Ontogenic events and swimming behavior of larvae of the characid fish Salminus brasiliensis (Cuvier) (Characiformes, Characidae) under laboratory conditions

Abstract

ABSTRACT. The larval ontogeny and swimming behavior of the characid fish Sa/minus brasiliensis (Cuvier, 1816) were studied under experimental laboratory conditions, from hatching to yolk absorption . At day I, the larvae were transparent, with sparse dendrite chromatophores and a well -developed adhesive organ on the head. The retinal epithelial cells were initiating pigmentation. The branchial arches were at the initial phase of differentiation. The larvae were able to perform only vertical displacements and, when resting on the tank bottom, remained in lateral decumbency, in groups of 3 to 15 larvae. On day 2, the mouth was open, with conical teeth, and the digestive tube presented lumen and folded mucosa. The gaseous bladder and pectoral fins also were in differentiation. The larvae performed vertical and horizontal movements, adhered to the water surface by means of the adhesi ve organ or formed groups of three to six on the tank bottom. On day 3, the adhesive organ turned dorsal, the retina was pigmented, the digestive tube mucosa showed goblet cells, and the yolk sac exhausted. The larvae were now scattering in the water column forming no groups on the bottom. KEY WORDS. Sa/minlls brasiliensis, larval ontogenic events, larval swimming behavior Knowledge on larval development of freshwater teleost is limited (SOUSA

O desenvolvimento embrionário da Piapara, Leporinus elongatus (Pisces, Anostomidae), utilizando técnicas de histologia, microscopia eletrônica de varredura e imunológicas empregando marcadores ósseos

“…Estes são indispensáveis durante o processo de metamorfose, alimentando o embrião e larva, até a abertura da boca, quando este passa então a possuir alimentação exógena, mecanismo também utilizado por outras espécies (Santos & Godinho 2002).…”

Desenvolvimento larval de Brycon hilarii (Characiformes, Characidae)

“…Sob essas condições, o órgão adesivo observado até o estágio de pré-flexão tornase funcional quando essas larvas, logo após a eclosão, começam a derivar rio abaixo, funcionando como um importante órgão para a dispersão das larvas por aderilas na superfície por meio da tensão superficial da água ou até mesmo em outras estruturas flutuantes (sanTOs & GOdinHO, 2002). Esse órgão também é encontrado em larvas de B. orthotaenia, Salminus brasiliensis (Cuvier, 1817), Astronotus ocellatus (Cuvier, 1829), Salminus hilarii Valenciennes, 1850 e Astyanax altiparanae Garutti & Britski, 2000.…”

Induced spawning and early ontogeny in hatchery-reared catfish Zungaro jahu (Siluriformes: Pimelodidae)

“…Such studies in Neotropical freshwater migrants are difficult to conduct because they spawn in the river channel during floods, allowing embryos and larvae to disperse downstream into the expanded floodplains, impairing the ability to obtain complete wild developmental series. Also the multi-species assemblages that result from wild collections render the embryonic and larval taxonomic identifications problematic (Santos & Godinho, 2002). However, hatchery-born migratory fish constitute an excellent alternative source for the study of their early life history.…”