Stenopterygii is a superorder of bony fishes inhabiting seawater. It comprises 2 orders, including Ateleopodiformes and Stomiiformes. Representatives of the latter inhabit the Adriatic Sea.
(Picture by American natural scientist and fisherman Charles Frederick Holder, 1851–1915)
Stomiiformes is an order of deep-sea pelagic fishes. They inhabit the depths up to 4,500 meters. Almost all members of the order are predators.
They are very widely spread in the world’s oceans, from subtropical and temperate to subarctic and even Antarctic waters.
Schools arranged by some species are so big that they make it difficult to determine the depth using an echo sounder, creating a “false bottom” effect on the device screen.
The Stomiatoidei order comprises about 400 species. The smallest representative is Valenciennellus tripunctulatus, the inhabitant of the Adriatic Sea. Its maximum length is 3.5 centimeters. The largest one is Opostomias micripnus, which grows up to half a meter long and inhabits the Atlantic, Indian and Pacific Oceans.
(Opostomias micripnus. Photo by © K. Parkinson / NORFANZ Founding Partners. fishesofaustralia.net.au)
In addition to their extraordinary looks and names placed by ichthyologists, all members of the family (except for one) have photophores, that is, luminous organs of some marine animals, mainly fish and mollusks.
During the day, representatives of the Stomiatoidei order swim in deep layers of water. When it gets dark, they start hunting, gradually rising closer to the surface in search of small fish and planktonic invertebrates. And they descend back to the depths at dawn.
The order comprises the Gonostomatoidei suborder with two families, including Gonostomatidae (the bristlemouths or lightfishes, or anglemouths) and Sternoptychidae (the marine hatchetfishes or deep-sea hatchetfishes), and the Phosichthyoidei suborder with two families, including Phosichthyidae and Stomiidae.
11 species of the Stomiiformes order from all 4 families inhabit the Adriatic Sea:
(Garrick. Photo by © Francesco Costa. colapisci.it)
It inhabits the depths of 10-2,000 meters, usually 200-900 meters. The maximum recorded length is 3.8 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
(Cyclothone pygmaea. Picture by © Francesco Costa. colapisci.it)
It inhabits the depths of 500-1,000 meters. The maximum recorded length is 3.5 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
(Gonostoma denudatum. Photo by © Alberto Monteleone. colapisci.it)
It inhabits the depths of 100-700 meters. The maximum recorded length is 14 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Silvery lightfish (Maurolicus muelleri).
(Silvery lightfish. Photo by © Erling Svensen. fishbase.org)
It inhabits the depths of 271-1.524 meters, usually 300-400 meters. The maximum recorded length is 8 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Constellationfish (Valenciennellus tripunctulatus).
(Constellationfish. Photo by © Francesco Costa. fishbase.org)
It inhabits the depths of 100-1.000 meters, usually 200-400 meters. The maximum recorded length is 3.1 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Half-naked hatchetfish (Argyropelecus hemigymnus).
(Half-naked hatchetfish. Photo by © Luciano Gomes Fischer. fishbase.org)
It inhabits the depths of 0-2.400 meters, usually 100-700 meters. The maximum recorded length is 3.9 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Lightfish (Ichthyococcus ovatus).
(Lightfish. Photo by © Francesco Costa. fishbase.org)
It inhabits the depths of 0-2.500 meters, usually 200-500 meters. The maximum recorded length is 5.5 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Slender lightfish (Vinciguerria attenuata).
(Slender lightfish. Photo by © Francesco Costa. colapisci.it)
It inhabits the depths of 100-2.000 meters. The maximum recorded length is 4.5 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Power’s deep-water bristle-mouth fish (Vinciguerria poweriae).
(Power’s deep-water bristle-mouth fish. Photo by © Francesco Costa. colapisci.it)
It inhabits the depths of 50-1.000 meters, usually 300-600 meters. The maximum recorded length is 4.3 cm. It feeds on zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Sloane’s viperfish (Chauliodus sloani).
(Sloane’s viperfish. Photo by © Francesco Costa. colapisci.it)
It inhabits the depths of 200-4.700 meters, usually 490-1.000 meters. The maximum recorded length is 35cm. It feeds on fish and zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.
Boa dragonfish (Stomias boa boa).
(Boa dragonfish. Photo by © Fran Martín de la Sierra. mundoabisal.com)
It inhabits the depths of 200-1.500 meters. The maximum recorded length is 32.2cm. It feeds on fish and zooplankton. It is the inhabitant of the southern part of the Adriatic Sea.