DEEP-SEA PAGES:
MESOPELAGIC (MIDWATER) ANIMALS

Paul H. Yancey, Whitman College
Updated Dec. 2011!


Below are fishes, vampire squid and other animals we caught or saw in the mesopelagic (midwater) and bathypelagic zones off Oregon (200-800m deep) and California (200-1000m).
Return to my MAIN DEEP-SEA PAGE for details on animal collection; and for TOPIC CONTENTS (or use pull-down menu, below).

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Some of these photos are mine, others are ones I took from the ROV Oceanic Explorer's or Alvin's cameras.

OTHER TOPICS

MESOPELAGIC (and some BATHYPELAGIC) ANIMALS
Pelagic animals are those that live in the open water, not closely associated with the seafloor. Benthic (bottom-associated) animals are found on most of my other animal webpages (use the menu, upper right).

A. DEEP PELAGIC FISHES -- Oregon/California
trawl2
Midwater trawl



Lanternfish accidentally caught with Alvin
(2006) and Viperfish caught with midwater trawl during Alvin expedition (2007)

These are fish that we caught either as our deep-sea bottom otter trawl rose, or by our midwater trawl (figure, left top). Most are MESOPELAGIC (about 200-1000m), but some of these species are also found in the deeper BATHYPELAGIC zone (below 1000m) and ABYSSOPELAGIC (below about 3000m, but poorly defined). The deepest known fish is at about 8300m (see Bathyal and Abyssal Fishes page). Other pictures below were obtained from submersibles.
Animals here--fishes, jellyfish, shrimp, etc.--must adapt to low food supplies. They eat each other, and/or the detritus falling down from above. Some species are vertical migrators--they migrate to the upper waters at night to eat where there is more food. Animals have very low protein contents and relatively weak muscles (our research found 5-10% protein in most deepsea fish species' muscles, compared to 15-20% for epipelagic fish like tunas). Many species also have elaborate mechanisms for catching food because it is so infrequent: devices such as huge teeth, and expandable jaws and stomachs that allow them to swallow prey larger than themselves. They also often have special adaptations to cope with low light levels, such as large eyes and photophores (light-producing organs)--about 75% of mesopelagic organisms are bioluminescent.
See the UCSB Bioluminescence or the KrillOil bioluminescence page for kids for more information on biological light production.

Thanks to Ruben Pohl for the depth ranges, which are listed first as peak abundance, followed by record depths.

TO FIND almost any FISH SPECIES in the world, go to FISHBASE. The Taiwan Fishbase site (mostly non-English) has many pictures of fishes from all depths, and can be searched by fish family names (in English).
MORE DETAILS on DEEP SEA FISH can be found at Jeff Drazen's U. Hawai'i site

bigscale
Crested Bigscale
Poromitra crassiceps
(Primary depth 300-3200m)
daggertooth
Daggertooth
Anotopterus pharao/nikparini
( 500-2700m; young rise to 20m ?)
barreleye
Barreleye
Macropinna microstoma
( mainly 500-1000m)
barreleye2
Barreleye,
top view
snipe eel
Snipe eel
Nemichthys scolopaceus
(mainly 50-1500m)
DragonfishAstronesthes martinii (depth 350-1500m) from the Red Sea; photos provided by Ruben Pohl of Vienna, Austria:

DiaphusDiaphus
Headlightfish
Diaphus theta
( 0-200 at night; 300-1000 during day; max 1687m?)
pearleye
Northern Pearleye
Benthalbella dentata
( mainly 400-1000m)
dragonfish
Dragonfish
Tactostoma macropus
( 50-200m at night; 300-1600m during day;
max 2000m?)
fangtooth.JPG
Fangtooth
Anoplogaster
cornuta

(mainly 300-2000m; larvae 0-200m)


Anglerfish
viperfish
Viperfish
Chauliodus macouni
( mainly 250-950m; max 4231m?)
viper2
Another viperfish
Note light organ behind eye
viper3

