Diet and cannibalism in plainfin midshipman Porichthys notatus.

The macroscopic and microscopic diversity of potential food items available in the nests of plainfin midshipman Porichthys notatus were quantified and compared with items that were found in the stomach and intestine (digestive tract) of the guarding males. In this species, males occur as one of two possible reproductive morphs: guarder males that care for young and sneaker males that parasitize the courtship and care of guarder males. Although it was predicted that guarder males would have fewer feeding opportunities due to their confinement to the nest, they in fact had more food items in their digestive tracts than did sneaker males and females. Date in the breeding season (a proxy of care duration) and body condition were not correlated with the amount of food consumed by guarder males. The main type of food consumed was P. notatus embryos; 69% of all guarder males sampled had cannibalized offspring. By comparing the diet of both sexes and tactics, this study sheds light on some of the strategies designed to cope with the costs of providing parental care.

Lipid composition of lung and lung lavage fluid from map turtles (Malaclemys geographica) maintained at different environmental temperatures.

The phospholipids of lung and lung lavage fluid from map turtles (Malaclemys geographica) acclimated to 5, 14, 22 and 32 degrees C have been analyzed. The yield of surfactant (lavage) lipid P was higher at 32 than at 5 degrees C, but there was no significant change in lung lipid P. The relative proportions of phospholipids from the lung were PC greater than PE greater than SM greater than PS greater than PI, while those for the lavage were PC greater than PI greater than PE greater than SM congruent to PS. PC constituted 71-78% of the surfactant phospholipid over the temperature range. Small changes in the amounts of PC and PE of lung and in PC and PI of lavage were observed at different temperatures. The fatty acid compositions of the lipids from the two sources were different in many respects. The lavage lipids contained more saturated acids, especially palmitic acid, than did the lung lipids. The fatty acid compositions indicated the presence of disaturated PC in lung lavage and diunsaturated species of PC and PE in lung. The total saturated fatty acids of PC and PE in lung and of PC in surfactant increased at higher temperatures. In the surfactant PC this increase reflected principally a rise in palmitate and a drop in palmitoleate contents. The saturated PC obtained from lavage at each temperature contained more than 85% palmitic acid, indicating that the principal saturated PC was DPPC. These changes are consistent with the type of alterations in the lipid composition of membranes which occur during homeoviscous adaptation.