The effects of CO2 level and temperature on embryos and free embryos of the Patagonian pejerrey Odontesthes hatcheri (Actinopterygii, Atherinopsidae)

• Published in: Hydrobiologia Vol. 849; no. 21; pp. 4787 - 4801
• Main Authors: Crichigno, Sonia A., Cussac, Víctor E.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2022; Springer Nature B.V
• Subjects: Abnormalities; Additives; Biomedical and Life Sciences; Blood cells; Body shape; Bubbling; Carbon dioxide; Climate change; Colour; Ecology; Embryos; Fish; Fish eggs; Freshwater & Marine Ecology; Global temperatures; Hatching; High temperature; Lakes; Life Sciences; Littoral environments; Malformations; Odontesthes hatcheri; pH effects; Pigmentation; Primary Research Paper; Shape effects; Spatial variations; Survival; Temperature; Temperature effects; Threatened species; Zoology; Acidification; Silverside; Early life; Global warming; Climate Change
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-022-05016-2

Climate Change includes an increase of both the concentration of atmospheric CO 2 and of global temperature. Embryos (= eggs) of Odontesthes hatcheri were collected in spring–summer from the littoral of Lake Morenito (Andes of Argentina). Embryos and free embryos were exposed to different temperatures (within a currently natural thermal range) and CO 2 levels (obtained by bubbling lake water with gaseous CO 2 ). High temperature and high CO 2 led to low embryonic survival. Embryonic abnormalities were observed. Incidence of colorless blood cells and delayed dorsal pigmentation increased significantly at high CO 2 level. Free embryo survival decreased with time, being particularly low at high CO 2 level. Free embryo body shape also signaled the effects of high CO 2 . The combined effect of temperature and CO 2 was additive. As temperature and atmospheric pCO 2 increasing continues, the best survival at hatching observed in our experiments (50–60%, pH 7.5, 14 °C) will deteriorate (< 20% at 18 °C and pH 7.0). These Climate Change-related results and the fact that the species is already threatened by translocated species suggest a fragile situation. Spatial variation of temperature and pCO 2 led us to reconsider the suitability of shallow littoral vegetated areas of the lakes as anti-predatory refuges for fish early life periods.