Melissa Casarez
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Melissa Casarez has a total of 6 co-authors. Here are the top co-authors by number of shared publications:
- Adam Cohen
Integrative Biology, Biodiversity Collections, The University of Texas at Austin, Austin, USA
1 shared publication - Benjamin D. Walther
Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, USA
1 shared publication - Dean A. Hendrickson
University of Texas
1 shared publication - Michael E. Curtis
Department of Biological Sciences, University of North Texas, Denton, USA
1 shared publication Nathan G. Smith
Texas Parks and Wildlife Department, Inland Fisheries Division, Austin, USA
1 shared publicationStephen Curtis
Texas Parks and Wildlife Department, Inland Fisheries Division, Austin, USA
1 shared publication
Latest Publications
- Open Access
- 16 September 2025
- Published by Springer Nature in Environmental Biology of Fishes
- Vol. 108 (10) , 1463-1476
Geographic variation in stable isotope ratios of subtropical American eel (Anguilla rostrata)
American eel (Anguilla rostrata) life history strategies and food web interactions are highly variable in temperate climates but not well understood in sub-tropical hydrologic systems. Intraspecific variability in isotopic niche breadth and overlap can have major implications for species of conservation concern by revealing dietary plasticity of populations across varied habitats. Muscle tissue stable isotope ratios of carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) were analyzed to assess geographic variance in recent trophic histories within and among American eels collected in tributaries of the northwestern Gulf of Mexico and to quantify isotopic niche breadths and overlaps of capture groups. A total of eight specimen groupings were designated according to the riverine and coastal basins where they were collected, with one group comprised of only individuals caught within a wastewater treatment plant. Univariate analyses revealed highly variable isotopic ratios within and between groups. The probability of groups being found in the niche region of another group was low, with only six instances in which the probability of overlap was over 10%. The Colorado (C) group showed the highest probability of overlap of any group, being found in 86.57% of the Brazos-San Jacinto (B-SJ) group’s niche region. Collectively, these results illustrate the high degree of geographic variation in isotope ratios within and between regional habitats in an understudied portion of the species’ range.
- 16 September 2025
- Published by Springer Nature in Environmental Biology of Fishes
- Vol. 108 (10) , 1463-1476
Open AccessGeographic variation in stable isotope ratios of subtropical American eel (Anguilla rostrata)
American eel (Anguilla rostrata) life history strategies and food web interactions are highly variable in temperate climates but not well understood in sub-tropical hydrologic systems. Intraspecific variability in isotopic niche breadth and overlap can have major implications for species of conservation concern by revealing dietary plasticity of populations across varied habitats. Muscle tissue stable isotope ratios of carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) were analyzed to assess geographic variance in recent trophic histories within and among American eels collected in tributaries of the northwestern Gulf of Mexico and to quantify isotopic niche breadths and overlaps of capture groups. A total of eight specimen groupings were designated according to the riverine and coastal basins where they were collected, with one group comprised of only individuals caught within a wastewater treatment plant. Univariate analyses revealed highly variable isotopic ratios within and between groups. The probability of groups being found in the niche region of another group was low, with only six instances in which the probability of overlap was over 10%. The Colorado (C) group showed the highest probability of overlap of any group, being found in 86.57% of the Brazos-San Jacinto (B-SJ) group’s niche region. Collectively, these results illustrate the high degree of geographic variation in isotope ratios within and between regional habitats in an understudied portion of the species’ range.