The effects of stress on blood sugar composition of the lobster, Homarus americanus.

Freshly caught intermolt lobsters show a highly significant elevation of blood glucose after a few minutes of mild stress. Females show a significantly greater increase than males. The small amounts of other sugars in the blood are great enough to explain the increase in glucose, and chromatographic analysis shows that they diminish under stress. In postmolt animals the stress hyperglycaemia is not as great but is still significant; the difference between the sexes is not apparent. Lobsters held in commercial pounds were found to be in a hyperglycaemic condition. The stress of commercial handling and prolonged fasting brings about significant changes in blood sugars and the sexes react differently. The rather better survival of females under these conditions may also be significant.