Parsimony network analysis of rDNA sequences was used to delimit phylogenetic species of yeasts in an objective, formal manner. Many strains assigned to Candida apicola (Starmerella clade), when compared to the type, fell outside the inclusion limits proposed by Kurtzman and Robnett (1998) based on a pair-wise comparison of the large subunit rRNA gene D1/D2 domains. However, when these sequences were analyzed jointly with ITS rDNA sequences by parsimony network analysis, 28 of the 30 strains formed a cohesive set. Two strains, MUCL 45721 and CBS 4353, were excluded from the species, but there was no evident justification to subdivide the rest. A similar analysis of 81 isolates originally assigned to Candida azyma (Wickerhamiella clade) yielded dramatically different results, giving rise to six independent networks corresponding to Candida azyma sensu stricto (18 strains), Candida azymoides (2 strains), a pair of isolates from Australian hibiscus flowers, a single isolate from the same substrate, a single isolate from Malaysian bertam palm nectar, and 57 isolates that are assigned to the new species Candida parazyma (type = UWOPS 91-652.1(T) = CBS 11563(T) = NRRL Y-48669(T)). The strains retained in C. azyma sensu stricto differed from one another by up to four substitutions in their D1/D2 sequences, but their polymorphism at the level of the ITS was considerable and suggested a history of divergence resulting from dispersal. Strains of C. parazyma fell into seven variant haplotypes based on sequences of the rDNA ITS and D1/D2 regions. The most abundant haplotype occurred across the global range of the species. Others were either endemic to Belize, Costa Rica, Rarotonga, or Tennessee, suggestive of vicariance, or occurred across remote localities, offering partial support to the notion of rapid dispersal.

The size and shape of red blood cells (erythrocytes) is determined by key life history strategies in vertebrates. They have a fundamental role to deliver oxygen to tissues, and their ability to do so is shaped by the tissues need and their shape. Despite considerable interest in how other components of blood are shaped by ecology and life history, few studies have considered erythrocytes themselves. We tested how erythrocyte size and shape varied in relation to energetically-demanding activities using a dataset of 631 bird species. We found that in general, birds undergoing greater activities such as long distance migration had smaller and more elongated cells, whilst those with greater male-male competition had smaller and rounder cells. Smaller, more elongated erythrocytes allow more rapid oxygenation/deoxygenation and support greater aerobic activity. The rounder erythrocytes found in species with strong male-male competition may stem from younger erythrocytes deriving from androgen-induced erythropoiesis rates. Finally, diving species of bird had larger erythrocytes, indicating that erythrocytes are acting as a vital oxygen store swimming. In summary, erythrocyte size and shape in birds is driven by the need to deliver oxygen during energetically-costly activities.

The genetic structure of populations of the out-crossing haplontic yeast species Metschnikowia lochheadii was investigated. The species is associated with floricolous beetles in Central America and Hawaii. The objective was to determine whether sexual reproduction is prevalent and to what extent the geographic distribution of genotypes can be viewed as historical. The genetic markers examined include the mating type (h (+) or h (-)) and nine polymorphic DNA loci. The data were used to assess population structuring based on F (ST) and linkage disequilibrium and the distribution of alleles using parsimony haplotype networks. In Central America, M. lochheadii is subdivided into sexually active demes between which gene flow is limited. Isolates from five Hawaiian islands had identical haplotypes, confirming that the species has undergone a founder effect concomitant with the recent import of a nitidulid beetle into the archipelago.

A novel species, Metschnikowia orientalis sp. nov., is described for haploid, heterothallic yeasts isolated from nitidulid beetles sampled in flowers in Rarotonga in the Cook Islands, and the Cameron Highlands of Malaysia. As evidenced by analysis of D1/D2 large subunit rDNA sequences, the species is related to Candida hawaiiana, to which it is similar in growth responses. Cylindrical, conjugated asci and acicular ascospores of moderate size are formed. Rudimentary mating reactions were observed with Metschnikowia aberdeeniae and Metschnikowia continentalis, but not with C. hawaiiana. The type strain of M. orientalis is UWOPS 99-745.6 T (h + ) (=CBS 10331 T =NRRL Y-27991 T ) and the designated allotype is UWOPS 05-269