Garibaldi (Hypsypops rubicundus) from artificial reefs and cooler island natural reefs consume more animal material, which is associated with greater adult size and body condition

Abstract

Access to and quality of dietary resources can affect marine fish life history metrics as ingested prey are transformed into the energy and nutrients used for growth and life-sustaining activities. Here, we analyze the diet composition of Garibaldi (Hypsypops rubicundus) populations across natural and artificial rocky reefs subject to a wide range of environmental conditions within the Southern California Bight (SCB). The diet of populations from the warmer islands and mainland natural reefs had higher proportions of algae, while the diet of populations from cooler island natural reefs and mainland artificial reefs had higher proportions of animal content. More animal material in the diet was positively associated with higher body condition in both sexes, larger adult average length, and higher initial growth rates, with relationships generally being stronger in females. These results support the role of the habitat-related variation in diet as a driver of local differences in growth patterns and body condition and provide a more comprehensive description of Garibaldi's omnivorous diet. These findings also provide implications for performance assessments of artificial reef habitats.