Consequences of Lower Food Intake on the Digestive Enzymes Activities, the Energy Reserves and the Reproductive Outcome in Gammarus fossarum

Conséquences d'un faible niveau de nourriture sur l'activité d'enzymes digestives, les réserves énergétiques et la reproduction chez Gammarus fossarum

L. Charron (1) , Olivier Geffard (2) , Arnaud Chaumot (2) , Romain Coulaud (2) , A. Jaffal (1) , V. Gaillet (1) , O. Dedourge Geffard (1) , A. Geffard (1)

1 URCA - Université de Reims Champagne-Ardenne
2 UR MALY - Milieux aquatiques, écologie et pollutions

Digestive enzyme activity is often used as a sensitive response to environmental pollution. However, only little is known about the negative effects of stress on digestive capacities and their consequences on energy reserves and reproduction, although these parameters are important for the maintenance of populations. To highlight if changes in biochemical responses (digestive enzymes and reserves) led to impairments at an individual level (fertility), Gammarus fossarum were submitted to a lower food intake throughout a complete female reproductive cycle (i.e. from ovogenesis to offspring production). For both males and females, amylase activity was inhibited by the diet stress, whereas trypsin activity was not influenced. These results underline similar sensitivity of males and females concerning their digestive capacity. Energy reserves decreased with food starvation in females, and remained stable in males. The number of embryos per female decreased with food starvation. Lower digestive activity in males and females therefore appears as an early response. These results underline the ecological relevance of digestive markers, as they make it possible to anticipate upcoming consequences on reproduction in females, a key biological variable for population dynamics.

Mots clés: ENZYMES; DIGESTION; ENERGY; REPRODUCTION

Mots clés: ENZYME; ENERGIE; GAMMARUS

Domaines: Sciences de l'environnement

L. Charron, Olivier Geffard, Arnaud Chaumot, Romain Coulaud, A. Jaffal, et al.. Consequences of Lower Food Intake on the Digestive Enzymes Activities, the Energy Reserves and the Reproductive Outcome in Gammarus fossarum. PLoS ONE, 2015, 10 (4), pp.1-14. ⟨10.1371/journal.pone.0125154⟩. ⟨hal-01181614⟩