387
determine the age (Brusher and Schull 2009; Artero et al. 2015) and for studies of
ontogenetic changes in habitat and diet, using δ
15
N (Tzadik et al. 2014). In the
future, these structures will be able to demonstrate the life history and connectivity
between the environments the Goliath Grouper visits, through the analysis of elementary chemical structures.
14.3.7 Non-lethal Method to Analyze Stable Isotopes
In ecology studies of animal species, especially the ones considered migratory, it is
very important to know which geographical regions are being used by certain individuals and their population variations during reproduction and feeding. Normally,
fish displacement is observed through external markers, in which the success of
markers recovery and the number of retrieved individuals are too low to have a good
analysis.
Based on these limitations, in the past decades new techniques emerged to assist
researchers to understand a little more about the ecology of animals in nature. These
techniques included the use of fatty acid profiles, analysis of molecular genetics, and
determination of natural occurrence of stable isotopes in different animal tissues.
There are many researches with stable isotopes in different animal groups. Here,
we will focus on the use of stable isotopes in fish, emphasizing non-lethal techniques, and finally, what has been done in this sense for the study of Goliath Grouper
in the United States of America. In most fish SIA applications, samples of white
muscle tissue, liver, gonads, bone, otoliths, brain or the whole fish are used for isotopic determinations (DeNiro and Epstein 1977; Pinnegar and Polunin 1999).
Fig. 14.10 Epinephelus itajara. A juvenile Goliath Grouper captured 4 times over 2 years: photographs of dorsal spine cross sections taken from (a) date of original capture, October 1999, 365 mm
total length (TL); and (b) from a subsequent capture event in December 2000, 487 mm TL. This
fish was injected with oxytetracycline (OTC) at time of capture in October 1999; note OTC stain
visible between 2nd and 3rd annuli in (b). Numbers above arrows refer to annuli. VM vascularized
matrix, OE outer edge (Brusher and Schull 2009)
14 The Atlantic Goliath Grouper: Conservation Strategies for a Critically Endangered…
determine the age (Brusher and Schull 2009; Artero et al. 2015) and for studies of
ontogenetic changes in habitat and diet, using δ
15
N (Tzadik et al. 2014). In the
future, these structures will be able to demonstrate the life history and connectivity
between the environments the Goliath Grouper visits, through the analysis of elementary chemical structures.
14.3.7 Non-lethal Method to Analyze Stable Isotopes
In ecology studies of animal species, especially the ones considered migratory, it is
very important to know which geographical regions are being used by certain individuals and their population variations during reproduction and feeding. Normally,
fish displacement is observed through external markers, in which the success of
markers recovery and the number of retrieved individuals are too low to have a good
analysis.
Based on these limitations, in the past decades new techniques emerged to assist
researchers to understand a little more about the ecology of animals in nature. These
techniques included the use of fatty acid profiles, analysis of molecular genetics, and
determination of natural occurrence of stable isotopes in different animal tissues.
There are many researches with stable isotopes in different animal groups. Here,
we will focus on the use of stable isotopes in fish, emphasizing non-lethal techniques, and finally, what has been done in this sense for the study of Goliath Grouper
in the United States of America. In most fish SIA applications, samples of white
muscle tissue, liver, gonads, bone, otoliths, brain or the whole fish are used for isotopic determinations (DeNiro and Epstein 1977; Pinnegar and Polunin 1999).
Fig. 14.10 Epinephelus itajara. A juvenile Goliath Grouper captured 4 times over 2 years: photographs of dorsal spine cross sections taken from (a) date of original capture, October 1999, 365 mm
total length (TL); and (b) from a subsequent capture event in December 2000, 487 mm TL. This
fish was injected with oxytetracycline (OTC) at time of capture in October 1999; note OTC stain
visible between 2nd and 3rd annuli in (b). Numbers above arrows refer to annuli. VM vascularized
matrix, OE outer edge (Brusher and Schull 2009)
14 The Atlantic Goliath Grouper: Conservation Strategies for a Critically Endangered…