Reproductive strategies and population genetics in Syngnathus abaster and other mediterranean syngnathids

Syngnathidae is a small teleost family well known for its unique form of parental care, where females deposit eggs into the male's specialized ventral incubating surface. Syngnathids are present in the Mediterranean sea with three genera: Nerophis, Syngnathus and Hippocampus. Among these, the genus Syngnathus have higher level of adaptability to different habitats (sea and brackish waters, and in some case even freshwaters) which determines, in some cases, different local morphotypes. The aim of this work is to clarify some aspects about the reproductive biology and populations structure of several Mediterranean Syngnathids and in particular Syngnathus abaster. In this thesis are present the followings articles:<br/> · mtDNA control region and D-HPLC analysis: a method to evaluate the mating system in Syngnathidae (Teleostei);<br/> · Sperm number and structure of the black-striped pipefish Syngnathus abaster (Teleostei,Syngnathidae);<br/> · Implication of male reproductive apparatus morphology for the insemination modality of the Syngnathus abaster ( teleosts, Syngnathidae);<br/> · Are pipefishes and seahorses inseminating species? Implication of male reproductive apparatus morphology in the syngnathids reproductive strategy;<br/> · First data on mitochondrial DNA variation in Syngnathus abaster (Teleostei);<br/> · Genetic and morphologic structure of the black-striped pipefish Syngnathus abaster populations from Sardinian and Adriatic sea.