Growth and Developmental Processes Alternate During Larval Development of Atlantic Herring

Area of Science:

• Marine biology
• Developmental biology
• Fish biology

Background:

• Fish larvae undergo significant physiological and locomotive development.
• Essential processes like digestion and respiration, and structures such as muscle and skeleton, form during larval stages.
• Atlantic herring larvae hatch at a semi-embryonic stage, requiring substantial developmental progression.

Purpose of the Study:

• To analyze gene expression related to myogenesis, skeletogenesis, and growth in Atlantic herring larvae.
• To correlate gene expression with length-stage ratios and histological data.
• To understand the interplay between growth and other developmental priorities in herring larvae.

Main Methods:

• Gene expression analysis of myogenesis, skeletogenesis, and growth factors.
• Histological analysis of herring larvae cross-sections.
• Evaluation of length-per-stage ratios across different larval stages.

Main Results:

• Two major growth periods identified: during dorsal fin development and the transition from caudal to pelvic fin development.
• Histological analysis confirmed increased muscle fibers during these growth periods.
• Gene expression for muscle development peaked before accelerated growth phases.

Conclusions:

• Growth and developmental priority periods alternate during larval development in Atlantic herring.
• Energetically costly processes like organogenesis occur when growth is less prominent.
• This alternating pattern is crucial for successful larval development in marine fish.