A comparative seasonal study of two populations ofHypnea musciformisfrom the East and West Coasts of Florida, USA II. Photosynthetic and respiratory rates

✍ Scribed by M. J. Durako; C. J. Dawes

• Publisher: Springer-Verlag
• Year: 1980
• Tongue: English
• Weight: 574 KB
• Volume: 59
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00396863

✦ Synopsis

Respiration rates of Hypnea musciformis (Wulfen) Lamouroux in Florida, USA, generally increased with increased temperature. Gulf coast H. musciformis respired at significantly higher rates than the Atlantic coast population, which exhibited a region of temperature independence between 24~176

Respiration rates were highest in the fall and winter, during the periods of rapid growth. Respiration rates were lowest in the summer indicating a period of storage and low metabolism. Photosynthetic responses to various levels of light and temperature indicated that the Gulf coast population was more tolerant to high light intensities than the Atlantic coast population. Maximum photosynthetic responses for both populations occurred between 24 ~ and 32 ~ which corresponds to the shallow slope region of the respiration-temperature curves. The results indicate that water temperature rather than light intensity is a significant factor in modifying seasonal photosynthetic capacities. The greatest seasonal variation in photosynthetic responses occurred at the light-temperature levels of highest responses while little seasonal variation was demonstrated at tolerance limits.