Molecular systematics of the butterfly tribe Preponini (Nymphalidae: Charaxinae)

The nymphalid butterfly tribe Preponini includes some of the Neotropical region's most spectacular and familiar butterflies, but the taxonomy of the group nevertheless remains unstable. Several recent studies of Nymphalidae phylogeny have suggested that both the tribe itself and several genera might not be monophyletic, but to date taxon sampling has not been sufficiently comprehensive to allow informed revision of the group's systematics. We therefore conducted the first complete species‐level phylogenetic study of the tribe to establish a firm higher classification. We used DNA sequence data from three genes, the two mitochondrial genes cytochrome oxidase subunits I and II (COI and COII), and the nuclear gene elongation factor‐1α (EF‐1α), to reconstruct the phylogeny of the tribe using maximum likelihood (ML), maximum parsimony (MP) and Bayesian inference (BI). We included 48 individuals representing the 22 recognised Preponini species, and an additional 25 out‐group taxa to explore taxonomic limits at different levels. Firstly, we found that Anaeomorpha splendida Rothschild never grouped with remaining Preponini, so that maintaining monophyly of the tribe requires the taxon to be excluded, and we thus reinstate the tribe Anaeomorphini stat.rev. Secondly, we investigated generic limits, in particular the relationship of Noreppa Rydon to Archaeoprepona Fruhstorfer, and that of Agrias Doubleday to Prepona Boisduval. The molecular results coupled with previous morphological studies suggest that Noreppa syn.n should be synonymised with Archaeoprepona, and that Agrias syn.n should be synonymised with Prepona. We found Prepona pheridamas (Cramer) to be sister to all other Prepona, and markedly divergent from them in both morphology and DNA sequences, suggesting the possibility that it should be placed in a separate genus. We also found a number of cases of significant DNA sequence divergence and paraphyly or polyphyly within putative species that require further taxonomic attention, including Prepona claudina (Godart) stat.n. and Prepona narcissus (Staudinger) stat.n., Prepona pylene Hewitson and Prepona deiphile (Godart). Future research should focus on a broader population sampling of widespread, polymorphic Preponini species to thoroughly revise the current species‐level taxonomy, thus creating a solid foundation for studies in ecology and conservation.     

Mechanisms of intracranial kinetics in fossil rhipidistian fishes (Crossopterygii) and their relatives

The fishes of the Order Crossopterygii are characterized by a unique articulation within the braincase, by which the anterior division of the endocranium may be moved dorso-ventrally with respect to the posterior division. The structure of the skull in both groups of crossoptery-gian fishes (the fossil Rhipidistia and the fossil and Recent Coelacanthini) is such that 'normal' operation of the intracranial mechanism involves lateral movements of the cheek region and palate corresponding to the dorso-ventral movements of the ethmoid portion of the braincase. The hyomandibular has a function of prime importance in integrating the movements of the various skull components relative to each other. There are important differences between the characteristic intracranial mechanisms of Rhipidistia and Coelacanthini which may be interpreted in adaptive as well as morphological terms. Analysis of the intracranial kinetics of the Rhipidistia reveals a trend, in certain lines, for the amount of relative movement between the skull components to be decreased and this may be used to explain the loss of the intracranial joint in the Amphibia during their evolution from the Rhipidistia. The functional significance of the intracranial articulation has both a kinetic and a dynamic aspect and while in the Amphibia the kinetic ability of the skull is almost wholly restricted, the dynamic features of the ancestral condition are modified and developed as the basal articulation between the palate and endocranium is retained.     

H. Newell Martin, W. K. Brooks, and the Reformation of American Biology

Johns Hopkins University pioneered a new model for graduateeducation in biology. Prior toits opening in 1876, opportunitiesfor graduate education in biology were extremely limited intheUnited States. Under the careful leadership of W. K. Brooksand H. Newell Martin, JohnsHopkins not only provided for theeducation of many of the first generation of American-trainedbiologists, but it also developed a new and workable model foradvanced training in the biological sciences. This model, formedaround laboratory training and original research, was adoptedbymany American universities by the end of the nineteenth century.     

The Mode of Attachment of Trypanosoma vivax in the Proboscis of the Tsetse Fly Glossina fuscipes: an Ultrastructural Study of the Epimastigote Stage of the Trypanosome*

SYNOPSIS. The ultrastructure of attached Trypanosoma vivax epimastigote clusters in the proboscis of the tsetse fly Glossina fuscipes is described from electron micrographs of thin sections. Some flagellates are attached directly to the lining of the insect's labrum by their flagella, most of which are aligned along the long axis of the proboscis. Other trypanosomes are attached indirectly, their flagella adhering to those of flagellates which are directly attached. Junctional complexes similar to those described from metazoan epithelia are found on the flagellar membrane. A long zonular hemidesmosome attaches the flagellum to the proboscis wall and a series of closely set macular desmosomes link the flagellar membranes of adjacent flagellates. Unlike the trypomastigote stages of T. vivax, more than one row of macular desmosomes may be present along the flagellum-body junction of the trypanosome. It is suggested that all these Junctional complexes serve to buttress the flagellate's attachment to its insect host and so maintain anchorage of the parasite during the fly's blood meals. The ability of the flagellum of trypanosomatids to form Junctional complexes may be a factor contributing to their success as parasites, this adaptation enabling them to multiply while attached to host surfaces.