Temporal and inter-individual changes in the integrated biochemical condition of the gonads of female swordfish (Xiphias gladius) from the Southeastern Pacific Ocean

Fabián Guzmán-Rivas; Juan Ortega; Sergio Mora; Patricio Barría; Rodrigo Riera; Ángel Urzúa

doi:10.7717/peerj.15524

Temporal and inter-individual changes in the integrated biochemical condition of the gonads of female swordfish (Xiphias gladius) from the Southeastern Pacific Ocean

PeerJ. 2023 Jun 6:11:e15524. doi: 10.7717/peerj.15524. eCollection 2023.

Authors

Fabián Guzmán-Rivas¹, Juan Ortega², Sergio Mora², Patricio Barría³, Rodrigo Riera⁴, Ángel Urzúa^{5

6}

Affiliations

¹ Facultad de Ciencias, Programa de Doctorado en Ciencias con mención en Biodiversidad y Biorecursos, Universidad Católica de la Santísima Concepción, Concepción, Biobío, Chile.
² Instituto de Fomento Pesquero, Talcahuano, Biobío, Chile.
³ Instituto de Fomento Pesquero, Valparaíso, Valparaíso, Chile.
⁴ Departamento de Biología, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, España.
⁵ Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Biobío, Chile.
⁶ Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Biobío, Chile.

Abstract

The integrated biochemical condition (IBC) of gonads is closely related to the reproductive success of highly migratory marine species. The IBC of gonads can be influenced not only by size and/or age, but also by environmental conditions. Here, female swordfish, Xiphias gladius, that migrate to temperate regions with a marked seasonality (e.g., the Southeastern Pacific Ocean, SEPO) were compared in relation to the IBCs (lipids, proteins, glucose and, fatty acid profiles) of their gonads; individuals with two body size ranges and distinct degrees of sexual maturity were evaluated, and considered as: small and/or virginal (SV: <170 cm lower jaw fork-length (LJFL), oocyte size (OS) <0.08 mm) vs large and/or maturing females (LM: >190 cm LJFL, OS >0.133 mm). This comparison was conducted in two environmentally contrasting seasons (winter vs spring). Our results showed that the gonadosomatic index (GSI) was significantly higher in LM than SV. Lipid contents varied significantly between seasons and body sizes. The highest lipid concentrations were recorded in the spring in large females. No significant differences were found when comparing the protein and glucose contents of the two evaluated seasons or body size ranges of the studied females. In turn, the fatty acid (FA) profiles of female gonads significantly varied for both seasons and body size ranges. A high content of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and poly-unsaturated fatty acids (PUFAs) were recorded in female gonads in the spring. The SFAs C16:0 and C18:0, the MUFA C18:1n9, and the essential PUFA C22:6n3 were the main contributors to the observed differences between spring and winter. These results could be used as indicators of the nutritional condition and health status of swordfish individuals. Hence, the IBC of female swordfish gonads have great potential to aid in estimating survival rates and stock abundances of this species. The integration of this information constitutes an asset in fishery management models with an ecosystem approach.

Keywords: Body size; Energy reserves; Gonads; Highly migratory fish species; Oocyte; Seasonality; Sexual maturity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Ecosystem*
Fatty Acids
Female
Glucose
Gonads
Pacific Ocean
Perciformes*

Substances

Fatty Acids
Glucose

Grants and funding

This work was supported by the Instituto de Fomento Pesquero (IFOP). The “Fisheries Project of Highly Migratory Resources” supported this work: grant 581136 (Biological-Fishing Aspects, IFOP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.