Thursday, November 12, 2020

Rare Bigfin Squid in Australian waters

Scientists record some striking footage.

Australia is home to a host of weird and wonderful creatures, and now it can add the rare Bigfin Squid to its inventory.


Credit: Matthew Marrison (MNF)

Scientists aboard a deep-sea research voyage led by the national science agency CSIRO have recorded five individuals in the Great Australian Bight at depths of up to three kilometres.

It’s a first for Australian waters, and one of only a dozen confirmed sightings worldwide.

Alongside its large fins, the appropriately named Bigfin Squid (family Magnapinnidae) has striking long arm and tentacle filaments.

“Differences in their appearance meant we were able to confirm they were five separate individuals, rather than the same squid multiple times, and although the surveys covered a relatively large area, the squid were actually found clustered close together,” says marine scientist Deborah Osterhage.

From the recordings, the team was able to measure the length of one squid, finding its tentacle filaments were more than 11 times their body length.

They also observed their colours and behaviours, including filament coiling behaviour which has not previously been seen in squids.

The findings are reported in the journal PLOS ONE.


Five Enormous Rarely Seen Squid Have Been Spotted In Australian Waters


THIS FLOCK OF NOODLES HAS NEVER BEFORE BEEN SEEN IN AUSTRALIAN WATERS. 
CSIRO, OSTERHAGE ET AL. PLOS ONE, 2020


By Rachael Funnell11 NOV 2020, 19:00


The ocean is home to some absolute whoppers and some of the largest creatures are also the most elusive. One such giant is the bigfin squid that belongs to the family Magnapinnidae, a group of deep-sea squid with large fins and long, noodly arms and tentacles. It has only been spotted in the flesh on a handful of occasions. Now, new research published in the journal PLOS One details the incredible discovery of five bigfin squid in the Great Australian Bight, the first time they’ve been seen in Australian waters.

Previous reports of these ocean giants have always been of a single individual, so to capture five of these on camera was a big deal for the team from Australia’s national science agency, CSIRO. Though they weren’t spotted all at once, the bigfins have small differences in their appearance, which made it easy for the team to recognize they were five different animals and not just one camera-hungry squid. All five were seen at depths of 2 to 3 kilometers (around 1.5 miles) over a 25-hour period but were within 300 meters (984 feet) of one another, constituting a veritable crowd for an animal that’s never been seen with a party of more than one.
Bigfins have modestly sized bodies compared to their incredible long tentacle filaments. Osterhage et al. (PLOS ONE, 2020) 
VIDEO https://www.iflscience.com/plants-and-animals/five-enormous-rarely-seen-squid-have-been-spotted-in-australian-waters/

The first-of-its-kind discovery offered a unique opportunity to shine some light on these creatures of the deep, and the team were able to get an accurate reading on their size for the first time. Previous in-situ attempts to measure them have involved using nearby objects of known length, such as the arm of a submersible, but this new research used lasers to get a more accurate picture of their size. The results? The largest individual was over 1.8 meters (almost 6 feet) long with a maximum tentacle length of almost 11 times its body size. The animal was mostly white at the tips of its arms and tentacles but was sporting a mix of brown, orange, and pink hues towards its upper limbs, mantle, and fins. The researchers also spotted a behavior never before observed in squid, as a bigfin adopted a raised arm posture known as the ‘elbow’ pose.


“We filmed the five bigfin squid in depths of 2 to 3 kilometers using a towed camera system and remotely operated vehicles (ROVs),” said marine scientist Deborah Osterhage from CSIRO in an email to IFLScience. “We were doing image-based surveys to find out more about the deep-sea environment in the Great Australian Bight. The first two were seen in the towed camera footage when it was watched back onshore in the video lab. We recognized them as bigfin squid and knew how rare it was to see them, so in the subsequent ROV survey we really kept an eye out for them. We were lucky enough to see three more and were able to watch in real-time on the ship while the ROV filmed them — pretty exciting!

“Little is known of bigfin squid, and many other deep-sea cephalopods, largely due to the inaccessibility of their vast yet little explored deep-sea environments and there is much more to learn about the deep-sea and the incredible animals that live there. So, for bigfin squid we need to wait for more sightings, or more ideally an adult specimen in good condition — which has never been collected before.”

Multiple sightings of mysterious bigfin squid documented in the Great Australian Bight

by Bob Yirka , Phys.org
Sighting 3: ROV images of a Magnapinna squid at a depth of 3060 m. (A) Close view of the Magnapinna squid encountered 5.3 m above the seafloor with proximal arms/tentacles seen slightly opened and fins undulating slowly. (B) Full extent of arms/tentacles, the longest being approximately 1680 mm. Credit: PLOS ONE (2020). DOI: 10.1371/journal.pone.0241066

A team of researchers from the CSIRO Energy, Commonwealth Scientific and Industrial Research Organization and Museums Victoria has documented multiple sightings of bigfin squid in the depths of the Great Australian Bight. In their paper published in PLOS ONE, the group describes their study of the unique creatures and what they learned about them.


Bigfin squid live deep in the ocean and are noteworthy for several reasons. The first is that they are rarely seen in the wild—researchers have documented just 12 sightings. They also have unique fins that jut out from the side of the head at an angle that resembles Dumbo's ears—and they serve the same purpose, though in the water instead of the air. They also have long tentacles that are multiple times longer than their bodies. And they live thousands of meters deep in the ocean.

Because of their remoteness, little is known about the bigfin squid other than their general physical attributes. This sighting is the first in the Great Australian Bight (the huge open bay on the country's southern coast). Additionally, this is the first time the squid has been observed in a group of sorts. Though hundreds of meters apart, they were apparently sharing parts of the ocean. Squid are typically loners.

Another first was taking laser measurements of one specimen: a bigfin squid with a body (mantle) that was 15 centimeters long. More impressive were its tentacles, which were measured at 1.8 meters. All previous measurements of bigfin squid had been estimates based on background information such as other fish in the vicinity.


PlaySighting 5 of Magnapinna sp. in the GAB. This video was taken by ROV on 25 March 2017 at a depth of approximately 3056 m. Blue boxes are present in the lower corners to mask embedded logos in accordance with publishing requirements. Credit: PLOS ONE (2020).
 DOI: 10.1371/journal.pone.0241066

The researchers found the squid while they were conducting underwater surveys in the Bight. When they came across the first specimen, they deployed further tools to get a better look. They used both remotely operated underwater vehicles and towed cameras. In all, they carried out over 40 hours of underwater observations at depths ranging from 950 to 2400 meters below the surface—and wound up getting footage of five of the rare squid.


Explore further  Did a shark clash with large squid and live to tell the tale?

More information: Deborah Osterhage et al. Multiple observations of Bigfin Squid (Magnapinna sp.) in the Great Australian Bight reveal distribution patterns, morphological characteristics, and rarely seen behavior, PLOS ONE (2020). 

Journal information: PLoS ONE

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