NIWA scientists have discovered a new-to-science species
An inside job – scientists notice hoppers trapped inside host organism
NIWA scientists have discovered a new-to-science species of sand-hopper living inside another deep sea organism on the Chatham Rise.
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Close up of the new-to-science speices Bryoconversor tutus.
Marine biologists Drs Dennis Gordon and Anne-Nina Loerz believe the discovery of an amphipod species living inside a bryozoan is the only example of a relationship between these two types of organisms observed anywhere in the world.
While examining specimens held in NIWA’s Marine Invertebrate Collection, the scientists noticed the organisms inside a see-through layer on the bryozoans which live between 500 and 1500 m deep on the Chatham Rise, Bounty Trough and Solander Trough.
“It is a significant find as much less is known about relationships among organisms in the deep sea, compared to those in shallower water,” Dr Gordon said.
Males, females and juvenile hoppers (Amphipoda), up to one centimetre long, have been found living inside a species of bryozoan that grows to about 5 cm in length. The hoppers are protected in the cavity by a transparent membrane.
“The question is if the hoppers
are trapped in there, how did they get in there in the first
place?”
The scientists believe the most likely scenario
is that the female hopper makes a slit in the see-through
layer on the back side of the bryozoan and enters the cavity
beneath it, accompanied by a dwarf male. The slit then
repairs itself. The hoppers then reproduce with the female
releasing juveniles from a brood pouch. When the bryozoan
dies, the amphipods leave and colonise another one in the
same habitat.
The scientists are unsure whether both the amphipods and the bryozoa benefit from the arrangement or whether the hoppers are the sole beneficiaries, deriving nutrients and protection from their host.
“We are also wondering if there is a two-way nutrient flow whereby the secretions of the hopper can be transferred to the bryozoan but we don’t really know. We do know that the hopper is incapable of forming the membrane.”
Dr Gordon says there are all sorts of weird associations in the sea between animals, including a fish that lives in the rectum of a sea cucumber and a species of crab that forces corals to form a protective growth around it, known as a gall.
“Other
bryozoans are known to have body cavities on their underside
but they’ve never been seen before in this family.
That’s what is really weird and mysterious about it,” Dr
Gordon said.
The scientists have named the new
species tutus (meaning safe) and the new amphipod
genusBryoconversor (living in Bryozoa).
They are
keen to gather fresh samples and conduct DNA testing. Dr
Loerz says while a lot of New Zealand’s marine
biodiversity is not known, this was a special
find.
ENDS