correlation was shown between the size of G. nigricans and number of parasites for the parasitized specimens (t = , df= \2, P < ). Too few specimens were analyzed to determine a correlation between sex and infestation. How might we account for this size variability in parasite infection? First, with time fishes probably encounter more parasites. Second, larger fishes have a larger surface area with which to accommodate higher degrees of infestation (Cailliet et al. 1986). Third, physiological differences between juveniles and adults, which may occur at or after age 5 +, may prevent attachment of the parasite or lead to death of the younger individual if attachment does occur. If the latter were true, all parasitized fish younger than 5 + years old might die as a result of infestation. This would account for the absence of parasitized fish in these age categories. It is known that juvenile and subadult G. nigricans seek out increasingly deeper water as they mature (Feder et al. 1974), and it is possible that differences in the habitats of juvenile and adult G. nigricans may account for the absence of parasites on the juveniles. However, 1 of the 8 adults (age 5 and older) examined was not parasitized as were the younger adults (age 3+-4+) collected in the same area. Thus, it is unlikely that habitat plays a major role and supports the idea that infestation may
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