Abstract
The protracted spawning period of broadcast-spawning marine fishes has potential to generate considerable variability in metrics of individual reproductive output. We undertook a temporally detailed genetic study of larvae produced by Atlantic cod (Gadus morhua) from two spatially proximate populations spawning under controlled semi-natural conditions over 94 days. Based on daily samples of larvae (n = 4489 in total), we document fine-scaled temporal changes in, and correlates of, offspring phenotype and reproductive output (egg batches produced or fertilized). Larval length and standardized yolk-sac volume declined 11 and 49% over the spawning period, respectively. The adaptive significance of these trends is unclear. Longer, heavier females produced longer, better-provisioned larvae. Body size affected the number of egg batches to which an individual contributed genetically but not spawning duration. Males contributed gametes to a greater number of egg batches (19.5 vs. 9.2), and spawned over a longer period of time (48.9 vs. 30.8 days), than females. After accounting for body size and condition, egg batch number and spawning duration differed between adjacent populations separated by < 10 km. Our work highlights the need to understand the environmental and adaptive causes of temporal variability in offspring quality and its consequences to individual fitness and per capita population growth in batch-spawning fishes.
| Original language | English |
|---|---|
| Pages (from-to) | 1353-1361 |
| Number of pages | 9 |
| Journal | ICES Journal of Marine Science |
| Volume | 75 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Jul 1 2018 |
Bibliographical note
Funding Information:We would like to acknowledge the contributions of the staff, technicians, students (especially E. Juliussen and D. Rivas-Sánchez), and volunteers at the Institute of Marine Research Flødevigen that assisted with experimental maintenance and data collection. We are grateful for the extensive, detailed comments provided by two referees. This study was funded by Canada’s Natural Sciences and Engineering Research Council (Discovery Grant to J.A.H. and Canada Graduate Scholarships to N.E.R. and R.A.O.), the Norwegian Research Council (HAVKYST Grant to J.A.H. and Leiv Eiriksson Mobility Grant to R.A.O., the Prediction and Observation of the Marine Environment network (mobility grants to N.E.R. and R.A.O.), and the European Regional Development Fund (Interreg IVa. “MarGen” project).
Publisher Copyright:
© International Council for the Exploration of the Sea 2018. All rights reserved.
ASJC Scopus Subject Areas
- Oceanography
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science
- Ecology
