Scientists believed there were only two species of hornerid bryozoans in Aotearoa New Zealand, but new research shows several more have been secretly evolving and thriving in the nation’s southern waters.
Bryozoans are small, usually hidden, invertebrate marine creatures which have existed for more than 250 million years.
Known for their lace-like skeletons, they are important structure-formers – an organism that creates habitat for other organisms – in deep waters around Aotearoa.
The majority of most ancient groups of bryozoans are extinct, yet researchers have recently discovered and named 11 new species in the Horneridae family in a new study.
Emeritus Professor Abby Smith
Lead author Emeritus Professor Abby Smith, of the University of Otago – Ōtākou Whakaihu Waka Department of Marine Science, says the discovery has important implications for conservation.
“You can’t conserve, manage, study or understand a species if you don’t know it’s there,” she says.
“We never thought there would be this many species and that they would turn out to be this diverse.”
Published in the Zoological Journal of Linnean Society, Emeritus Professor Smith collaborated with scientists Dr Helen Jenkins, Dr Paul Taylor and Dr Andrea Waeschenbach from the Natural History Museum, in London.
They used a combination of molecular and morphological approaches to find the species on the seafloor around southern Aotearoa, between Cook Strait and the subantarctic islands.
They describe, illustrate and name 11 species (seven of which are new) in three genera (one of which is new and one reinstated).
Three were given sentimental names, honouring the Otago research vessel RV Polaris II (Hornera polaris) and scientists Elizabeth Girvan and Kim Currie (Hornera girvanae and Hornera currieae) who had a major impact on understanding seafloor creatures in the area.
“While it seems like taxonomists are just naming things, actually, they are finding connections (who is related to who) and providing certainty in identification (who is who).”
Emeritus Professor Smith was surprised to find so many new species of hornerid bryozoans.
“We thought that this group of bryozoans (the cyclostomes) was a kind of remnant taxon, leftover from the Paleozoic Era, about 540 to 250 million years ago,” she says.
“All the other bryozoan groups from that time are extinct, but the cyclostomes persist as small weedy species in a few niches around the world.
“It turns out that hornerids are remarkably diverse: evolving and changing, developing new life tactics and thriving in southern Aotearoa – not a remnant at all.”
And there may be more to come.
“We have specimens from northern New Zealand that need examining, classifying, identifying, and naming. It may be that we find even more species in this fascinating genus.”
