Intraspecific Variability in the Life History of Endemic Coral Reef Fishes between Photic and Mesophotic Depths in the Central North Pacific Ocean

Winston, Morgan

Intraspecific Variability in the Life History of Endemic Coral Reef Fishes between Photic and Mesophotic Depths in the Central North Pacific Ocean

Files

2016-08-ms-winston_r.pdf (15.92 MB)

2016-08-ms-winston_uh.pdf (15.98 MB)

Date

2016-08

Authors

Winston, Morgan

Publisher

[Honolulu] : [University of Hawaii at Manoa], [August 2016]

Abstract

For many coral reef-associated organisms, mesophotic coral ecosystems (MCEs) represent the lowest depth distribution inhabited by their species. Research on fishes associated with MCEs is sparse, so there is a critical lack of knowledge of how reef fish found at mesophotic depths may vary from their shallow reef conspecifics. We investigated intraspecific variability in body condition and growth of three Hawaiian endemic fish species collected from shallow, photic reefs (5-33 m deep) and MCEs (40-75 m) throughout the Hawaiian Archipelago and Johnston Atoll: the planktivorous threespot chromis Chromis verater and Hawaiian dascyllus Dascyllus albisella, and the detritivorous goldring surgeonfish Ctenochaetus strigosus. Estimates of body condition, weight-at-length, and size-at-age varied between shallow and mesophotic depths, and among the locations sampled within the central North Pacific Ocean. All three species exhibited lower body condition and weight-at-length in pooled mesophotic sites compared to shallow reef sites. However, there was no difference in parameter values of age-based growth curves between pooled shallow and mesophotic sites for all species. Body condition and maximum body size were lowest in samples collected from shallow and mesophotic Johnston Atoll sites, with no difference occurring between depths. Samples from the Northwestern Hawaiian Islands tended to have the highest body condition and reached the largest body sizes, with differences between shallow and mesophotic sites found to be highly variable between species. The findings of this study are first to demonstrate intraspecific variability in the life history of coral reef fish species whose distributions span shallow and mesophotic reefs. This information suggests that the application of conservation and fisheries management tools developed from studies of shallow reef fishes should be applied with caution to conspecific populations in mesophotic coral environments.

Description

M.S. University of Hawaii at Manoa 2016.
Includes bibliographical references.

Keywords

coral reef fish, life history, mesophotic coral ecosystems, growth, body condition

URI

http://hdl.handle.net/10125/51468

Related To

Theses for the degree of Master of Science (University of Hawaii at Manoa). Marine Biology

Collections

M.S. - Marine Biology

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