Bile acids as potential pheromones in pintado catfish Pseudoplatystoma corruscans (Spix & Agassiz, 1829): eletrophysiological and behavioral studies

Abstract

Bile acids are potent olfactory and gustatory stimulants for fish. Electro-olfactogram recording was used to test whether the olfactory epithelium of pintado catfish Pseudoplatystoma corruscans is specifically sensitive to bile acids, some of which have been hypothesized to function as pheromones. Five out of 30 bile acids that had been pre-screened for olfactory activity in fish were selected. Cross-adaptation experiments demonstrated that sensitivity to bile acids is attributable to at least 3 independent classes of olfactory receptor sites. The taurocholic acid (TCA) and taurochenodeoxycholic acid (TCD) were the most potent compounds. By using avoidance/preference tests, we found that P. corruscans prefers water containing TCA. Bile acids are discriminated by olfactory epithelium of pintado, supporting that these compounds could function as pheromones.Os ácidos biliares são potentes estimulantes olfatórios e gustatórios em peixes. Registros em eletro-olfactograma foram usados para testar se o epitélio olfatório de Pseudoplatystoma corruscans, pintado, é sensível aos ácidos biliares, alguns dos quais têm sido propostos como feromônios. Foram selecionados cinco de uma lista de trinta ácidos biliares previamente testados em atividade olfatória em peixes. Testes de adaptação cruzada demonstraram que a sensibilidade aos ácidos biliares se dá por 3 classes independentes de sites de receptores olfatórios. O ácido taurocólico (TCA) e o ácido tauroquenodesoxicólico (TCD) foram os compostos mais potentes. Em testes de evasão/preferência, P. corruscans prefere água contendo o ácido TCA. Os ácidos biliares são discriminadas por epitélio olfatório de pintado, evidenciando que estes compostos podem funcionar como feromônios.

Physiology, endocrinology and chemical communication in aggressive behaviour of fishes

“…During transmission, pheromone action may be compromised by other dissolved chemicals, which can bind pheromones or inhibit receptors, e.g ., humic acids (Hubbard et al ., 2002), or disrupt the function or cause degeneration of olfactory sensory neurons (OSN), e.g ., heavy metals (Tierney et al ., 2010). Pheromones may be released to the environment through the gills, or via the urine, skin mucus, faeces, semen and ovarian fluids (Almeida et al ., 2005; Bayani et al ., 2017; Brown et al ., 1995; Døving et al ., 1980; Félix et al ., 2013; Giaquinto et al ., 2015; Giaquinto & Hara, 2008; Hubbard et al ., 2003; Lecchini et al ., 2018; Marui & Caprio, 1992; Rosenthal et al ., 2011; Saraiva et al ., 2017; Scott et al ., 2019; Stacey & Sorensen, 2009). In O. mossambicus , C. auratus and S. salar , the urine is an important vehicle for pheromone release (Almeida et al ., 2005; Appelt & Sorensen, 1999, 2007; Barata et al ., 2007, 2008a).…”

Less water renewal reduces effects on social aggression of the cichlid Pterophyllum scalare

“…Fish use chemicals to signal their reproductive state (Miranda et al, 2005;Stacey and Sorensen, 2006), to recognize conspecifics (Reebs, 1994;Thünken et al, 2009), to warn conspecifics of predators (Jordão and Volpato, 2000), to identify size (Giaquinto and Volpato, 2005), to find well-nourished males in sexual selection (Giaquinto, 2010), and to communicate social rank in a social hierarchy system (Giaquinto and Volpato, 1997;Gonçalves-de-Freitas et al, 2008). These signals are released with the urine (Hubbard et al, 2014) and with bile acids (Giaquinto et al, 2015). In aquaculture systems, water needs to be renewed to remove food leftovers, feces, and toxic nitrogen compounds, as well as to maintain adequate environmental quality for fish health (Goldstein, 2001).…”