https://popups.lib.uliege.be/2984-0317/index.php?id=583 Entrées d’index fr 0 https://popups.lib.uliege.be/2984-0317/index.php?id=903 In contrast to tropical environments, Mediterranean fish assemblages have been exposed to greater seasonal fluctuations of climatic factors (water temperature, photoperiod), which have impacted more or less significantly on the biology of fish. The labrid fishes (wrasses) are good examples of how climatic changes influence behavioural strategies. The European wrasses differ mainly from the tropical ones by their particular reproductive behavioural patterns. In these wrasses, the variety of the reproductive strategies (hermaphroditism or gonochorism, spawning seasonality in open water or on substrates, degrees of parental care, etc.) make it possible to study the evolution of these srrategies. If in tropics, most of wrasses exhibit planktonic spawning, the Mediterranean ones adapted their behaviour, developing modes of reproduction unusual in the tropics : short periods of reproduction, spawning eggs on substrates or in elaborated nests, parental care. This evolution is dictated, in particular, by the pressure of climatic factors, such as water temperature, on the presence or the absence of parental care. Of the 21 Mediterranean species, almost all the species studied lay their eggs on substrates or in a nest built by the large territorial male. Only Coris julis, Thalassoma pavo and Xyrichthys novacula (protogynous hermaphroditism fish species) spawn in open water (planktonic spawning) as tropical species do. Moreover, the majority of Symphodus males have complex social structures where nesting territorial males, satellite and sneaker males can be recognized. These sneakers adopt reproductive behavioural patterns known as alternative reproductive behaviour. They can either steal the spawn (streaking) or steal the female (sneaking). Finally, the majority of these Symphodus give parental care throughout each nesting cycle (2 to 5 nests are elaborated during the reproductive season in spring), which always comprises three phases : nest building phase (construction with alive algae of a substrate for spawning or a true nest in form of cup), sexual activity phase (the very moment the females come to spawn in the nest), and fanning phase (oxygenation of eggs, by the beat of the pectoral fins, until hatching). The diversity of the biological and behavioural adaptations developed by numerous tropical and temperate species of labrid fishes allow us to consider the family as an ideal group to investigate various problems in behavioural ecology. Tue, 30 Jan 2024 16:03:56 +0100 Tue, 30 Jan 2024 16:04:04 +0100 https://popups.lib.uliege.be/2984-0317/index.php?id=903 https://popups.lib.uliege.be/2984-0317/index.php?id=573 It could be misleading to consider that the social behaviour of newts and salamanders is simple and can be generalized. Indeed, individuals are faced with external and internal conditions which are extremely variable. In response to these factors, they may respond in a particular way. The behavioural variations, called alternative tactics, allow individuals to improve their fitness, i.e. to ensure the survival of their genes. They can be exhibited in reaction to a large range of factors such as the mere presence or density of competitors, the operational sex-ratio, the behaviour and kinship of the other individuals, the abiotic characteristics of the environment, the experience of the individuals involved. These alternative tactics are favoured in urodeles. Indeed, although the main process of fertilization is internal, they breed by means of a spermatophore deposited in the external environment. Each species of newts and salamanders exhibits specific behavioural patterns as they developed and evolved in particular environments which have exerted selective pressures on the individuals and in this way on the species. As a consequence, the understanding of patterns of behaviour requires that we know the environment in which they appeared. The main occurrence of parental care and territoriality in terrestrial environments may be explained by the features of these habitats in which eggs could not survive without protection and in which adults may defend areas of particular interest and communicate by means of pheromones. All of these characteristics show that we have to study the behaviour of individuals of different species under several conditions. Without such an analysis, it would be difficult to understand biodiversity. Fri, 26 Jan 2024 14:05:49 +0100 Fri, 26 Jan 2024 14:09:36 +0100 https://popups.lib.uliege.be/2984-0317/index.php?id=573