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| Author(s): |
Beatriz Pereira Cunha
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2023-04-28 |
| Examining board members: |
Antonia Cecília Zacagnini Amaral;
Maikon Di Domenico;
Thais Navajas Corbisier;
Fabiane Gallucci;
André Rinaldo Senna Garraffoni
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| Advisor: | Antonia Cecília Zacagnini Amaral |
| Abstract | |
Phylum Nematoda is characterized by huge taxonomic, ecological, and geographic diversity, and by an astronomical number of individuals. Despite its ecological importance, the taxonomic knowledge about the group is limited mainly due to the lack of knowledge about morphological homology and specialists. Cyatholaimidae Filipjev, 1918 is a family composed of relatively common and abundant taxa in marine environments. As with other groups of marine nematodes, the identification of organisms is challenging due to the overlapping of some diagnoses and the lack of knowledge about the evolutionary history of the group. The present work aimed to carry out a taxonomic review of the family and evaluate the morphological and molecular data, seeking to understand the phylogenetic relationships within the group, as well as describe the new species identified, increasing the knowledge of marine biodiversity in the São Paulo State. The taxonomic review of Cyatholaimidae here presented revealed 20 genera and 211 species considered valid. In the bibliographic survey carried out, it was found 619 records of species around the world, mainly in the intertidal and sublittoral regions of beaches and rocky shores. Additionally, there are species of Cyatholaimidae found in freshwater and terrestrial environments, all classified in the genus Paracyatholaimus. A critical analysis of the geographic distribution and habitat patterns of these species was elaborated, together with some future perspectives on the study of these taxa. Phylogenetic analyzes based on the SSU and LSU rDNA regions indicated the close relationship between Paracanthonchus, Paracyatholaimus, and Praeacanthonchus, which, despite not reflecting the current classification, agrees with the initial proposal for delimiting the subfamily Paracanthonchinae. The tubular-shaped precloacal supplement and the transversely oriented opening of the pore complex are likely synapomorphies of this clade. The paraphyly of Cyatholaiminae was confirmed and the validity of Pomponematinae has not been verified due to the low number of sequences available. The present study presents the redescription of two species (Paracanthonchus cochlearis Gerlach, 1957 and Paracyatholaimus vitraeus Gerlach, 1957) and the description of three new species (Biarmifer nesiotes Cunha, Fonseca & Amaral, 2023, Pomponema longispiculum Cunha, Fonseca & Amaral, 2023 and Longicyatholaimus sp. nov.), expanding the number of records in the country to 14 genera and 23 species of Cyatholaimidae (AU) | |
| FAPESP's process: | 17/21986-2 - Diversity of free-living marine nematodes: integrative taxonomy of family Cyatholaimidae |
| Grantee: | Beatriz Pereira Cunha |
| Support Opportunities: | Scholarships in Brazil - Doctorate |