New Species of Lagenophrys (Ciliophora,Peritrichia) from New Zealand and Australia1

Lagenophrys novazealandae n. sp. occurs on the gills of Paranephrops zealandicus, a parastacid crayfish from New Zealand. The new species has the hemispheroidal lorica most common among members of its genus and is distinguished by its possession of large tubercles on the thickened edge of the anterior lip of the lorica aperture, a deep cleft in the left side of the lip's edge, and a ovoid to reniform macronucleus located in the right-hand part of the body. It is probable that an as yet unnamed species of Lagenophrys known to occur on another species of Paranephrops in New Zealand is distinct from L. novazealandae but phylogenetically related to it. Lagenophrys petila n. sp. occurs on setae of Parastacoides tasmanicus, a parastacid from Tasmania. The new species has an ovoid lorica tapering to a slender pseudostalk at the posterior end, a type of lorica possessed by only two other members of its genus that also attach to their host's setae. It is distinguished from the other ovoid species by the proportions of the lorica, the extreme shortness of the lips of the lorica aperture, and an ovoid macronucleus located in the right, anterior part of the body. Clefts in the lips of L. novazealandae and other members of Lagenophrys may function as points of flexure to allow the lips to bend in ways that accommodate interspecific differences in the size of the epistomial disk and its operation during suspension feeding.     

Revision of the Family Lagenophryidae Bütschli, 1889 and Description of the Family Usconophryidae N. Fam. (Ciliophora,Peritricha)1

Ten species of lagenophryid peritrichs in three genera are redescribed or described for the first time. Based on this information, the family Lagenophryidae was found to consist of five genera: Lagenophrys, Paralagenophrys, Clistolagenophrys n. g., Setonophrys, and Operculigera. Lagenophryid genera differ in gross structure of the lorica aperture and the peristomial sphincter associated with it. Shape of the lorica and mode of attachment to the host are not generic characteristics in the Lagenophryidae. Differences in shape evolved within each of the three largest lagenophryid genera merely as adaptations for attachment to different parts of a host. Usconophrys, formerly in the Lagenophryidae, and Cyclodonta are assigned to the family Usconophryidae n. fam., which is characterized by possession of a lorica, lack of a closure apparatus operated by the peristomial sphincter, and possession of an operculariform peristome. Lagenophrys, Setonophrys, and Paralagenophrys appear to have evolved separately and convergently from ancestors within Operculigera. Lagenophryid lorica apertures consisting of opposing lips probably evolved as tight seals to prevent water loss when the host is temporarily out of water. The greater diversity and wider distribution of Lagenophrys compared with other lagenophryid genera may result from an advantage in recolonizing hosts conferred by second-type division.     

Redescription of Lagenophrys eupagurus Kellicott (Ciliophora, Peritricha, Lagenophryidae) and a Comparison of It with Three Similar Species

Lagenophrys eupagurus , a poorly known loricate peritrich ectocommensal on the hermit crab Pagurus longicarpus , has been rediscovered and is redescribed. Lagenophrys lunatus and L. articularis were found to be conspecific with L. eupagurus based on close similarities, especially with regard to structure of the lorica aperture and proportions of the lorica. Lagenophrys callinectes , although resembling L. eupagurus , was determined to be a separate species because of distinct, consistent differences in structure of the lorica aperture and proportions of the lorica. Lagenophrys eupagurus and L. callinectes share some features of the lorica aperture with 3 other species of Lagenophrys , prompting the speculation that the 5 species may constitute a cluster of related species within the genus. Lagenophrys eupagurus utilizes a relatively wide variety of hosts compared to other species of Lagenophrys and appears to subsist mainly on phytoplankton. In some cases, the feeding behavior of the host may assist L. eupagurus in obtaining food. Lagenophrys callinectes appears to be restricted to brachyuran crabs of the genus Callinectes. It appears to be a bacterivore and is probably assisted in obtaining food by the preference of its hosts for estuarine areas that are rich in organic material.     

