RESPUESTA A LA PRIMERA ALIMENTACIÓN EN LARVAS DE BARBILLA Rhamdia sebae C.F. (PISCES: SILURIFORMES, PIMELODIDAE).

RESPONSE TO THE FIRST FEEDING FOR CATFISH'S LARVAES Rhamdia sebae C.F. (PISCES: SILURIFORMES, PIMELODIDAE).

One of the biggest problems that face the modern fish breeding is found in the phase of the larviculture, since a great number of the just born larvaes usually die at the moment of begin with their first feeding, the surveys carried out about this issue in native catfishes are scarces and specially for the Ramidia Sebae. In the Unity of Larviculture of the Aquiculture Institute de los Llanos (IALL), of the University de los Llanos (Villavicencio -- Colombian City), were carried out four tests in april and may of the 2004 to assess the influence of the first feeding in the growth and surviving of the catfish's larvaes Rhamidia Sebae. The larvaes were obtained from wild individuals through induced reproduction with Extract of Hipofisis of Carpa (type of fish) (EHC). In each one of the four tests were tested three types of food along with a witness without feeding, each test was carried out three times. For each trial was developed a protocol: To 68 hours after the eclosion hpe (hpe means hours arfter/post eclosion). The larvaes were put in 5000 cm3 glass containers, with a density of 50 larvaes/1000cm3 (3000 cm3 used), with steady air cooling. 72 hpe the larvaes were put in four different groups; three of them were fed with different food, each 6 hour during 48 hours, and the other was left without feeding. The foods supplied were nauplii of Artemia sp, wild zooplankton, contreted micro- pulverized of 48% of protein for fishes. After ended the tests, it was found that the larvaes started external feeding (This is that the larvaes are born with some food for three days, after that, they got to start feeding from outside) at 72 hpe without watching cannibal behaviour. The best result for surviving, weight and size was when the larvaes were fed with the nauplii of Artemia sp. Two elements to highlight in the survey were; first that the larvaes accepted as first feeding a concentred commonly and second that they have actually grown up and survived as they did comparing with those fed with the nauplii of Artemia sp. Up to the date, is not know it a similar behaviour in other catfish specie, whichallows to propose this specie (catfish) as a promising one for the fish breeding taking into account the saving that means to feed them with concentre since their larvae state. [ABSTRACT FROM AUTHOR]

Uno de los grandes problemas que enfrenta la piscicultura moderna se encuentra en la etapa de larvicultura, ya que la gran población de larvas eclosionadas generalmente muere en el momento de iniciar su primera alimentación; los estudios realizados sobre éste aspecto en bagres nativos es escaso y especialmente para Rhamdia sebae. En la Unidad de Larvicultura del Instituto de Acuicultura de los Llanos (IALL), de la Universidad de los Llanos (Villavicencio), fueron realizados cuatro ensayos entre abril y mayo de 2004 para evaluar la influencia de la primera alimentación en el crecimiento y sobrevivencia de larvas de barbilla Rhamdia sebae. Las larvas se obtuvieron a partir de individuos silvestres mediante reproducción inducida con extracto de hipófisis de carpa (EHC). En cada uno de los cuatro ensayos, se experimentaron tres tipos de alimento frente a un testigo en ayuno, cada tratamiento se replicó tres veces. Para cada ensayo, se desarrollo el siguiente protocolo: a las 68 horas pos eclosión (hpe), las larvas fueron confinadas en recipientes de vidrio de 5 I, a densidad de 50 larvas / I (3 I útiles), con aireación permanente. A las 72 hpe las larvas se distribuyeron en cuatro grupos; tres de ellos se proveyeron con diferentes alimentos, cada seis horas durante 48 horas, y el otro se mantuvo en ayuno. Los alimentos ofrecidos fueron: naúplios de Artemia sp., zooplancton silvestre, concentrado micropulverizado para peces del 48% de proteina bruta. Finalizados los ensayos, se encontró que las larvas iniciaron alimentación exógena a las 72 ± 2 hpe sin observarse comportamiento canibal EImejor resultado de sobrevivencia, peso, y talla se obtuvo cuando las larvas fueron alimentadas con naúplios de Artemia sp. Dos elementos a resaltar en el presente trabajo son: primero que las larvas hayan aceptado como primer alimento un concentrado comercial y segundo que hayan crecido y sobrevivido de la manera que lo hicieron comparativamente con las larvas alimentadas con naúplios de Artemia sp. Hasta la fecha no se encontraron reportes similares en otra especie de bagre, lo que permite proponer a esta especie como promisoria para la piscicultura considerando el ahorro que significa la alimentación con concentrado desde su estado larval. [ABSTRACT FROM AUTHOR]