Physiological studies onMarphysa gravelyi VII. Tissue respiration
© Biologischen Anstalt Helgoland 1967
Published: 1 August 1967
1. The respiratory rate of body tissues of the polychaeteM. gravelyi ranged from 3.13 µl/mg/hr to 6.34 µl/mg/hr in the four experimental salinities 10 ‰, 14‰, 17 ‰ and 24 ‰ Since similar estimations in other polychaetes are not available in literature a comparison is difficult. However, the trends, i. e., increase of respiratory rates with increasing salinity, are similar to those reported for whole individuals ofN. diversicolor.
2. InM. gravelyi, both the organic and inorganic ions are regulated. It is argued that the trend reported above may be traced to the operation of an effective ion transport system.
3. Two adaptations that may help to understand the trend of evolution inM. gravelyi are the reduction in permeability and the lowering of the body fluid concentration.
4. These two adaptations may indicate a tendency towards life in freshwater. A few other features, such as corresponding changes in the reproductive patterns ofM. gravelyi and the geographical distribution of the genusMarphysa support this assumption.