# Fish species identification and composition across the Scotia Sea during austral summer 2019

## TL;DR

This study identified 56 fish species in the Scotia Sea during 2019's austral summer, providing detailed taxonomic data to help understand marine biodiversity.

## Contribution

The study provides a high-resolution taxonomic encyclopedia of fish species in the Scotia Sea using both visual and molecular methods.

## Key findings

- 56 fish taxa were identified using visual and molecular methods in the Scotia Sea.
- Lanternfish species Electrona antarctica and Gymnoscopelus braueri dominated in numbers and catch weight.
- The study offers detailed taxonomic descriptions and images to support future marine community assessments.

## Abstract

An assessment of the fish species composition was conducted during the austral summer of 2019 in the Southwest Atlantic sector of the Southern Ocean (FAO Fishing Areas 48.1–48.4). Samples were collected from stations systematically spaced across the Scotia Sea region using a fine meshed pelagic trawl (“Macroplankton trawl”) towed through the ~200-0 m depth stratum (n = 127 hauls) and a coarser meshed and larger pelagic trawl (“Harstad trawl”) hauled from ~1000-0 m (n = 8 hauls), particularly suitable for catching somewhat larger sized specimens. In total, 56 fish taxa were identified from both traditional taxonomic visual and molecular identification methods. The dominating taxa, both in numbers and catch weight across the study area, were the two lanternfish species Electrona antarctica and Gymnoscopelus braueri (Myctophidae), together with the deep-sea smelt genus Bathylagus (Bathylagidae). The given description of taxonomic identification features including images of type specimens presented, constitutes a high-resolution and comprehensive encyclopedia that will facilitate future assessment of fish communities and interspecific relationships.