Ultrastructure and Ecology of Calycomonas ovalis Wulff, 1919, (Chrysophyceae) and Its Redescription as a Testate Rhizopod,Paulinella ovalis N. Comb. (Filosea: Euglyphina)1

An exceptional bloom (10⁹ cells/liter) of a unicellular alga, Aureococcus anophagefferens, in Narragansett Bay, RI, was accompanied by unusually high numbers (6 times 10⁶ tests/liter) of vase-shaped cells of Calycomonas ovalis Wulff, hitherto considered a flagellated chrysophyte. Phase contrast light microscopy showed the characteristic oval lorica or test of C. ovalis, ca. 3.0 times 4.5 μm. Transmission electron microscopy of thin sections of natural populations revealed, however, that C. ovalis is actually a rhizopod within a test of electron-dense scales. This estuarine, planktonk testacean extends a pseudopodium through a narrow pseudostome and lacks chloroplasts or flagella. It is a bacterivore and feeds primarily on unicellular cyanobacteria. The morphology, ultrastructure, and cell division of C. ovalis are described. These characteristics place C. ovalis with the genus Paulinella (Sarcodina: Filosea: Euglyphina), which at present contains the single species, P. chromatophora Lauterbom. Calycomonas ovalis is thus assigned to Paulinella as P. ovalis n. comb.     

There and back again: switching between host orders by avian body lice (Ischnocera: Goniodidae)

Studies of major switches by parasites between highly divergent host lineages are important for understanding new opportunities for parasite diversification. One such major host switch is inferred for avian feather lice (Ischnocera) in the family Goniodidae, which parasitize two distantly‐related groups of birds: Galliformes (pheasants, quail, partridges, etc.) and Columbiformes (pigeons and doves). Although there have been several cophylogenetic studies of lice at the species level, few studies have focused on such broad evolutionary patterns and major host‐switching events. Using a phylogeny based on DNA sequences for goniodid feather lice, we investigated the direction of this major host switch. Unexpectedly, we found that goniodid feather lice have switched host orders, not just once, but twice. A primary host switch occurred from Galliformes to Columbiformes, leading to a large radiation of columbiform body lice. Subsequently, there was also a host switch from Columbiformes back to Galliformes, specifically to megapodes in the Papua–Australasian region. The results of the present study further reveal that, although morphologically diagnosable lineages are supported by molecular data, many of the existing genera are not monophyletic and a revision of generic limits is needed. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 614–625.     

Thermoregulation in the Papuan-New Guinean boid and colubrid snakes, Candoia carinata, Candoia aspera and Boiga irregularis

Thermoregulation was investigated in the Papuan-New Guinean boids, Candoia carinata and C. aspera , and the arboreal colubrid, Boiga irregularis , based upon radiant and solar heating with thermocouple implants in the head and mid-body. Significant differences were found between head and body thermal preferenda values with either grouped data or between specimens in C. carinata and B. irregularis , but not in C. aspera , although higher temperatures were tolerated by the body than the head in all species examined. Less diversity in thermal control methods was found in this study than in previous investigations on some Australian pythons and elapid snakes, suggesting that possibly there is less need for such diversity in tropical rainforest snakes, as compared to those living in more temperate or arid environments.     

Revision of the genus Psix Kozlov & Lê (Hymenoptera: Scelionidae)

The genus Psix Kozlov & Lê (Hymenoptera: Scelionidae) is revised from a worldwide perspective. Twelve species are described as new: annulatus [Cameroon], asper [Uganda], aulax [Australia], confluus [Sri Lanka], flavicoxa [Ivory Coast, Zimbabwe], fusm [Australia], lacunatus [Pakistan east to Taiwan, south to Australia], metopa [Australia], rasilis [Ivory Coast, Gambia], sulcifer [Malaysia], viriosus [India east to Philippine Is.] and watshami [E. Africa, Madagascar] . Psix abnormis Kozlov & Lê [W. Africa east to at least India], glabris-crobus (Girault) nxomb. [Australia], olympus (Dodd) n.comb. [Australia], saccharicola (Mani) n.comb. [India], striaticeps (Dodd) n.comb. [W. Africa east to India, Madagascar] and tunetanus (Mineo and Szabó) n.comb. [Tunisia, Gambia, Ivory Coast, Saudi Arabia, S.W. Nearctic, Venezuela] are redescribed. An identification key for the species of Psix is presented. The relationships among species are discussed. The earliest derived species are generally found in Australia and southeast Asia. The more apomorphic species occur generally in Africa, southwest Asia and India. The distribution of Psix tunetanus has possibly been influenced by man. Details of the relationship with Trissolcus and Archi-phanurus are unclear; the position of Psix within the subfamily is therefore also obscure.