The sea with its unusually high swells in recent weeks has washed out a rare squid species, commonly referred to as glass or cranch squid. A photo was sent to marine biologist Dr Marek Lapinski who confirmed it as a Cranchiid squid. The species name will still have to be confirmed if it is known to science.
These squid possess a large bouyancy chamber, are mostly transparent (only the digestive organ is usually visible) and spend most of their time in the upper sunlight waters of the ocean as juveniles. Being transparent they remain reasonably undetected in this habitat. The digestive organ is spindle-shaped and the squid orientate themselves in an upright manner so as to minimise the shadow cast by it while floating in the upper surface layers.
Cranchiid squid from Nahoon Point Nature Reserve, East London
One of the challenges for identifying this specimen (if it has been noted before) is that the zoological family Cranchiidae contains 13 genera and 60 species. Dr Lapinski has indicated his intention to do a full description of the find. Some of the species have a bioluminescent organ at the bottom of their eyes and the light emitted will cancel out their shadow making the squid almost invisible!
The specimen will be deposited at the South African Institute of Aquatic Biodiversity in Grahamstown as part of the national collection. Ilse Rheeder of the East London Aquarium is thanked for retrieving this specimen and bringing it to the attention of museum scientist Kevin Cole.
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