Purification and properties of a toxin from the South African sea anemone, Pseudactinia varia.

A comparison was made of the hemolytic potency of aqueous extracts prepared from five species of intertidal sea anemones from the coast of South Africa. The active agent in an extract of Pseudactinia varia was purified by ammonium sulfate precipitation, gel permeation chromatography and isoelectric focusing. The hemolytic toxin, termed variolysin, is a protein having a molecular weight of 19,500 and an isoelectric pH of 9.8. It retained appreciable activity after heating to 70 degrees for 40 min. Amino acid analysis revealed that it lacked methionine and cysteine. Its hemolytic activity was inhibited by sphingomyelin. The properties of variolysin show that it is broadly similar to cytolytic toxins isolated from a number of other anthozoans.

Effectiveness of a nutrition program for mothers and their anemic children under 5 years of age.

The purpose of this study was to determine the effectiveness of the Supplemental Food Program for Women, Infants, and Children (WIC) for mothers and their anemic children under 5 years of age. Sample for the study was 50 anemic children, 25 in each of two groups. The interventions (treatments) for the experimental group included individual counseling, group nutrition classes, and provision of WIC food vouchers for purchasing foods containing essential nutrients that are deficient in the diets of this high-risk population. An initial dietary assessment was done, and hemoglobin and hematocrit measurements were taken. At the end of 6 months, each participant's diet was reassessed, and hemoglobin and hematocrit measurements were again taken. Results of the study showed a 1.8 gm change in the hemoglobin measurements of the members of the experimental group and a 1.1 gm change in the hemoglobin measurements of the members of the control group.

Competition in Bembicium auratum (Gastropoda) and its effect on microalgal standing stock in mangrove muds.

Field experiments were undertaken on the intertidal gastropod Bembicium auratum, which is one of the dominant organisms in sheltered bays and mangroves in New South Wales. Animals were caged at various densities ranging from natural levels to about four times normal density. Increased density resulted in increased mortality (particularly of juveniles), reduced body weight, and (less conclusively) a decline in growth rate. Chlorophyll levels of the mangrove mud within the cages were monitored as an index of food availability, and increased rapidly in the control cages in the absence of Bembicium, remained steady at normal Bembicium densities, and declined at higher densities. Parallel experiments were conducted on the effects of substratum on Bembicium. One series of animals was allowed access to a hard substratum and the other only to mud. Body weights and survivorship were proportionally lower in animals deprived of a hard substratum. Juveniles were particularly susceptible to a shortage of food and more dependent on a hard substratum than adults. The population structure also suggests a high juvenile mortality but high adult survival and longevity. Bembicium is very abundant low on the shore but numbers decline and body weights increase higher up. Chlorophyll levels and amounts of hard substratum also decline up the shore. Possibly juveniles settle selectively (or survive better) low on the shore where oysters provide a dense hard substratum. Adults are less dependent on the hard substratum and may disperse up the shore, explaining the patterns of abundance and size.As Bembicium limits its own food supply and seemingly is limited by it, predation is unlikely to play an important role in restricting population density.