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Lipofuscin density in Giant Crab (Pseudocarcinus gigas) brain tissue was estimated through fluorescent microscopy. The intent was to relate lipofuscin to crab age. Some known age specimens were included in the sample, these were reared from larvae.
Inter-moult duration in giant crabs (Pseudocarcinus gigas) was estimated by an alternative method to utilising tag-recovery data. Reproduction in female giant crabs occurs in annual cycles, although females occasionally “skip” a reproductive season and do not become ovigerous; it has been noted previously that this appears to be associated with molting. Thus the proportion of females that do not participate in reproduction may indicate the proportion molting. This approach was tried with a sample of 342 females and the number that were “skipping” a reproductive season was measured by computerized tomography scanning (CT-scanning) of their ovaries prior to the extrusion of eggs. Radiometric aging (228Th/ 228Ra) of carapaces was also undertaken with the focus of this work on testing an assumption of the method, rather than describing the intermolt duration of a population.
Conducted a series of laboratory experiments to investigate the effect of temperature on swimming behaviour and development. Swimming behavioural responses were monitored for the first two zoeal stages, while larvae in development trials were reared through all five zoeal stages to the megalopa stage.
In giant crabs (Pseudocarcinus gigas), two sets of data were collected: the first examined changes in egg composition during embryogenesis and the second assessed effects of female size on egg composition.
Fecundity and egg size of giant crabs (Pseudocarcinus gigas) were determined from egg masses of 162 crabs sampled from three sites in south-eastern Australia: western Victoria, western Tasmania and eastern Tasmania. Crabs ranged in carapace length from 126 to 220 mm and egg number ranged from 830000 to 2500000.