Native fish larvae take advantage of introduced mussel larvae: field evidence of feeding preferences on veligers of the introduced freshwater bivalve Limnopernafortunei

• Published in: Hydrobiologia Vol. 745; no. 1; pp. 211 - 224
• Main Authors: Paolucci, Esteban M., Almada, Pablo, Cataldo, Daniel H., Boltovskoy, Demetrio
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.02.2015; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Ecology; Feeding behavior; Fish; Food webs; Freshwater & Marine Ecology; Freshwater ecology; Freshwater organisms; Larvae; Life Sciences; Mollusks; Predation; Prey; Primary Research Paper; Rivers; Trophic relationships; Water column; Zoology; South America; Invasive species; Dietary shift; Fish larvae; Feeding plasticity; Ichthyoplankton; Prey selection
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-014-2108-x

Previous work has shown that the invasive bivalve Limnoperna fortunei has had a measurable impact on local food webs, but knowledge of the trophic interactions involved is still very limited. On the basis of samples collected along the lower Paraguay-middle Paraná rivers, we studied the feeding behavior and selectivity of larval fish, with emphasis on veligers of the introduced bivalve L. fortunei . Among feeding larvae (i.e., without a yolk sac), 16.5% had only Limnoperna veligers in their guts, while 15.6% had veligers and some other prey. Half of the fish taxa recorded (8 out of a total of 16) consumed Limnoperna veligers. The Paraguay and Paraná rivers differed strongly in the proportions of fish larvae that consumed veligers: 14 and 68%, respectively. This difference paralleled the availability of veligers in the water column, which was significantly lower in the Paraguay (0.8 ± 0.5 ind. l −1 ) than in the Paraná River (5.5 ± 2.3 ind. l −1 ). Conversely, cladocerans, originally the staple food of fish larvae, were more abundant in the Paraguay (consumed by 48% of the individuals) than in the Paraná River (26%). These results indicate that, when widely available, Limnoperna veligers largely replace the original prey of fish larvae, especially in their younger stages (protolarvae).