hrvatski

Značajke reagiranja stigofilnih rakušaca na uvjete u hiporeičkoj zoni u ulozi strategije rasta

The growth and age structure estimation in crustaceans is severely limited since their hard exoskeleton does not grow. Moreover, the loss of the old exoskeleton and appearance of the new one is followed by weight loss during the molt cycles. In the absence of permanent growth structures and parameters (such as the otoliths of fishes or shells of bivalves), indirect approaches have been developed to define age. Using the length-based methods and growth model, the aim of this study was to determine: i) age length ; ii) age frequency (growth parameters - asymptotic total body length -TBL∞), and iii) growth coefficient (K) of freshwater stygophilous amphipod Synurella ambulans from the hyporheic zone of the Sava River (sampling sites: Medsave and Jarun) sampled seasonally from December 2018 to October 2019. The estimated parameters of the von Bertalanffy growth function for Jarun were: L∞ = 6.09 mm, K = 0.26 y- 1 in females and: L∞ = 4.46 mm, K = 1.30 y-1 for males ; while for Medsave they were: L∞ = 6.67 mm, K= 0.46 y-1 in females and: L∞ = 5.04 mm, K = 4.20 y-1 in males. On both study sites the growth parameters were different between sexes, especially regarding to the higher value of K calculated for males. Our results give the first insight into the growth patterns of S. ambulans living in vulnerable ecotone, exposed to anthropogenic impacts. Moreover, the water temperature, dissolved O2 concentration and food availability affected the metabolic rate and the growth strategy.

podzemni rakušci ; starost ; stopa rasta ; ekoton ; slatkovodni okoliš / subterranean amphipods ; age ; growth rate ; ecotone ; freshwater environment

nije evidentirano

engleski

Stygophilous amphipod traits respond to hyporheic conditions as a function of growth strategy

The growth and age structure estimation in crustaceans is severely limited since their hard exoskeleton does not grow. Moreover, the loss of the old exoskeleton and appearance of the new one is followed by weight loss during the molt cycles. In the absence of permanent growth structures and parameters (such as the otoliths of fishes or shells of bivalves), indirect approaches have been developed to define age. Using the length-based methods and growth model, the aim of this study was to determine: i) age length ; ii) age frequency (growth parameters - asymptotic total body length -TBL∞), and iii) growth coefficient (K) of freshwater stygophilous amphipod Synurella ambulans from the hyporheic zone of the Sava River (sampling sites: Medsave and Jarun) sampled seasonally from December 2018 to October 2019. The estimated parameters of the von Bertalanffy growth function for Jarun were: L∞ = 6.09 mm, K = 0.26 y- 1 in females and: L∞ = 4.46 mm, K = 1.30 y-1 for males ; while for Medsave they were: L∞ = 6.67 mm, K= 0.46 y-1 in females and: L∞ = 5.04 mm, K = 4.20 y-1 in males. On both study sites the growth parameters were different between sexes, especially regarding to the higher value of K calculated for males. Our results give the first insight into the growth patterns of S. ambulans living in vulnerable ecotone, exposed to anthropogenic impacts. Moreover, the water temperature, dissolved O2 concentration and food availability affected the metabolic rate and the growth strategy.

subterranean amphipods ; age ; growth rate ; ecotone ; freshwater environment

nije evidentirano