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Sponges perceive and respond to a range of stimuli. How they do this is still difficult to pin down despite now having transcriptomes and genomes of an array of species. Here we evaluate the current understanding of sponge behaviour and present new observations on sponge activity in situ. We also explore biosynthesis pathways available to sponges from data in genomes/transcriptomes of sponges and other non-bilaterians with a focus on exploring the role of chemical signalling pathways mediating sponge behaviour and how such chemical signal pathways may have evolved. Sponge larvae respond to light but opsins are not used, nor is there a common photoreceptor molecule or mechanism used across sponge groups. Other cues are gravity and chemicals. In situ recordings of behaviour show that both shallow and deep-water sponges move a lot over minutes and hours, and correlation of behaviour with temperature, pressure, oxygen and water movement suggests that at least one sponge responds to changes in atmospheric pressure. The sensors for these cues as far as we know are individual cells and, except in the case of electrical signalling in Hexactinellida, these most likely act as independent effectors, generating a whole-body reaction by the global reach of the stimulus to all parts of the animal. We found no evidence for use of conventional neurotransmitters such as serotonin and dopamine. Intriguingly, some chemicals synthesized by symbiont microbes could mean other more complex signalling occurs, but how that interplay might happen is not understood. Our review suggests chemical signalling pathways found in sponges do not reflect loss of a more complex set.
CTD profile in IODP CORK U1364A borehole at ONC NEPTUNE observatory site Clayoquot Slope, Cascadia Accretionary Prism
CTD (Conductivity-Temperature-Depth) profile measured during an experiment to determine the open depth of IODP borehole observatory CORK U1364A. The CTD profile was obtained during Ocean Networks Canada NEPTUNE Maintenance Cruise 2014-05 using the remotely operated vehicle (ROV) CSSF-ROPOS from the CCGS John P. Tully. Video and dive log entries of the experiment were recorded during Dive R1694 and are accessible at https://data.oceannetworks.ca/SeaTube?resourceTypeId=1000&resourceId=1001&diveId=410&time=2014-05-24T15:43:08.000Z. This data set contains all raw, metadata, and calibrated data files that were retrieved and generated from the CTD after the experiment