Reproductive traits and natural mortality of the cardinalfish Epigonus crassicaudus: crucial information for stock assessment and sustainable management measures

Abstract

Reproductive traits and natural mortality rate of cardinalfish females (Epigonus crassicaudus) were studied from samples collected onboard commercial fishing vessels, from 2012 to 2015, on the Chilean coast. The reproductive cycles of females analyzed thought gonadosomatic index (GSI) showed a maximum reproductive activity in austral fall, between March and May. Length (L50%) and age (A50%) at maturity, estimated using a macroscopic scale of the developed ovary, was 22.3 cm fork length (FL) and 9.3 years, respectively. Natural mortality (M) was estimated by two age-related methods. Using maximum age (tmax) M was estimated in 0.063 yr-1 and through age-at-maturity (A50%) in 0.15 yr-1. A potential bias in the reproductive study is discussed when a macroscopic maturity scale is used. Nevertheless, its usefulness is validated when funding is scarce, and time is limited. Although M uncertainty was not evaluated, the estimated range appears to be into the expected values to long-lived species. The life history parameters estimated in the present study can be used to evaluate possible time variability in maturity and M rates. Also, these results could be used in stock assessment analysis and to apply effective management measures in the fishery.

Fishing opportunities for the deepwater cardinalfish ( Epigonus crassicaudus ) in the continental shelf break along central Chile

“…In Chile, the cardinalfish Epigonus crassicaudus is an endemic species (Pequeño, 1989), mesopelagic, inhabiting deep waters, preferably the continental shelf, shelf break and seamounts (Moyano et al, 2020; Niklitscheck et al, 2010). The distribution of the cardinalfish extends between Caldera (27ºS) and Chiloé (43º30'S) (Gálvez et al, 2000) and between 100 and 500 m deep (Wiff et al, 2008).…”

“…There are reports on feeding (Leal et al, 2009; Sepúlveda et al, 2018) and reproductive aspects (Flores et al, 2015; Moyano et al, 2020). Life history parameters such as age, growth, and mortality have been studied by Cubillos et al (2009), Ojeda et al (2010), Contreras‐Reyes and Arellano‐Valle (2013), suggesting low growth rate and longevity greater than usual.…”