Otolith Microstructure and Early Ontogeny of a Myctophid Species Benthosema pterotum

Abstract

The correlation between otolith microstructure and early ontogeny was studied with the larvae, juveniles and adults of a myctophid species Benthosema pterotum collected in Kagoshima Bay, southern Japan. From the width and shape of rings, the otolith structure was divided into the inner, middle, and outer zones surrounding a nucleus. Each zone had a different relationship between the standard length and otolith radius. The rapid change of photophore formation and melanophore pattern corresponded to the latter half of middle zone, and their completion to the start of outer zone. Considering the first half of middle zone to reflect the initiation event of metamorphosis, the inner, middle, and outer zones were correlated with larval, metamorphic, and juvenile to adult stages, respectively. The daily periodicity of ring formation was tested by tracing cohorts having different modes of body size, but the expected results could not be gained. © 1990, The Japanese Society of Fisheries Science. All rights reserved.