Do grazers respond to or control food quality? Cross-scale analysis of algivorous fish in littoral Lake Tanganyika

Simple item page
dc.contributor.authorMunubi, Renalda N.
dc.contributor.authorMclntyre, Peter B.
dc.contributor.authorVadeboncoeur, Yvonne
dc.date.accessioned2021-07-09T07:05:48Z
dc.date.available2021-07-09T07:05:48Z
dc.date.issued2018
dc.descriptionJournal Articleen_US
dc.description.abstractFood quality determines the growth rate of primary consumers and ecosystem trophic efficiencies, but it is not clear whether variation in primary consumer densities control, or is controlled by, variation in food quality. We quantified variation in the density and condition of an abundant algae-eating cichlid, Tropheus brichardi, with respect to the quality and productivity of algal biofilms within and across rocky coastal sites in Lake Tanganyika, East Africa. Adjacent land use and sediment deposi- tion in the littoral zone varied widely among sites. Tropheus brichardi maximized both caloric and phosphorus intake at the local scale by aggregating in shallow habitats: algivore density decreased with depth, tracking attached algae productivity (rETR MAX ) remarkably well (r 2 = 0.84, P = 0.00033). In contrast, algivore density was unrelated to among-site variation in algal productivity. Rather, there was significant increase in algal quality (r 2 = 0.44, P = 0.011) and decrease in algal biomass (r 2 = 0.53, P = 0.0068) with T. brichardi density across sites, consistent with strong top-down control of primary producers. The amount of inorganic sediment on rock surfaces was the strongest predictor of among-site variation in algivore density (r 2 = 0.69, P = 0.00096), and algivore gut length increased with sedimentation (r 2 = 0.36, P = 0.034). These patterns indicate extrinsic and top-down forcing of algal food quality and quantity across coastal landscapes, combined with adaptive habitat selection by fish at the local scale. Factors that degrade food quality by decreasing algal nutrient content or diluting the resource with indigestible material are likely to depress grazer densities, potentially dampening top-down control in high- light, low-nutrient aquatic ecosystems.en_US
dc.identifier.urihttps://www.suaire.sua.ac.tz/handle/123456789/3698
dc.language.isoenen_US
dc.publisherSpringer-Verlag GmbH Germanyen_US
dc.subjectFood qualityen_US
dc.subjectalgivorous fishen_US
dc.subjectecosystem trophicen_US
dc.subjectMicrophytobenthosen_US
dc.subjectTropheusen_US
dc.subjectLake Tanganyikaen_US
dc.subjectLittoralen_US
dc.subjectSedimenten_US
dc.titleDo grazers respond to or control food quality? Cross-scale analysis of algivorous fish in littoral Lake Tanganyikaen_US
dc.typeArticleen_US
dc.urlhttps://doi.org/10.1007/s00442-018-4240-1en_US

Files

Original bundle

Now showing 1 - 1 of 1
No Thumbnail Available
Name:
Munubi-Do-grazers-2018.pdf
Size:
1.31 MB
Format:
Adobe Portable Document Format
Description:
Download

License bundle

Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.67 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Articles, Conference and Workshop Papers Collection