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Integrating ontogenetic shift, growth and mortality to determine a species' ecological role from isotopic signatures.

Fontoura NF, Rodrigues LR, Batista CB, Persch TS, Janowicz ME - PLoS ONE (2015)

Bottom Line: Stable isotopes provide information on the trophic level of species, food-web length, and origin of organic matter ingested by consumers.In this study, we analyzed the ontogenetic variability of δ13C and δ15N obtained from samples of three Neotropical fish species: silver sardine (Lycengraulis grossidens, n=46), white lambari (Cyanocharax alburnus, n= 26), and the red-tail lambari (Astyanax fasciatus, n=23) in Pinguela Lagoon, southern Brazil.We developed a new metric, called the Weighted Isotopic Signature (φ 15N or φ 13C, ‰), that incorporates ontogenetic variability, body growth, and natural mortality into a single number.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Biociências; Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

ABSTRACT
Understanding species linkages and energy transfer is a basic goal underlying any attempt at ecosystem analysis. Although the first food-web studies were based on gut contents of captured specimens, the assessment of stable isotopes, mainly δ13C and δ15N, has become a standard methodology for wide-range analyses in the last 30 years. Stable isotopes provide information on the trophic level of species, food-web length, and origin of organic matter ingested by consumers. In this study, we analyzed the ontogenetic variability of δ13C and δ15N obtained from samples of three Neotropical fish species: silver sardine (Lycengraulis grossidens, n=46), white lambari (Cyanocharax alburnus, n= 26), and the red-tail lambari (Astyanax fasciatus, n=23) in Pinguela Lagoon, southern Brazil. We developed a new metric, called the Weighted Isotopic Signature (φ 15N or φ 13C, ‰), that incorporates ontogenetic variability, body growth, and natural mortality into a single number.

No MeSH data available.


Astyanax fasciatus in Pinguela Lagoon, southern Brazil: (a) survival curve; (b) weight growth curve; (c) δ15N-to-age response; (d) weighted impact of δ15N according to age.
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pone.0125059.g002: Astyanax fasciatus in Pinguela Lagoon, southern Brazil: (a) survival curve; (b) weight growth curve; (c) δ15N-to-age response; (d) weighted impact of δ15N according to age.

Mentions: Starting from birth, the probability of survival decreases exponentially, with almost no individual reaching the age of four (Eq 1; M = 1.78; Fig 2A). With an asymptotic length (L∞) of 13 cm, growth constant (K) of 1.16, proportionality constant (a) of 0.0099, and allometric constant (b) of 3.06, the species grows asymptotically to ± 25 g according to the von Bertalanffy growth formula (Eq 4; Fig 2B). By converting the δ15N-to-length response (; Fig 1) into the δ15N-to-age response (; Eq 7; Fig 2C), a pattern very similar to a von Bertalanffy growth curve for length can be achieved, expressing not the length-to-age, but the expected δ15N-to-age relationship:


Integrating ontogenetic shift, growth and mortality to determine a species' ecological role from isotopic signatures.

Fontoura NF, Rodrigues LR, Batista CB, Persch TS, Janowicz ME - PLoS ONE (2015)

Astyanax fasciatus in Pinguela Lagoon, southern Brazil: (a) survival curve; (b) weight growth curve; (c) δ15N-to-age response; (d) weighted impact of δ15N according to age.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440762&req=5

pone.0125059.g002: Astyanax fasciatus in Pinguela Lagoon, southern Brazil: (a) survival curve; (b) weight growth curve; (c) δ15N-to-age response; (d) weighted impact of δ15N according to age.
Mentions: Starting from birth, the probability of survival decreases exponentially, with almost no individual reaching the age of four (Eq 1; M = 1.78; Fig 2A). With an asymptotic length (L∞) of 13 cm, growth constant (K) of 1.16, proportionality constant (a) of 0.0099, and allometric constant (b) of 3.06, the species grows asymptotically to ± 25 g according to the von Bertalanffy growth formula (Eq 4; Fig 2B). By converting the δ15N-to-length response (; Fig 1) into the δ15N-to-age response (; Eq 7; Fig 2C), a pattern very similar to a von Bertalanffy growth curve for length can be achieved, expressing not the length-to-age, but the expected δ15N-to-age relationship:

Bottom Line: Stable isotopes provide information on the trophic level of species, food-web length, and origin of organic matter ingested by consumers.In this study, we analyzed the ontogenetic variability of δ13C and δ15N obtained from samples of three Neotropical fish species: silver sardine (Lycengraulis grossidens, n=46), white lambari (Cyanocharax alburnus, n= 26), and the red-tail lambari (Astyanax fasciatus, n=23) in Pinguela Lagoon, southern Brazil.We developed a new metric, called the Weighted Isotopic Signature (φ 15N or φ 13C, ‰), that incorporates ontogenetic variability, body growth, and natural mortality into a single number.

View Article: PubMed Central - PubMed

Affiliation: Faculdade de Biociências; Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

ABSTRACT
Understanding species linkages and energy transfer is a basic goal underlying any attempt at ecosystem analysis. Although the first food-web studies were based on gut contents of captured specimens, the assessment of stable isotopes, mainly δ13C and δ15N, has become a standard methodology for wide-range analyses in the last 30 years. Stable isotopes provide information on the trophic level of species, food-web length, and origin of organic matter ingested by consumers. In this study, we analyzed the ontogenetic variability of δ13C and δ15N obtained from samples of three Neotropical fish species: silver sardine (Lycengraulis grossidens, n=46), white lambari (Cyanocharax alburnus, n= 26), and the red-tail lambari (Astyanax fasciatus, n=23) in Pinguela Lagoon, southern Brazil. We developed a new metric, called the Weighted Isotopic Signature (φ 15N or φ 13C, ‰), that incorporates ontogenetic variability, body growth, and natural mortality into a single number.

No MeSH data available.