A new genus and species of mite (Acari: Acaridae) from Mexico

Comerinia chuetolamina gen. & sp. nov. was collected from a cargo of dried Daphnia imported to Britain from Mexico. Females can be distinguished from all others described in the family Acaridae in that setae 14, 15 and d5 are flattened dorsoventrally over most of the basal half. This region appears blade-like, bearing numerous strong pectinations along the ventral side. Males may be recognized by a series of characters, some of which reflect a close relationship with Forcellinia Ouds., 1924 and others with Tyrophagus Ouds., 1924. The position of the new genus in a commonly used key to adults of the family Acaridae is indicated.     

An Evaluation of the Carbon Dioxide Component in the GasPak Anaerobic System

The GasPak disposable hydrogen and carbon dioxide generator is a convenient and reliable method for producing anaerobiosis in the GasPak system. As a source of carbon dioxide, however, the generator is inadequate, uncontrolled and unreliable.     

Xylem Sap from Actinidia chinensis: Gradients in Sap Composition

In early spring, just prior to leaf break, there were substantialgradients in the concentration of many solutes in xylem sapcollected by vacuum extraction from shoots of different ages,from the branches, trunk and roots of mature Chinese gooseberryvines (Actinidia chinensis Planchon) For most nutrients therewas a progressive fall in concentration from youngest shootsdown to the roots and nitrate was the only nutrient to showa trend in the opposite direction These gradients in concentrationare probably sufficient to account for most of the changes observedin the composition of bleeding xylem sap during the first fewhours of bleeding after a branch is cut or wounded Actinidia chinensis, Chinese gooseberry, kiwifruit, xylem sap, nutrient gradients     

Enzyme heterozygosity and growth of rainbow trout reared at two rations

The relationship between heterozygosity at nine enzyme loci and both size and growth in rainbow trout ( Salmo gairdneri ) reared at either low (LRT) or high (HRT) ration for 84 days is reported. The experimental fish were progeny produced from a pooled mating of 25 female and 25 male rainbow trout captured in spawning condition at the Ganaraska River, Ontario. There is a significant negative regression between the number of heterozygous loci per fish and size (fork length and weight) among fish at the beginning of the experiment. Heterozygotes at two loci, Sod and Mdh3,4 , were significantly smaller than homozygotes. A significant negative regression between multilocus heterozygosity and size was detectable among the fish reared at HRT for 84 days but not at LRT. Ration appeared to affect the strength of the association between heterozygosity and growth because at HRT homozygotes at the majority of loci grew faster than heterozygotes, but the reverse was true at LRT.