V. Odonovan et O. Tully, LIPOFUSCIN (AGE PIGMENT) AS AN INDEX OF CRUSTACEAN AGE - CORRELATION WITH AGE, TEMPERATURE AND BODY-SIZE IN CULTURED JUVENILE HOMARUS-GAMMARUS L, Journal of experimental marine biology and ecology, 207(1-2), 1996, pp. 1-14
Morphological lipofuscin was quantified in laboratory cultured Homarus
gammarus to determine if the amount of pigment was correlated with ag
e and culture temperature in this species. Two cohorts were monitored
for 34 and 18 months, respectively. An age dependent accumulation of l
ipofuscin concentration (expressed as % area fraction) occurred (Y = -
2.22 + 0.084X, R(2) = 46.8%, p less than or equal to 0.0001 and incorp
orating carapace length as a covariate). Carapace length accounted for
3.3% of the variation in lipofuscin. The effect of temperature on lip
ofuscin accumulation was assessed using three regimes: 8, 11 and 13.5
+/- 5 degrees C. Temperature had a significant effect on lipofuscin ac
cumulation (F = 15.9, p less than or equal to 0.0009). Carapace length
also responded significantly to temperature although the trend was no
r linear (F = 68.1, p < 0.0001). There was no significant correlation
between lipofuscin concentration and body size in lobsters of the same
age (r = 0.067, -0.2, 0.154 and 0.5 for each of four groups). The age
dependent increase in morphological lipofuscin and the lack of correl
ation between body size and lipofuscin in cultured H. gammarus indicat
es significant potential for this technique as a method of ageing lobs
ters. As lipofuscin accumulation is a function of metabolic age, facto
rs other than temperature, such as population density, which affects g
rowth rate in the wild, could potentially affect metabolic rate and th
erefore lipofuscin accumulation. However the independence between grow
th and lipofuscin in laboratory animals indicates that this may not be
a problem.