Biochemical changes throughout early- and middle-stages of embryogenesis in lobsters (Homarus americanus) under different thermal regimes

Abstract

Most marine crustacean eggs contain the full complement of nutritional resources required to fuel their growth and development. Given the propensity of many ovigerous (egg-bearing) American lobsters (Homarus americanus) to undergo seasonal inshore-to-offshore migrations, thereby potentially exposing their eggs to varying thermal regimes, the goal of this study was to determine the impact of water temperature on egg quality over their course of development. This was accomplished by documenting changes in total lipids, proteins, and size (volume) of eggs subjected to one of three thermal regimes: inshore, offshore, and constant (16 °C) conditions. Total egg lipids showed a marked decrease over time, while protein levels increased over the same period. Although there were no significant differences in total lipids, proteins, or egg sizes between eggs exposed to inshore and offshore temperatures, they differed from values for eggs exposed to a constant temperature, which also hatched almost three months sooner. This is most likely due to the fact that eggs held at a constant temperature did not experience a period of slow development during the colder months from November to March that are important for synchronizing egg hatch and may be compromised by elevated seawater temperatures.

Keywords

• Lobster
• Egg development
• Ovigerous
• Gulf of Maine
• H. americanus
• Vitellogenesis