I have been blessed in that I have just observed the mating ‘ritual’ of C. dennerli, the Cardinal shrimp. I am so privileged to be able to document it!
C. dennerli reproduces entirely in freshwater, involving no larval stages. The eggs take roughly 3 weeks to hatch. Juvenile C. dennerli immediately assume a benthic lifestyle after hatching.
As typical for shrimp, reproduction is stimulated by the moulting of the female. As the female undergoes apolysis, she begins to release pheromones that attract males, which wait around the female in anticipation. Following apolysis, the female attempts to escape the males to moult alone in safety, but is pursued. She then undergoes ecdysis, frantically flicking her uropods to separate herself from the old exoskeleton. Following moulting, the female releases more pheromones that induce restless swimming in the males. When a male finds the female it mates with her and then resumes normal behaviour. The other males continue to swim for a short while until resuming normal behaviour also, presumably coinciding with the decrease in pheromones as the female ceases to produce them.
Female minutes after moulting and being fertilised.