Image-Based Analysis of Morphometric Differences Between Sea-Caught and Farmed Large Yellow Croaker (Larimichthys...

Area of Science:

• Marine Biology
• Aquaculture Science
• Computational Biology

Background:

• Morphological variations in fish are influenced by environmental factors and domestication.
• Objective quantification of these differences is crucial for commercially important species like the large yellow croaker (Larimichthys crocea).

Purpose of the Study:

• To develop and validate an image-based phenotyping workflow for quantifying external morphological traits in sea-caught and farmed L. crocea.
• To objectively compare the morphometrics of wild and aquacultured large yellow croaker.

Main Methods:

• Utilized an image-based phenotyping workflow with visible-light imaging under standardized conditions.
• Applied a YOLOv11-based instance segmentation model for automatic delineation of anatomical regions.
• Calculated surface areas and proportional indices after geometric calibration.

Main Results:

• The segmentation model achieved high accuracy (mAP@50 > 98%).
• Farmed L. crocea displayed larger body surface areas and reduced relative proportions of pectoral fins and tail.
• Sea-caught fish showed greater proportional investment in locomotor structures.

Conclusions:

• Aquaculture leads to morphological shifts in L. crocea, favoring trunk growth over propulsion-related structures.
• The developed workflow offers a rapid, non-invasive method for fish morphometric analysis and phenotypic monitoring.
• Provides quantitative evidence for domestication-driven morphological divergence in marine fish.