Mitochondrial DNA phylogeny of the family Cichlidae: monophyly and fast molecular evolution of the neotropical assemblage.

A mitochondrial DNA (mtDNA) phylogeny of cichlid fish is presented for the most taxonomically inclusive data set compiled to date (64 taxa). 16S rDNA data establish with confidence relationships among major lineages of cichlids, with a general pattern congruent with previous morphological studies and less inclusive molecular phylogenies based on nuclear genes. Cichlids from Madagascar and India are the most basal groups of the family Cichlidae and sister to African-Neotropical cichlids.

[Mercury hazard in pediatric practice].

Medical doctors, nurses, attendants, and patients at the UFRJ paediatric hospital were accidentally exposed to inorganic mercury. From July to December 1992, 228 mercury thermometers were broken in 6 paediatric wards. Contamination of the exposed group was assessed by a comparative cross sectional study in January 93.

Biochemical adjustments to hypoxia by Amazon cichlids.

The isozyme distribution of cichlid lactate dehydrogenase (LDH) is related to species environmental preferences. Cichlasoma amazonarum occurs in different environments and presents LDH tissue distribution patterns that correlate with oxygen tension at the capture location. Cichlasoma amazonarum was exposed to long-term severe hypoxia (51 days at 36.

Effects of temperature on leucocytes of Colossoma macropomum and Hoplosternum littorale (Pisces).

1. The effects of different thermal regimens on qualitative and quantitative characteristics of leucocytes were evaluated in two fish species of the Amazon region. 2.