scholarly journals Photobleaching and Recovery of Symbiodiniaceae Effrenium voratum SCS01 Reveals Life Form Transformation Under Thermal Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Sanqiang Gong ◽  
Gang Li ◽  
Xuejie Jin ◽  
Dajun Qiu ◽  
Jiayuan Liang ◽  
...  

Dinoflagellates in the family Symbiodiniaceae contain a number of species and play an important role in the establishment of coral reef ecosystems in oligotrophic marine waters. Effrenium voratum is likely an exclusively free-living and heterotrophic species of Symbiodiniaceae. How this species responds and acclimates to warming is largely unknown. The present study experimentally established the phenotypic landscapes related to the photobleaching and recovery processes of Effrenium voratum SCS01 following thermal stress. We found that thermal stress bleached the plastids of E. voratum SCS01 and caused the cells to become lighter in color. Thereafter, the bleached cells recovered rapidly when they returned to the optimal temperature. The dominant life form of E. voratum SCS01 shifted from mastigote cells to coccoid cells then returned to mastigote cells. Transcriptome analysis revealed that the photobleaching of E. voratum SCS01 was due to increased degradation and decreased biosynthesis of photosynthetic pigments. The thermally induced life form changes were related to the downregulation of genes for cell motility. Our results revealed the mechanism of photobleaching in E. voratum SCS01 and indicated life form transformation as a newly identified survival strategy of Effrenium voratum SCS01 under thermal stress.

2021 ◽  
pp. 269-278
Author(s):  
M. Lenguas Francavilla ◽  
L. Negrete ◽  
A. Martínez-Aquino ◽  
C. Damborenea ◽  
F. Brusa

Girardia Ball, 1974 is the most diverse and widely distributed genus of the family Dugesiidae (Platyhelminthes: Continenticola) in the Neotropical region. Seven out of the 52 species of the genus are known for Argentina. The Somuncurá Plateau is a region in northern Patagonia with several endemic flora and fauna, but little is known about the free-living Platyhelminthes. We describe two new species of Girardia partially inhabiting in sympatry in the Somuncurá Plateau: Girardia somuncura sp. nov. and Girardia tomasi sp. nov. The identification criteria that we followed was an integrative taxonomic approach based on morphological and molecular data. Thus, we used anatomical features focused on the reproductive system, together with a phylogenetic analysis, using a mitochondrial (COI barcode region) genetic marker. This study is the first phylogenetic analysis of the genus Girardia in which we include the southernmost representatives of America here described, thus making it possible to incorporate them in global phylogenies.


Zoosymposia ◽  
2021 ◽  
Vol 20 ◽  
Author(s):  
LIANA JOHANN ◽  
GUILHERME LIBERATO DA SILVA

The family Tydeidae consists of small, free-living, soft-bodied mites with a diversity of feeding habits, including phytophages, pollen feeders and even predators, but the majority are scavengers or fungivores. Approximately 330 species in 30 genera have been described from throughout the world, but only a few species (<1% of all species) have been studied for their life history. This review provides a survey of their life history with a focus on their lifespan.


2012 ◽  
Vol 81 (3) ◽  
pp. 125-146 ◽  
Author(s):  
Francesca Benzoni ◽  
Roberto Arrigoni ◽  
Fabrizio Stefani ◽  
Bastian T. Reijnen ◽  
Simone Montano ◽  
...  

The scleractinian species Psammocora explanulata and Coscinaraea wellsi were originally classified in the family Siderastreidae, but in a recent morpho-molecular study it appeared that they are more closely related to each other and to the Fungiidae than to any siderastreid taxon. A subsequent morpho-molecular study of the Fungiidae provided new insights regarding the phylogenetic relationships within that family. In the present study existing molecular data sets of both families were analyzed jointly with those of new specimens and sequences of P. explanulata and C. wellsi. The results indicate that both species actually belong to the Cycloseris clade within the family Fungiidae. A reappraisal of their morphologic characters based on museum specimens and recently collected material substantiate the molecular results. Consequently, they are renamed Cycloseris explanulata and C. wellsi. They are polystomatous and encrusting like C. mokai, another species recently added to the genus, whereas all Cycloseris species were initially thought to be monostomatous and free-living. In the light of the new findings, the taxonomy and distribution data of C. explanulata and C. wellsi have been updated and revised. Finally, the ecological implications of the evolutionary history of the three encrusting polystomatous Cycloseris species and their free-living monostomatous congeners are discussed.


Zootaxa ◽  
2018 ◽  
Vol 4527 (3) ◽  
pp. 381 ◽  
Author(s):  
FABRICIO H. SANTOS ◽  
CRISTINA A. RHEIMS

Spiders of the family Philodromidae are free-living active predators, with laterigrade legs, eyes without tubercles, two tarsal claws and claw tufts. Although very common in zoological collections, their systematics is poorly known, especially in the Neotropics, and their specimens are usually identified only at family level. In this paper, the genus Gephyrellula Strand, 1932 is revised and the type species, G. violacea (Mello-Leitão, 1918) is redescribed and illustrated. Gephyrellula paulistana (Soares, 1943) is considered a junior synonym of G. violacea and thus, the genus becomes monotypic. In addition, the geographical distribution is extended and an updated distribution map is provided. 


2019 ◽  
Vol 21 (1) ◽  
pp. 3 ◽  
Author(s):  
Saura R. Silva ◽  
Ana Paula Moraes ◽  
Helen A. Penha ◽  
Maria H. M. Julião ◽  
Douglas S. Domingues ◽  
...  

