Thermal tolerance and phenotypic plasticity in juvenile Hippocampus erectus Perry, 1810: Effect of acute and chronic exposure to contrasting temperatures
Por:
Mascaró M., Amaral-Ruiz M., Huipe-Zamora I., Martínez-Moreno G., Simoes, N., Rosas C.
Publicada:
1 oct 2016
Resumen:
The seahorse Hippocampus erectus inhabits estuaries and coastal areas
from southern Canada to northern Brazil, including the Yucatan Peninsula
(YP), Mexico. Fish species living in thermally heterogeneous
environments have developed physiological and behavioural adjustments
that provide individuals with the phenotypic plasticity to respond to
environmental changes within certain limits. When thermal changes exceed
the ability of fish to adjust, energy supply is predominantly directed
to fuel essential maintenance costs at the expense of growth and
reproduction. In such circumstances, not only temperature, but also time
of exposure, are elements that determine the adaptive value of
phenotypic plasticity. The present study was designed to examine the
consequences of acclimation of juvenile H. erectus to 18 and 30 degrees
C on the phenotypic plasticity associated with exposure to acute thermal
events (measured through the thermal limits) and chronic exposure during
longer periods (measured through growth). Similar survival and growth
was found in all seahorses that experienced acute exposure (similar to 1
min) to temperatures ranging from 7 to 33 degrees C and 12 to 36 degrees
C in both acclimation treatments, respectively. Chronic exposure to 30
degrees C compared to 18 degrees C, however, significantly reduced
seahorse growth. A thermal tolerance polygon calculated as 302 degrees
C-2 suggests that H. erectus has a wide tolerance to the extreme
conditions commonly present in estuarine environments. Given that the
amplitude in the thermal tolerance polygon was mainly due to an increase
in the lower limits of the interval and that no minimum temperature
threshold could be determined, thus suggesting that the populations from
YP are near their upper thermal limit. (C) 2016 Elsevier B.V. All rights
reserved.
Filiaciones:
Mascaró M.:
Unidad Multidisciplinaria de Docencia e Investigación, Universidad Nacional Autónoma de México, Puerto de Abrigo s/n, Sisal, Yucatán 97355, Mexico
Amaral-Ruiz M.:
Unidad Multidisciplinaria de Docencia e Investigación, Universidad Nacional Autónoma de México, Puerto de Abrigo s/n, Sisal, Yucatán 97355, Mexico
Huipe-Zamora I.:
Unidad Multidisciplinaria de Docencia e Investigación, Universidad Nacional Autónoma de México, Puerto de Abrigo s/n, Sisal, Yucatán 97355, Mexico
Martínez-Moreno G.:
Unidad Multidisciplinaria de Docencia e Investigación, Universidad Nacional Autónoma de México, Puerto de Abrigo s/n, Sisal, Yucatán 97355, Mexico
Rosas C.:
Unidad Multidisciplinaria de Docencia e Investigación, Universidad Nacional Autónoma de México, Puerto de Abrigo s/n, Sisal, Yucatán 97355, Mexico
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