| Argyropelecus olfersii | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Stomiiformes |
| Family: | Sternoptychidae |
| Genus: | Argyropelecus |
| Species: | A. olfersii |
| Binomial name | |
| Argyropelecus olfersii (Cuvier, 1829) | |
Argyropelecus olfersii is a common species of marine hatchetfish, [1] found in mesopelagic waters.
Argyropelecus olfersii was described by Georges Cuvier in Chapter 27 of Histoire Naturelle des Poissons , based on specimens held in the National Museum of Natural History in Paris and the Natural History Museum, Berlin. The specific name honours the German diplomat and natural historian Ignaz von Olfers, who presented the Berlin specimen to the museum upon his return from a diplomatic excursion to Brazil. [2]
A. olfersii is found in temperate waters worldwide, with a preferred temperature range of 5.1-13.3°C. [3] The fish is present in all oceans save the Southern, however records are rare from the Indian Ocean. [1] During daylight hours, subadult and adult fish live at depths of 200–800m, undergoing a vertical migration to 100–600m at sunset. [3]
Like other members of the subfamily Sternoptychinae, Argyropelecusolfersii has a laterally compressed and extremely deep body, contributing to the characteristic "hatchet" shape which the group is named after. This shape, alongside the counterillumination provided by the well-developed ventral photophores, reduces the silhouette of the fish when viewed from beneath, concealing it from potential predators. In addition to the ventral photophores, an eye-facing photophore is found in the snout, used as part of a feedback system to allow the ventral bioluminescence to match the intensity of downwelling light. [4] A. olfersii has a dark, heavily pigmented back and silvered flanks, again helping to reduce visibility in its native midwater habitat. Like all members of the genus Argyropelecus, A. olfersii has dorsally-directed, tubular eyes, which in life have a metallic blue colouration that is rapidly lost in preserved specimens. [2]
A. olfersii is distinguished from other members of the genus by its two postabdominal spines, which are equal in length and curvature. There are 9 rays in the dorsal fin, 10–11 in the pectorals, 6 in the pelvic fin and 12 rays in the anal fin. [5] In addition to these fins, there is a long, low adipose fin on the ventral surface of the tail and a dorsal blade anterior to the dorsal fin. The otoliths in this species are small, and located under the cranium behind the eyes.
Argyropelecus olfersii is a predator, feeding on small fish and crustaceans. [3] Despite being an abundant member of the mesopelagic community, A. olfersii is a relatively poor source of energy, and there is evidence suggesting that it is actively avoided by some marine mammal predators in favour of more energy-rich myctophids. [6]
Argyropelecus olfersii is not fished commercially, and has an assessment of Least Concern under the IUCN Redlist. [7] Organohalogen pollutants have been found in A. olfersii specimens caught in the Bay of Biscay. [8]
The Squaliformes are an order of sharks that includes about 126 species in seven families.
Marine hatchetfishes or deep-sea hatchetfishes are small deep-sea mesopelagic ray-finned fish of the stomiiform subfamily Sternoptychinae. They should not be confused with the freshwater hatchetfishes, which are not particularly closely related Teleostei in the characiform family Gasteropelecidae.
The marine hatchetfishes or deep-sea hatchetfishes as well as the related bottlelights, pearlsides and constellationfishes are small deep-sea ray-finned fish of the stomiiform family Sternoptychidae. They are not closely related to and should not be confused with the freshwater hatchetfishes, which are teleosts in the characiform family Gasteropelecidae. The Sternoptychidae have 10 genera and about 70 species altogether.
Argyropelecus is an oceanic ray-finned fish genus in the deep sea hatchetfish family Sternoptychidae. A collective name is "silver hatchetfishes", but this can also refer to a species of the freshwater hatchetfishes which are not particularly closely related to this. The large pupils of these marine hatchetfishes enable them to see dim objects in the deep sea, where light barely penetrates.
Lanternfish are small mesopelagic fish of the large family Myctophidae. One of two families in the order Myctophiformes, the Myctophidae are represented by 246 species in 33 genera, and are found in oceans worldwide. Lanternfishes are aptly named after their conspicuous use of bioluminescence. Their sister family, the Neoscopelidae, are much fewer in number but superficially very similar; at least one neoscopelid shares the common name "lanternfish": the large-scaled lantern fish, Neoscopelus macrolepidotus.
Barreleyes, also known as spook fish, are small deep-sea argentiniform fish comprising the family Opisthoproctidae found in tropical-to-temperate waters of the Atlantic, Pacific, and Indian Oceans.
The Pacific viperfish, is a predatory deep-sea fish found in the North Pacific. It is reported as being either mesopelagic or bathypelagic, with diel vertical migration to shallower waters. The Pacific viperfish is one of the nine different species that belong to the genus Chauliodus, the viperfish. The Pacific viperfish tend to be the largest of the species, typically reaching lengths of up to 1 foot and are considered an example of deep-sea gigantism. The length-weight relationship of the pacific viperfish varies with sex with females tending to be longer and heavier than males.
