293 research outputs found
The Evolutionary Reorganization of Ontogeny and Origin of Multicellularity
The formation of morphogenetic mechanisms during emergence of multicellularity is discussed
in this article
A hydrothermal vent mite (Halacaridae, Acari) with a new Corynophrya species (Suctoria, Ciliophora), description of the suctorian and its distribution on the halacarid mite
Copidognathus nautilei Bartsch, 1997, from a hydrothermal vent field of the Mid-Atlantic Ridge at about 13 degrees N, 45 degrees W and 4090 m depth, was infested with the suctorian Corynophrya abyssalis n. sp., with up to 58 epizoans per mite. The new suctorian has a sacciform body with seven longitudinal ribs, a compact macronucleus and up to 40 non-retractile tentacles. The budding is exogenous. The systematic position of the new species and the genus Corynophrya is discussed, as well as infestation rates and sites of suctorians on their halacarid hosts
Suctorian ciliates (Ciliophora, Suctorea) as epibionts of stream-dwelling aquatic beetles (Coleoptera) and water mites (Acari: Hydrachnidia) in the southwestern Palaearctic region
Based on original data from recent research, numerous new records of the suctorian species living as epibionts on streamdwelling
aquatic beetles (Coleoptera) and water mites (Acari, Hydrachnidia) in the southwestern Palaearctic area are given.
The following species are reported for the first time for the national faunas: Setodiscophrya deplanata (Matthes, 1954)
(Bosnia and Hercegovina, Montenegro, Serbia, Bulgaria, Turkey), Discophrya helmidis Matthes, 1954 (Montenegro, Turkey),
Elatodiscophrya hochi (Matthes, 1954) (Bosnia and Hercegovina, Turkey), Periacineta buckei (Kent, 1881) (Montenegro,
Greece), Discophrya lichtensteinii (Claparede & Lachmann, 1859) (Turkey, Iran). The characteristics of the
suctorians as epibionts of stream-dwelling arthropods are briefly outlined
Polynomial tuning of multiparametric combinatorial samplers
Boltzmann samplers and the recursive method are prominent algorithmic
frameworks for the approximate-size and exact-size random generation of large
combinatorial structures, such as maps, tilings, RNA sequences or various
tree-like structures. In their multiparametric variants, these samplers allow
to control the profile of expected values corresponding to multiple
combinatorial parameters. One can control, for instance, the number of leaves,
profile of node degrees in trees or the number of certain subpatterns in
strings. However, such a flexible control requires an additional non-trivial
tuning procedure. In this paper, we propose an efficient polynomial-time, with
respect to the number of tuned parameters, tuning algorithm based on convex
optimisation techniques. Finally, we illustrate the efficiency of our approach
using several applications of rational, algebraic and P\'olya structures
including polyomino tilings with prescribed tile frequencies, planar trees with
a given specific node degree distribution, and weighted partitions.Comment: Extended abstract, accepted to ANALCO2018. 20 pages, 6 figures,
colours. Implementation and examples are available at [1]
https://github.com/maciej-bendkowski/boltzmann-brain [2]
https://github.com/maciej-bendkowski/multiparametric-combinatorial-sampler
Biotopic distribution of naked amoebas (protista) in ukrainian polissya area
Forty-one species of naked amoebas were found in the different types of waterbodies of
Zhytomyr and Volyn’ parts of Ukrainian Polissya region. The major part of species of naked amoebas
in this region demonstrated the prevalence to living in a certain type of water body that possible depends
on the hydrochemical and trophic parameters of water. The limnetic and floodplain species complexes
of amoebas are distinguished in Ukrainian Polissya
An overview of Suctorian ciliates (Ciliophora, Suctorea) as epibionts of halacarid mites (Acari, Halacaridae)
Scant information is available regarding the prevalence and distribution of suctorian ciliates on halacarid mites. However,
using this limited information and data from our laboratory on the systematics, biology, ecology and distribution of
suctorian ciliates that are epibionts of halacarid mites, we redescribed four suctorian species: Limnoricus ceter (Jankowski),
Praethecacineta halacari (Schulz), Thecacineta calix (Schroder) and Acineta sulcata Dons. We also recognized
Lissacineta allgeni Jankowski and Thecacineta allgeni (Jankowski) as synonyms of Praethecacineta halacari (Schluz),
and Thecacineta laophontis Jankowski and Paracineta moebiusi Kahl as synonyms of Thecacineta calix (Schroder).
Many suctorians have been reported, but not properly identified in the halacarid literature. So, we have attempted to
identify those suctorians to species level. Lastly, the interactions between the suctorians and their hosts are also discussed
and Praethecacineta halacari is also reported for the first time from the Indian coast
New Records of Thecacineta cothurnioides and Trematosoma rotunda (Ciliophora, Suctorea) as epibionts on nematodes from the Indian Ocean
This article deals with the report of two suctorian ciliates species viz. Thecacineta
cothurnioides Collin, 1909 and Trematosoma rotunda (Allgén, 1952 ) as epibionts
on Tricoma sp. and Pseudochromadora sp. (Nematoda) respectively from Ratnagiri,
west coast of India, Arabian Sea (Indian Ocean). Redescription of two species with
distribution and nomenclatural notes are given. Both species are recorded here first
time from Indian coast and the Indian Ocean. Genus Tricoma Cobb, 1894 is also
recorded here first time as a host of Th. cothurnioides
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