Dietary Composition of Big Head Croaker, Collichthys lucidus, in the Early Stage of the “10-Year Fishing Ban” Policy

Fishes, Journal Year: 2025, Volume and Issue: 10(5), P. 193 - 193

Published: April 23, 2025

Big head croaker (Collichthys lucidus) is a dominant fish species in the Yangtze River estuary, with significant economic and ecological value local ecosystem. In this study, dietary composition of big estuary from 2022 to 2023 was determined using stomach content analysis. Statistical methods such as cluster analysis canonical correspondence were also applied study ontogenetic variation feeding habits their relationships environmental factors. The results indicated that fed primarily on 15 prey groups 33 species. Copepods group, followed by mysids, shrimp, fish. included Acanthomysis longirostris, Neomysis awatschensis, Calanus sinicus. Compared historical studies, proportion large crustaceans diet has increased since implementation “10-Year Fishing Ban” River, which reflects improved aquatic habitat for organisms some extent. exhibited clear seasonal variations. empty rate gradually decreased body size main shifted small individuals Acetes chinensis A. longirostris larger individual fishes Brachyura. addition, N. awatschensis spring, summer autumn, Acrocalanus gibber winter. Canonical salinity length factors most strongly correlated croaker, latitude longitude.

Language: Английский

Comparing trophic position estimates using bulk and compound specific stable isotope analyses: applying new approaches to mackerel icefish Champsocephalus gunnari

PeerJ, Journal Year: 2024, Volume and Issue: 12, P. e17372 - e17372

Published: May 17, 2024

Quantifying the tropic position (TP) of an animal species is key to understanding its ecosystem function. While both bulk and compound-specific analyses stable isotopes are widely used for this purpose, few studies have assessed consistency between within such approaches. Champsocephalus gunnari a specialist teleost that predates almost exclusively on Antarctic krill Euphausia superba . This well-known nearly constant trophic relationship makes C. particularly suitable assessing TP methods under field conditions. In present work, we produced compared estimates main prey using standard two amino acid-specific isotope approaches (CSI-AA). One based difference glutamate phenylalanine (TP Glx-Phe ), other proline-phenylalanine Pro-Phe ). To do that, samples from gunnari, E. four pelagic invertebrate fish species, all potential C.gunnari, were collected off South Orkney Islands January March 2019, analyzed isotopic ratio mass spectrometry interpreted following Bayesian approach. Median (CI 95% ) similar (3.6; CI : 3.0-4.8) (3.4; :3.2-3.6), lower (3.1; :3.0-3.3). differences 1.4, 1.1 1.2, compatible with expectations monospecific diet predator (ΔTP=1). these results suggest greater accuracy Pro-Phe, observed CSI-AA suggests may require further validation before becoming tool ecology.

Language: Английский

Consumption of Antarctic krill Euphausia superba by mackerel icefish, Champsocephalus gunnari off the South Orkney Islands: filling an information gap in the current ecosystem-based management approach

Polar Biology, Journal Year: 2024, Volume and Issue: 47(10), P. 989 - 1000

Published: July 1, 2024

Language: Английский