ABSTRACT This study was undertaken to examine the histopathological effects of CCl(4) on rosy barbs and amphioxus with an aim to compare the homology between rosy barb liver and amphioxus digestive caecum. It was found that the 96 h LC(50) values were 23.9 +/- 4 mg/L and 18.9 +/- 2 mg/L for rosy barbs and amphioxus, respectively. Histological examinations showed that exposure to sublethal CCl(4...

In the course of a revision of Haemonchus Cobb, 1898 (Nematoda), commonly referred to as large stomach worms, significant new morphological information was discovered that allows the recognition of 2 species believed for more than 50 yr to be synonymous. Both species, Haemonchus mitchelli Le Roux, 1929, from the eland Taurotragus oryx and other African ruminants and H. okapiae van den Berghe, 1...

We present the first explicit theory of the growth of feather shape, defined as the outline of a pennaceous feather vane. Based on a reanalysis of data from the literature, we propose that the absolute growth rate of the barbs and rachis ridges, not the vertical growth rate, is uniform throughout the follicle. The growth of feathers is simulated with a mathematical model based on six growth par...

A series of new silver(i) 5,5-diethylbarbiturate (barb) complexes with the formulas [Ag2(μ-barb)2(PPh3)2] (1), [Ag(barb)(PPh2Cy)] (2), [Ag(barb)(PPhCy2)] (3) and [Ag(barb)(PCy3)] (4) (PPh3 = triphenylphosphine, PPh2Cy = diphenylcyclohexylphosphine, PPhCy2 = dicyclohexylphenylphosphine and PCy3 = tricyclohexylphosphine) were synthesized and fully characterized by elemental analysis, IR, NMR, ESI...

Comparative study of completed down feathers from seven of the major tracts of newly-hatched Silver Campine chicks reveals tract-specific differences in the total length of the primary group of barbs and in the length of their barbule-free tips. Two classes of barbs can be distinguished on the basis of overall length in feathers of any one of the tracts: (a) those barbs that form from the first...

this study was conducted to determine the optimal dietary protein requirement for lemon fin barb hybrid fingerlings. triplicate groups of fish (1.00 ± 0.05 g) were fed twice a day until apparent satiation with five isocaloric (16 kj/g) diets containing varying protein level ranging from 20 to 40% for 60 days. survival was not affected by the dietary protein level. the weight gain and specific g...

The evolution of bilaterally symmetric feathers is a fundamental process leading toward flight. One major unsolved mystery is how the feathers of a single bird can form radially symmetric downy feathers and bilaterally symmetric flight feathers. In developing downy feather follicles, barb ridges are organized parallel to the long axis of the feather follicle. In developing flight-feather follic...

Melanin has been associated with increased resistance to abrasion, decreased wear and lowered barb breakage in feathers. But, this association was inferred without considering barb position along the rachis as a potentially confounding variable. We examined the cross-sectional area, breaking force, breaking stress, breaking strain and toughness of melanized and unmelanized barbs along the entir...