Reproductive seasonality of Geophagus steindachneri Eigenmann & Hildebrand, 1922 (Perciformes: Cichlidae) in a tropical mountain river

Abstract

Reproductive seasonality in tropical freshwater fishes is strongly influenced by rainfall. In lowlands, floods spill laterally to floodplains and fishes usually breed during the flooding season. In mountain rivers, floods are sudden and flush out aquatic organisms. Fishes in mountain rivers usually breed during dry seasons, what has been hypothesized as a strategy to reduce mortality due to strong floods. If that is the case, mouth-brooding fishes should suffer less from strong floods and should have more prolonged breeding seasons in mountain rivers. Here we investigated the breeding activity of a mouth-brooding cichlid (Geophagus steindachneri) in a mountain river in Colombia using three kinds of evidence: monthly variation of gonad weight, macroscopic and histological observations of the gonads, and occurrence of mouth-brooding females. Analysis was made on adults captured monthly throughout a year. The results indicate that G. steindachneri breeds during the dry season in the mountain river studied. Female mouth brooding was related with a halt in the maturation of their ovaries. Other factors than the flushing-out effect of floods on offspring may be determining dry-season breeding of fishes in tropical mountain rivers.La estacionalidad reproductiva de los peces tropicales de agua dulce esta influida por los patrones de lluvia. En tierras bajas, las aguas se expanden hacia el plano de inundación y los peces generalmente se reproducen en aguas altas. En ríos de montaña las inundaciones son repentinas y arrastran a los organismos acuáticos. Los peces de ríos de montaña usualmente muestran que se reproducen durante las temporadas secas, posiblemente como estrategia para reducir la mortalidad producto de las inundaciones repentinas. Si esta hipótesis es cierta, los peces que realizan incubación bucal estarían menos afectados por las inundaciones repentinas y tendrían una temporada reproductiva más prolongada en los ríos de montaña. En este trabajos estudiamos la temporada reproductiva de un cíclido con incubación bucal (Geophagus steindachneri) en un río de montaña en Colombia, usando tres tipos de evidencia: la variación mensual del peso gonadal, observaciones macroscópicas e histológicas de las gónadas y la frecuencia de las hembras incubando. Los análisis se realizaron en adultos capturados mensualmente durante un año. Nuestros resultados indican que la temporada reproductiva de G. steindachneri en este río de montaña ocurre en la época seca. Se observó una pausa en el desarrollo ovárico durante la incubación bucal. Otros factores, diferentes al arrastre producido por las inundaciones, deben estar determinando la reproducción durante la temporada seca de los peces en los ríos de montaña.

Reproductive pattern and population dynamics of Anchovia surinamensis in a seasonal floodplain lake of the Amazon basin

“…Water quality presents the physicochemical characteristics that can alter the growth, reproduction, behavior, and frequency of organisms (Rangel-Serpa and Torres, 2015;Lima et al, 2017). For this reason, the parameters of water are frequently evaluated to establish environmental quality standards and their interactions with the dynamics of the fish populations (Coimbra et al, 2017;Sousa et al, 2020).…”

Gonadal morphology and difference in reproductive development of two isolated populations of Astyanax rivularis (Teleostei, Characidae)

“…There is a direct relationship between the riparian zone and freshwater fish, since the riparian zone acts as a regulator of the transfer of energy and materials between aquatic and terrestrial ecosystems, which can directly interfere with food quality and consequently with reproduction (Pusey & Arthington, 2003). It is due to these variations between habitats and very unstable environments that different populations of the same species tend to develop different reproductive tactics (Rangel-Serpa & Torres, 2015;Vazzoler, 1996).…”

Reproductive biology of the saddle cichlid, Aequidens tetramerus (Heckel, 1840) (Cichliformes: Cichlidae), in small forest streams in the Machado River basin, southwestern Amazonia

“…D. Costa et al Knowledge of the reproductive cycle of ishes, including endogenous and exogenous factors that control this activity, are crucial to establishing stock management programs (MIAH, 2015). Recurrent changes in environmental conditions affect fish phenology (CHAPMAN et al, 2005), which is mostly inluenced by rainfall and biotic conditions in the tropics (RANGEL-SERPA;TORRES, 2015).…”