TY - JOUR
T1 - Cannibalism and Habitat Selection of Cultured Chinese Mitten Crab
T2 - Effects of Submerged Aquatic Vegetation with Different Nutritional and Refuge Values
AU - Zeng, Qingfei
AU - Jeppesen, Erik
AU - Gu, Xiaohong
AU - Mao, Zhigang
AU - Chen, Huihui
PY - 2018
Y1 - 2018
N2 - We examined the food preference of Chinese mitten crabs, Eriocheir sinensis (H. Milne Edwards, 1853), under food shortage, habitat choice in the presence of predators, and cannibalistic behavior by comparing their response to the popular culture plant Elodea nuttallii and the structurally more complex Myriophyllum verticillatum L. in a series of mesocosm experiments. Mitten crabs were found to consume and thus reduce the biomass of Elodea, whereas no negative impact on Myriophyllum biomass was recorded. In the absence of adult crabs, juveniles preferred to settle in Elodea habitats (appearance frequency among the plants: 64.2 ± 5.9%) but selected for Myriophyllum instead when adult crabs were present (appearance frequency among the plants: 59.5 ± 4.9%). The mortality rate of mitten crabs in the absence of plant shelter was higher under food shortage, primarily due to cannibalism. The proportion of molting crabs dying in the structurally more complex Myriophyllum habitats was significantly lower than in the less complex Elodea habitats, indicating that Myriophyllum provides better protection from cannibalistic behavior, likely due to its structurally more complex canopy. Stable isotope analyses of crab samples revealed a trophic shift in both δ
13C and δ
15N (Δδ
13C: 2.2-4.0h; Δδ
15N: 1.5-2.8h) during the experimental period. Significant positive correlations between body mass and δ
13C and δ
15N were recorded, suggesting that cannibalistic feeding might further increase crab growth and lead to ontogenetic increases in trophic position with increasing size. Our study overall demonstrates that a combination of submerged aquatic vegetation functioning as a highly suitable food with other less palatable plant species acting as efficient refuges against predators may be the optimal method of plant stocking in mitten crab aquacultures to ensure both high crab growth and a high survival rate.
AB - We examined the food preference of Chinese mitten crabs, Eriocheir sinensis (H. Milne Edwards, 1853), under food shortage, habitat choice in the presence of predators, and cannibalistic behavior by comparing their response to the popular culture plant Elodea nuttallii and the structurally more complex Myriophyllum verticillatum L. in a series of mesocosm experiments. Mitten crabs were found to consume and thus reduce the biomass of Elodea, whereas no negative impact on Myriophyllum biomass was recorded. In the absence of adult crabs, juveniles preferred to settle in Elodea habitats (appearance frequency among the plants: 64.2 ± 5.9%) but selected for Myriophyllum instead when adult crabs were present (appearance frequency among the plants: 59.5 ± 4.9%). The mortality rate of mitten crabs in the absence of plant shelter was higher under food shortage, primarily due to cannibalism. The proportion of molting crabs dying in the structurally more complex Myriophyllum habitats was significantly lower than in the less complex Elodea habitats, indicating that Myriophyllum provides better protection from cannibalistic behavior, likely due to its structurally more complex canopy. Stable isotope analyses of crab samples revealed a trophic shift in both δ
13C and δ
15N (Δδ
13C: 2.2-4.0h; Δδ
15N: 1.5-2.8h) during the experimental period. Significant positive correlations between body mass and δ
13C and δ
15N were recorded, suggesting that cannibalistic feeding might further increase crab growth and lead to ontogenetic increases in trophic position with increasing size. Our study overall demonstrates that a combination of submerged aquatic vegetation functioning as a highly suitable food with other less palatable plant species acting as efficient refuges against predators may be the optimal method of plant stocking in mitten crab aquacultures to ensure both high crab growth and a high survival rate.
KW - Cannibalistic behavior
KW - Crab culture
KW - Elodea nuttallii
KW - Myriophyllum verticillatum L.
KW - Stable isotope
UR - http://www.scopus.com/inward/record.url?scp=85055856256&partnerID=8YFLogxK
U2 - 10.3390/w10111542
DO - 10.3390/w10111542
M3 - Journal article
SN - 2073-4441
VL - 10
JO - Water
JF - Water
IS - 11
M1 - 1542
ER -