Choanoflagellates (Sarcomastigophora, Protozoa) from the Coastal Waters of Taiwan and Japan. I. Three New Species

Three new acanthoecidaean species collected from the coastal waters of Taiwan and Japan are described: Acanthocorbis camarensis n. sp. resembles Acanthocorbis unguiculata in lorica morphology, but differs in having regularly arranged longitudinal and transverse costae at the anterior lorica chamber, and in lacking a nail at the apical end of anterior spine; Diaphanoeca spiralifurca n. sp. is characterized by the spiral arrangement of the costal strips in the posterior half of the lorica chamber and is closely related to Diaphanoeca grandis; Stephanoeca supracostata n. sp. is closely related to Stephanoeca elegans, but differs in having an additional transverse costa at the anterior lorica chamber.     

Pollen size in Carex: The effect of different chemical treatments and mounting media

Pollen size and pollen aperture size for ten species of the genus Carex L., native to Estonia, have been measured using light microscopy. The species selected represent different sections of the genus, a range of habitats and different chromosome numbers. The effects of two basic chemical treatments, two mounting media and the effect of chemically induced dehydration with tertiary butyl alcohol (TBA) on the size of pollen grains were then recorded.

In general pollen size and pollen aperture size of the species examined is highly variable at both intraspecific and interspecific levels. Carex hirta has notably larger pollen grains than any of the other species investigated and, although correlations between size and chromosome number in the species examined are limited, it also has the highest chromosome number. Statistically significant size differences resulted from variations in chemical treatment, mounting media and tertiary butyl alcohol (TBA) induced dehydration. Acetolysed pollen grains are larger than potassium hydroxide (KOH) treated pollen grains. Pollen grains dehydrated after chemical treatment with TBA are larger than pollen grains not dehydrated. Pollen grains mounted in silicon oil are smaller than grains mounted in glycerine. But considering the great size variation of Carex pollen grains, the size changes caused by preparation procedures fall within the size variation range of the species examined.

All the samples contained a high number of deformed pollen grains and pollen grains with hardly distinguishable or no lateral apertures.     

Studies in Montia L. and Claytonia L. and Allied Genera

The pollen morphology of several genera in Portulacaceae is described. Particular attention has been paid to the genera of the subfamily Montioideae, as a stage of continued monographical studies. Among genera especially dealt with are Claytonia, Montia, Crunocallis, Naiocrene, Neopaxia, Mona, Maxia, Limnalsine, and Montiastrum. In the taxonomical treatment of these genera the pollen morphology has proved to afford many important additional characters.

The pollen grains of Claytonia are distinguished from those of the remainder in being 3-colpate. The grains of the Claytonia-type have many similarities with those of Lewisia, a genus of the subfamily Portulacoideae. The other genera of Montioideae have pantocolpate pollen grains. Among these genera several different pollen types are distinguished, chiefly with regard to the sexine structures and the aperture membranes. The Montiastrum-type is especially interesting, with tholate grains, a particular pollen type not met with in any other genus in the family. The pollen morphology of some genera in the Portulacoideae is also treated. In some species in Calandrina and Talinum pantotreme pollen grains are observed with apertures transitional between pori and colpi. The apertures of the pantotreme grains are arranged in characteristic patterns.

Particular attention has been given to the variation of the pollen morphological characters. This variation has been examined with regard to the differences between different populations of the same species as well as between different species. The greatest variation has been observed in the shape and size of the grains. The structure and sculpture and thickness of the sexine and the aperture membranes are less variable. Some polyploid taxa are connected with the occurrence of pollen grains with divergent and varying aperture numbers.

In a survey of the genera the taxonomical results of the investigation are presented with particular regard to the pollen morphology. The new genus, Maxia Ö. Nilss., is described. One new species, Montia clara Ö. Nilss., is described and some new combinations are made.