Ventral light organs on
viper and lanternfish
.
Viper/Dragonfish gape
blacksmelt..fish gel
Stout Blacksmelt and "gel" layer
Pseudobathylagus (Bathylagus) milleri
(200-1400m; max. 6600m !)
--see related fish just below and notes below**--
2009 pictures (Monterey Bay)
lampfish
Northern Lampfish
Stenobrachius leucopsarus
( mainly 31-1189m; max 3400m?)
hatchetfish1
Hatchetfish
Argyropelecus?
hatchetfish1
Hatchetfish's large mouth
hatchetfish1
Hatchetfish's ventral (belly) light organs or photophores
witcheel
Witch eel
Facciolella sp.
(935m?)
blacksmelt
Slender Blacksmelt
Bathylagus pacificus
(0-7700 m! usually 600-800m)
--see related fish just above and notes below**
**Our Research: In the 1980s we found that some midwater fish have buoyant gelatinous layers (ABOVE 2 rows, RIGHT: layer just under skin in the blacksmelt cross-section). They also have very low protein content in muscles. These are probably adaptations to an energy-poor environment; it also means these are not very good for human consumption. Our publications on midwater fish anatomy and biochemistry:
--Siebenaller, J.F., P.H. Yancey (1984). The protein composition of white skeletal muscle from mesopelagic fishes having different water and protein contents. Mar. Biol. 78: 129-137
--Yancey, P.H., R. Lawrence-Berrey, M. D. Douglas (1989). Adaptations in mesopelagic fishes. I. Buoyant glycosaminoglycan layers in species without diel vertical migrations. Mar. Biol. 103: 453-459
--Yancey, P.H., T. Kulongoski, M.D. Usibelli, R. Lawrence-Berrey, A. Pedersen (1992). Adaptations in mesopelagic fishes. II. Protein contents of various muscles and actomyosin contents and structure of swimming muscle. Comp. Biochem. Physiol. 103B: 691-697
MORE INFORMATION:
  • Bigscales have large scales often lost during capture. Eaten by diving mammals and larger fish.
  • Barreleyes and Blacksmelts are some of the few fish known to eat gelatinous midwater animals such as salps (below). One report places this blacksmelt down to 6600m, in the abyssopelagic. Barreleyes have their huge eyes permanently focused to look straight up. In 2009, MBARI [Monterey Bay Aquarium Research Inst.] obtained the first-ever video of these, revealing that (before capture), they have a bizarre-looking clear dome over their eyes! Following that, Steven Colbert of Comedy Central TV did a hilarious news story on this weird fish.
  • Snipe Eels, Witch eels use their elongated jaws to catch shrimp, perhaps by entangling shrimp antennae.
  • Headlightfish, Lampfish and other Lanternfishes (Myctophidae family) are found in all oceans, and have photophores all along their ventral (belly) sides, and some have headlight ones on their heads. They migrate up to the surface at night then down during the day.
  • Pearleyes have tubular eyes directed up as well as forward.
  • Dragonfish have no scales, have ventral and sometimes near-eye photophores. In 1998, R. H. Douglas et al. reported (Nature 4-June-98, p423; and New Scientist 6-June-98, p16) that some midwater dragonfish have chlorophyll in their retinas that help them see red light. Red light normally does not exist in the midwater twilight as red wavelengths are absorbed strongly by water (and blue weakly, hence the ocean's color). Thus most deep-sea animals have lost the ability to see red. But dragonfish have photophores that can make red light, which they use to illuminate prey. This allows the dragonfish's light to be virtually invisible to all but itself (a "sniperscope").
  • Anglerfish have a glowing lure (often shaped like an animal) dangling on a fin ray over their huge jaws. See Animal Pictures Archives and Ramkat's site for great pictures.
  • Hatchetfish: these fish have ventral (belly) light organs, possibly to provide illumination that blends them in with the weak light from above ("counterillumination"). They are also very narrow (laterally compressed) like a knife blade, which also makes them hard to see by a predator looking up into the light. Their large eyes are pointed up to look for silhouettes of prey above them. Other pictures can be found at Animal Pictures Archives and Monterey Bay Aquarium.
  • Viperfish have a hinged skull, allowing the skull to rotate up for swallowing large prey. They also have large stomachs. They have various light organs, including one on a long dorsal fin that serves as a lure. From submerisbles they have been seen hanging motionless with their lure over their mouths, waiting for prey (see Randall and Farrell book above).
  • Gulper Eels (not shown) have huge mouths and jaws to swallow almost anything. See the Monterey Bay Aquarium's photo and information

B. OTHER DEEP PELAGIC ANIMALS--Oregon, California/NE Pacific
Some of these images are low-resolution ones from a submersible video camera.
**CLICK PICTURES FOR LARGE VERSIONS**
Gelatinous zooplankton--Salps, larvaceans, siphonophores; 250-880m deep. Most are Larvacea (taken from submersible camera). I took the leftmost-one with Alvin's video at 880m.
Midwater/mesopelagic salp* caught with net
Unknown--rear (left) tentacles were moving
Jelly or hydrozoan medusa* at 511m
Atolla wheeltop
jelly (mesopelagic)
CEPHALOPODS
VAMPIRE SQUID. See MOLLUSC PAGE for details
Cirrate octopods. See MOLLUSC PAGE for details
Chiroteuthis calyx=GLASS SQUID with intact feeding arms! See MOLLUSC PAGE for details
Teuthowenia-type squid
(seen from Alvin at 880m)

C. DEEP PELAGIC ANIMALS--NEW ZEALAND: PETER BATSON'S Photos
**These great pictures are not mine, but are copyrighted and courtesy of PETER BATSON , marine researcher and author of DEEP NEW ZEALAND-Blue Water, Black Abyss (2003). Please do NOT use the pictures without his permission! See his website: Exploretheabyss.com.
**CLICK PICTURES FOR LARGE VERSIONS**

Teuthowenia, an odd midwater squid

Ever-
manella

Argyropelecus
Astronesthes
Bathysaurus
Hydrolagus, a
chimaera (relative of sharks)


FOR MORE DETAILS, see these WEB SITES and REFERENCES

A nice overview of common and interesting deepsea animals (with some of my pictures) can be found at Sea and Sky. The Monterey Bay Aquarium Deepsea page has excellent pictures
Pictures and descriptions of the strange bathypelagic Anglerfish are at Ramkat's website.
For pictures and information on the giant oarfish, click here
A nice site with drawings and animations of deep pelagic animals (vampire squids, anglerfish, etc.) can be found at CYBERSPACE: Below the EDGE. The Monterey Bay Aquarium Deepsea page has excellent pictures of real pelagic animals in their habitats, including Gulper Eels, jellies, ctenophores, etc..
Pictures of the bizarre midwater Vampire squid can be found at Smithsonian Magazine.
See the UCSB Bioluminescence or the Harbor Branch Oceanographic Bioluminescence page for more information on biological light production, including in the deep sea.
For more information and pictures of deepsea fishes beyond the internet, see
-- Scientific American
, July 1995, and
-- TIME
magazine Aug. 14, 1995;
-- Deep-Sea Fishes by D.J. Randall & A.P. Farrell, Academic Press, 1997
--For an article on countries that have been catching midwater fish for food, see New Scientist, Nov. 8, 1997