ALBERT

Notes: . Morphological and ultrastructural studies on a new ciliate, Paraptychostomum almae, from the digestive tract of an oligochaete (Alma emini) from the Cameroons are carried out. The flattened cell has a large size; its left lateral face bears an anterior thigmotactic zone that includes seven-nine short kinetal segments. The somatic cortex is composed of flattened alveoli, a thin epiplasm and a microfibrillar ecto-endoplasmic boundary. Kineties are made of monokinetids, each particularly characterized by a long anteriorly directed kinetodesmal fiber, and a hyperdivergent postciliary ribbon. The postero-ventral buccal apparatus consists of a short peristome and a deep longitudinal infundibulum. The paroral organelle is a long stichodyad. The three adoral organelles are of different types: ADI and AD3 are of the membranoid type, respectively with two and one rows of ciliated kinetosomes; AD2 is of the peniculus type with six-seven rows of ciliated kinetosomes. A microfibrillar network with nodes arises from all the buccal kinetosomes and extends under the naked wall. Mitochondria are small and numerous and dispersed throughout the whole cell. The existence of an AD2 with more than two rows of kinetosomes warrants the creation of the new genus Paraptychostomum and a new family, Ptychostomatidae. The presence of a distinct ecto-endoplasmic boundary and of somatic kinetids exclusive without transversal dense tractus, hyperdivergent postciliary ribbons, and dispersed numerous mitochondria, added to particularities of the stomatogenesis, allow us to clearly separate hysterocinetians from the scuticociliates and to set up for them the new subclass Hysterocinetia, within the class Oligohymenophorea, with a single new order Hysterocinetida.

Notes: SYNOPSIS. Holotrich ciliates from the stomach contents of Hippopotamus amphibius are described, including details of their infraciliature. They are placed in 4 families: subclass Holotrichia, order Gymnostomatida, suborder Rhabdophorina, family Buetschliidae: Blepharozoum binucleatum n.sp., Cucurbella vivax n.g., n.sp.; order Trichostomatida, family Plagiopylidae: Paraplagiopyla kiboko n.g., n.sp.; family Paraisotrichidae: Paraisotricha minuta Hsiung, 1930; family Blepharocorythidae: Charonina hippopotami n.sp. Paraisotricha minuta appears identical to the form found in the cecum and colon of the horse; Blepharozoum binucleatum, Cucurbella vivax and Charonina hippopotami also approach species found in the digestive tract of Equidae. By contrast, Paraplagiopyla kiboko resembles species that are free-living or are commensal in the digestive tract of Echinodermata.

Notes: Le cortex de la face dorsale (non ciliée) ne contient pas de cinétosomes; sous des alvéoles bien développés se trouve un épiplasme épais, puis une couche irrégulière de microtubules longitudinaux; de nombreux pores cylindriques traversent le cortex. La région ventrale, limitée aux faces internes des 2 lèvres apicales, porte la ciliature somatique répartie en 2 champs inégaux (droit 〉 gauche). Chaque cinétie somatique comporte une seule rangée de cinétosomes qui, tous, possèdent des formations fibrillaires associées: (a) dérivés classiques: fibres transverses, fibres postciliaires, fibre cinétodesmale; (b) une lame transverse gauche, dense, accompagnant les fibres transverses; (c) une couche de microtubules sous-cinétiens s'étendant vers l'avant de la cinétie.L'existence d'une ciliature buccale spécialisée est démontrée; elle consiste en une cinétie “circumorale” don l'infraciliature est faite de paires de cinétosomes (1 cilifère, l'autre non), que ne sont pas des dyades; de ce fait, cette infraciliature n'est pas l'equivalent de celle d'une membrane ondulante ou d'une parorale de Cilié des Ordres supérieurs. De plus, sa polarité antéro-postérieure est inversée par rapport à celle des cinéties somatiques, donc par rapport à celle du Cilié; elle est accompagnée sur sa droite par quelques cinéties somatiques (3 au maximum) qui sont également inversées; il est probable que ces inversions résultent de mouvements morphogénétiques identiques à ceux qui se produisent lors de la stomatogénese chez les Chlamydodontidae et les Dysteriidae. Aucune armature de némadesmes n'entoure le cytopharynx; ce dernier est soutenu par des rideaux de microtubules qui lui donnent un aspect feuilleté trèe particulier, et le phagoplasme qui l'accompagne renferme des tubules complexes (vermicelles).L'organisation du cortex dorsal est comparée à celle d'autres Ciliés de divers groupes. Les formations fibrillaires associées aux cinétosomes somatiques sont identiques à celles décrites chez des Chlamydodontidae, des Dysteriidae, certains Rhynchodina et les bourgeons ciliés de certains Acinétiens.La disposition et la constitution de l'infraciliature somatique, la présence et les caractéristiques d'une différenciation infraciliaire périorale (“circumorale”), l'aspect feuilleté de la paroi cytopharyngienne, la présence de tubules complexes (vermicelles) dans le phagoplasme, l'origine de l'appareil fixateur, l'héteromérie du macronoyau, sont autant de caractères communs avec les families Chlamydodontidae et Dysteriidae. Aussi, une révision systématique est envisagée, avec l'établissement de 2 sous-ordres, proches l'un de l'autre, et appartenant à l'ordre des Hypostomatida: S/O Chonotrichina et S/O Cyrtophorina (ce dernier limité aux seules families Chlamydodontidae et Dysteriidae).〈section xml:id="abs1-2"〉〈title type="main"〉SYNOPSISThe non-ciliated dorsal cortex is devoid of kinetosomes, but perforated with numerous pores; it contains large alveoli, an important epiplasm and an irregular sheet of longitudinal microtubules. The ventral side is confined to the internal faces of the 2 apical lips which bear 2 unequal fields of somatic ciliature (right 〉 left). A somatic kinety has only one line of kinetosomes, the associated fibers of which are: (a) classical derivatives: transverse, postciliary and kinetodesmal fibers; (b) a dense transverse spur, running along the transverse fibers; (c) a sheet of subkinetal microtubules extending forward along the kinety.The special buccal ciliature is a “circumoral kinety,” the infraciliature of which is composed of pairs of kinetosomes (1 ciliated, 1 nonciliated), which are different from dyades; so, this circumoral kinety is not homologous to the UM of ciliates included in superior orders. Furthermore, its anteroposterior polarity is inverse with regard to that of the somatic kineties and that of the cell; the circumoral kinety is accompanied by some inverse somatic kineties (maximum 3); all these inversions are probably the result of morphogenetic movements analogous to these which are described in the stomatogenesis of Chlamydodontidae and Dysteriidae. The wall of the cytopharynx is composed of overlapping sheets of microtubules. “Vermicelles” form the phagoplasm. Nemadesmata are absent.The dorsal cortical organization is compared with that of other ciliates. The fibers associated with somatic kinetosomes are identical to those of Chlamydodontidae, Dysteriidae, rhynchodine Ancistrocomidae, and ciliated buds of some Acineta.All the characteristics (somatic infraciliature and its derivates, cytopharyngeal wall, vermicelles, origin of the fixative apparatus, heteromerous macronucleus) are common for Chilodochona and the 2 families Chlamydodontidae and Dysteriidae. A revision of the systematics is envisaged, with the establishment of 2 new close suborders, belonging to the order Hypostomatida: S/O Chonotrichina and S/O Cyrtophorina (the last one with only the 2 familes: Chlamydodontidae, Dysteriidae).