Stable isotope analysis: a tool for certifying captive or wild caiman leather origin

Name: Stable isotope analysis: a tool for certifying captive or wild caiman leather origin
License: https://creativecommons.org/licenses/by-sa/2.5/ar/
Keywords: Carbon isotopes

Datos de investigación

Stable isotope analysis: a tool for certifying captive or wild caiman leather origin

Autores: Simoncini, Melina Soledad Icon

; Piña, Carlos Ignacio Icon

; Marques , Thiago; Verdade , Luciano; Camargo , Plinio; Pierini, Sofía Evelyn Icon

; Bassetti , Luis; Lara, Neliton

Publicador: Consejo Nacional de Investigaciones Científicas y Técnicas

Fecha de depósito: 12/12/2024

Fecha de recolección: 01/10/2022-01/06/2024

Clasificación temática:

Conservación de la Biodiversidad

Resumen

We must provide tools to discriminate products from captive and wild sources products to improve wildlife use sustainability. Stable isotopes of carbon and nitrogen ratios can be potentially useful for such purpose. In this study, we evaluated δ15N and δ13C in Caiman latirostris skins from captive individuals (from Argentina and Brazil) and wild individuals (from Argentina) and leathers (from tanned skins) from both captive and wild individuals (from Argentina). In addition, we compared the isotopic ratios of caiman claws from both wild and captive caimans from Brazil. The main goal of this study was to evaluate the possible differences on the variability of δ15N and δ13C ratios between skins, leathers, and claws from wild and captive animals. As a result, skins, leathers, and claws from the wild individuals have a larger variability of isotopic ratios than those from captive ones. In addition, tanning does not affect data variability. We can thus distinguish skins and leathers from wild and captive animals. Such pattern might be particularly useful in regions where hunting is banned, and only farmed individuals can be traded.

Información Técnica

We collected skin samples from captive (juveniles < 1m) and wild individuals (juveniles 1 m, and adults < 2m) from the ranching program in Santa Fe, Argentina, and captive C. latirostris (juveniles < 1m) from the farming program in São Paulo, Brazil. In addition, we collected claws, from wild (adults and juveniles) and captive animals (juveniles) in Brazil. Claw samples have been removed by clipping 5 mm of claw tipping from the third finger (counting from inside out) of the right foot. We collected 2 cm² skin samples by cutting the single scale of the tail, according to the markings on the tails of the caimans. Both methods are commonly used to mark crocodilians, and are not considered harmful (Marques et al., 2013). After collection, and in order to preserve the claws and single scale on the tail samples until processing, they were kept in a freezer (-18°C). Some of single scale on the tail were tanned according to commercial caimans’ leather process by Curtipiel-Argentina. Whereas, samples of leathers from captivity were taken directly from tanned whole skins. The sampling effort of the present study is described in Table 1. 2.2Analytical methodology Frozen samples were thawed for laboratory processing. All samples were then dried at 50 °C until a constant weight was reached. Subsequently, we cut samples to pieces of 0.8-1.2 mg, and placed them in small tin capsules. The isotopic composition of carbon and nitrogen was determined by on-line combustion by CF-IRMS in a Carlo Erba elemental analyzer (CHN-110) coupled to a Delta Plus mass spectrometer at Labóratorio de Ecologia Isotópica of Centro de Energia Nuclear na Agricultura at the Universidade de São Paulo. We calculated the isotopic composition of carbon and nitrogen by the following equation: δ^13 C or δ^15 N=((Rsample -Rstandard)/Rstandard)*1000 where R is the 13C/12C or 15N/14N molar ratio in the sample and in the standard. The results are expressed in parts per thousand (‰). We used the standards for carbon and nitrogen from Pee Dee Belemnite (PDB) and atmospheric air (AIR), respectively. The analytical error of the isotopic measurements was estimated to be 0.5 ‰ for δ15N and 0.3 ‰ for δ13C by repeated measurements of the internal standard (sugarcane). The interest of this study was to compare the variability of isotopic ratios (δ15N and δ13C) of both wild and captive skins and leathers, as well as claws of C. latirostris.

Palabras clave: Carbon isotopes, Crocodilians, Fractionation, Nitrogen isotopes

Alcance geográfico

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Identificador del recurso

URI: http://hdl.handle.net/11336/250343

Colecciones

Datos de Investigación(CCT - SANTA FE)
Datos de Investigación de CTRO.CIENTIFICO TECNOL.CONICET - SANTA FE

Datos de Investigación(CICYTTP)
Datos de Investigación de CENTRO DE INV.CIENT.Y TRANSFERENCIA TEC A LA PROD

Citación

Simoncini, Melina Soledad; Piña, Carlos Ignacio; Marques , Thiago; Verdade , Luciano; Camargo , Plinio; Pierini, Sofía Evelyn; Bassetti , Luis; Lara, Neliton; (2024): Stable isotope analysis: a tool for certifying captive or wild caiman leather origin. Consejo Nacional de Investigaciones Científicas y Técnicas. (dataset). http://hdl.handle.net/11336/250343

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Excepto donde se diga explícitamente, este item se publica bajo la siguiente descripción: Creative Commons Attribution-ShareAlike 2.5 Unported (CC BY-SA 2.5)