Ecological implications of abundant cryptobenthic reef fishes: estimating previously unknown life history traits of the Masked/Glass Goby Coryphopterus personatus/hyalinus complex

Abstract

Fishes of the smallest size classes that inhabit benthic reef habitats are collectively known as cryptobenthic reef fishes, and they constitute a significant portion of reef fish biodiversity and biomass production. However, for many cryptobenthic reef fishes such as gobies, much is unknown about their life history. Understanding the demographics of a species can clarify its functional role, productivity, and resilience to disturbances in an ecosystem. The masked/glass goby Coryphopterus personatus/hyalinus is an understudied Caribbean reef goby complex that is common and abundant. Otolith microstructure techniques reveal that C. personatus/hyalinus exhibits an extreme life history relative to other vertebrates due to its short lifespan, fast larval growth, and early maturity with linear growth in body length throughout reproductive age. Average daily larval growth largely determines pelagic larval duration where faster-growing individuals complete the larval stage in less time. The back-calculation of body length at settlement indicates that individuals with slower average larval growth had longer larval durations, and they compensate by attaining larger body lengths at settlement. Average daily growth substantially decreases over the settlement transition zone which approximately corresponds to sexual maturity. Notably, linear growth in body length may serve to support greater fecundity in older, larger-bodied females and enhance survivorship. The quick generational turnover, high abundance/productivity, broad depth range, and planktivorous diet of C. personatus/hyalinus indicates that it plays an important trophic role in transferring nutrients from pelagic plankton to reef predators and the reef benthos. Estimating life history traits related to survival, reproduction, and population size has useful applications in conservation biology and resource management.