Presentation Title

Integrating the Early Behavioral and Physiological Development of the Respiratory Capacity in Young Humpback Whales

Faculty Mentor

Dr. Cori Newton, Dr. Rachel Cartwright

Start Date

18-11-2017 10:00 AM

End Date

18-11-2017 11:00 AM

Location

BSC-Ursa Minor 48

Session

Poster 1

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

As humpback whales age, they develop the adaptive capacity to hold their breath for extensive periods of time. Key adaptations that are important for muscle maturation to extend dives in hypoxic conditions include resistance to pH changes, increasing myoglobin levels to store oxygen, and development of specific fiber type compositions. Typically, marine mammal calves require postnatal development of these muscle adaptations; however, limited information is available regarding the level of muscle maturity of humpback calves and how it relates to their dive capacity. Therefore, humpback calf myoglobin levels, muscle buffering capacity, and muscle fiber type compositions were determined. To analyze myoglobin concentrations, myoglobin was extracted from swim muscles, run under an assay, and measured by applying Reynafarje’s method. Buffering capacity was determined by homogenizing muscle tissue samples and titrated with drops of NaOH to shift the pH one unit. In addition, composition of type I and II muscle fibers was determined by immunohistochemical staining. Collected results overall have shown that young humpbacks have lower myoglobin levels leading to short-term oxygen storage, lower buffering capacity, and an increase in fast twitch muscle fibers in comparison to older humpback whales. The findings of this study support that immature muscle biochemistry correlates with observed calf dive durations, indicating that the energetic behavior of juvenile calves is developed to increase survival. Understanding the relationship between muscle biochemistry and dive capacity plays a significant role in understanding how humpback whale calves adapt to improve their foraging abilities, avoid predation, and strengthen their modes of survival.

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Nov 18th, 10:00 AM Nov 18th, 11:00 AM

Integrating the Early Behavioral and Physiological Development of the Respiratory Capacity in Young Humpback Whales

BSC-Ursa Minor 48

As humpback whales age, they develop the adaptive capacity to hold their breath for extensive periods of time. Key adaptations that are important for muscle maturation to extend dives in hypoxic conditions include resistance to pH changes, increasing myoglobin levels to store oxygen, and development of specific fiber type compositions. Typically, marine mammal calves require postnatal development of these muscle adaptations; however, limited information is available regarding the level of muscle maturity of humpback calves and how it relates to their dive capacity. Therefore, humpback calf myoglobin levels, muscle buffering capacity, and muscle fiber type compositions were determined. To analyze myoglobin concentrations, myoglobin was extracted from swim muscles, run under an assay, and measured by applying Reynafarje’s method. Buffering capacity was determined by homogenizing muscle tissue samples and titrated with drops of NaOH to shift the pH one unit. In addition, composition of type I and II muscle fibers was determined by immunohistochemical staining. Collected results overall have shown that young humpbacks have lower myoglobin levels leading to short-term oxygen storage, lower buffering capacity, and an increase in fast twitch muscle fibers in comparison to older humpback whales. The findings of this study support that immature muscle biochemistry correlates with observed calf dive durations, indicating that the energetic behavior of juvenile calves is developed to increase survival. Understanding the relationship between muscle biochemistry and dive capacity plays a significant role in understanding how humpback whale calves adapt to improve their foraging abilities, avoid predation, and strengthen their modes of survival.