# High‐Throughput DNA Sequencing Reveals Gastric Content Composition and Inter‐Specific Variation in Pampus Fishes

## TL;DR

This study uses DNA sequencing to reveal the diets of three types of Pampus fish, showing differences in what they eat and how they fit into marine food webs.

## Contribution

The study introduces eDNA high-throughput sequencing as an effective method for analyzing gastric content in Pampus species, overcoming limitations of traditional methods.

## Key findings

- eDNA sequencing identified distinct prey species in the diets of three Pampus species, including anchovies and specific crustaceans.
- Crustaceans were the most diverse and abundant dietary component across all Pampus species, comprising over 60% of identified taxa.
- Cephalopods were found in two Pampus species but absent in P. cinereus, highlighting inter-specific dietary variation.

## Abstract

Pampus species play a significant role in offshore food webs and are regarded as representative economically important fish. Owing to variations in their geographical distribution, distinct differences in feeding habits exist among pomfret species. However, the presence of an esophageal sac in pomfrets complicates accurate identification of their dietary composition through conventional stomach content analysis. Consequently, research on the feeding ecology of pomfrets remains limited and imprecise. This study employed environmental DNA (eDNA) high‐throughput sequencing technology to analyze the composition and relative abundance of gastric contents in three Pampus species (
P. argenteus
,
P. punctatissimus
, and
P. cinereus
) collected from Qingdao, Shandong Province and Wenchang, Hainan Province. Key findings include: (1) Analysis revealed 21, 7, and 2 fish species in the gastric contents of
P. argenteus
,
P. punctatissimus
, and
P. cinereus
respectively, with anchovy (
Engraulis japonicus
) demonstrating the highest relative abundance in the former two species, while
Thryssa hamiltonii
predominated in
P. cinereus
. (2) Crustacean communities comprised 49, 42, and 26 species across the respective species, constituting over 60% of total identified taxa and indicating their trophic importance.
Acetes japonicus
exhibited maximal relative abundance in
P. argenteus
and
P. punctatissimus
, whereas
Acetes chinensis
dominated in
P. cinereus
. (3) Cephalopod analysis identified 8 and 6 species in
P. argenteus
and
P. punctatissimus
respectively, with
Loligo beka
and
Sepiola birostrata
showing peak abundance in each species, while no cephalopod species were detected in
P. cinereus
. Comparative analysis with traditional dissection methods and stable carbon‐nitrogen isotope techniques confirmed crustaceans as the most diverse dietary component across Pampus species. This investigation demonstrates the efficacy of eDNA metabarcoding for elucidating feeding ecology in Pampus spp., providing critical insights into their trophic interactions and ecological significance within marine food webs.

In this study, we employed high‐throughput sequencing of environmental DNA (eDNA) to conduct an analysis of the gastric contents composition and relative abundance from samples of P. argenteus and P. punctatissimus collected at the Jimiya Fish Pier in Qingdao, Shandong Province, and P. cinereus collected at the Qinglan Port in Wenchang, Hainan Province. Using the P. argenteus as a case study, we recorded the detection frequency of each prey organism across all stomach content samples. The relative detection frequency of each prey taxon was calculated by dividing its individual detection count by the total number of detections for all prey organisms. From the eDNA analysis of P. punctatissimus gastric contents, a total of seven marine fish species were identified: Acanthogobius flavimanus, Engraulis japonicus, Hypomesus nipponensis, Jaydia lineata, Pampus argenteus, Scomberomorus niphonius, and Sphyraena pinguis. Among these, Engraulis japonicus (93.66%) and Jaydia lineata (5.03%) dominated in relative abundance. These two species are recognized as the primary prey organisms in the sampling area of P. punctatissimus, and their juveniles serve as palatable prey for Pampus punctatissimus, consistent with experimental findings.