Plasticity in Reproductive Traits, Condition and Energy Allocation of the Non-Native Pyrenean Gudgeon Gobio lozanoi in a Highly Regulated Mediterranean River Basin

Abstract

The invasion success of non-native fish, such as Pyrenean gudgeon Gobio lozanoi in several Iberian rivers, is often explained by the expression of its life history traits. This study provides the first insights into the reproductive traits, fish condition, and energy allocation (protein and lipid contents of tissues) of this species, along a longitudinal gradient in one of the most regulated river basins in the Iberian Peninsula, the Segura river. Larger sizes of first maturity, higher fecundity and larger oocytes were found in fluvial sectors with the most natural flow regimes, characterised by a low base flow with high flow peaks in spring and autumn. A delay in the reproductive period, lower fish condition and no differences in sex-ratio were observed in fluvial sectors with a high increase in base flow and notable inversion in the seasonal pattern of flow regime. Lipid contents in the liver and gonads were stable during the reproductive cycle and decreases in muscle were noted, whereas ovarian and liver proteins increased. In relation to energy allocation for G. lozanoi, an intermediate energy strategy was observed between income and capital breeding. Our results support the hypothesis that the high plasticity of G. lozanoi population traits plays a significant role in its success in a highly regulated Mediterranean river basin. Understanding the mechanisms by which flow regulation shapes fish populations in Mediterranean type-rivers could inform management actions.

Effects of 2,4,6-Trichlorophenol on Clarias batrachus: a biomarkers approach

“…For the lowest exposure concentration (0.5 mg/L), the decrease was approximately 30%, whereas for the highest concentration (1.0 mg/L), it was approximately 85%, highlighting a similar impact in both sexes. The reallocation of energy reserves from gonad to other tissues or even the detoxification processes may have decreased the relative gonad size (Amat-Trigo et al 2021 ; Sun et al 2011 ). The decrease in male’s MI exposed to sublethal concentration of 2,4,6-TCP was probably due to a fall in testicular cell proliferation and spermatogenesis inhibition (Dong et al 2018 ).…”

Alokasi Energi, Fekunditas, dan Sintasan Larva Cacing Nipah Simpatrik (Polychaeta: Nereididae)

“…Cacing nipah pada penelitian ini hidup secara simpatrik dan hal ini akan berpengaruh pada kesamaan sumber energi dari makanan dan menyimpannya dalam oosit. Amat-Trigo et al, (2021) dan Sieiro et al, (2020) mengemukakan bahwa alokasi energi dapat diketahui dari protein dan lipid. Pada penelitian ini, energi diukur dengan pendekatan berbeda sehingga tidak diketahui berdasarkan kandungan protein dan lipid.…”

Ecology and Conservation of Freshwater Fishes Biodiversity: We Need More Knowledge to Develop Conservation Strategies

“…Latorre et al [14] assess the variability in dietary traits of the bleak in the Iberian Peninsula and compare the dietary characteristics of this species among the main Iberian rivers and a native bleak population from France. Similarly, Amat-Trigo et al [15] evaluate other biological traits in addition to the diet. The results of both studies suggest that this wide interpopulation variability will contribute to the species' successful establishment throughout Mediterranean Europe, posing a severe risk to native fish fauna.…”