Ageing the European lobster Homarus gammarus by the lipofuscin in its eyestalk ganglia

Abstract

In this study, lipofuscin was examined in the eyestalk ganglia of tagged European lobsters Homarus gammarus released into the wild at Scapa Flow, Orkney. Scotland, at approximately 3 mo of age and recaptured at ages between 5.4 and 9.6 yr. Lipofuscin deposits were often most abundant in cell cluster A of the medulla terminalis (MT-A), where they exhibited typical autofluorescence, histochemical, distributional and structural properties. Confocal fluorescence microscopy and image a'nalysis were used to quantify the deposits The study demonstrated that lipofuscin accumulation in the MT-A is age-dependent (r = 0 640, p -0.0002). For the available sample range, no other statistically significant relationships were found (carapace length vs age: r = 0.147, p = 0.359, body weight vs age: r = -0.054, p = 0.738; carapace length vs lipofuscin concentration: r = 0.331, p = 0.0849; body weight vs lipofuscin concentration: r = 0.181, p = 0.358). Body size had no age discriminating power. There was no difference in lipofuscin accumulation rate between males and females. When placed in perspective against the highest lipofuscin concentrations so far measured for wild individuals of this species, it was apparent that the available sample of tagged lobsters, spanning an age interval of about 4 yr, represented only a very small window of the total lifespan. The results indicate that measurement of MT-A lipofusc~n concentration will provide considerably more accurate age determination of fished lobsters than the current body-size-based approach. MT-A lipofuscin concentration correctly ages approximately 4 3 % of lobsters in a sample to within 1 yr or less of their true age, and 95 % of lobsters to within 3.5 yr Carapace length correctly ages only 3% of individuals correctly to withi.n 1 yr The width of the 95% confidence intervals for carapace-length-based age estimates are so large as to render these estimates meaningless. Size-at-age and number-at-age data obtained using lipofuscin will prove useful for estimating growth and mortality in wild lobster populations and provide insight into potential biases in the current, conventionally derived estimates of these parameters. From a practical perspective, it is easier to sample nerve tissue containing lipofuscin from the eyestalk than the brain and has the advantage of leaving the lobsters in marketable condition.

Survivorship of juvenile surf clams Donax serra (Bivalvia, Donacidae) exposed to severe hypoxia and hydrogen sulphide

“…There are few studies that deal with independent measurements of age and lipofuscin in situ concentration in invertebrates, and most of them refer to crustaceans (Sheehy, 1990(Sheehy, , 1992Sheehy et al, 1994;O'Donovan and Tully, 1996;Sheehy et al, 1996;Wahle et al, 1996;Belchier et al, 1998;Vila et al, 2000). If seasonal oscillations are not taken into account, the majority of these studies points towards a linear relationship between age and lipofuscin throughout the greater part of the lifespan.…”

Stress response of two coral species in the Kavaratti atoll of the Lakshadweep Archipelago, India

“…These are induced in response to free radicals generated during oxidative stress (Gaugler 1997 (Sheehy et al 1996). Concentrations of lipofuscin granules increased significantly in semi-bleached colonies of P. lutea and were negligible in fully bleached colonies.…”

“…Sections of 6 µm thickness were stained with hematoxylin and eosin and were viewed under 40X objective and photographed in Olympus BX 60 microscope (Tokyo, Japan) with camera attachment. The sections were also checked for the presence of lipofuscin granules (Sheehy et al 1996). The sections (6 µm) were de-waxed, mounted in DPX and covered with cover glass.…”

Evidence of lipofuscin accumulation in the deep-water red shrimp Aristaeomorpha foliacea (Risso, 1827)

“…Despite the heterogeneous composition and genesis of lipofuscin, its relationship with aging has been demonstrated in many groups of crustaceans such as krill (NICOL et al, 1991), amphipods (BLUHM et al, 2001), clawed (O'DONOVAN & TULLY, 1996SHEEHY et al, 1996;WAHLE et al, 1996;SHEEHY et al, 1999;CASTRO et al, 2002;) and spiny lobsters (SHEEHY et al, 1998), crayfish (SHEEHY, 1990a;SHEEHY et al, 1994;BELCHIER et al, 1998) and shrimps, both caught in the wild or raised in aquaculture (SHEEHY et al, 1995;VILA et al, 2000;MEDINA et al, 2000;SOBRINO et al, 2001;PEIXOTO et al, 2002;VILA GORDILLO, 2005). These studies, based also on animals kept in controlled conditions, allowed the improvement of extraction and methods of analysis, as well as the confirmation that, regardless the sex, lipo- Medit.…”