Skip to main content

New pink nudibranch, feather stars and crustaceans in a clam found in PNG lagoon

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


There's a new species convention happening somewhere right now and none of us got the memo because old. But that's okay because we've got ROFLCon and Anthrocon Playstations.

This week an international team of researchers announced that they've identified some 80 new species of plants and animals along Papua New Guinea's Hindenburg Wall, a 50-km long, 300 m high limestone cliff face running through the Star Mountains region of the Western Province. Included in the haul is a native rat the size of a Chihuahua, frogs, butterflies and the littlest wallaby.

Papua New Guinea is also responsible for over 30 underwater delegates on their way to SpeciesCon from Madang Lagoon, which is a large, incredibly rich area skirted by tiny islands and coral reefs, and arguably the most diverse reef on Earth. A team of researchers led by James Thomas from Nova Southeastern University's Oceanographic Center in Florida and hosted by a team of scientists from the Paris Museum of Natural History have identified new species of nudibranchs, feather stars (or crinoids) and shrimp-like amphipods after a three-week survey of the 15 km x 4 km lagoon.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


"The work was quite taxing for the group," says Thomas. “We drove in trucks to boats and then to our dive sites. Upon completing our dives/collections, we returned to a large lab complex established and hosted by the a French expedition team on site and sorted our materials and took photographs and prepared specimens for museum collections and DNA analysis.”

Thomas's team had originally carried out a survey of the lagoon more than two decades years ago, and found that the same species plus more now inhabited the warm, calm environment. "We wanted to see how the diversity had changed in the intervening 25 years. What we found was that it is still thriving despite encroaching human-related impacts," he says.

Judging by the variety of nudibranchs, feather stars and amphipods, which can act as model organisms or 'indicator species' for an ecosystem's level of diversity, this lagoon is richer in species than the entire Great Barrier Reef. Speaking with Australia's ABC Radio last week,

"Finding new species on reefs is not unusual," he says. "We did find a lot of unique and interesting species. I was especially excited to find one of my species living within the mantle of a clam. Few reports of this are known."

This new, unnamed amphipod belongs to the genus Leucothoe, members of which are often found living in the interior canals of sponges and sea squirts. Less often, these little crustaceans make their way inside the shells of bivalve mollusks such as clams, and Thomas's clam-dwelling amphipod had even set up its home with a mate. Sometimes these amphipods will live inside a host in communities of over 100 individuals.

J. Emmett Duffy from the Viriginia Institute of Marine Science was the first to document eusocial behavior, which describes a kind of complex social organisation, in marine sponge-inhabiting snapping shrimp, in 1996 and again in 2003. Thomas has documented eusociality, communal living, and "nest guarding" in tropical leucothoid species. Prior to this, scientists had assumed eusocial behaviour, was restricted to insects and naked mole rats. "The inner canals of sponges provide a protective breeding habitat for amphipods, where adults provide extended parental care of juveniles until they reach sexual maturity," Thomas reported in a 2007 issue of Zootaxa (PDF download).

James's team also found a new distinctive species of nudibranch. The charismatic sea slug looks like a marshmallow coated in pink chocolate and popping candy, with two little rhinophores, which are the pair of sensory antennae that sit on the head area and do most of its smelling and tasting. And now's a good time to mention that a certain relative (of the nudibranch!) has a detachable penis and two back-ups coiled up inside its body for the Ultimate College Experience.

For all its diversity, the Madang Lagoon environment is threatened by land-based pollution runoffs from nearby mines and a new tuna canneries scheduled to open, and Thomas says that while there are some efforts by NGO’s in the region that are mainly terrestrial, many conservation organisations are yet to really commit in a larger capacity in the marine systems. "The cultural and political realities in the area make it very difficult to make substantial progress," he says. "Since conservation organisations cannot generate a lot of fundraising for this little-known site, most of them have bypassed it for more lucrative areas for financial fundraising."

The team will begin analysis and description of species and plan to share their findings with the local Madang villagers and regional and federal governments in the hope that conservation efforts in the region are ramped up.

Correction: A picture of a feather star was originally posted here and labelled as a new species discovered by Thomas's team in the Madang Lagoon. It was included in the series of images provided to me, so I assumed that it was one of the new species found. This species is Oxycomanthus bennetti and was actually discovered by Johannes Müller in 1841 and photographed by Greg Rouse from the Scripps Institution of Oceanography.

***

My book, Zombie tits, astronaut fish and other weird animals, will be released in the US next month, and is available for pre-order from Amazon now.

About Becky Crew

Bec Crew is a Sydney-based science writer and award-winning blogger. She is the author of 'Zombie Tits, Astronaut Fish and Other Weird Animals' (NewSouth Press).

More by Becky Crew