First reproductive record of <i>Dekeyseria picta</i> (Siluriformes: Loricariidae): insights into embryonic development plasticity

This study describes the embryonic and larval development of the Atabapo butterfly pleco <i>Dekeyseria picta</i> under captive conditions. A total of 19 wild-caught adults (male-to-female ratio of 9:10) were maintained together in a single 1000-L tank operated with a recirculating aquaculture system (RAS), at approximately 26°C, under a controlled 12:12 h light-dark cycle. A total of 21 natural spawning events produced an average of 66.5 ± 2.43 spherical eggs with a mean diameter of 3.896 ± 0.022 mm, characterized by a yellow yolk and a strongly adhesive chorion. Embryonic development lasted between three and seven days, and hatched larvae were classified into five developmental phases. Early phases exhibited limited differentiation and weak pigmentation, whereas advanced phases showed visible eyes, increased pigmentation, and progressive yolk absorption. Heartbeat activity and tail movements were observed throughout all phases. The hatching rate was below 40%, likely influenced by differences in chorion rupture efficiency among embryos at distinct developmental stages. Two developmental strategies potentially contributing to embryonic plasticity were identified: (i) a diapause-like state in which embryos temporarily arrested development at early phases without yolk utilization while remaining responsive to stimuli, and (ii) delayed hatching, in which embryos remained within the chorion for up to seven days, allowing further larval development in a protected environment. These strategies may represent adaptive responses to rapidly fluctuating hydrological and environmental conditions characteristic of the natural habitat of the species and emphasize the role of aquaculture in advancing reproductive knowledge and conservation.