Influence of aluminum and acid pH, associated with temperature variations, on seminal quality and reproductive variables of Astyanax altiparanae (Teleostei: Characidae)

Author(s)

João Paulo Silva Pinheiro

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2021-02-05

Examining board members

Renata Guimarães Moreira; Rachel Ann Hauser Davis; Luis David Solis Murgas; Camilo Dias Seabra Pereira

• Advisor: Renata Guimarães Moreira Whitton

Abstract

Anthropic actions, such as the introduction of metals into the water, can cause genotoxic effects in animals, and affect physiological processes, such as reproduction. The toxicity of these metals, among them aluminum (Al), can be potentiated by changes in temperature, influencing fish health and the quality of gametes, threatening the reproductive success. The general objective of this study was to evaluate the effects of acute exposure to Al and synergistic actions of water temperature on blood toxicity, seminal parameters, gamete fertilization and larval hatching, and the embryonic development of Astyanax altiparanae. Males were exposed for 24 h and 96 h in different experimental groups, resulting from the combination of each temperature (20, 25 and 30 ºC), with neutral pH (7.0) or acidic pH (5.5) and with or without the presence of 0.5 mg L-1 of Al. After exposure, Al bioconcentration (testicles and semen), comet test (erythrocytes and sperm), nuclear abnormality test (micronucleus and erythrocytes), pH and seminal osmolality, sperm concentration, morphology, kinetics, and sperm ultrastructure, fatty acid seminal profile, fertilization, and hatching percentages, as well as the embryonic development were analyzed. The temperature rise increased the bioaccumulation of Al in the testes after 96 h, while after 24 h it already triggered the bioaccumulation of Al in the semen. Temperature and pH potentiated Al\'s genotoxic effects. Besides, the exposure to Al and water temperature at 30oC reduced seminal osmolality after 24 h and 96 h of exposure, as well as the sperm concentration (24 h) was reduced. Acid water induced changes in sperm kinetics, but the addition of Al accentuated this reduction, mainly in motility and curvilinear velocity of sperm. Al also affected the sperm ultrastructure (96 h), fertility, the percentage of some seminal polyunsaturated fatty acids (PUFA), such as C20:4n6 and C22:5n3, besides the morphology of the larvae. The activation/incubation medium at acid pH and/or with Al impaired fertilization, hatching, and embryonic development. Finally, it was observed that the percentage of fertilization, the fatty acid profile, and the embryonic development are temperature-dependent. Therefore, the data allowed to conclude that Al, in a temperature-dependent way, triggered genotoxic effects in blood and sperm, in addition to reducing seminal quality, interfering in the fertilization, hatching, and embryonic development in A. altiparanae. Acidity, instead, influenced the seminal quality and the reproductive parameters, but to a lesser extent. (AU)

• FAPESP's process: 16/08770-8 - Evaluation of the semen quality, mutagenicity and genotoxicity in Astyanax altiparanae (Teleostei, Characidae) exposed to aluminum in different water temperatures
• Grantee: João Paulo Silva Pinheiro
• Support Opportunities: Scholarships in Brazil - Doctorate