Kalliapseudes schubartii (Crustacea: Tanaidacea) is a tube dwelling invertebrate living in estuarine soft bottoms with distribution along the south-east and southern Brazilian and Uruguayan coasts. Individual growth, and reproduction were examined by taking samples for a year in the estuarine region of the Lagoa dos Patos (southern Brazil). The von Bertalanffy model described growth of K. schubartii (K=4.54 y−1, L∞=13.22 mm). Reproductive activity was observed in spring and summer. No relationship was observed between total length of females and brood size. Eggs, embryos, and mancas were often observed in a marsupium. Relative growth analysis showed two levels of allometry in the growth of chelipeds of males.
The predatory action of the pink shrimp (Farfantepenaeus brasiliensis and Farfantepenaeus paulensis) trawling fishery in south-western Brazil affects populations of some benthic species and Hepatus pudibundus is an abundant by-catch in this fishery. Individual growth and mortality of H. pudibundus were studied by taking monthly samples for a year from the by-catch of the pink shrimp fishery in the Ubatuba region. The von Bertalanffy growth model described growth of H. pudibundus (K=2.73 y-1, CW∞=82.97 mm; K=2.62 y-1, CW∞=66.72 mm, for males and females respectively). Modal progression of the monthly average sizes was related to increasing values of relative condition index. The instantaneous coefficients of total, natural, and fishing mortality were: males, Z=7.62 y-1; M=1.80 y-1; F=5.83 y-1; females, Z=7.36 y-1; M=1.80 y-1; F=5.56 y-1. Length composition and mortality analysis suggest that H. pudibundus in the Ubatuba region might be overfished.
We present the results of the first quantitative, whole-lifespan study of the relationship between age-specific neurolipofuscin concentration and natural mortality rate in any organism. In a convenient laboratory animal, the African migratory locust, Locusta migratoria, we find an unusual delayed-onset neurolipofuscin accumulation pattern that is highly correlated with exponentially accelerating age-specific GompertzMakeham death rates in both males (rZ0.93, pZ0.0064) and females (rZ0.97, pZ0.0052). We then test the conservation of this association by aggregating the locust results with available population-specific data for a range of other terrestrial, freshwater, marine, tropical and temperate arthropods whose longevities span three orders of magnitude. This synthesis shows that the strong association between neurolipofuscin deposition and natural mortality is a phylogenetically and environmentally widespread phenomenon (rZ0.96, p!0.0001). These results highlight neurolipofuscin as a unique and outstanding integral biomarker of ageing. They also offer compelling evidence for the proposal that, in vital organs like the brain, either the accumulation of toxic garbage in the form of lipofuscin itself, or the particular molecular reactions underlying lipofuscinogenesis, including free-radical damage, are the primary events in senescence.
Postmolt longevity and changes in the shell condition and body integrity of male snow crab Chionoecetes opilio after their terminal molt were assessed through a mark-recapture experiment and population censuses in a commercially unfished locality of eastern Canada. The experiment explored the value of dactyl wear as a quantitative measure and shell condition (SC; measured on a five-stage scale) as a relative index of shell age. Males were recaptured up to 6 years after release. Much of the extensive variation in observed dactyl wear was explained by time at liberty (Dt) and male size, and the extent of change in SC was positively correlated with Dt. The conservative wear-based estimate of male longevity was 7.7 years, a value 1-3 years greater than previously estimated. Dactyl wear and recapture data confirmed that SC is a relative, albeit rough, index of shell age. Shell hardness was positively correlated with male size and peaked in stage 3 about 3.5 years after the terminal molt. The number of missing pereopods increased with shell age and SC stage and overall was negatively correlated with male size. The commercial value of adult males may be highest at 1-4.5 years post-terminal molt and the reproductive value at 2-5.5 years.
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