Pollen morphological diagnoses are given for 46 different taxa. The aperture conditions for 96 different species are presented.     

Morphological Form Variation in a Loricate Rotifer,Keratella tropica APSTEIN from a Perennial Pond,Janaktal, Gwalior,India

Morphological form variation in a loricate rotifer, Keratella tropica APSTEIN is decribed. Form variation in this rotifer involves appearance and development of the left postero-lateral spine. The right postero-lateral spine varies, too. It increases with increasing length of lorica and left postero-lateral spine. Three morphological forms, viz. reducta, asymmetrica and heterospina are recognized.     

Lorica Construction in Eufolliculina sp. (Ciliophora,Heterotrichida)1

ABSTRACT. The structure and ultrastructure of the chitinous lorica of Eufolliculina sp. are described. The lorica is produced from precursor material secreted by the motile swarmer immediately after settling. This material is located in numerous vesicles found in the cortical region of the cells and is secreted by exocytosis. Initially, material is secreted from the ventral part of the cell to produce the attachment plate of the lorica. After this, exocytosis occurs over most of the body surface as the ampulla part of the lorica is constructed. During the later stages of lorica formation, secretion is mainly limited to the anterior of the cell as the neck is formed. The lorica is shaped mainly by the action of the cilia and by the behavior of the cell. While the neck is being formed, the anterior part of the cell is deformed by a local accumulation of cytoplasmic vacuoles. This deformation is employed in shaping the neck. No changes were detected in the organization of the cortical infraciliature during the first stages of lorica formation, but they do occur after the neck has been produced and as the swarmer develops into the sessile form.     

Morphological Variation of <Emphasis Type="Italic">Keratella cochlearis</Emphasis> (Gosse) in a Backwater of the River Thames

The morphological variation of Keratella cochlearis in a Thames backwater has been studied over 4 years. There was a general inverse relationship between lorica length and temperature, but the annual cycle of change depended upon the rate of change of the temperature, and there was considerable variation between years. There was a similar inverse relationship between posterior spine length and temperature, and a shift in both relationships depending on whether the temperature was increasing or decreasing. As the water temperature increased from winter to summer the lorica and posterior spine were longer than at the same temperature as the water cooled from summer to winter. This shift can be modified by anomalous temperatures, such as a late spring or a cool summer.The form lacking a posterior spine usually, but not consistently, had a longer lorica than the typical spined forms. It usually disappeared from the samples at the end of November and did not reappear until March, although with a mild autumn and winter it persisted until January before disappearing. Forms without posterior spines did not all have the same origins.     

A Light and Scanning Electron Microscopic Study of the Closing Apparatus in Tintinnid Ciliates (Ciliophora,Spirotricha, Tintinnina): A Forgotten Synapomorphy

ABSTRACT. A membranous closing apparatus shuts the lorica opening in disturbed tintinnids of six genera belonging to four families. The homology of the apparatuses is investigated, using data from the literature and Mediterranean tintinnids studied in vivo and by scanning electron microscopy. Morphological and functional similarities indicate that the foldable closing apparatus is not only a synapomorphy of the genera Codonella (Codonellidae) and Dictyocysta (Dictyocystidae), as suggested 80 years ago, but also of Codonaria (Codonellidae) and Codonellopsis (Codonellopsidae). In Codonaria, Codonella, and Dictyocysta, the apparatuses merge posteriorly into membranous lorica sacs, which probably represent homologous structures. The diagnoses of these genera are improved according to the new findings. The close relationship of Codonella, Codonellopsis, and Dictyocysta is also inferred from small subunit rRNA phylogenies and the ultrastructure of the capsules. It contradicts the current lorica‐based classification of the tintinnids. The assumption that the diaphragm‐like apparatus in the genera Salpingacantha and Salpingella is not homologous to the foldable ones in the genera mentioned above is supported by molecular and cytological features.     

