Energy balance and temperature relations of Azorella compacta, a high-elevation cushion plant of the central Andes

The environmental relationships and ecophysiology of Azorella compacta, a giant cushion plant, were investigated in Parque Nacional Lauca, Chile (18°10'–18°25' S and 69°16' W, 4400 m asl). The diurnal temperature range can reach 42 °C on some days of the year. The surface temperature of A. compacta was 13 °C below that of the air temperature of −7 °C at dawn, but from midmorning to late afternoon, the plant surface temperature remained within a few degrees of the air temperature. Soil surface temperatures did not differ between north- and south-facing slopes, but a model showed an increase in radiation reception by north-facing slopes throughout most of the year. Gas exchange measurements of A. compacta measured at the onset of the wet season ranged from −0.6662 to 11.4 μmol·m⁻²·s⁻¹, and maximum stomatal conductance (Gs) was 410 mmol·m⁻²·s⁻¹. The estimated light compensation point was 89 μmol·m⁻²·s⁻¹ and estimated light saturation occurred at about 1280 μmol·m⁻²·s⁻¹. Diurnal water potential measurements for A. compacta ranged from −1.67 to −2.65 MPa. This is one of the first ecophysiological studies of a tropical alpine cushion plant.     

A new species of dactyloid anole (Iguanidae, Polychrotinae, Anolis) from the southeastern slopes of the Andes of Ecuador

We describe a new species of Anolis from the southeastern slopes of the Andes of Ecuador, province of Zamora-Chinchipe, Parque Nacional Podocarpus. It belongs to (1) the aequatorialis species-group by being of moderate to large size with narrow toe lamellae, and (2) the eulaemus sub-group by having a typical Anolis digit, in which the distal lamellae of phalanx II distinctly overlap the proximal scales of phalanx I. The new species is most similar morphologically to Anolis fitchi but differs from it mainly by having a dewlap with longitudinal rows of 2-5 granular, minute scales separated by naked skin (longitudinal rows of one or two keeled, large scales separated by naked skin in Anolis fitchi) and a vertically shorter dewlap (longer dewlap in Anolis fitchi).     

Limited genetic differentiation of Mycetomoellerius mikromelanos in Parque National Soberanía,Panama: Implications for queen dispersal

The coevolutionary relationship between fungus-growing ants (Formicidae: Attini: Attina) and their symbionts has been well studied in the Panamanian rain forests. To further understand the ecological context of these evolutionary relationships, we have examined the population-genetic structure of the fungus-growing ant species Mycetomoellerius mikromelanos Cardenas, Schultz, Adams 2021 in the Panama Canal Zone. We specifically investigated the presence of population structure, the significance of geographic features (i.e., creeks) limiting gene flow, and relatedness between ant colonies. To accomplish this, we genotyped 85 ant colonies from nine creeks across an approximately 30 km transect in Parque National Soberanía, Panama, using double-digest restriction-site-associated DNA sequencing. We did not find distinct population structure using two genetic clustering methods; however, we did detect an effect of isolation by distance. Furthermore, related colonies were frequently detected on the same creek or neighboring creeks, and some at further geographic distances. Collectively, these findings demonstrate that new colonies tend to establish on natal creeks and occasionally on distant creeks following long-distance dispersal events. We discuss how population-genetic patterns reveal the natural history of M. mikromelanos in Parque National Soberanía and how these results fit into the context of fungus-growing ant mutualisms. Abstract in Spanish is available with online material.     

Threatened fishes of the world: <Emphasis Type="Italic">Trichomycterus chungaraensis</Emphasis> Arratia 1983 (Trichomycteridae)

Trichomycterus chungaraensis is an endemic and endangered fish from the south high Andean plateau; mainly due to its habitat total extension thus has been calculated to be 2,910 m² and inhabiting solely in Mal Paso stream, at the UNESCO Biosphere Reserve and Lauca National Park.     

Haltung und Zucht des Spix-Aras (Cyanopsitta spixii) in der Loro Parque Fundación auf Teneriffa

Since 2004 the Loro Parque Fundación (LPF) has again achieved breeding success with the Spix's Macaw (Cyanopsitta spixii), and has been regularly rearing young (n=4) by hand-feeding. Currently this parrot species, which went extinct in the wild in 2000, cannot be seen on exhibit in any zoo in the world. There are only five breeding centres worldwide which keep this species, all being members of the Spix's Macaw Recovery Programme. The conditions and techniques used by the LPF to maintain, breed and hand-rear this species are described.     

Cyanobacterial diversity in Salar de Huasco, a high altitude saline wetland in northern Chile: an example of geographical dispersion?

The diversity of Cyanobacteria in water and sediment samples from four representative sites of the Salar de Huasco was examined using denaturing gradient gel electrophoresis and analysis of clone libraries of 16S rRNA gene PCR products. Salar de Huasco is a high altitude (3800 m altitude) saline wetland located in the Chilean Altiplano. We analyzed samples from a tributary stream (H0) and three shallow lagoons (H1, H4, H6) that contrasted in their physicochemical conditions and associated biota. Seventy-eight phylotypes were identified in a total of 268 clonal sequences deriving from seven clone libraries of water and sediment samples. Oscillatoriales were frequently found in water samples from sites H0, H1 and H4 and in sediment samples from sites H1 and H4. Pleurocapsales were found only at site H0, while Chroococcales were recovered from sediment samples of sites H0 and H1, and from water samples of site H1. Nostocales were found in sediment samples from sites H1 and H4, and water samples from site H1 and were largely represented by sequences highly similar to Nodularia spumigena. We suggest that cyanobacterial communities from Salar de Huasco are unique - they include sequences related to others previously described from the Antarctic, along with others from diverse, but less extreme environments.     

