File:Allonautilus scrobiculatus (crusty nautilus) (Solomon Islands, Solomon Sea) 1 (23793602509).jpg

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search

Original file(2,097 × 2,758 pixels, file size: 2.73 MB, MIME type: image/jpeg)

Captions

Captions

Add a one-line explanation of what this file represents

Summary

[edit]
Description

Allonautilus scrobiculatus (Lightfoot, 1786) - crusty nautilus shell (BMSM 73300, Bailey-Matthews Shell Museum, Sanibel Island, Florida, USA)

This shell is from one of only 6 living species of an entire group of molluscs - the nautiloids. Nautiloids are basically a squid in a shell. Most modern squids do not have an external hard shell, but the crusty nautilus does. The shell is composed of aragonite (CaCO3 - calcium carbonate). In the fossil record, most nautiloids had a long, straight, slightly tapering shell. Some fossil forms had slightly curved or open coiled or tightly coiled shells. The modern crusty nautilus shell is tightly coiled. All nautiloid shells are/were hollow, but they were separated into many chambers by curvilinear walls. A tube of tissue called the siphuncle runs through the shell's chambers - it passively pumps gas into or out of the chambers. Increased gas content within the shell's chambers results in a low-buoyancy body, and the organism rises in the water column. As water is added to the chambers by the siphuncle, the organism's body becomes heavier and it sinks. These changes do not occur quickly.

Classification: Animalia, Mollusca, Cephalopoda, Nautiloidea, Nautilidae

Locality: Solomon Islands, southwestern Pacific Basin


More info. at: en.wikipedia.org/wiki/Allonautilus and en.wikipedia.org/wiki/Chambered_nautilus and

en.wikipedia.org/wiki/Siphuncle
Date
Source Allonautilus scrobiculatus (crusty nautilus) (Solomon Islands, Solomon Sea) 1
Author James St. John

Licensing

[edit]
w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 2.0 Generic license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/23793602509. It was reviewed on 3 February 2016 by FlickreviewR and was confirmed to be licensed under the terms of the cc-by-2.0.

3 February 2016

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current08:49, 3 February 2016Thumbnail for version as of 08:49, 3 February 20162,097 × 2,758 (2.73 MB)Patko erika (talk | contribs)Transferred from Flickr via Flickr2Commons

There are no pages that use this file.

Metadata