Journal Article
Title | Cardiac function and critical swimming speed of the winter flounder (Pleuronectes americanus) at two temperatures. |
Publication Type | Journal Article |
Authors | Joaquim, N, Wagner, GN, A Gamperl, K |
Year of Publication | 2004 |
Journal | Comp Biochem Physiol A Mol Integr Physiol |
Volume | 138 |
Issue | 3 |
Date Published | 2004 Jul |
Pagination | 277-85 |
ISSN | 1095-6433 |
Keywords | Animals, Flounder, Heart, Heart Rate, Stroke Volume, Swimming, Temperature |
Abstract | Using Transonic flow probes and a uniquely designed swimming flume, we directly measured cardiac parameters (Q, cardiac output; SV, stroke volume; and fH, heart rate) in winter flounder (Pleuronectes americanus) before and during critical swim speed (Ucrit) tests at 4 and 10 degrees C. Resting Q, SV and fH averaged 9.8 ml min(-1) kg(-1), 0.5 ml kg(-1) (1.0 ml g ventricle(-1)) and 21 beats min(-1) at 4 degrees C and 15.5 ml min(-1) kg(-1), 0.5 ml kg(-1) (0.95 ml g ventricle(-1)) and 34 beats min(-1) at 10 degrees C (Q10 values of 2.13, 0.91 and 2.35, for Q, SV and fH, respectively). Cardiac output, SV and fH increased by approx. 170%, 70% and 60% at both temperatures during the Ucrit test. However, cardiac parameters generally reached near maximal levels almost immediately upon swimming and remained at these levels until Ucrit (0.65 +/- 0.06 bl s(-1) at 4 degrees C and 0.73 +/ -0.07 bl s(-1) at 10 degrees C). This rapid rise in cardiac function to near maximal levels did not appear to be the result of stress alone, as Q only fell slightly when flounder were swum for 75 min at < 0.4 bl s(-1), speeds at which they appeared to swim comfortably. Our results suggest that both Q and Ucrit have been significantly overestimated in flatfishes, and that "lift-off"/slow swimming is energetically expensive. Furthermore, they show that maximum and resting stroke volume (per g of ventricle) are extremely high in the flounder as compared with other teleosts. |
DOI | 10.1016/j.cbpb.2004.03.016 |
Sapientia | |
Alternate Journal | Comp. Biochem. Physiol., Part A Mol. Integr. Physiol. |
PubMed ID | 15313481 |