Squid update

By Nicole Webster

Last week I showed you a larval squid of unknown age *n*, here’s n+7!

Full body shot of Doryteuthis opalescens Credit: N Webster

Full body shot of Doryteuthis opalescens Credit: N Webster

They are much more active, with clearly visible heart beats, functional chromatophores, and active swimming. As a result it wouldn’t stay still long enough to get a good depth photo, so I resorted to a series:

Shot of the iridescent eye, and two apparent types of chromatophores: red ( erythrophores) and black (melanophores). The eye appears fully developped this week, whereas is was still red, and undefined last week. Credit: N Webster

Shot of the iridescent eye, and two apparent types of chromatophores: red ( erythrophores) and black (melanophores). The eye appears fully developped this week, whereas it was still red, and undefined last week. Credit: N Webster

A close up view of the tentacles with evident suckers, although they seem out of proportion. Credit: N Webster

A close up view of the tentacles with evident suckers, although they seem out of proportion. Credit: N Webster

The mantle cavity seen here is still transparent. Left: The tree-like structure is one of two ctenidia used for gas exchange. The bubble on the left side is the beginnings of the reproductive and gastrointestinal tracts and organs. The distictive large black spot is probably the inksac! The heart is visible as the blob between the ctenidium and the 'gut'. It was beating regularly. Right: The structure of the epidermis is visible , and the chromatophores are in focus. Credit: N Webster

The mantle cavity seen here is still transparent. Left: The tree-like structure is one of two ctenidia used for gas exchange. The bubble on the left side is the beginnings of the reproductive and gastrointestinal tracts and organs. The distictive large black spot is probably the inksac! The heart is visible as the blob between the ctenidium and the ‘gut’. It was beating regularly. Right: The structure of the epidermis is visible , and the chromatophores are in focus. Credit: N Webster

The Octopus of Saanich

By Jackson Chu and Danielle Ludeman

As part of the Oceans Network Canada observatory, the Victoria Experimental Network Under the Sea (VENUS) provides real-time measurements, images, and sound to researchers and observers on-shore.

Anyone, from scientists to the general public, can access the network’s data and monitor environmental changes as they happen (see here for a previous post on accessing and graphing VENUS using R). The VENUS instrumentation is found in the coastal waters of the Salish Sea and is the sister network to the offshore NEPTUNE Canada regional cabled ocean network

Video and data provided by Jackson Chu

Captured in this time-lapse video from Saanich Inlet is a juvenile, ~10 cm long, Pacific Red Octopus (Octopus rubescens), which had temporarily moved underneath the VENUS Camera Array for a month. When the oxygen levels drop to near zero, it decides to pack up and move somewhere more hospitable. You would to if you had a dozen squatters (Munida quadrispina) hanging around your neighborhood all day!
Note: You can see the white ball sponges (Suberites sp.) contracting in the video – the first time this behavior has been captured in situ on the bottom of the ocean. You can check out another time lapse of a contracting sponge done in the lab, Tethya wilhelma, and one of a freshwater sponge Ephydatia muelleri.

Metadata:
Location: Saanich Inlet, 96 m depth
Camera: Olympus C8080WZ
Exposure Settings: 7mm @ F5.6, 1/30s, ISO100, with offcamera strobe in custom housing
Time start: Sept. 14, 2012 @ 07:47:42 UTC
Time end: Oct. 09, 2012 @ 14:47:28 UTC
Total # of images: 1691 8MP still images (3264p x 2448p) taken in doublets (10 s interval) every 30 mins
Workflow:
Images were batched processed to 1440p x 1080p dimensions (Adobe Photoshop) and made into a 15 frames per second (fps) time lapse movie (Avidemux). The time lapse video was then stabilized and re-rendered (Adobe After Effects) because the images did not perfectly overlay on top of one another which resulted in shakey raw footage. Oxygen data profile for the time sequence was downloaded from the VENUS website, processed (Matlab), and plotted (Adobe Illustrator, Adobe Photoshop). The Oxygen profile was then overlaid onto the time lapse video (Adobe After Effects), and an animated time marker was added using keyframes before finalizing the video by pillarboxing into a 1080p HD-video with audio accompaniment (Adobe Premiere Pro).

Squid-totomy

by Nicole Webster

Autotomy is a common defense mechanism for many animals; leave a small part behind to distract your predator, while your important parts escape to play again another day.

Two well known marine examples are many crustaceans and echinoderms (not exactly a small subset, hey?), both groups that have excellent regenerative powers (crustaceans at each moult, and echinoderms, well… because they’re made of magic*). A recent paper has shown this feature in a new group: squids. It was known already that octopuses can also autotomize, but my favorite part of this article is that the squid will actually counter-attack it’s predator (or bottle-brush, see video), attaching the arm before dropping it and jettisoning to safety. Not only does the dropped limb grasp its attacker and wiggle distractingly, it also glows!

You can read about the article, which was expertly summarized by Ed Yong at Not Exactly Rocket Science, here.

*No, not actually, but they are amazing!