EARLY BACKGROUND ADAPTATION IN THE MEDAKA Oryzias latipes

FERNANDINO, JI; SALLEMI JULIETA; VISSIO, PG; DI YORIO, MP; DELGADÍN TH; PEREZ SIRKIN, DI; SACKS, C; FERNANDINO, JI; VISSIO, PG; SALLEMI JULIETA; DI YORIO, MP; DELGADÍN TH; PEREZ SIRKIN, DI; SACKS, C

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

Background colour adaptation is both an endocrine and a physiologicalresponse to the surrounding environment that many vertebratesare able to display owing to changes in specialized cellscalled chromatophores present in the skin. However, it is not knownif such a process of adaptation may take place during early developmentalstages and how they can influence other aspects of developmentsuch as growth. The aim of this work was to evaluate if backgroundcolor adaptation occurs during early developmental stagesin the medaka and its possible effects on growth. Thus, we analyzedthe number of melanophores, a type of chromatophore, in the head,from medakas adapted to 18, 21, 25, 40 and 60 days post fertilization(dpf) to white or black background. To do this, medaka eggswere taken from 2 to 3 spawnings of different male and femalesmedaka pairs for each timepoint and randomly assigned to blackor white backgrounds, reared in Petri dish until hatching and thentransferred to tanks of the same background till sampling. Additionally,total length and bodyweight were registered. Data were analyzedby two way ANOVA followed by post hoc comparison. P-valueswere corrected to avoid type I error. Black adapted medaka larvaepresented more head melanophores than white adapted ones(p=0.0001). This difference is not present at 18dpf (p=0.118) but beginsat 21dpf (p=0.0292) and increases at 25dpf (p