{"title":"Experimental evidence of a mixed breeding strategy and food-dependent maternal and larval traits in chub mackerel","authors":"Michio Yoneda, Masahiro Nakamura, Taizo Morioka, Tatsuo Tsuzaki, Hiroyuki Togashi, Ryuji Yukami","doi":"10.3389/fmars.2025.1674359","DOIUrl":null,"url":null,"abstract":"Food availability plays a critical role in shaping reproductive success of small pelagic fishes, and in natural population, reduced prey access often arises under conditions of intra- and inter-specific density dependence. While energy allocation to egg production has often been viewed along a capital–income continuum, recent studies suggest that reproductive strategies may be more flexible or mixed than previously assumed. However, few studies have empirically examined how the timing and location of prey availability affect reproductive traits in the context of density-dependence. To address this gap, we conducted stable isotope tracer and controlled feeding experiments using chub mackerel (<jats:italic>Scomber japonicus</jats:italic>) to determine when and how feeding conditions influence reproductive output. A diet-switch experiment using carbon and nitrogen stable isotope ratios revealed much slower isotopic turnover in chub mackerel compared to income-breeding anchovy in similar experiments, suggesting that chub mackerel primarily rely on stored reserves (capital breeding), with limited reliance on dietary resources during spawning. Food restriction during the five months prior to spawning significantly reduced somatic condition and egg production in repeat spawners. Larvae from food-restricted females exhibited reduced growth and starvation tolerance compared to those from well-fed females. These findings demonstrate that maternal nutritional history has marked effects on both egg production and larval performance, highlighting the importance of considering energy allocation tactics when evaluating density-dependent reproduction. Our findings further provide a basis for discussing recent changes in the reproductive output of the Pacific stock of chub mackerel in the light of maternal nutritional history and its role in reproductive success.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"114 1","pages":""},"PeriodicalIF":3.0000,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers in Marine Science","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.3389/fmars.2025.1674359","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MARINE & FRESHWATER BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Food availability plays a critical role in shaping reproductive success of small pelagic fishes, and in natural population, reduced prey access often arises under conditions of intra- and inter-specific density dependence. While energy allocation to egg production has often been viewed along a capital–income continuum, recent studies suggest that reproductive strategies may be more flexible or mixed than previously assumed. However, few studies have empirically examined how the timing and location of prey availability affect reproductive traits in the context of density-dependence. To address this gap, we conducted stable isotope tracer and controlled feeding experiments using chub mackerel (Scomber japonicus) to determine when and how feeding conditions influence reproductive output. A diet-switch experiment using carbon and nitrogen stable isotope ratios revealed much slower isotopic turnover in chub mackerel compared to income-breeding anchovy in similar experiments, suggesting that chub mackerel primarily rely on stored reserves (capital breeding), with limited reliance on dietary resources during spawning. Food restriction during the five months prior to spawning significantly reduced somatic condition and egg production in repeat spawners. Larvae from food-restricted females exhibited reduced growth and starvation tolerance compared to those from well-fed females. These findings demonstrate that maternal nutritional history has marked effects on both egg production and larval performance, highlighting the importance of considering energy allocation tactics when evaluating density-dependent reproduction. Our findings further provide a basis for discussing recent changes in the reproductive output of the Pacific stock of chub mackerel in the light of maternal nutritional history and its role in reproductive success.
期刊介绍:
Frontiers in Marine Science publishes rigorously peer-reviewed research that advances our understanding of all aspects of the environment, biology, ecosystem functioning and human interactions with the oceans. Field Chief Editor Carlos M. Duarte at King Abdullah University of Science and Technology Thuwal is supported by an outstanding Editorial Board of international researchers. This multidisciplinary open-access journal is at the forefront of disseminating and communicating scientific knowledge and impactful discoveries to researchers, academics, policy makers and the public worldwide.
With the human population predicted to reach 9 billion people by 2050, it is clear that traditional land resources will not suffice to meet the demand for food or energy, required to support high-quality livelihoods. As a result, the oceans are emerging as a source of untapped assets, with new innovative industries, such as aquaculture, marine biotechnology, marine energy and deep-sea mining growing rapidly under a new era characterized by rapid growth of a blue, ocean-based economy. The sustainability of the blue economy is closely dependent on our knowledge about how to mitigate the impacts of the multiple pressures on the ocean ecosystem associated with the increased scale and diversification of industry operations in the ocean and global human pressures on the environment. Therefore, Frontiers in Marine Science particularly welcomes the communication of research outcomes addressing ocean-based solutions for the emerging challenges, including improved forecasting and observational capacities, understanding biodiversity and ecosystem problems, locally and globally, effective management strategies to maintain ocean health, and an improved capacity to sustainably derive resources from the oceans.