Rob Hutchins, Claws for effect: New hermit crab found off Queensland, Oceanographic, 19 November 2024
Nicknamed ‘Strawberry Claws’ for its distinctive, crimson-red appendages, the newly described hermit crab is the latest discovery within southeastern Australian waters – a region quickly becoming recognised as a stronghold for the species.
If its crimson-red claws aren’t distinctive enough, then perhaps its unique approach to underwater singing will set a newly discovered species of hermit crab – known to scientists at Queensland Museum colloquially as Strawberry Claws – apart from his fellow crustaceans?
Introducing the newest addition to the hermit crab genus, this is Strigopagurus fragarchela; a resident of the ‘relatively deep’ waters (somewhere between the depths of 120 to 260 metres, to give you an idea) off south-eastern Queensland, an area of Australia fast becoming a recognised “stronghold” for the extended hermit crab family.
With a name derived from the Latin form for ‘strawberry’ (Fragaria) combined with ‘chela’ from the Ancient Greek for ‘claw’, you can be sure that the Strawberry Claws crab stands very much apart from each of the other three species of hermit crab endemic to the region.
Scientifically described by researchers from Queensland Museum, this newly discovered species bears several highly distinctive features.
Most striking, admits Dr Marissa McNamara, collection manager at Queensland Museum – who scientifically described the new species alongside Queensland Museum Honorary, Peter Davie – is its bright red claws. But this species has another string to its bow, because it’s also evolved a unique method of producing underwater sound through stridulation by rubbing together specific body parts to produce sound, “much like cicadas do in the air.”
“We knew straight away this was a special hermit crab, and quickly gave it the nickname ‘Strawberry Claws,’” said Dr McNamara. “The identification of Strigopagurus fragarchela is an exciting addition to the genus, for which Australia appears to be the stronghold. We now have four endemic species, two of which are only found in Queensland.”
The central Indo-West Pacific diogenid genus, Stripopagurus currently contains five known species: S. strigimanus, S. bilineatus, S. boreonotus, S. elongatus, and S. poupini. Two of these (S. strigimanus and S. elongatus) are endemic to temperate southern Australia, while S. bilineatus is currently only known from off tropical Queensland. All of them are distinct for their stridulation – their tendency to produce chirping sounds by rubbing body parts together.
In the case of the Strawberry Claws crab, this is produced by rubbing the uropod (a flattened appendage on the last abdominal segment of the crustacean) against its shell. But if you’re anticipating romance, think again. In the last 70 years of research, it’s been discovered that in this particular species, this sound is produced as a defensive mechanism in response to an attack rather than for courtship. So perhaps think more ‘fingernails down a chalkboard’ than Tchaikovsky.
As it stands, little more is currently known about the ecology of the Strawberry Claws hermit crab as this new addition to the genus has, so far, only been collected by trawler catches. Despite this, scientists at the Museum maintain – “without doubt” – that they are important members of the “rich biological communities of the continental shelf off southeastern Queensland.”
With this discovery, attention has turned to its conservation status and what measures might be needed to ensure its survival. The impact of destructive practices such as deep-sea fishing or those of climate change and rising sea temperatures are not yet known. However, the depths at which the hermit crab has been found suggests it makes its habitat in cooler waters.
Future studies will, however, be essential to develop an understanding of those habitat requirements, ecology, and lifecycle.
Queensland Museum ceo, Dr Jim Thompson, said: “The work of scientists and researchers at Queensland Museum helps in providing a record of our state’s biodiversity for future generations. Our natural history collections are more than just preserved specimens – they are vital tools for scientific discovery, conservation and public education.”
The scientific paper describing the Strawberry Claws crab – authored by Dr Marissa McNamara and Queensland Museum Honorary Peter Davie – has been recently published in Memoirs of Queensland Museum.