Utricularia belongs to Lentibulariaceae, a widespread family of carnivorous plants that possess ultra-small and highly dynamic nuclear genomes. It has been shown that the Lentibulariaceae genomes have been shaped by transposable elements expansion and loss, and multiple rounds of whole-genome duplications (WGD), making the family a platform for evolutionary and comparative genomics studies. To explore the evolution of Utricularia, we estimated the chromosome number and genome size, as well as sequenced the terrestrial bladderwort Utricularia reniformis (2n = 40, 1C = 317.1-Mpb). Here, we report a high quality 304 Mb draft genome, with a scaffold NG50 of 466-Kb, a BUSCO completeness of 87.8%, and 42,582 predicted genes. Compared to the smaller and aquatic U. gibba genome (101 Mb) that has a 32% repetitive sequence, the U. reniformis genome is highly repetitive (56%). The structural differences between the two genomes are the result of distinct fractionation and rearrangements after WGD, and massive proliferation of LTR-retrotransposons. Moreover, GO enrichment analyses suggest an ongoing gene birth–death–innovation process occurring among the tandem duplicated genes, shaping the evolution of carnivory-associated functions. We also identified unique patterns of developmentally related genes that support the terrestrial life-form and body plan of U. reniformis. Collectively, our results provided additional insights into the evolution of the plastic and specialized Lentibulariaceae genomes.


2012 ◽  
Vol 723 ◽  
pp. 275-279
Author(s):  
Jian Chen ◽  
Gui Cheng Wang ◽  
Wei Song ◽  
Gang Liu

The principle of the HSK shrink toolholder is expanding with heat and contracting with cold. The heat performance of HSK is analyzed. Firstly, the induction heating performance is studied by using electromagnetism-thermal-structure FEA in ANSYS software and experiment, the optimal temperature of HSK shrink toolholder is got. Secondly, thermal fatigue and calculation of the fatigue life is analyzed by using thermal-stress in ANSYS software and Coffin-Manson formula. The loads applied on the FEA model are temperature during the cycle of heating and cooling.


Zootaxa ◽  
2017 ◽  
Vol 4250 (4) ◽  
pp. 347
Author(s):  
ANTONELA MARTELLI ◽  
VIRGINIA LO RUSSO ◽  
GABRIELA VILLARES ◽  
CATALINA T. PASTOR DE WARD

Two new free-living marine nematodes of the family Oxystominidae are described from San Antonio Bay (Río Negro) and San José Gulf (Chubut). Litinium australis sp. n., is characterized by having a rounded tail, by the first and second crown of cephalic setae with different lengths, gubernaculum with apophysis and by the presence of at least four precloacal papillae; Thalassoalaimus nestori sp. n., is characterized by having a conical tail, cephalic setae equal in length, gubernaculum with rounded and dorso-caudally directed apophysis and two precloacal papillae. An emended diagnosis of the genus Thalassoalaimus and a key to species are given. 


2019 ◽  
Vol 24 (10) ◽  
pp. 2369-2394 ◽  
Author(s):  
Diana Rueda-Ramírez ◽  
Jandir C. Santos ◽  
Nazer Famah Sourassou ◽  
Peterson R. Demite ◽  
Andrés Puerta-gonzález ◽  
...  

Morphological details of specimens collected from several localities in Brazil and identified as Africoseius lativentris (Karg 1982) are provided. The taxonomic position of Africoseius Krantz, 1962 has been debated over the years, with repeated changes in its familial placement. A phylogenetic study based on 18S and 28S rDNA sequences of the Brazilian population of A. lativentris collected at Jaboticabal, São Paulo State, and similar data of 70 taxa representing 11 families of Gamasina indicated that Africoseius is a member of the well-supported Podocinidae (sensu Lindquist et al. 2009) clade. The main morphological similarities and differences between Africoseius and the group of species until now placed in Podocinidae sensu Lindquist et al. (2009) are listed. Apomorphic characteristics uniting those taxa include the hypotrichous condition of tibia I (eight and nine setae instead of ten or more in other free-living Gamasina) and the insertions of av2 and pv2, considerably more distal on tarsi II and III than in the majority of the free-living Gamasina. Within Podocinidae, a new subfamily, Africoseiinae, is proposed, based on uniquely apomorphic characteristics of the setae ad4 and pd4 (sensu  Evans 1969) of tarsi II–IV absent, and setae av4 and pv4 of same basitarsi long, incurved and close to each other and to a posterior longitudinal extension of the peripodomeric suture and on the attenuated form of the lateral (rather than the medial) hypostomatic setae. This subfamily is currently represented by Africoseius areolatus Krantz and Africoseius lativentris (Karg 1982), while all other presently known species of the family are now placed in the subfamily Podocininae.


Zootaxa ◽  
2020 ◽  
Vol 4763 (3) ◽  
pp. 354-370
Author(s):  
GABRIEL CIDREIRA ◽  
VIRÁG VENEKEY ◽  
ORANE F. DE SOUZA ALVES ◽  
FRANCISCO KELMO

A new free-living marine nematode of the family Xyalidae is described from Armação Beach, northeastern Brazil, and the genus Pseudosteineria is reviewed. Pseudosteineria longisetis sp. n. is characterized by having six groups of long subcephalic setae, amphids situated slightly anterior to the groups of subcephalic setae or at the level of the first subcephalic setae, long somatic setae located posteriorly to subcephalic setae and distributed along the body, one papiliform precloacal supplement, and gubernaculum with dorso-caudal apophysis. An emended diagnosis of the genus, an updated list of species and dichotomous identification key, and a pictorial key are given. A comparative table including the main characters of all Pseudosteineria species is also provided. 


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