Exploring Puerto Rico’s Seamounts, Trenches, & Troughs





The Gelata of Océano Profundo 2015

April 28, 2015

Mike Ford
NOAA National Marine Fisheries Service

Disponible en español ]

During Océano Profundo, we saw a number of exciting gelatinous organisms. I’ve listed some of the most exciting ones below.

 


 

Atlantis II Seamount Inter-flow Carbonate Layer

Bathypelagic Ctenophore

Three of these wonderful animals were seen near the bottom on Dive 1 at about 4,000 meters. Eight rows of ciliated combs along the bottom of the body and very long tentacles originating from thick tentacle sheaths make this an unusual find. A similar animal was seen on a remotely operated vehicle dive over the Mid-Atlantic Ridge in 2010.

Image courtesy of NOAA Okeanos Explorer Program.

Download high-resolution version (1.3 Mb). | Watch video of the ctenophore.


 

This beautiful hydromedusa was seen at about 3900 m during Dive 4.  Clearly imaged are two sets of tentacles: an inner ring of short tentacles and a longer set of tentacles originating from the bottom edge of the bell.  Red canals running from the edge of the bell to the top of the bell and uniquely shaped gonads suggest placing this medusa in the genus Crossota.

Hydromedusa from the Genus Crossota

This beautiful hydromedusa was seen at about 3,900 meters during Dive 4. Clearly imaged are two sets of tentacles: an inner ring of short tentacles and a longer set of tentacles originating from the bottom edge of the bell. Red canals running from the edge of the bell to the top of the bell and uniquely shaped gonads suggest placing this medusa in the genus Crossota.

Image courtesy of NOAA Okeanos Explorer Program.

Download high-resolution version (1.6 Mb). | Watch video of the hydromedusa.


 

This delicate ctenophore almost always requires an ROV for proper observation.  So delicate it usual breaks apart upon contact with traditional net sampling, this ctenophore is a lobate ctenophore.  It contracts its lobes to push on the water and propel itself forward.  These same lobes serve a prey capture function as well.

Ctenophore from the Genus Bathocyroe – Most Likely Bathocyroe fosteri

This delicate ctenophore almost always requires a remotely operated vehicle for proper observation. So delicate it usual breaks apart upon contact with traditional net sampling, this ctenophore is a lobate ctenophore. It contracts its lobes to push on the water and propel itself forward. These same lobes serve a prey capture function as well.

Image courtesy of NOAA Okeanos Explorer Program.


 

This ctenophore, seen during Dive 1, is characterized by its jet black pigmentation.  This animal appears to be similar in form to species found closer to the coast, this one sets itself apart with pigmentation and a long tentacle.  Only one tentacle is seen in these images and it is not clear whether a second tentacle was lost.

Black Ctenophore

This ctenophore, seen during Dive 1, is characterized by its jet black pigmentation. This animal appears to be similar in form to species found closer to the coast; this one sets itself apart with pigmentation and a long tentacle. Only one tentacle is seen in this image, and it is not clear whether a second tentacle was lost.

Image courtesy of NOAA Okeanos Explorer Program.

Download high-resolution version (1.6 Mb).


 

This long creature is a strange gelatinous animal and related to the bell shaped medusa we have seen on this expedition.  The bright spot on the tip is a buoyant pneumatophore.  Each of the clear segments below that are actually individual animals highly modified only to pulse in support of motion.  In this animal, each individual has a modified body that supports single function while being connected to a common stem.  We saw several siphonophores of various lengths on this expedition.  Siphonophores typical prey on small crustacean plankton and small fish.

Physonect Siphonophore

This long creature is a strange gelatinous animal and related to the bell-shaped medusa we have seen on this expedition. The bright spot on the tip is a buoyant pneumatophore. Each of the clear segments below that are actually individual animals highly modified only to pulse in support of motion. In this animal, each individual has a modified body that supports single function while being connected to a common stem. We saw several siphonophores of various lengths on this expedition. Siphonophores typical prey on small crustacean plankton and small fish.

Image courtesy of NOAA Okeanos Explorer Program.

Download high-resolution version (1.5 Mb).


 

This animal was seen at the 800 m transect on Dive 11.  This coronate jellyfish had a single ‘hypertrophied’ tentacle extending behind the open bell.

Coronate from the Genus Atolla

This animal was seen at the 800-meter transect on Dive 11. This coronate jellyfish had a single ‘hypertrophied’ tentacle extending behind the open bell.

Image courtesy of NOAA Okeanos Explorer Program.

Download high-resolution version (832 kb).

 

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