Reproductive traits of stream‐dwelling brown trout Salmo trutta in contrasting neighbouring rivers of central Spain

Abstract

1. Reproductive traits were studied in seven wild populations of resident brown trout in Spain. We examined whether growth, and certain environmental conditions such as water temperature or food abundance, could explain interpopulation variation in the reproductive characters. 2. The results indicated that nearby populations subjected to a wide variation in environmental conditions exhibited a similar reproductive performance. 3. Age distributions and sex ratios were not significantly different among populations. Age ranged from 0+ to 4+ years but the populations were dominated by the 0+ to 2+ groups. In all rivers females matured at age 2+ as opposed to age 1+ and 2+ for males. Mean length at the end of the growth period differed significantly among populations. However, annual growth rate was similar among rivers and was not significantly correlated with either biomass of the benthos or water temperature during the growth season. 4. Reproductive effort, body condition, fecundity and egg size did not correlate significantly with either the abundance of benthic invertebrates or water temperature. Once the effect of body length on both egg size and number was removed, a significant negative correlation was found between these two traits among populations.

Dispersal and demography of brown trout, Salmo trutta, inferred from population and family structure in unstable Mediterranean streams

“…Parent-offspring relationships should be rare or absent in young fish because the age at maturity is class 2? or older in Iberian brown trout (Lobón-Cerviá, 2000;Nicola & Almodóvar, 2002).…”

Influence of hydrologic attributes on brown trout recruitment in low-latitude range margins

“…The Hoz Seca is fed by limestone aquifers and therefore water temperature remains close to 10°C all year round. Further details of the study area are given in Nicola and Almodóvar (2002) and Almodóvar and Nicola (2004). Brown trout is the only fish species present throughout the study area and its populations comprise exclusively resident individuals.…”

The reproductive traits of brown trout (Salmo trutta fario L.) from the Yadong River, Tibet

“…Similarly, high correlation was also found between female size and salmonid fecundity in relation to fish length in an earlier study (Taube 1976). Nicola and Almodovar (2002) also described a significant relationship between female length and fecundity in brown trout populations in seven study streams in Spain. According to Olsen and Vollestad (2003), fecundity increased with fish length and there was no consistent difference in fecundity, based on comparing all eight populations.…”

“…The reproductive traits of brown trout have been described in geographically different populations previously (Hegge et al 1991;Crisp 1994;Sorensen et al 1995;Garcia-Vazquez et al 2001;Nicola and Almodovar 2002;Pender and Kwak 2002;Alp et al 2003;Estay et al 2004;Olsen and Vollestad 2005;Rubin et al 2005;Arslan and Aras 2007).…”