Overview on the diversity of sounds produced by clownfishes (Pomacentridae): importance of acoustic signals in their peculiar way of life.

Background: Clownfishes (Pomacentridae) are brightly colored coral reef fishes well known for their mutualistic symbiosis with tropical sea anemones. These fishes live in social groups in which there is a size-based dominance hierarchy. In this structure where sex is socially controlled, agonistic interactions are numerous and serve to maintain size differences between individuals adjacent in rank. Clownfishes are also prolific callers whose sounds seem to play an important role in the social hierarchy. Here, we aim to review and to synthesize the diversity of sounds produced by clownfishes in order to emphasize the importance of acoustic signals in their way of life. Methodology/Principal Findings: Recording the different acoustic behaviors indicated that sounds are divided into two main categories: aggressive sounds produced in conjunction with threat postures (charge and chase), and submissive sounds always emitted when fish exhibited head shaking movements (i.e. a submissive posture). Both types of sounds showed size-related intraspecific variation in dominant frequency and pulse duration: smaller individuals produce higher frequency and shorter duration pulses than larger ones, and inversely. Consequently, these sonic features might be useful cues for individual recognition within the group. This observation is of significant importance due to the size-based hierarchy in clownfish group. On the other hand, no acoustic signal was associated with the different reproductive activities. Conclusions/Significance: Unlike other pomacentrids, sounds are not produced for mate attraction in clownfishes but to reach and to defend the competition for breeding status, which explains why constraints are not important enough for promoting call diversification in this group

Impact of the Microenvironment on Tumour Budding in Colorectal Cancer.

Tumour Budding (TB) is recognized as an adverse prognostic factor in colorectal cancer (CRC). TB is the detachment of isolated cancer cells or small clusters of such cells mainly at the invasion front. One question that arises is of the role of the tumour stroma regarding the permissiveness of the formation and progression of TB. In this review, we will examine potential factors affecting TB, in particular we will analyse the potential effect of inflammation, hypoxia, extracellular matrix and Cancer-Associated Fibroblasts (CAFs).info:eu-repo/semantics/publishe