A beautiful coloured Hairy Yellow Hermit Crab (Aniculus maximus) chose the shell of a Horse Conch (Fasciolariidae) as its house. These crabs are among the larger and more colourful hermit crabs that reside in empty mollusk shells. The Hairy Yellow Hermit Crab, which is one of the bigger members of the crustaceans, can grow up to 10 cm in width and ventures out on the outer edges of the reef and in caves and crevices, such as the one filmed here in this underwater video clip.
Their distribution on coral and rocky reefs ranges across the Indo-Pacific area, from the African East coast to southern Japan and south to Australia's Great Barrier Reef, and eastward to French Polynesia. They are usually found in depths from 10m/30ft to a maximum of 35m/115ft.
The Hairy Yellow Hermit Crab stands out due to its striking coloration in combination with its hairy appearance. The hairs or bristles grow on its carapace and on all of its yellow/orange pereiopods (legs) and claws. When threatened, these claws act as a barrier to seal the crab inside the shell. These Hermit Crabs are known as the left-handed Hermit Crab because its left claw is slightly larger than the right one.
These crabs possess two sets of antennae: one short pair with sensory organs in the middle and another longer pair that extends outwards. They are omnivores, eating both algae and fish. They may opportunistically prey on helpless organisms, and sometimes they scavenge. They will break open any mollusk they can handle and consume its meat.
Thanks to pheromones, males can detect when a female is fertile and approach her, often holding onto the female until she is ready to mate. Once fertilised, the eggs are kept on the underside or abdomen of the female and thus inside her shell. Once the eggs hatch, the little larvae become planktonic and are at the mercy of the ocean's currents until they are large enough to find small shells and start a benthic life for themselves.
As they grow larger, they require larger shells, which can be scarce at certain moments, so they often have to fight with other Hermit Crabs to acquire the best real estate. As one of the bigger Hermit Crab species, they also require larger shells, such as the beautiful shell of the Triton (Charonia tritonis) or, like in this video, where the Hairy Yellow Hermit Crab has found a home in the shell of a Horse Conch (Fasciolariidae).
To accentuate the hollowness of the cavern where the animal was venturing, a reverberating sound effect was placed over the accompanying music. Although it is impossible to determine whether this underwater video was filmed by an underwater videographer inside a cave, the resonating sound effect added to the music in post-production makes the viewer feel as if they are exploring a mysterious and hidden underwater cave. The combination of the visuals and sound creates a sense of immersion and excitement, evoking the feeling of a real-life adventure. The use of post-production techniques, such as sound effects, can be a powerful tool in enhancing the overall experience of an underwater video, making it more engaging and memorable for the audience.
This short underwater videoclip has been filmed in Mauritius 🇲🇺
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