Trophic polymorphism in introduced pumpkinseed (Lepomis gibbosus) inhabiting Iberian reservoirs

被引:17
作者
Bhagat, Yakuta [1 ]
Fox, Michael G. [2 ,3 ]
Ferreira, Maria Teresa [4 ]
机构
[1] Trent Univ, Environm & Life Sci Grad Program, Peterborough, ON K9J 7B8, Canada
[2] Trent Univ, Environm & Resource Studies Program, Peterborough, ON K9J 7B8, Canada
[3] Trent Univ, Dept Biol, Peterborough, ON K9J 7B8, Canada
[4] Tech Univ, Forest Res Ctr, P-1349017 Lisbon, Portugal
关键词
Ecomorph; Introduced; Internal morphology; Gill rakers; Pharyngeal jaws; Pharyngeal muscles; CHARR SALVELINUS-ALPINUS; PHENOTYPIC PLASTICITY; ARCTIC CHARR; MORPHOLOGICAL-DIFFERENTIATION; RESOURCE POLYMORPHISMS; ADAPTIVE RADIATION; BLUEGILL SUNFISH; NICHE SHIFTS; POPULATION; EVOLUTION;
D O I
10.1007/s10641-011-9773-7
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
Introduced pumpkinseed in Iberian reservoirs display marked external morphological differentiation along two simultaneous dimensions of flow and trophic structure. We assessed the degree of internal morphological differentiation using gill rakers, pharyngeal jaws and the levator posterior muscle among pumpkinseeds occupying four different habitats and determined whether prey consumption accounted for any discernible differences in feeding structures among ecomorphs. Results showed significant differentiation by habitat based on pharyngeal muscle and jaw dimensions in all study reservoirs, with pelagic pumpkinseeds having smaller jaws than littoral pumpkinseeds in four of the five reservoirs. Gill rakers, however, differentiated morphs in only three of the five reservoirs, corresponding to differences in zooplankton consumption among pelagic and littoral individuals in those reservoirs. Based on all internal morphological traits, greater divergence was seen along the littoral-pelagic trophic axis in the lacustrine zones of reservoirs compared to the fluvial zone. Overall differences noted in internal morphology are likely the result of phenotypic plasticity; the ability of this species to readily adapt to changing physical environments may explain the success of the pumpkinseed in its introduced range.
引用
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页码:203 / 217
页数:15
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