ABSTRACT
A total of 200 of Crassostrea virginica populations of average weight range from 41.19 ± 3.42 to 47.53 ± 1.06 g were studied to determine the effect of the feed diets of Caulerpa lentillifera and sucrose as growth enhancement. Growth rates increased that range from 56.99 ± 3.16 to 61.56 ± 2.87 g for 90 days period using an artificial water tank system. Previous studies conducted that C. lentillifera contained high protein and were the most abundant component. This seaweed also contained high amounts of minerals and balanced amino acid and notably very rich in iodine. phosphorus, calcium, magnesium and copper that will contribute to oysters growth. Oysters are known to have the ability to uptake dissolved organic matter as nutrients. In the present study, the effects of culture water supplemented with sucrose were tested on oysters. Results revealed that this organic matter promotes growth to the oysters. Sugars will be metabolized into pyruvate through the glycolysis pathway and will result in the supply of energy. Therefore, supplementation of sugar to oysters may have contributed as an energy source together with the lipid and protein content from the algae diet.
ABSTRACT
With the aim to observe any color effect on the shell or nacre of juvenile red abalone (Haliotis rufescens), three diets were formulated adding carotene pigments (astaxanthin, cantaxanthin and β-carotene) and one control diet without pigments. Juvenile abalone (n = 504) with a shell length and weight of 5.46 ± 0.87 mm and 0.03 ± 0.16 g, respectively, were utilized. The abalones were randomly distributed in twelve buckets (20 L) connected to a recirculation system under controlled temperature and constant water flow. Each treatment was done in triplicate. After 90 days of experimentation, the organisms fed on diets with inclusion of pigments showed a length growth rate of 53.06 ± 6.91 μm/day and weight of 1.34 ± 0.24 mg, whereas the juveniles fed with the control diet showed a growth rate of 74.93 ± 14.63 μm/day and weighed 2.13 ± 0.40 mg. The formation of shell and color recorded resulted in a minor color change compared to the control diet. However, in spite of these changes the supplementation of pigment at this point is not recommended. Nevertheless, more efforts should be made to research the shell color manipulation.
Con el propósito de observar cambios en la coloración de la concha y nácar de juveniles de abulón rojo (Haliotis rufescens), se formularon tres dietas a las que se les agregaron pigmentos carotenoides (astaxantina, cantaxantina y β-caroteno) y una dieta testigo sin pigmentos. Se obtuvieron juveniles de abulón (n = 504) de 5.46 ± 0.87 mm y 0.03 ± 0.16 g de longitud promedio de la concha y peso, respectivamente. Los abulones se distribuyeron aleatoriamente en 12 cubetas de 20 L, conectadas a un sistema cerrado de recirculación, con temperatura y flujo constante. Cada tratamiento se realizó por triplicado. Después de 90 días de experimentación, los organismos alimentados con dietas con inclusión de pigmentos presentaron una tasa de crecimiento en longitud de 53.06 ± 6.91 μm/dia y peso 1.34 ± 0.24 mg, mientras que los abulones de la dieta testigo crecieron a razón de 74.93 ±14.63 μm/dia y pesaron 2.13 ± 0.40 mg, sin que se observaran diferencias significativas entre los tratamientos (α = 0.05) experimentales. La formación de la concha y la coloración se registraron mediante imágenes fotográficas y con ayuda de una paleta de colores se observó un ligero cambio en la coloración de la parte exterior de la concha hacia tonalidades amarillas de los abulones alimentados con dietas que incluían pigmentos, siendo más intensa para aquellos que contenían β-caroteno. Sin embargo, a pesar de estos cambios no se recomienda la incorporación de pigmentos para abulón en ese momento, pero será necesario investigar más sobre la manipulación del color de sus conchas.