The degree of dietary specialization has a fundamental impact on the ecological function and interactions of suspension feeders.While niche differentiation by food particle size is common among obligate suspension fee...The degree of dietary specialization has a fundamental impact on the ecological function and interactions of suspension feeders.While niche differentiation by food particle size is common among obligate suspension feeders,its role is not evident in facultative ones.In this study,we aimed at providing new insights on the matter by focusing on sympatric mysid species.As mysids use different mechanisms for raptorial and filter-feeding,they represent a more adequate model system than for example,the more extensively studied copepods.We made morpholog-ical measurements on the 4 coexisting invasive Ponto-Caspian mysid species to determine the areas and mesh sizes of their filters.We also quantified their clearance rates on the microalga Cryptomonas sp.in a laboratory experiment to reveal how morphological differences manifest in their overall filtering capacity.We found relatively small but consistent differences in the primary filter area among the species,indicating that morphological constraints due to the enclosed position of the setae might limit the possibility for differentiation.The primary filter mesh sizes were small in all 4 species(0.69-2.73μm)with moderate but consistent intraspecific differences,suggesting that the benefit of being able to capture small particles might outweigh the pressure for differentiation.The observed clearance rates were in accordance with the morphological characteristics of the species,highlighting that auxiliary filters(present in one of the species,Limnomysis benedeni)are needed to increase filtering capacity considerably.Our study confirmed that food particle size can contribute to the niche differentiation of facultative filter feeders,but also indicated that they can tolerate a higher overlap than obligate ones.The observed differences were related to the habitat preferences and predatory potentials of the species,suggesting that complementarity among the different niche axes might further facilitate theircoexistence.展开更多
基金The authors thank Peter Dobosy,Adam Egri,Bence Gergacz,Eszter Laczkovszki,Sarah Lecoq,Nicolas Malinge,and Karoly Palffy for their assistance in various phases of the research.Project no.132605 has been implemented with the support provided from the National ResearchDevelopment and Innovation Fund of Hungary,financed under the FK_19 funding scheme.VR acknowledges further support by the NKFIH-138215project.
文摘The degree of dietary specialization has a fundamental impact on the ecological function and interactions of suspension feeders.While niche differentiation by food particle size is common among obligate suspension feeders,its role is not evident in facultative ones.In this study,we aimed at providing new insights on the matter by focusing on sympatric mysid species.As mysids use different mechanisms for raptorial and filter-feeding,they represent a more adequate model system than for example,the more extensively studied copepods.We made morpholog-ical measurements on the 4 coexisting invasive Ponto-Caspian mysid species to determine the areas and mesh sizes of their filters.We also quantified their clearance rates on the microalga Cryptomonas sp.in a laboratory experiment to reveal how morphological differences manifest in their overall filtering capacity.We found relatively small but consistent differences in the primary filter area among the species,indicating that morphological constraints due to the enclosed position of the setae might limit the possibility for differentiation.The primary filter mesh sizes were small in all 4 species(0.69-2.73μm)with moderate but consistent intraspecific differences,suggesting that the benefit of being able to capture small particles might outweigh the pressure for differentiation.The observed clearance rates were in accordance with the morphological characteristics of the species,highlighting that auxiliary filters(present in one of the species,Limnomysis benedeni)are needed to increase filtering capacity considerably.Our study confirmed that food particle size can contribute to the niche differentiation of facultative filter feeders,but also indicated that they can tolerate a higher overlap than obligate ones.The observed differences were related to the habitat preferences and predatory potentials of the species,suggesting that complementarity among the different niche axes might further facilitate theircoexistence.
