Synonymy of Perkinsus olseni Lester & Davis, 1981 and Perkinsus atlanticus Azevedo, 1989 and an update on the phylogenetic position of the genus Perkinsus

Sequences of the rRNA nontranscribed spacer (NTS) were determined for six isolates of Perkinsus olseni, seven isolates of Perkinsus sp. from Anadara trapezia and one isolate of Perkinsus sp. from Austrovenus stutchburyi. These sequences were compared with previously published NTS sequences for R atlanticus, P. marinus and P. andrewsi. Consensus sequences for Perkinsus olseni, the Perkinsus isolates and P. atlanticus were approximately 98-99% similar to each other but only 65-79% similar to P. marinus and P. andrewsi sequences. Some individual P. olseni sequences were less similar to each other (97.4%) than they were to P. atlanticus sequences (97.8-98.2%), therefore NTS provides further evidence that P. atlanticus, P. olseni, Perkinsus sp. from Anadara trapezia and Perkinsus sp. from Austrovenus stutchburyi are conspecific. We propose that P. atlanticus be synonymised with P. olseni Lester & Davis, 1981 which has taxonomic priority, and that Perkinsus sp. from Anadara trapezia and Perkinsus sp. from Austrovenus stutchburyi belong to R olseni sensu lato as well. A phylogenetic analysis of SSU rDNA, incorporating recently published Perkinsus sequences, supports the placement of the Perkinsus species with Parvilucifera infectans within the Dinoflagellata.

Estimation of body fatness from body mass index and bioelectrical impedance: comparison of New Zealand European, Maori and Pacific Island children

Objective: To compare percentage body fat (%BF) for a given body mass index (BMI) among New Zealand European, Maori and Pacific Island children. To develop prediction equations based on bioimpedance measurements for the estimation of fat-free mass (FFM) appropriate to children in these three ethnic groups. Design: Cross-sectional study. Purposive sampling of schoolchildren aimed at recruiting three children of each sex and ethnicity for each year of age. Double cross-validation of FFM prediction equations developed by multiple regression. Setting: Local schools in Auckland. Subjects: Healthy European, Maori and Pacific Island children (n = 172, 83 M, 89 F, mean age 9.4 +/- 2.8(s. d.), range 5 - 14 y). Measurements: Height, weight, age, sex and ethnicity were recorded. FFM was derived from measurements of total body water by deuterium dilution and resistance and reactance were measured by bioimpedance analysis. Results: For fixed BMI, the Maori and Pacific Island girls averaged 3.7% lower % BF than European girls. For boys a similar relation was not found since BMI did not significantly influence % BF of European boys ( P = 0.18). Based on bioimpedance measurements a single prediction equation was developed for all children: FFM (kg) = 0.622 height (cm)(2)/ resistance +0.234 weight (kg)+1.166, R-2 = 0.96, s. e. e. = 2.44 kg. Ethnicity, age and sex were not significant predictors. Conclusions: A robust equation for estimation of FFM in New Zealand European, Maori and Pacific Island children in the 5 - 14 y age range that is more suitable than BMI for the determination of body fatness in field studies has been developed. Sponsorship: Maurice and Phyllis Paykel Trust, Auckland University of Technology Contestable Grants Fund and the Ministry of Health.