Analyzing standard curves in the chemistry of waters used for aquaculture

A practical guide is given to help aquaculture researchers identify and correct common problems associated with the colorimetric analysis of water. Hints in making standard solutions, choosing standard concentrations for making a standard curve and making measurements are included. Various types of standard curves and some problems are outlined and details provided regarding the evaluation of standard curves

Analyzing standard curves in the chemistry of waters used for aquaculture

Water analysis, Colorimetric techniques, Analytical techniques, Aquaculture

Feed transition in larval rearing of bocudo, Steindachneridion scripta (Pisces, Pimelodidae), using Artemia spp. nauplii and artificial diet Transição alimentar na larvicultura do bocudo, Steindachneridion scripta (Pisces, Pimelodidae), com o uso de náuplios de Artemia spp. e dieta artificial

Feed transition of Steindachneridion scripta larvae was investigated using seven treatments in which the reference diet, Artemia spp. nauplii, was totally substituted for a 56% crude protein artificial diet in two-day intervals. Initially, all treatments were fed with Artemia spp. nauplii and, subsequently, during the transition period, feed was equally composed by Artemia sp. nauplii and artificial diet. Everyday, one of the treatments began the feed transition, which was implemented between the second and the eighth days of culturing. Two treatments were used as control: one exclusively fed Artemia spp. nauplii and another only with artificial diet. Total weight, total length, and survival rate were not influenced by the day in which feed transition was implemented (P>0.05), and their mean values (± SD) were 31.1&plusmn;25.0mg, 13.3&plusmn;1.5mm and 58.8&plusmn;12.0%, respectively. This suggests that Steindachneridion scripta larvae adapted well the transition to artificial diet.<br>A transição alimentar de larvas de Steindachneridion scripta foi investigada utilizando-se sete tratamentos, nos quais a dieta básica, composta por náuplios de Artemia spp., foi integralmente substituída, em intervalo de dois dias, por uma dieta artificial contendo 56% de proteína bruta. Inicialmente, todos os tratamentos receberam náuplios de Artemia spp. No período de transição alimentar, metade da alimentação foi formada por náuplios de Artemia spp. e metade por dieta artificial. A cada dia, um dos tratamentos entrou na fase de transição, que foi implementada entre o segundo e o oitavo dia de cultivo. Utilizaram-se dois tratamentos como controle; em um as larvas foram alimentadas, exclusivamente, com náuplios de Artemia spp. e em outro, somente, com dieta artificial. Peso total, comprimento total e sobrevivência não foram influenciados pelo dia de implantação da transição alimentar (P>0,05) e, apresentaram valores médios iguais a (&plusmn; desvio padrão) 31,1&plusmn;25,0mg, 13,3&plusmn;1,5mm e 58,8&plusmn;12,0%, respectivamente, sugerindo que as larvas Steindachneridion scripta aceitaram bem a transição alimentar para a dieta artificial