New species of the genus Spectracanthicus (Loricariidae, Hypostominae, Ancistrini) from the Rio Javaés (Rio Araguaia basin), with a description of gross brain morphology.

A new species of Spectracanthicus is described from the Rio Javaés, Rio Araguaia basin. The new species is distinguished from its congeners (except Spectracanthicus immaculatus) by colour pattern: body dark grey to dark brown without dots or blotches (v. body colour with yellowish small dots in Spectracanthicus murinus, Spectracanthicus punctatissimus and Spectracanthicus tocantinensis and large white dots in Spectracanthicus zuanoni). It can be further distinguished from S. immaculatus by having thicker and less numerous teeth, with up to eight premaxillary and 20 dentary teeth (v. teeth thinner and more numerous with up to 22 premaxillary and 30 dentary teeth); dorsal and caudal fins without curved spines (v. dorsal and caudal fins with curved spines). Other osteological characters can also diagnose the new species from its congeners. In addition, a gross brain description and brief comments on the new species' ecological habitat are given.

Chromosome evolution in fish: sex chromosome variability in Eigenmannia virescens (Gymnotiformes: Sternopygidae).

New data are presented on the sex chromosomes of the fish species Eigenmannia virescens (Gymnotiformes, Sternopygidae). A new finding, involving the occurrence of ZZ/ZW sex chromosomes, is described in specimens sampled from the São Francisco and Amazon river basins in Brazil. All individuals had a chromosome number of 2n = 38. The homologs of the sex chromosome pair from the São Francisco river basin sample differed only in their morphology, while those from the Amazonian sample differed both in morphology and heterochromatin pattern. A possible model for the evolution of the sex chromosomes in E. virescens is proposed, including data from populations from the Paraná (Brazil) river basin, in which male heterogamety has already been described. The occurrence of different sex chromosome systems in species and populations of the neotropical freshwater fish fauna is discussed.

Trial of Badoe's maintenance solution.

The adult West African on intravenous fluid therapy requires 130 mmol of sodium, 50 mmol of potassium and 3L of water daily. At least 100g of glucose is usually provided. Three liters of Badoe's Maintenance Solution which contains 43.3 mmol of sodium of sodium, 16 mmol of potassium, 0.65 mmol of calcium, 9 mmol of bicarbonate, 51.7 mmol of chloride and 100g of sorbitol per litre, provides all the daily requirements of sodium, potassium and water. It also provides about 5000j of energy, nearly two-thirds of the resting energy expenditure. The trial in seven ill patients from the first day after operation has shown that the serum concentration of sodium and potassium and the urinary output of patients on 3L of Badoe's Maintenance Solution alone daily remain normal. Badoe's Maintenance solution is, therefore, recommended as the standard maintenance solution for patients in balance who need intravenous fluid therapy. It simplifies fluid therapy for medical and nursing staff as only one solution is used.