Histological description of the larval development of Brycon gouldingi Lima, 2004 (Teleostei, Characidae)

Piabanha, Brycon gouldingi, is an endemic species in the Tocantins-Araguaia basin. It has aroused the interest of both fish farmers, who started its creation in confinement, and riverine people who appreciate it as a food source. In order to provide information about organic systems of B. gouldingi larvae, a histological description was performed after capturing adult specimens in the Rio das Mortes (Mato Grosso, Brazil), adapted to captivity and induced to spawn at Buriti Fisheries (Nova Mutum, MT, Brazil). The collection of samples took place at pre-defined moments after hatching, and the processes relating to morphological differentiation of digestive, excretory, cardiorespiratory, nervous/sensory systems and gas bladder were characterized. At the hatching were found: undifferentiated digestive system; pronephros (primitive kidney), rudimentary heart, central nervous system characterized by primary vesicles, optic vesicle forming the optic cup and crystalline lens. In the course of ontogeny, these organic systems were developed and at the time of the total absorption of the yolk at 55 hours post-hatching were found: the digestive system consisting of the head gut, foregut, midgut and hindgut; two heart chambers and branching of gill arches; three regions of the brain (forebrain, midbrain and hindbrain), neuromasts, olfactory cavity, taste buds; eye consisting of well-defined layers; presence of gas bladder. The results of this study may be useful in providing support for the captive breeding of B. gouldingi during the larval stage.