Frontonia microstoma, Kahl

Frontonia microstoma , a ciliate living in brackish water, is described. The somatic infraciliature, the buccal in-fraciliature and the fibrillar buccal system show essential characteristics of species of Frontoniidae Kahl. The number and the arrangement of vestibular kineties are specific. Dark blue-green pigment is formed by small ectoplasmic vesicles. Formation of cysts is frequent in natural medium and cultures. There is no dedifferentiation of ciliates when encysted. Excystment is induced readily. Thriving cultures of F. microstoma have been obtained by feeding the ciliates with appropriate species of Cyanophyceae. Growth was better in brackish water than in either sea water or fresh water.     

Onset of algal endosymbiont specificity varies among closely related species of Acropora corals during early ontogeny

Juveniles of a number of corals with horizontal transmission of dinoflagellate endosymbionts naturally acquire and maintain Symbiodinium types that differ from those found in adult populations. However, the duration of this early period of symbiont flexibility and successional changes leading to dominance by the characteristic adult (homologous) type are unknown. To document natural succession of Symbiodinium types within juvenile corals, we monitored Symbiodinium communities in juveniles of Acropora tenuis and Acropora millepora for 3.5 years. Juveniles originating from one of three reef populations, characterized by differing adult coral- Symbiodinium associations, were raised in a common environment. In four out of five cases, juveniles became dominated initially by a nonhomologous adult type. Changes in Symbiodinium communities associated with A. tenuis juveniles led to the establishment of the adult homologous association at ∼3.5 years of age. These changes were not linked to the onset of reproductive maturity, but may be linked to micro-environmental changes associated with vertical growth of juvenile corals. We hypothesize that fine-tuning of specificity mechanisms takes place during ontogeny in A. tenuis , leading to the eventual establishment of the adult homologous association. However, Symbiodinium communities in A. millepora juveniles did not change significantly over the 3.5 years, potentially reflecting (i) lack of specificity, (ii) more than a 3.5-year delay in the onset of specificity, or (iii) lack of availability of the adult Symbiodinium type. This study demonstrates that juvenile corals may survive for extended periods of time with nonhomologous Symbiodinium types and that closely related species of Acropora differ in the timing of the onset of specificity for algal symbionts.     

Ten microsatellite loci for the reef‐building coral Acropora millepora (Cnidaria,Scleractinia) from the Great Barrier Reef,Australia

Here we present nine novel, polymorphic microsatellite loci developed for the scleractinian coral Acropora millepora (Acroporidae) from the Great Barrier Reef. In addition, we have assessed the specificity and polymorphism of five microsatellite loci previously developed for a Caribbean congener and one locus developed for an Indo‐Pacific congener. Only one of the latter six loci produced reliable results, yielding a total of 10 polymorphic microsatellite loci for A. millepora. Variability was tested on 20–23 individuals from a single population, plus another ～10 individuals from each of three different populations, resulting in five to 20 alleles per locus.     

Trois Especes Nouvelles d'Ophryoglenes: O. gelifera n. sp., O. mucosa n. sp., O. multimicronucleata n. sp. (Cilies Holotriches Peniculiens)

SYNOPSIS. A previous study with P. de Puytorac on O. bacterocaryon(3) has shown the methods of studying this Ciliate and has specified the general and buccal morphology, the morphogenesis, and the biology of vegetative individuals (theront, trophont, tomont, tomites) of this species. Three species we are describing now offer numerous common features with O. bacterocaryon. We consider them as the proper characters of genus Ophryoglena and we only insist on the specific particularities of O. gelifera, O. mucosa and O. multimicronucleata. O. gelifera is a large Ophryoglene differing from the others by a slightly asymetric, curved, spindle-shaped theront; the ellipsoidal tomont secretes abundant and clear jelly. The theront possesses one thick spindle-shaped macronucleus, one voluminous spherical micronucleus, fitting with the macronucleus. Its somatic infraciliature is dense, its buccal infraciliature is characteristic, especially in the shape of peniculus P1. This species cannot be mistaken for O. pectans Mugard(2) although it is rather near it. O. mucosa is a very small Ophryoglene. The theront has one thick elliptical macronucleus, one small micronucleus; the buccal orifice is not kidney-shaped, but quite pointed in front; there is no tragus; the somatic infraciliature is not close; the peniculus P1 is characteristic. The tomont is ellipsoidal and surrounded by a thick mucous gangue. The tomites are not close together. O. mucosa is very different from O. gelifera and O. pectans Mugard(2). O. multimicronucleata. Near to O. polymicrocaryon Mugard(2), this Ophryoglene differs from it by the small size of all its vegetative elements and especially by its nuclear-apparatus. The latter includes numerous (5 to 6) bulky spherical micronuclei and one macronucleus looking like blackpudding which can be compared to that of O. singularis Canella and Trinchas(1). The theront is spindle-shaped and of a dark-grey colour. The spherical tomont secretes a mucous gangue which is not very thick. Besides, the somatic infraciliature and buccal in fraciliature of the theront (peniculus P1 especially) make O. multi micronucleata quite distinct from O. polymicrocaryon Mugard(2).     

