Subject:
A Daytime Octopus (Octopus cyanea) is crawling away from my underwater camera. In its hasty escape, the octopus startles an Indian Lionfish (Pterois muricata), who, in turn, darts away from the turmoil.
Octopuses do not hunt the venomous-spined lionfish. In fact, lionfish have no reason to fear octopuses. Most octopus species prey on crustaceans, making it highly unlikely for an octopus to attack or target lionfish for food. The risk of sustaining serious injuries is probably deterrent enough from engaging with members of the scorpionfish family.
An octopus facing a life-threatening situation would likely release a cloud of ink to facilitate a quick escape. However, this did not occur at the time of filming. It's more probable that the octopus simply felt uncomfortable in my immediate presence. Judging by the lionfish's rapid departure, it appears the lionfish was more alarmed by the situation than the octopus.
Predicting animal behaviour is a daunting task. While filming this captivating octopus, I did not expect this particular reaction from this rather enigmatic invertebrate. Octopuses are renowned for their intelligence, rivalling that of dogs, and the behaviour of the octopus in this video deviated significantly from my expectations as I was sure that the animal in this video was probably used to encounter scuba divers.
This experience reinforces the notion that predicting marine wildlife behaviour is an intricate challenge. It underscores the importance of respecting and preserving the habitats of these remarkable creatures, allowing them to thrive in their natural environment, where they can continue to surprise and inspire us with their unexpected actions and behaviours.
Technique:
Several corrections were necessary to make this underwater videoclip suitable for broadcast. First, the normally white sandy patch had a pronounced greenish hue in the original clip. Second, the colours of the octopus appeared dull and dark and his skin structure was hard to distinguish, and finally, the blue background exhibited considerable visual noise.
To address all these different issues, I employed three identical layers in post-production. In the lowest layer, I rectified the sand's colour by desaturating the greenish and blue hue, meticulously masking areas devoid of sand. For the second layer, I isolated the octopus from the image using DaVinci Resolve's "magic mask" tool (a task that would have been time-consuming in Final Cut Pro). Subsequently, I enhanced the reddish and warm tones of the octopus's skin. Finally, I applied noise reduction software to smooth out the blue water in the background.
There are some air bubbles from scuba divers ascending to the surface in the background. Given their distance and inconspicuousness, I opted to leave them in the video. Most viewers would likely not have noticed them anyway, but now that I've mentioned it, you may have become aware of them.
To enhance the overall realism of the video, in addition to selecting the appropriate music, I incorporated various sounds. I added a slimy sound effect to emphasise the octopus's movements and a brief whoosh sound to accentuate the hasty departure of the startled lionfish.
Filming location:
This short underwater videoclip has been filmed in Mauritius 🇲🇺
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