Journal Entry
Classification

Naming, identification, and classification of organisms often poses problems. Classification schemes may not always represent true organismal relationships, and because of limited samples or difficulty in collecting samples, duplicate names for the same organism sometimes occur. This week's Science Talk, presented by Dr. Dhugal Lindsay, was on the development and use of a DNA barcoding database to aid in identifying organisms. For example, when jellyfish or ctenophores are caught in nets, their soft bodies often leave little more than a blob of goo to be identified. Using DNA from this "blob" can show if that organism has already been identified even in the absence of distinguishing structural features. This can lead to a greater understanding of geographic distribution and life cycle strategies. During this talk, I also learned that there are both benthic and pelagic jellys and ctenophores. It's an amazing world out there with new things to see and learn each day!

The dumbo octopus (Grimpoteuthis spp.) shown in the photos below captivated us in front of the big screen during a recent ROV dive. This is classified in a family (Opisthoteuthidae) of deep-sea octopuses also known as umbrella octopuses. These photos are stills taken from a video color corrected and edited by Caitlin Bailey.

Dumbo elephantDumbo elephant from ROV footage. Still taken from video edited and color corrected by Caitlin Bailey. Dumbo elephantDumbo elephant from ROV footage. Still taken from video edited and color corrected by Caitlin Bailey. Dumbo elephantDumbo elephant from ROV footage. Still taken from video edited and color corrected by Caitlin Bailey.

Question of the Day

Question: Why is the octopus shown above referred to as a "dumbo octopus"?

Answer From Yesterday's Q: "Arthropod" is loosely translated as "jointed foot". Arthropods are invertebrates with exoskeletons, jointed appendages, and segmented bodies. Insects, crustaceans, and arachnids are all examples of arthropods.

Comments

Judy Fahnestock

What a treat to see such unique underwater organisms! How deep was the ROV when it captured these on video? Do you know if there is any structural function for 'Dumbo's' ears?

Michelle Eno

These pictures are so neat! I've never seen anything like this before. It's as if the octopus is wearing a skirt, and what are the "ears" on the sides of its head? I'm dying to know what those protrusions are for. I don't think I've ever seen an octopus with legs like that. How big would you say that octopus is? Where (depth) would he generally live?
As always, you do an amazing job of sharing your world with us. I have learned so much by following this! Keep up the great work!

Sandra Thornton

Good questions, Judy and Michelle! I shared your question with one of the scientists on board, and he said the dumbo octopus uses the ear-like appendages for propulsion. As with other octopuses, it does have "jet propulsion" capability, but that is used more for changing direction/position rather than strictly moving along/speed. These are also known as "umbrella" octopuses, and so few specimens have been observed and/or collected that an exact number of species isn't known for this family. It is a pelagic creature - I will have to check on its usual depth range.