Argonauta

GPO87

Sepia elegans
Staff member
Moderator
Joined
Jan 6, 2005
Messages
797
Location
Dancing between Vancouver and Auckland
#1
Commonly known as the paper nautilus, Argonauts are octopods which secrete a thin calcareous shell around their mantle. There are 4 known species in the genera. They can get moderately large, with shells reaching a diameter of up to 30 cm.



Info at: http://tolweb.org/Argonautidae/20204
 

Attachments

Tentacle Toast

GPO
Registered
Joined
Oct 8, 2012
Messages
171
#3
My day is brightened..do you just do image searches? This is two threads now with wicked pix. I've gotta tell ya, TONMO is great to check in the mornings, but it leaves you daydreaming all day...
 

DWhatley

Certified Ceph Head For Life
Staff member
Moderator
Joined
Sep 4, 2006
Messages
20,146
Location
Gainesville, GA
#6
Biological and environmental signals recorded in shells of Argonauta argo(Cephalopoda, Octobrachia) from the Sea of Japan
Kevin Stevens, Yasuhiro Iba, Akihiko Suzuki, Jörg Mutterlose

Abstract
The argonauts (genus Argonauta) are enigmatic cephalopods. They have a cosmopolitan distribution in subtropical and tropical seas, where they inhabit the epipelagic zone. Their biology, ecology, and life cycle are poorly understood. It is for the first time that stable isotope (δ13C, δ18O) and element ratios (Mg/Ca, Sr/Ca, Ba/Ca) from three argonaut shells have been analyzed in order to test whether their life cycle and habitat are reflected in these data. The three studied shells have been collected in October 2012 from a mass stranding in Yoichi Bay, Hokkaido, Japan. The specimens were sampled along the keel of the shells to acquire ontogenetic records and along growth-sections of the shells to obtain synchronous data of differing shell growth rates. Carbon and oxygen isotope values as well as Mg/Ca ratios are in part controlled by the shell growth rate. Sr/Ca values show similar ontogenetic trends in the three shells. Comparison with measured sea surface temperature data indicates a temperature control on δ18O, Mg/Ca, and Sr/Ca, and a fast growth of the argonaut shell. Ba/Ca ratios of the shells might record environmental parameters. These new data highlight the influence of vital effects, but they also demonstrate that argonaut shell isotopic and elemental records can be used to understand the life cycle of these animals better.
 

DWhatley

Certified Ceph Head For Life
Staff member
Moderator
Joined
Sep 4, 2006
Messages
20,146
Location
Gainesville, GA
#7

DWhatley

Certified Ceph Head For Life
Staff member
Moderator
Joined
Sep 4, 2006
Messages
20,146
Location
Gainesville, GA
#8
Scientists solve millennia-old mystery about the argonaut octopus
Not Exactly Rocket Science Ed Yong 2010

... Into this debate came Finn and Norman. Their names may be familiar to regular readers – they have discovered the smash-hit octopus that carries coconut shells as a suit of armour, dolphin chefs that can prepare a cuttlefish meal, and the awesome mimic octopus. As with these earlier discoveries, their work on argonauts was based on observations of wild animals. They rescued three greater argonauts (Argonauta argo) from nets in the Sea of Japan, released them into Okidomari Harbour and filmed them as they adjusted to their freedom. It’s their beautiful video that graces the top of this post. ...
 

DWhatley

Certified Ceph Head For Life
Staff member
Moderator
Joined
Sep 4, 2006
Messages
20,146
Location
Gainesville, GA
#9
Australian Survey

(check out the link for more)
There is still very little known of the distribution, biology and behaviours of argonauts. Through funding by the Hermon Slade Foundation and Australian Biological Resources Survey, Museum Victoria is undertaking a detailed survey of argonauts in Australian waters.



A live female argonaut (Argonauta nodosus) with shell-secreting webs covering the outside of the shell. Photo: © Rudie Kuiter

This survey is reviewing the species that occur in Australian waters, their distributions, their roles in oceanic food webs, data on strandings, and where possible, live animal observations.

At this stage, three species are confirmed from Australian waters:

Knobbed Argonaut (Argonauta nodosus)

Distribution: known from southern Australia - from New South Wales to Tasmania and South Australia

Greater Argonaut (Argonauta argo)

Distribution: known from southern Western Australia. Shells occasionally collected in South Australia, Victoria, Tasmania, New South Wales and Queensland.

Lesser Argonaut (Argonauta hians)

Distribution: known from northern Australia - from the North West Shelf of Western Australia to Queensland . Shells occasionally collected in New South Wales.
 

DWhatley

Certified Ceph Head For Life
Staff member
Moderator
Joined
Sep 4, 2006
Messages
20,146
Location
Gainesville, GA
#10
Argonauts: the Astronauts of the Sea
Article in The Guardian March 27, 2018 by Mark Carnall

...
Argonauts, several species in the genus Argonauta, are a group of octopod cephalopods, the group that contains all the eight armed, soft bodied cephalopods. Collectively they’re known as octopuses but perhaps confusingly there’s a large number of species in the genus Octopus and many other genera of non-Octopus octopuses too such as Argonauta.
...
 

Members online

No members online now.

Forum statistics

Threads
19,325
Messages
201,730
Members
8,252
Latest member
RSG

Monty Awards

TONMOCON IV (2011): Terri
TONMOCON V (2013): Jean
TONMOCON VI (2015): Taollan
TONMOCON VII (2018): ekocak

About the Monty Awards
Top