The respiratory metabolism of the castes of two leaf cutting ants, Atta laevigata (F. Smith, 1858) and Atta sexdens rubropilosa forel, 1908

1. 1. The respiration of the different castes of two species of leaf-cutting ants, Atta laevigata and Atta sexdens rubropilosa was measured in both workers and sexed forms. 2. 2. The respiratory rates (μl O2/mg(live)/hr) were, in A. laevigata, 0.644 (gardeners), 0.594 (cutters), 0.354 (soldiers), 0.233 (males) and 0.085 (females); in A. s. rubropilosa, 0.803 (gardeners), 0.748 (cutters), 0.510 (soldiers), 0.375 (males) and 0.274 (females), significantly higher than A. laevigata. 3. 3. All castes considered, the b-values of the equation relating oxygen consumption and weight in A. laevigata (0.53) were significantly different from that in A. s. rubropilosa (0.73). © 1981.

Respiratory regulation in workers of the leaf cutting ant Atta sexdens rubropilosa Forel, 1908

1. Respiratory rates of workers of the leaf cutting ant Atta sexdens rubropilosa were measured at different oxygen pressures, at 25°C. 2. In experiments where different ants were used at each of the oxygen pressures, respiration was regulated down to 70.8 mmHg. 3. When the same ants were submitted in sequence to declining pO2, the 'oxygen dependence indexes' (Tang P.S. (1933) Quart. Rev. Biol. 8, 260-274) also suggested a good regulatory capacity. 4. The results are discussed in terms of the variation of the partial pressures of O2 and CO2 that the ants probably encounter when wandering to and from the nest to forage, and when performing their heavy tasks (leaf transport, offspring and fungus care). 5. CO2 rise and O2 fall, from ants' respiration inside the ant hill, may act as the factors that, in a reflex way, keep the spiracles open and increase ventilation and the frequency of CO2 emission to keep the oxygen supply adequate to face the energetic demand of the routine level of activity of the workers, when passing from normoxia (air) to hypoxia (in nest galleries).

Caracterização transcriptômica de vias metabólicas na formiga Attini Atta sexdens rubropilosa Forel, 1908 (Hymenoptera, Formicidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolismo nutricional em Atta sexdens rubropilosa Forel, 1908: voo nupcial, fundação e desenvolvimento da colônia

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

PB1908-27 Loss From Cornstalk Disease in Custer County, Nebraska, During the Winter of 1906-1907 (Distributed January 1908, Reprinted December 1930)

"Cornstalk disease" is the name given to the cause or causes of death of cattle allowed to run in fields of standing cornstalks from which the ears have been gathered. It is probable that "many different maladies have been included under this name." In Nebraska, however, there is such a similarity in the symptoms reported by the farmers that it seems probable that the great majority of the losses attributed to cornstalk disease are really due to some common cause. As to the exact nature of this cause nothing is known. However, various theories have been advanced, and methods of prevention or treatment based upon these theories have been described.

A new species of Leporinus Agassiz, 1829 from the upper Rio Paraná basin (Characiformes, Anostomidae) with redescription of L. elongatus Valenciennes, 1850 and L. obtusidens (Valenciennes, 1837)

Leporinus obtusidens Valenciennes, 1837 and L. elongatus Valenciennes, 1850 are redescribed based on the type specimens, including those of their junior synonyms, and recently collected specimens. Leporinus obtusidens is considered to be widespread, occuring in the river drainages of La Plata, São Francisco, and Parnaíba. Leporinus aguapeiensis Campos, 1945, described from the upper Rio Paraná, and L. silvestrii Boulenger, 1902, described from the Rio Paraguay, are considered junior synonyms of L. obtusidens. Leporinus elongatus is endemic to the Rio Jequitinhonha and Rio Pardo, two eastern Brazilian river basins, and the locality cited for the lectotype, Rio São Fransico, likely to be erroneous. Leporinus crassilabris Borodin, 1929, and L. crassilabris breviceps Borodin, 1929, both described from the Rio Jequitinhonha, are considered junior synynoms of L. elongatus. A new species of Leporinus, endemic to the upper Rio Paraná, very similar and sometimes mistaken with L. obtusidens, is formally described. In addition, comments on Leporinus pachyurus Valenciennes, 1850 and on L. bimaculatus Castelnau, 1855 are provided, and a lectotype for L. bimaculatus is selected.

Influencia de la temperatura en el comportamiento y color de Palaemon elegans (Rathke, 1837) (Crustacea, Decapoda)

[ES] El camarón de charco (Palaemon elegans) soporta altos rangos de temperatura, pero a medida que ésta baja (hasta 5 ºC) comienza a reducir sus movimientos hasta quedar completamente inmóvil, casi en letargo. A este cambio de comportamiento va unido un cambio en la coloración del cuerpo del animal, que pasa de ser completamente transparente con tonos vivos azules y amarillos a ser translúcido, con azules y amarillos mucho más pálidos

Comportamiento de apoyo social en especies territoriales: "Parablennius parvicornis" (Valenciennes, 1836) y "Mauligobius maderensis" (Valenciennes, 1837)

[ES] Se estudia el comportamiento de apoyo social entre individuos de dos especies de peces territoriales (Parablennius parvicornis y Mauligobius maderensis) ante una situación de estrés. Se observa que a medida que la densidad de individuos aumentaba el estrés respiratorio en los individuos disminuía.