Abstract. We investigated the potential of red algae cultivated with deep-sea water (D) as dietary anti-oxidants to ameliorate the redox levels in the main organs and in bone metabolism using SAMP1 and its control SAMR1, in comparison with the same algae cultivated with surface seawater. Only the D group showed marked increases of glutathione (GSH) levels in the liver (R1, 134%) and brain (R1, 128% and P1, 126%) as well as activities of GSH non-dependent peroxidase in the liver (R1, 138%) and the brain (R1, 117% and P1, 112%) but not GSH-dependent peroxidase. The D diet also exhibited beneficial effects on bone metabolism; elevations of femoral calcium, phosphorus, hydroxyproline for collagen, hexosamine for polysaccharides, and suppression of urinary excretion of hydroxyproline as an index of increased bone resorption. A three-point bending test showed that the D diet increased the stiffness and the strength of the femur, which correlated with increases in femoral calcium and phosphorus contents. The results suggest that red algae of the Gracilaria sp. cultivated with deep-sea water has the potential to ameliorate degenerative diseases of aging. D

A small Neotropical frog, Dendrobates pumilio, undergoes interpopulational variation in color, degree of toxicity, size, and habits. Differences in body coloration encompass the visible spectrum from red to blue, as well as achromatic black and white. There are wide variations in the degree of toxicity, but these variations are not correlated with supposed warning colors. Extracts of skin yield two toxic compounds characterized as steroidal alkaloids with molecular formulae C(19)H(33)NO(2) and C(l9)H(33)NO(3). The rapid rate of divergent evolution among populations of this frog may result from isolation and chance restriction of original heterozygosity, with subsequent selection acting on different and greatly limited mixtures of alleles.

Two new species of Myersiohyla are described from the 1984-1985 Cerro de la Neblina Expedition in southern Venezuela, together with notes on the genus and a test of its monophyly, which has been challenged in recent studies. The inclusion of new sequences results in a monophyletic Myersiohyla that is better supported than in earlier analyses. One of the new species is similar to M. inparquesi, with which it has been confused previously. This newly described species has, like M. inparquesi, a tadpole with a dorsoventrally flattened body and the largest labial toothrow formula so far reported for anuran larvae (16/21). It differs from M. inparquesi in larval characters, adult coloration, and vocalization. The other new species is unique in having a color pattern composed of stellate melanophores over a greenish ground color. Comments on the holotype of M. loveridgei provide details overlooked in previous references to this rare species and stress the need to establish diagnostic characters that might differentiate it from M. aromatica. Furthermore, we report one specimen not assigned to any species from Huachamacary Tepui, only 25 km from the type locality of M. loveridgei. So far, all studied species of Myersiohyla have relatively large (2.8-3.2 mm), yolky ovarian eggs, a character state shared with several other frogs in Cophomantini (Hyloscirtus, Aplastodiscus, the Hypsiboas benitezi species group), and likely a

Amphibians of the family Bufonidae contain high levels of skin compounds that both inhibit Na+- and K+-dependent adenosinetriphosphatase and antagonize the binding of ouabain to the enzyme. In species of Bufo and Atelopus, these compounds are relatively nonpolar bufodienolides, whereas Dendrophryniscus and Melanophryniscus contain more polar compounds of unknown structure. Skin extracts from 30 of 48 species of frogs representing an additional eight families contained relatively low levels of compounds that inhibit binding of ouabain to Na+,K+-adenosinetriphosphatase. The widespread occurrence of low levels of inhibitory compounds is consonant with the role for these compounds as physiological regulators of Na+,K+-adenosinetriphosphatase in amphibian skin; high levels in the Bufonidae probably also serve as a defense against some predators.