The purpose is not to provide an exhaustive overview of the topics. Contact Eric Parmentier for more details and redirection to the project managers. Other topics may be available within the laboratory, they are discussed in advance between the sponsor and the candidate.
Structural characterization of Onuxodon fowleri (Carapidae) rocker bone
Fish of the genus Onuxodon (Carapidae) have a skeletal piece in their swim bladder responsible for producing sounds. Although this part is called "rockerbone", the preliminary results clearly indicate that it is not a bone and that this hard part would be the result of a stiffening of the swim bladder. The purpose of this work is to describe what is similar to a new type of skeletal structure and to understand how tissues could develop from the swim bladder. Similar work already done in another unrelated species may help to identify the subject. Parmentier et al. 2008. The rocker bone: a new kind of mineralised tissue? Cell and Tissue Research 334: 67-69.
Bioacoustics of catfish from Rio Paraopeba and Rio Araguari (Brazil)
Rio Paraopeba and Rio Araguari are part of the São Francisco and Paraná watersheds, two major watersheds in southeast Brazil, respectively. The proposed study focuses on the genera Bergiaria, Pimelodus, Lophiosilurus, Franciscodoras but especially on the genus Hypostomus. A large number of specimens of these catfish were recorded during a mission to Brazil in 2018. The proposed work consists of an acoustic analysis of these sounds to (1) describe them and (2) compare them. As the identification of species of the genus Hypostomus is known to be difficult, this work will test whether acoustics can be an adequate means to help differentiate them. In parallel, dissections will be carried out on some specimens in order to understand the structures involved in sound production.
Comparative study of the eco-morphological diversity of ichthyological lagoon communities of the Great Tulear Reef (Madagascar)
The Great Reef of Tulear (Madagascar) was known as one of the hotspots of marine diversity in the Indian Ocean during the 1970s and 1980s. However, anthropogenic pressure on this reef has been increasing over the past 40 years. Overfishing, for example, threatens fish stocks for artisanal fishing. In this context of global changes, this work will aim to compare the trophic and morphological diversity of several ichthyological lagoon communities of the Tulear Reef subjected to different levels of fishing pressure. The approach will be multiple, combining both isotopic and morphometric analyses. Several indices and various statistical methods will be applied to these data in order to best quantify the phenotypic diversity present within this disturbed ecosystem. The equipment necessary to carry out this work is already located in the Functional and Evolutive Morphology Laboratory, which ensures the feasibility of the project.
Morphological integration and modularity in damselfish fish (Pomacentridae)
Actinopterygian fish show extreme morphological disparity, particularly in their body shape. One hypothesis that could explain the diversity of their morphology is that it would be facilitated by a modular organization. According to this hypothesis, these "modules" would vary almost independently during ontogeny or evolution, facilitating the capacity for morphological diversification. The objective of this thesis will be to test this hypothesis in a family of teleosteal fish that have been highly successful in coral ecosystems: damselfish fish (Pomacentridae). The morphological diversity of these fish will be quantified using geometric morphometry at the family, population and ontogeny levels. Several tests and various statistical methods will be applied to verify the presence of such modules. The equipment necessary to carry out this work is already located in the Functional and Evolutive Morphology Laboratory, which ensures the feasibility of the project.
Study of sound production in Labridae fish
Acoustic communication has only very rarely been addressed in Labridae fish, although taxa are one of the richest in terms of biodiversity. In preliminary work, we were able to observe some sound-producing species during nest building and land defence. The purpose of this work is logically to be able to determine the behavioural contexts corresponding to sounds in certain Mediterranean Labridae fish species. The study will also aim to determine the mechanism used. This study, which involves several species, will require field trips over a period of 6 to 8 weeks.
Biology of sound production in Gobiidae Neogobius melanostomus
Synodontis catfish have the ability to emit sounds and electrical shocks from the same muscles. The purpose of this work is to compare its capacities in different species and to trace the nervous network from the muscle to the brain. The study can be completed by a study