Keratella cochlearis (Gosse) in Africa

Keratella cochlearis occurs over the complete latitudinal range of Africa, and over a considerable altitudinal range, but not in the highest mountain tarns. Physical, chemical, and biological factors may affect the distribution of this species. Lack of suitable food, and competition or predation by larger zooplankters are probably important limiting factors. Morphometric variation in samples from Zimbabwe is much less than in samples from the Auvergne. In particular, posterior spine length shows a much lower relative growth in relation to lorica size.     

Ultrastructural and Protargol Studies of Lagenophrys callinectes* (Ciliophora: Peritrichida)

Ultrastructural and protargol studies reveal that the trophont of Lagenophrys callinectes, though highly specialized, generally conforms to the basic peritrich structural pattern. Features described for L. callinectes trophonts which are unique for the genus are the fine structure and arrangement of the lorica and lips, the attachment organelle of the peristomial cytoplasm, its attachment to the loricastome walls, and the arrangement of the aboral kinetosomes of the trophont. Lack of a distinct scopularized region, and of a ventral lorica wall also characterize L. callinectes trophonts. The 4-row terminal peniculus, as revealed by protargol staining, differs from the 6-row terminal peniculus of L. nassa suggesting that the patterns of infundibular structure, as revealed by protargol, should be useful in future taxonomic studies of Lagenophrys species.     

Allozyme and shell variation in two marine snails (Littorina, Prosobranchia) with different dispersal abilities

As adults Littorina littorea and L. saxatilis have overlapping distributions, both on the shore and on a geographical scale, this implies that they are affected by similar selective forces to a large extent. The two species have, however, different reproductive strategies. Littorina littorea has a planktonic larval stage lasting 4–6 weeks, whereas L. saxatilis has direct development. This influences dispersal rates of the two species, and gene flow and effective population size are both assumed to be much smaller in L. saxatilis than in L. littorea. Intraspeciflc variation in morphological and allozyme characters differs between the two species. Littorina littorea is homogeneous for both types of characters, both within and between populations, while populations of L. saxatilis may show pronounced differences in shell characters with micro-environment changes, and allozyme variation is markedly higher in this species too. The polymorphism in shell characters of L. saxatilis and the monomorphism of L. littorea, may be expected from theory as a consequence of the different dispersal strategies. Also the lack of divergence between geographically separate populations of L. littorea, but the high degree of between population differentiation in L. saxatilis, could be attributed to the high and low dispersal rates, respectively. However, the larger allozyme variation within subpopulations of L. saxatilis compared to that of L. littorea, is surprising as the former species has a smaller effective population size than the latter. Furthermore, there is no correlation between dispersal ability and overall allozyme heterozygosity, when 10 additional species of Littorina are included in the comparison. It is suggested that different evolutionary backgrounds of different species will possibly explain this, as neither selectionist nor neutralist models alone account for the observation. That is, an earlier passage through a population bottleneck may, for example, influence the genetic variation for a long period of time.     

LIFE HISTORY AND TAXONOMY OF RHIZOOCHROMONAS ENDOLORICATA GEN. ET SP. NOV., A NEW FRESHWATER CHRYSOPHYTE INHABITING DINOBRYON LORICAE1

The life cycle of a previously undescribed chrysophyte, assigned to the new genus Rhizoochromonas, is described. It includes a small motile stage with heterokont flagellation which invades a Dinobryon lorica. Reproduction by cell division of the nearly spherical rhizopodial vegetative stage frequently leads to expulsion of the host protoplast through overcrowding of the lorica. Endogenous cysts (stomatocysts) are also formed within the Dinobryon lorica. The new family, Brehmiellaceae, is established to accommodate pseudopodial/rhizopodial chrysophytes with heterokont flagellation in the motile stage. Rhizoochromonas endoloricata gen. et sp. nov. has been found at two widely separated softwater locations in Ontario, and at one it constituted a major component of the planktonic flora during the autumns of six successive years.