Short Communication

Early life stages of Aquitanian pike Esox aquitanicus (Teleostei, Esocidae): first description of morphological development and trials of rearing

¹ INRAE, L2A, University of Lorraine, Nancy, F-54000, France
² Université de Lorraine, CNRS, LIEC, F-54000 Nancy, France
³ Unité Patrimoine Naturel – Centre d’expertise et de données (UAR 2006 OFB– MNHN – CNRS), Muséum national d’Histoire naturelle, 36 rue Geoffroy-Saint-Hilaire CP 41, 75005 Paris, France
⁴ Fédération Départementale des Landes pour la Pêche et la Protection du Milieu Aquatique, 102 allées Marines 40400 Tartas, France
⁵ Aquarium de Limoges, 2 Bd Gambetta, 87000 Limoges
⁶ UMR Biologie des organismes et écosystèmes aquatiques (BOREA 8067), MNHN, CNRS, IRD, SU, UCN, UA, 43 rue Cuvier CP 26, 75005 Paris, France
⁷ Union des Fédérations pour la pêche et la protection du milieu aquatique du Bassin Adour-Garonne, 5 chemin de Bramofan, 31120 Roques, France

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 3 April 2025
Accepted: 26 November 2025

Abstract

Aquitanian pike, Esox aquitanicus, is a new esocid species described in 2014 and endemic to Southwestern France. The four main goals of the present study were to (i) obtain the first morphological data on the early life stages, (ii) test the effects of temperature on their survival and development, (iii) compare the results with the Northern pike, and (iv) produce a few individuals to exhibit them at the Aquarium of Limoges. Eggs are yellowish, demersal, and sticky. The mean diameter was 2.73 ± 0.08 mm (n = 174). The larval size at hatching was 9.09 ± 0.24 mm (n = 14). The morphological development of 15 larvae was followed during 11 weeks as well as the snout growth in relation to eye size. It appeared that already after three weeks, slight differences between the two species were apparent, and after nine weeks, this snout/eye ratio was twice greater for Northern pike than Aquitanian pike. At the end of the yolk-feeding period, which lasted from 12 days at 18 °C to 36 days at 6 °C, the overall survival rate was over 85% and larvae were of similar size, except at 6 °C. After three months, the best results in term of survival were obtained at 12 °C (60%) and for growth at 15 °C (34.11 mm), followed at 12 °C (27.85 mm). Based on these results, we were able to rear Aquitanian pike for more than 2 years in the Aquarium of Limoges in order to promote the conservation of the species to the public.