Diet of Southern Muriquis in Continuous Brazilian Atlantic Forest

We systematically collected data on feeding behavior for one group of 33–39 southern muriquis (Brachyteles arachnoides) in Parque Estadual Carlos Botelho (PECB), São Paulo State, Brazil (37,432.45 ha of continuous Atlantic Forest), between January and December 1995. We determined food item consumption from instantaneous scans of behavior. Fruits were the most eaten food items in all 12 mo (40–80% of scan in every mo, average = 71.3%). Muriquis ate young leaves more than mature leaves or flowers. Our results are consistent with previous findings at the same and neighboring forest sites that southern muriquis have a consistently frugivorous diet when inhabiting less disturbed habitats, but contrast with previous observations on oppportunistic frugivory in muriqui populations inhabiting fragmented forests. Sustained high levels of frugivory probably result from year-round availability of fruit within large continuous forests.     

Parallel evolution in the major haemoglobin genes of eight species of Andean waterfowl

Theory predicts that parallel evolution should be common when the number of beneficial mutations is limited by selective constraints on protein structure. However, confirmation is scarce in natural populations. Here we studied the major haemoglobin genes of eight Andean duck lineages and compared them to 115 other waterfowl species, including the bar-headed goose ( Anser indicus ) and Abyssinian blue-winged goose ( Cyanochen cyanopterus ), two additional species living at high altitude. One to five amino acid replacements were significantly overrepresented or derived in each highland population, and parallel substitutions were more common than in simulated sequences evolved under a neutral model. Two substitutions evolved in parallel in the αA subunit of two (Ala-α8) and five (Thr-α77) taxa, and five identical βA subunit substitutions were observed in two (Ser-β4, Glu-β94, Met-β133) or three (Ser-β13, Ser-β116) taxa. Substitutions at adjacent sites within the same functional protein region were also observed. Five such replacements were in exterior, solvent-accessible positions on the A helix and AB corner of the αA subunit. Five others were in close proximity to inositolpentaphosphate binding sites, and two pairs of independent replacements occurred at two different α¹β¹ intersubunit contacts. More than half of the substitutions in highland lineages resulted in the acquisition of serine or threonine (18 gains vs. 2 losses), both of which possess a hydroxyl group that can hydrogen bond to a variety of polar substrates. The patterns of parallel evolution observed in these waterfowl suggest that adaptation to high-altitude hypoxia has resulted from selection on unique but overlapping sets of one to five amino acid substitutions in each lineage.     

Embryonic and post-embryonic lethals induced by diethyl sulfate in mature sperm of Drosophila melanogaster.

It has recently been reported that, in Drosophila melanogaster, when sperm treated with diethyl sulfate was stored in the females, II–III translocations were detected as from the 6th day after the treatment, though none was recovered without storage. Chromosome breaks being currently considered the main cause of dominant lethality and the embryonic period lasting about one day at 25°C, it was thought of interest to study the ability of DES to induce this type of damage with and without storage. It was found that the treatment increased embryonic lethality (measured as frequency of unhatched eggs) and post-embryonic lethality (measured as frequency of larval and pupal death) over the control values. The frequency of embryonic lethals after storage in the females for 6 days was similar to that shown by the unstored samples. In contrast with this, the yield of post-embryonic lethality was markedly raised by that storage time. It is suggested that: (1) lesions are induced as “pre-breaks”, and storage and cell divisions are instrumental in their opening; (2) potential breaks can undergo DNA replication and cell division as such and become open in different cell cycles, impairing embryonic and post-embryonic development; (3) chromosome breaks induced by DES seem to behave in a way similar to those induced by other mono- and poly-functional alkylating agents; and (4) when the potential ability of chemical compounds to induce chromosome breaks is assessed, post-embryonic lethality can be used as a simple one-generation preliminary test, to establish delayed effects.     

Tracing the native ancestors of the modern Theobroma cacao L. population in Ecuador

The native Theobroma cacao L. population from Ecuador, known as Nacional, is famous for its fine cocoa flavour. From the beginning of the twentieth century, however, it has been subjected to genetic erosion due principally to successive introductions of foreign germplasm whose hybrid descendants gradually replaced the native plantations, implying a decrease in cocoa quality. We attempted to trace this native cacao within a wide pool of modern Ecuadorian cacao population. Three hundred and twenty-two cacao accessions collected from different geographical areas along the pacific coast of Ecuador and maintained in two living collections were analysed using 40 simple-sequence repeat markers. Most of Ecuadorian cacao accessions displayed a high diversity and heterozygosity level. A factorial analysis of correspondence (FAC) showed a continuous variation among them, with a few ones, grouped at an extreme side of the FAC cloud, showing higher levels of homozygosity and lower introgression level by foreign cacaos. A paternity analysis revealed that these highly homozygous individuals are the most probable ancestors of the modern Nacional hybrid pool. These particular accessions studied could represent the native Nacional cacao present in Ecuador before the foreign introductions. Their identification will help to conserve valuable genetic material and to improve cocoa quality in new cacao varieties.