Banca de DEFESA: Angie Patiño Montoya

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Angie Patiño Montoya
DATE: 16/02/2023
TIME: 09:00
LOCAL: Meio virtual
TITLE:

Response of the giant African snail (Lissachatina fulica, Bowdich 1822) to global, regional and local climate variation and to resource variation

KEY WORDS:

Achatina fulica, geometric morphometry, life history, realized climatic niche, resource availability.

PAGES: 131
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Nonnative populations of an invasive species must face obstacles during their transport, introduction, establishment, and dispersal. Climate and resource availability represent some of these obstacles. The response of nonnative populations to climate will depend on the realized climatic niche of the species. With respect to resource availability, the response will depend on how the life history attributes of the organisms react to variations in resources. The giant African snail (Lissachatina fulica, Bowdich 1822) is a mollusk native to East Africa and classified as invasive. Nonnative populations of L. fulica occur throughout the tropical region of the world and are recognized for their wide climatic tolerance and association with humans. This thesis aims to evaluate the response of the giant African snail (L. fulica) to global, regional, and local climate variation and resource variation. In the first chapter, through a systematic literature review, the attributes that define the invasive potential of L. fulica and the characteristics of the sites where it occurs are identified. In the second chapter, by modeling the potential distribution, the expansion of the climatic niche of L. fulica is evaluated as a function of its dispersal around the world. In the third chapter, through multivariate ordination analysis, the variation in L. fulica population density in climate and intervention in the Neotropical region is evaluated. In the fourth chapter, through fieldwork, we evaluate how the nonnative population of L. fulica located in the Brazilian Federal District (DF) responds to small variations in climate and the presence or absence of resources. In the fifth chapter, through the morphometric evaluation of L. fulica growth in the laboratory, a new method for the identification of hermaphroditic individuals is proposed. The systematic review showed fragmented knowledge about the attributes of L. fulica and almost no knowledge about where it occurs. Potential distribution modeling showed that the realized climatic niche of L. fulica has changed since its dispersal from Africa, in part by its trajectory along different biogeographic regions. Multivariate ordination analysis showed that the population density of L. fulica in the Neotropics responds to specific combinations of temperature and precipitation but not intervention. Fieldwork with the DF population of L. fulica showed that the percentages of dead individuals and of individuals with eggs respond to maximum temperature and minimum relative humidity. Regarding resources, the results obtained in the field show that population density responds to the presence of soil and that the percentage of hermaphrodites responds to the percentage of builtup area. The morphometric evaluation of the shell of L. fulica pointed to a shell length range where the transition to hermaphrodites probably takes place and suggests two morphological indices that aim to identify individuals who have already gone through this transition. These results open the door to the development of multiple lines of knowledge generation on nonnative populations of L. fulica, making it possible to optimize management strategies.

BANKING MEMBERS:
Externo à Instituição - Roberto Eugênio Vogler - CONICET
Externa à Instituição - Silvana Aparecida Rogel Carvalho Thiengo - Fiocruz
Interna - 1365470 - ISABEL BELLONI SCHMIDT
Interno - 1143936 - MIGUEL ANGELO MARINI
Presidente - 1194783 - ROSANA TIDON