Title: INTRASPECIFIC VARIABILITY IN LIFE HISTORY TRAITS OF FISHES BETWEEN SHALLOW CORAL REEFS AND MESOPHOTIC CORAL ECOSYSTEMS IN THE CENTRAL PACIFIC OCEAN

Abstract: Many inhabitants of mesophotic coral ecosystems (MCEs), such as reef fishes, represent a lower depth distribution of their species as they are also found occupying shallow coral reefs in relatively close geographic proximity. Research on fishes associated with MCEs is sparse; hence there is a critical lack of knowledge of how reef fish found at mesophotic depths may vary from their shallow reef complements. We investigated intraspecific variability in growth, reproductive potential and energy partitioning of three Hawaiian endemics collected from shallow, photic reefs and MCEs throughout the Hawaian Archipelago and Johnston Atoll: the detritivorous goldring surgeonfish Ctenochaetus strigosus, and the planktivorous threespot chromis Chromis verater and Hawaiian dascyllus Dascyllus albisella. The von Bertalanffy growth function was used to establish species-specific growth models using otolith-derived ages, and energy investment towards reproduction and body condition was quantified using the gonado-somatic index and Fulton’s condition index. Body condition was higher for all species in shallow waters than MCEs; however, variability in reproductive investment between shallow and deep populations differed between species. For all species, fishes from shallow waters reached larger asymptotic lengths than their conspecifics. This ongoing study addresses the life history of coral reef fish, a key component of both shallow and mesophotic reef communities, while providing structure for the development of conservation and fisheries management tools in understudied mesophotic environments.

Authors: Winston MS, Taylor BM, Hixon MA, Franklin EC

Presentation: Oral

Session: 29

Date: 06/21/16

Time: 15:15

Location: 308 A/B

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