Global trophic position comparison of two dominant mesopelagic fish families (Myctophidae, Stomiidae) using amino acid nitrogen isotopic analyses.
PLoS One
; 7(11): e50133, 2012.
Article
in En
| MEDLINE
| ID: mdl-23209656
ABSTRACT
The δ(15)N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer trophic connectivity. We undertook a novel cross-basin comparison of trophic position in two ecologically well-characterized and different groups of dominant mid-water fish consumers using amino acid nitrogen isotope compositions. We found that trophic positions estimated from the δ(15)N values of individual amino acids are nearly uniform within both families of these fishes across five global regions despite great variability in bulk tissue δ(15)N values. Regional differences in the δ(15)N values of phenylalanine confirmed that bulk tissue δ(15)N values reflect region-specific water mass biogeochemistry controlling δ(15)N values at the base of the food web. Trophic positions calculated from amino acid isotopic analyses (AA-TP) for lanternfishes (family Myctophidae) (AA-TP â¼2.9) largely align with expectations from stomach content studies (TP â¼3.2), while AA-TPs for dragonfishes (family Stomiidae) (AA-TP â¼3.2) were lower than TPs derived from stomach content studies (TPâ¼4.1). We demonstrate that amino acid nitrogen isotope analysis can overcome shortcomings of bulk tissue isotope analysis across biogeochemically distinct systems to provide globally comparative information regarding marine food web structure.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Fishes
/
Nitrogen
/
Nitrogen Isotopes
Limits:
Animals
Language:
En
Journal:
PLoS One
Journal subject:
CIENCIA
/
MEDICINA
Year:
2012
Type:
Article
Affiliation country:
United States