Biology, fisheries and population status of ispi Orestias ispi (Vertebrata: Ciprinodontidae) on Lake Titicaca, Peru

The ispi (Orestias ispi) is one of the species targeted by artisanal fishing in Lake Titicaca. The aim of this study was to understand the most important aspects of ispi biology and fishing, to offer an evaluation of its population situation and degree of exploitation, and to contribute to fisheries management. Information on official fish landings from the Ministry of Production and Puno Regional Production Directorate (1981–2021) and capture, effort and biological data from the Peruvian Sea Institute (2008–2021) were used. Fish landings show an established pattern, with values below 1500 t/year and a biomass of 42336 t for 2021. The size structure was 3.5 a 9.5 cm total length (TL) and the mean size range was 6.1 to 7.1 cm TL, show-ing a non-significant negative trend in relation to the minimum catch size. Growth parameters showed a maximum asymptotic length (Linf) of 9.76 cm TL and a growth rate (K) of 1.01 year-1. The gonadosomatic index showed greater intensity of repro-ductive activity between July and October, and the size at maturity (LM50%) was 5.2 cm TL. Simulations carried out with the method based on catch maximum sustainable yield indicate that the ispi is at the full exploitation level.