Morphology and cardiac physiology are differentially affected by temperature in developing larvae of the marine fish mahi-mahi (Coryphaena hippurus)

作者：Perrichon Prescilla^*; Pasparakis Christina; Mager Edward M; Stieglitz John D; Benetti Daniel D; Grosell Martin; Burggren Warren W

来源：Biology Open, 2017, 6(6): 800-809.

DOI：10.1242/bio.025692

• Mahi-mahi
• Development
• Heart rate
• Stroke volume
• Cardiac output
• Q(10)

Cardiovascular performance is altered by temperature in larval fishes, but how acute versus chronic temperature exposures independently affect cardiac morphology and physiology in the growing larva is poorly understood. Consequently, we investigated the influence of water temperature on cardiac plasticity in developing mahi-mahi. Morphological (e.g. standard length, heart angle) and physiological cardiac variables (e.g. heart rate f(H), stroke volume, cardiac output) were recorded under two conditions by imaging: (i) under acute temperature exposure where embryos were reared at 25 degrees C up to 128 h post-fertilization (hpf) and then acutely exposed to 25 (rearing temperature), 27 and 30 degrees C; and (ii) at two rearing (chronic) temperatures of 26 and 30 degrees C and performed at 32 and 56 hpf. Chronic elevated temperature improved developmental time in mahi-mahi. Heart rateswere 1.2-1.4-fold higher under exposure of elevated acute temperatures across development (Q(10)>= 2.0). Q(10) for heart rate in acute exposure was 1.8-fold higher compared to chronic exposure at 56 hpf. At same stage, stroke volumewas temperature independent (Q(10)similar to 1.0). However, larvae displayed higher stroke volume later in stage. Cardiac output in developing mahi-mahi is mainly dictated by chronotropic rather than inotropic modulation, is differentially affected by temperature during development and is not linked to metabolic changes.

• 出版日期2017-6-15