Age-based δ15N and δ13C values of otolith organic matter reveal trophic ecology in marine fishes

Fish inhabiting a similar environment confront space and resource sharing and thus develop diverse feeding strategies to adjust their trophic niches during the ontogeny to avoid competition. To explore the topic, we reconstructed the trophic trajectory of five Sciaenidae species by sequentially analysing the δ13C and δ15N values of otolith organic matter along the growth axis of the otolith. The isotope values were aligned to the age based on growth ring counting and 3D scanning of otolith morphology during organic matter extraction. The δ13C and δ15N values revealed the habitat shift and trophic levels of prey items, respectively. Sciaenidae fish use the benthic resources during their whole life and may move close to the estuary around 1.5-3 years old. They mainly prey on herbivores/zooplankton at the larval and early juvenile stage, but when they grow, there is minimisation of competition among age groups and species., For the age-based trophic niche using stable isotope values recorded in otolith OM, we first adopted the ultrafiltration method because two stable isotope systems provide more trophic information. Then, we dissolve one of the paired otoliths layer by layer, extract the otolith OM in each layer and apply a 3D scanning technique to track the morphological change of each dissolution. Second, we estimate the fish age corresponding to each dissolved layer by image analysis. Third, we evaluate the habitat uses and trophic level of Sciaenidae fishes by comparing the stable isotope values of the particulate organic matter (POM).
Thirty-three fish samples of five Sciaenid species (Atrobucca nibe, Chrysochir aureus, Nibea albiflora, Pennahia macrocephalus, and Protonibea diacanthus) were collected off the western coast of Taiwan in 2020-2023. Muscle tissues and otoliths were collected from each sample. Muscle tissues were freeze-dried in which 0.7 mg dry powder was packed into tin capsules for fu..., , # Age-based δ15N and δ13C values of otolith organic matter reveal the inter- and intraspecific trophic partitioning in marine fishes

[https://doi.org/10.5061/dryad.547d7wmh9](https://doi.org/10.5061/dryad.547d7wmh9)

This study aims to investigate the trophic trajectory of five commercially important Sciaenidae species inhabiting coastal and estuarine environments, where they experience spatial and resource competition. To achieve this, we conducted a comprehensive analysis of their trophic ecology.

The study comprises three datasets: (1) Baseline stable isotope values, (2) Isotopic niche derived from stable isotope values of muscle tissue and otolith organic matter, and (3) Stable isotope values of otolith organic matter

## Description of the data and file structure

Baseline: The stable carbon and nitrogen isotope values of particulate organic matter (POM) were collected from inshore and offshore seawater. These samples represent the pelagic ecosystem and are compared to published...,