Parallel Phylogenies of Pneumocystis Species and their Mammalian Hosts

ABSTRACT. The single name Pneumocystis carinii consists of an heterogeneous group of specific fungal organisms that colonize a very wide range of mammalian hosts. In the present study, mitochondrial large subunit (mtLSU) and small subunit (mtSSU) rRNA sequences of P. carinii organisms from 24 different mammalian species were compared. The mammals were included in six major groups: Primates (12 species). Rodents (5 species). Carnivores (3 species). Bats (1 species), Lagomorphs (1 species), Marsupials (1 species) and Ungulates (1 species). Direct sequencing of PCR products demonstrated that specific mtSSU and mtLSU rRNA Pneumocystis sequence could be attributed to each mammalian species. No animal harbored P. carinii f. sp. hominis. Comparison of combined mtLSU and mtSSU aligned sequences confirmed cospeciation of P. carinii and corresponding mammalian hosts. P. carinii organisms isolated from mammals of the same zoological group systematically clustered together. Within each cluster, the genetic divergence between P. carinii organisms varied in terms of the phylogenetic divergence existing among the corresponding host species. However, the relative position of P. carinii groups (rodent, carnivore or primate-derived P. carinii) could not be clearly determined. Further resolution will require the integration of additional sequence data.     

Maternity of emergency queens in the Cape honey bee,Apis mellifera capensis

During reproductive swarming, some workers of the Cape honey bee, Apis mellifera capensis, lay eggs in queen cells, many of which are reared to maturity. However, it is unknown if workers are able to lay in queen cells immediately after queen loss during an episode of emergency queen rearing. In this study we experimentally de‐queened colonies and determined the maternity of larvae and pupae that were reared as queens. This allowed us to determine how soon after queen loss workers contribute to the production of new queens. We were further interested to see if workers would preferentially raise new queens from queen‐laid brood if this was introduced later. We performed our manipulations in two different settings: an apiary setting where colonies were situated close together and a more natural situation in which the colonies were well separated. This allowed us to determine how the vicinity of other colonies affects the presence of parasites. We found that workers do indeed contribute to queen cell production immediately after the loss of their queen, thus demonstrating that some workers either have activated ovaries even when their colony has a queen or are able to activate their ovaries extremely rapidly. Queen‐laid brood introduced days after queen loss was ignored, showing that workers do not prefer to raise new queens from queen brood when given a choice. We also detected non‐natal parasitism of queen cells in both settings. We therefore conclude that some A. m. capensis genotypes specialize in parasitizing queen cells.     

RELATIONS BETWEEN THE FEEDING AND RADIO-SENSITIVITY CYCLES AND THE ECDYSONE CYCLE IN BOMBYX MORI, AT THE END OF EMBRYONIC DEVELOPMENT AND DURING THE FIRST FOUR LARVAL INSTARS

The cycle of ecdysone secretion in Bombyx mori was determined at the end of embryonic development and during the first four larval instars by means of radio-immunological titration (RIA). There is a relationship between this cycle and the radio-sensitivity cycle of this insect. This radio-sensitivity (tested through the percentage of abnormal ecdysis and of permanent larvae) is minimum when the hormone rate is important during X-irradiation; the effect is maximum when the hormonal rate is minimum. The fall of the ecdysone rate during the first food-intakes entails a reverse radio-sensitivity.