The effect of temperature on brood duration in three Halicarcinus species (Crustacea :Brachyura: Hymenosomatidae)

The effect of temperature on brood development was investigated for three intertidal hymenosomatid crabs: Halicarcinus cookii, H. varius and H. innominatus in Kaikoura, New Zealand. The duration of brood incubation decreased as temperature increased, as did the interbrood period. The duration of each stage of brood development also decreased with increased temperature, but the proportion of total incubation time for each stage remained relatively similar at different temperatures. Hymenosomatid crabs have determinate growth, but moult to maturity at different sizes, thereafter devoting most of their energy to reproduction. The number of broods a female could carry in her lifetime was estimated for each species. Halicarcinus cookii was estimated to be able to produce eight complete broods of 1146 eggs per lifetime, H. varius was estimated to be able to produce seven complete broods of 1051 eggs per lifetime and H. innominatus was estimated to be able to produce six complete broods of 1081 eggs per life time. With the predicted global temperature rise of 2°C in the next 50 years, the authors estimate that, for all three species, a female could produce one extra brood per lifetime (a 10–15% increase in fecundity depending on species), even more if crabs reach maturity faster, potentially leading to a significant population increas

Psychology and aggression

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68264/2/10.1177_002200275900300301.pd

The effect of temperature on brood duration in three Halicarcinus species (Crustacea :Brachyura: Hymenosomatidae)

The effect of temperature on brood development was investigated for three intertidal hymenosomatid crabs: Halicarcinus cookii, H. varius and H. innominatus in Kaikoura, New Zealand. The duration of brood incubation decreased as temperature increased, as did the interbrood period. The duration of each stage of brood development also decreased with increased temperature, but the proportion of total incubation time for each stage remained relatively similar at different temperatures. Hymenosomatid crabs have determinate growth, but moult to maturity at different sizes, thereafter devoting most of their energy to reproduction. The number of broods a female could carry in her lifetime was estimated for each species. Halicarcinus cookii was estimated to be able to produce eight complete broods of 1146 eggs per lifetime, H. varius was estimated to be able to produce seven complete broods of 1051 eggs per lifetime and H. innominatus was estimated to be able to produce six complete broods of 1081 eggs per life time. With the predicted global temperature rise of 2°C in the next 50 years, the authors estimate that, for all three species, a female could produce one extra brood per lifetime (a 10–15% increase in fecundity depending on species), even more if crabs reach maturity faster, potentially leading to a significant population increas

Dedifferentiation of rat mammary myoepithelial-like cell lines after passage in vivo or cloning in vitro

Myoepithelial-like cell lines from normal mammary glands of neonatal Ludwig Wistar rats, rat mammary (Rama) 401 and Rama 704E, were injected into fat pads of syngeneic animals or were single-cell cloned in vitro. Rama 401 produced tumors that were predominantly composed of elongated cells, while the subclones of both cell lines yielded multilayered structures of elongated cells when grown on floating 0.3% collagen gels in vitro. Immunocytochemical analysis of histologic sections for markers of myoepithelial cells revealed that anti-actin-myosin and human keratin sera failed to stain the Rama 401 tumor cells or subclones of both cell lines on collagen gels, but both were stained with antilaminin serum. Immunofluorescent analysis of cultures of Rama 401 tumors showed that the resulting elongated cells failed to stain with antikeratin serum, but abundant staining was observed with antilaminin and antivimentin sera, as in the tumors. Ultrastructural analysis of the Rama 401 tumor cells identified intermediate junctions and extracellular basement membrane-like material in the vicinity of plasma membrane-associated pinocytotic vesicles, but neither true desmosomes nor myofilamental bundles were observed. Thus growth of rat mammary myoepithelial-like cells as tumors in syngeneic animals or as subclones in vitro can lead to selective loss of myofilaments and prekeratin-containing intermediate filaments. Similar relatively undifferentiated elongated cells may be responsible for some of the cellular heterogeneity observed in certain carcinogen-induced rat mammary tumors