Massive Siphonophore Colony Near Western Australia Rivals Blue Whale Length

Deep-sea exploration conducted in 2020 off the Ningaloo Coast of Western Australia documented a colossal siphonophore colony estimated to extend between 45 and 47 meters. This finding positions the gelatinous organism as a contender for the longest creature on the planet, directly challenging the established length record typically held by the blue whale.

The documentation was achieved by researchers affiliated with the Schmidt Ocean Institute and the Western Australian Museum, utilizing the remotely operated vehicle (ROV) SuBastian during an expedition focused on underwater canyons in the Indian Ocean. While the blue whale remains the largest animal by sheer biomass, the linear dimension of this siphonophore necessitates a re-evaluation of size metrics in the marine environment. Siphonophores are intricate colonial organisms, not solitary animals, comprised of thousands of specialized, genetically identical units known as zooids, which function as a single, cohesive entity.

The expedition, which involved 20 dives reaching depths up to 4,500 meters, was part of the Schmidt Ocean Institute's year-long initiative to survey Australian waters. The research effort, spearheaded by Dr. Nerida Wilson, Chief Scientist from the Western Australian Museum, aimed to characterize benthic biodiversity in the Cape Range and Cloates Canyons near Ningaloo. Beyond the giant siphonophore, the team documented approximately 30 other potentially new underwater species, including sea cucumbers, molluscs, barnacles, and lobster species.

Dr. Lisa Kirkendale, of the Western Australian Museum, noted that these finds represented significant extensions in depth and range records for numerous species. The discovery of this specific Apolemia genus specimen, estimated at 45 meters, is particularly significant, though one spokesperson suggested its full potential length could reach up to 119 meters. The fragility of these gelatinous structures means that accurate assessment requires observation in their deep-sea habitat, as surface turbulence can easily cause fragmentation.