Critter of the Week: Macrolabrum maui – a hermit with a difference
Some of our colleagues have just published an article on a new species of tanaid from New Zealand that was found living inside tiny gastropod shells!
This was a unique find considering Tanaids (tiny clawed crustaceans) are usually found living in sandy or muddy sediments.
Tanaids are related to hoppers and slaters but are only distant cousins to the hermit crabs in the crustacean family tree.
Pagurapseudidae - shell-loving tanaids
The family of tanaids that have this “conchicolid” (shell-loving) specialisation are the Pagurapseudidae. They are not uncommon but are known from mainly shallow tropical habitats and warm waters. It is not surprising that this species was eventually found and described from the northern part of New Zealand in Tokomaru Bay on the North East coast of the North Island, although probably the same species (but undescribed) was known from the Leigh area, north of Auckland.
Te Papa's DeCLASSIFIED! exhibition's discoveries: Tanaid crustacean
This particular species has adapted to living in micro molluscs with shells less than 5 mm diameter so they are pretty tiny little creatures and might easily be overlooked by people looking for them at the beach. Among other characteristics, the specially adapted tanaids have a twisted abdomen and asymmetrical telson, legs with sucker-like spines, and uropods (tail appendages) with tough spine-like setae that probably help to anchor the tanaid into the shell (Bird & Webber, 2015).
A fitting name
The new species Macrolabrum maui Bird & Webber, 2015 was named after two different ‘Maui’s’. The first is the Māori mythological character Maui, whom emerged from the sea wrapped up in seaweed by spirits, alluding to the fact that the new species was found amongst coralline and brown algae. And the second reason it was named maui, is after a well-known holiday camper-van hire firm in New Zealand alluding to the use of the gastropod shell as a mobile home in this family.
This story is featured in the DeCLASSIFIED! Nature’s secrets exposed exhibition at Te Papa – the National Museum of New Zealand, which runs until the 25 October. The exhibition explores the 'behind the scenes' work of Te Papa’s scientists. Worth checking it out if you are in Wellington, and it is free!
Bird & Webber (2015). The first pagurapseudid species (Peracarida: Tanaidacea) from New Zealand with remarks on paguridean (Decapoda: Paguridea) and pagurapseudid convergence and competition Zootaxa 3995 (5): 149-168.