Discovery of a New Deep Chemosynthetic Community
Deepwater Canyons Project Science Team
After several days of lost dives due to bad weather and making dives under difficult conditions, we are today in calm seas exploring an area that was discovered last year during a NOAA mapping cruise. While conducting a seafloor survey, NOAA Ship Okeanos Explorer found bubbles coming from the seafloor at a site south and offshore of Norfolk Canyon; they thought these bubbles may indicate a new methane seep site, but they had no way of verifying this idea.
Today, we deployed the Jason remotely operated vehicle (ROV) from the NOAA Ship Ron Brown to 1,600 meters (nearly a mile deep—our deepest dive yet!) to explore the area around those bubbles. After transecting over soft sediment for a short time, we saw some indications that we were getting close to a probable methane seep. These indications included white patches of bacteria on the sediment surface that feed on the methane and sulfides, plus shells of dead mussels, which are the dominant animals of methane seep communities…
(via: NOAA Ocean Explorer)
(photos: Deepwater Canyons 2013 - Pathways to the Abyss, NOAA-OER/BOEM/USGS)
Black Swallower (Chiasmodon niger)
As feeding opportunities in the deep ocean are rare, deep sea fish have evolved amazing feeding adaptations.
The Black Swallower has a distensible stomach and is able to swallow prey twice its length and ten times its mass.
These fish are known to eat themselves to death. Sometimes, their prey is too large and decompose before they can be digested. The resulting gases float the fish to the ocean surface.
Sharks Warn Off Predators by Wielding Light Sabers
Lanternshark uses light to camouflage itself and warn off predators, study finds.
by Helen Scales
Diminutive deep-sea sharks illuminate spines on their backs like light sabers to warn potential predators that they could get a sharp mouthful, a new study suggests.
Paradoxically, the sharks seem to produce light both to hide and to be conspicuous—a first in the world of glowing sharks.
“Three years ago we showed that velvet belly lanternsharks (Etmopterus spinax) are using counter-illumination,” said lead study author Julien Claes, a biologist from Belgium’s Catholic University of Louvain, by email.
In counter-illumination, the lanternsharks, like many deep-sea animals, light up their undersides in order to disguise their silhouette when seen from below. Brighter bellies blend in with the light filtering down from the surface.
Fishing the 2-ft-long (60-cm-long) lanternsharks up from Norwegian fjords and placing them in darkened aquarium tanks, the researchers noticed that not only do the sharks’ bellies glow, but they also had glowing regions on their backs…
(read more: National Geo) (photos: Jérôme Mallefet)
Deep Sea Hermit Crabs (Pylopagurus discoidalis), family Paguridae, This species has never before been photographed alive. Seen here ocupying tusk shellls, and riding a sea cucumber.
Learn more about the study of these creatures: NMNH
[Photo courtesy of Barry Brown]
Bigfin Squid (Genus Magnapinna)
bigfin squid are a family of elusive squid presumably found in deep Atlantic waters. Only several specimens of these unusual squid have been observed and as such not much it known about them. It is speculated that they drag their long arms across the sea floor scooping up any food that bumps their tentacles. It is also thought they could live a more lazy lifestyle floating in the water column waiting for prey to bump into their tentacles.
Phylogeny
Animalia-Mollusca-Cephalopoda-Teuthida-Oegopsina-Magnapinnidae-Magnapinna
Deep Ocean Sea Spider
Among the stranger things that MBARI scientists see crawling around the deep seafloor are giant “sea spiders” or pycnogonids. They are very distant relatives of land spiders, scorpions, and horseshoe crabs. Shallow-water pycnogonids are typically a cm (1/3 inch) or less in size. However, several deep-sea species, such as this one, grow much larger.
Most pycnogonids feed by inserting their proboscises into soft-bodied invertebrates, such as jellies or sea anemones, and then sucking the juices out. The bodies of some pycnogonids are so small that part of their digestive tract extends into their legs. This pycnogonid has just been removed from the sample drawer of the remotely operated vehicle Tiburon, after having been collected on the seafloor, thousands of meters below.
(via: MBARI)
Splitfin Flashlightfish
(Anomalops katoptron)
is a species of fish found in shallow and deep waters of the central and western Pacific Ocean. The name flashlight-fish comes from two organs under the fishes eyes that give off light. This is probably an adaptation to the fish’s nocturnal and deep sea lifestyle.
Phylogeny
Animalia-Chordata-Actinopterygii-Beryciformes-Anomalopidae-Anomalops-kartoptron
