Variation
in lipid, protein, and carbohydrate content during the embryonic development
of the crayfish Cherax quadricarinatus (Decapoda: Parastacidae)
M. García-Guerrero, I.S. Racotta, H. Villarreal-2003
Journal
of Crustacean Biology, 23(1) : 1-6
Abstract:
Eggs
of 20 females were sampled to
analyze lipid, protein and carbohydrate content during the embryonic
development of Cherax quadricarinatus. Sampling was performed on recently
spawned eggs to first juvenile stage. Ten eggs were sampled every 48 h
during the first two weeks and every 72 h thereafter for biochemical
analysis. Total proteins, lipids, and carbohydrates were measured. Proteins
were the most abundant egg component (63.2%), followed by lipids (32.3%),
and carbohydrates (4.4%). A steady decrease of lipid content was observed
(y=895.38 – 9.93x, r²=0.94; y=lipid concentration, x=days). For proteins,
two different depletion rates were observed, with the initial rate
maintained for 30 days (y1=1,443.0 – 4.46x1, r²=0.90)
and an increased depletion rate after hatching (y2=1,936.60 –
21.10x2, r²=0.96). Carbohydrates were always present as a minor
constituent, and its concentration did not change significantly. Water
content increased from 52% in recently spawned egg to 85% in juveniles.
Energy equivalents were calculated from each component, and the overall
energy expenditure is represented by the equation y=13.86 – 0.11x (r²=0.95).
Relevant morphological features for each sample day are indicated.
(Centro
de Ivestigaciones Biológicas del Noroeste, S.C. (CIBNOR) Mar Bermejo # 195,
Col Playa Palo de Santa Rita Apartado Postal 128, La Paz, Baja California
Sur, 23090 Mexico, e-mail of H. Villarreal: humberto@cibnor.mx)