Scuba-diving marine biologists have discovered two new species of sponge, one in Indonesia and the other in Vietnam – and now realise that other sponges found as far apart as Thailand and Hawaii had previously been misidentified.
Led by Marco Bertolino of the University of Genoa’s Department of Earth, Environmental & Life Sciences (DISTAV) in Italy, the divers were at a depth of about 20m off Bangka Island in North Sulawesi when they started noticing fan-shaped, shaggy-textured purple sponges with what they described as a “peculiar” body arrangement.
Specimens were taken and the species was recognised as distinct based on its body shape, internal skeleton and texture, although it proved impossible to sample its DNA precisely enough to differentiate it from other species genetically. Belonging to the Cladocroce genus, it was named C lamellata because of its fan shape.
While undertaking another survey in sheltered Ha Long Bay on Vietnam’s north coast, about 100 miles east of Hanoi, the dive-team were exploring inside a tunnel when they lit up another unfamiliar sponge, this time one with pale green colouring.
They went on to find more of the sponges scattered around on rocks and reefs, and collected eight specimens, some tubular and others with thin branches. In this case the DNA could be analysed, and on that basis and the shapes this too was determined to be a new species. It was named Cladocroce pansinii after DISTAV zoologist Prof Maurizio Pansini.
The sponge was found to grow up to about 20cm in length and in some cases would appear more yellow than green.
This identification led the researchers to reclassify other sponges found in Hawaii and Thailand and previously misidentified. Thought to have been Cladocroce burapha, these are now also recognised as C pansinii sponges, although in those locations their colours range from light blue and light grey to violet.
The dive-team also made the first sighting in Indonesia of another named Cladocroce sponge, C aculeata. Their study has been published in the Journal of Marine Science & Engineering.
Also on Divernet: Sponges: Glue of the reef, World's biggest sponge found off Hawaii, First self-lit sponges identified, Secret upwardly mobile life of sponges
