Gabriela Pedrotti 2020-10-15 01:27:28
A larvae study published by scientists from the Smithsonian Tropical Research Institute (STRI) in Panama detected eight potentially new species of these marine creatures scientifically called phoronids. "The global diversity of small and rare marine animals such as phoronids is greatly underestimated," said Rachel Collin, STRI scientist. "We do not know what animals are out there, and we know even less about what their role might be in the world's oceans."
Because phoronid larvae swim and drift in seawater, they are much easier to sample than their adult forms, which live on the seafloor within sands, sediment, or rubble. And the larvae do not look like the adults, making it difficult to tell which larva belongs to which adult without doing a sort of paternity testing: comparing larval DNA sequences to the DNA of their potential parents.
Named for the Egyptian goddess Phoronis, tubular adult horseshoe worms anchor their bodies to rocks or corals and wave a crown of ciliated tentacles to capture tiny food particles. To reproduce, their eggs and sperm unite to create embryos that hatch as swimming larvae, which then become members of the microscopic plankton. Scientists collected plankton from the Bay of Panama on the Pacific Coast and Bocas del Toro on the Caribbean coast. By examining plankton with a stereomicroscope, they found more than 50 phoronid larvae; 23 from the Pacific and 29 from the Atlantic.
Using a genetic technique called barcoding based on DNA sequencing, they were able to distinguish three distinct phoronids in the plankton from the Bay of Panama and four others from the Caribbean. The DNA of particular genes from each of these animals was different from anything recorded in GenBank, a global collection of DNA from more than 300,000 organisms, suggesting that these larvae may belong to species that are new to science. However, finding the adults of these species may take years, especially since very few scientists study horseshoe worms.