Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction
|Author(s)||Brosset Pablo1, 2, Lloret Josep3, Munoz Marta3, Fauvel Christian4, Van Beveren Elisabeth2, Marques Virginie2, Fromentin Jean-Marc2, Menard Frederic5, Saraux Claire2|
|Affiliation(s)||1 : Univ Montpellier, IRD, IFREMER, UMR MARBEC,CNRS, F-34203 Sete, France.
2 : UM, IFREMER, UMR MARBEC,IRD, CNRS, F-34203 Sete, France.
3 : Univ Girona, Fac Sci, Girona, Spain.
4 : UM, UMR MARBEC, CNRS, IFREMER,IRD, F-34250 Palavas Les Flots, France.
5 : Univ Toulon & Var, Aix Marseille Univ, CNRS, MIO,IRD,UM 110, F-13288 Marseille, France.
|Source||Royal Society Open Science (2054-5703) (Royal Soc), 2016-10 , Vol. 3 , N. 10 , P. 160202 (1-15)|
|WOS© Times Cited||8|
|Keyword(s)||maternal effect, northwest Mediterranean, anchovy, sardine|
|Abstract||Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions.|