The bluntsnout smooth-head, black slickhead, Cope's bluntsnout smooth-head, or Atlantic gymnast, Xenodermichthys copei, is a slickhead of the genus Xenodermichthys, found in the Atlantic, Indian, and Pacific oceans, and the Tasman Sea, at depths of 100 to 2,600 m. This species grows to a length of 31 centimetres (12 in) TL.
Maurolicus muelleri, commonly referred to as Mueller's pearlside,Mueller's bristle-mouth fish, or the silvery lightfish, is a marine hatchetfish in the genus Maurolicus, found in deep tropical, subtropical and temperate waters of the Pacific Ocean and the Atlantic Ocean, from the surface to depths of 1,500 metres (4,900 ft). It can grow to a maximum total length of 8 centimetres (3.1 in).
The blackbelly lanternshark or lucifer shark is a shark of the family Etmopteridae found around the world in tropical and temperate seas at depths between 150 and 1,250 meters – the mesopelagic zone. Compared to other mesopelagic fish predators and invertebrates, the blackbelly lanternshark is thought to reside in shallower, more southern waters. E. lucifer can reach up to 47 centimeters in length and consumes mesopelagic cephalopods, fish, and crustaceans. Blackbelly lanternsharks are bioluminescent, using hormone controlled mechanisms to emit light through ventral photogenic organs called photophores and are presumed to be ovoviviparous. The blackbelly lanternshark has been classified as "Not Threatened" within the New Zealand Threat Classification System.
The velvet belly lanternshark is a species of dogfish shark in the family Etmopteridae. One of the most common deepwater sharks in the northeastern Atlantic Ocean, the velvet belly is found from Iceland and Norway to Gabon and South Africa at a depth of 20–2,490 m (66–8,169 ft). A small shark generally no more than 45 cm (18 in) long, the velvet belly is so named because its black underside is abruptly distinct from the brown coloration on the rest of its body. The body of this species is fairly stout, with a moderately long snout and tail, and very small gill slits. Like other lanternsharks, the velvet belly is bioluminescent, with light-emitting photophores forming a species-specific pattern over its flanks and abdomen. The ventral photophores are thought to function in counter-illumination, which camouflages the shark against predators and prey. The bioluminescent flank markings may play a role in intraspecific communication.
The fringefin lanternshark is a shark of the family Etmopteridae found in the western central Atlantic from Texas to Florida, northern Gulf of Mexico, and Mexico. It is endemic to this area. It is a deep water shark and is found about 220 to 915 meters below the surface, on the upper continental slopes of the Gulf. E. schultzi is a small shark, about 27–30 cm long and feeds on squid. It is also bioluminescent, which counter-illuminates it and helps with intraspecific interaction. Due to its limited range and the difficulty of collecting deep water species, it has not been evaluated by the IUCN Red List, but due to recent oil spills in the Gulf of Mexico, it is likely that fringefin lanternsharks have decreased in population.
The splendid lanternshark is a shark of the family Etmopteridae found in the western Pacific at depths between 120 and 210 m. Through the classification of Etmopterus species into several clades based on the positioning of their bioluminescent photophores, the splendid lanternshark can be considered a member of the Etmopterus pusillus clade.
Argyropelecus aculeatus, the lovely hatchetfish or Atlantic silver hatchetfish, is a species of fish in the family Sternoptychidae. It may exceed 70 millimetres (2.8 in) standard length (SL). It lives in the mesopelagic zone of all oceans and performs diel vertical migration. A. aculeatus feeds on a large range of prey items; in the Gulf of Mexico ostracods and copepods dominated the diet of small individuals and euphausiids, molluscs, and fish the diet of larger ones. The silvery coloration and bioluminescence of the lovely hatchetfish allows it to hide from predators and prey in the down-welling light of the twilight zone.
Counter-illumination is a method of active camouflage seen in marine animals such as firefly squid and midshipman fish, and in military prototypes, producing light to match their backgrounds in both brightness and wavelength.
Argyropelecus affinis is a species of ray-finned fish in the family Sternoptychidae, described by Garman in 1899, found in the tropical and subtropical Atlantic, Indian and Pacific Oceans. Common names for this fish include Pacific hatchetfish, deepsea hatchetfish and slender hatchetfish. It inhabits the upper mesopelagic zone between 350 and 600m during the day, and between 100m and 350m during the night and is either non-migratory or performs short daily vertical migrations. They are distributed widely throughout all tropical and temperate seas. They are known for its laterally compressed body and characteristic photophores, which aid in bioluminescence. Argyropelecus affinis is closely related to Argyropelecus gigas.
Argyropelecus sladeni, or Sladen's hatchetfish, is a species of ray-finned fish in the family Sternoptychidae, found in the tropical and subtropical Atlantic, Indian and Pacific Oceans. This small fish lives in the mesopelagic zone by day and makes a daily vertical migration to the epipelagic zone at night.
Sternoptyx diaphana, the diaphanous hatchetfish, is a species of deep sea ray-finned fish in the family Sternoptychidae. It is the type species of the genus Sternoptyx, and was first described by the French naturalist Johann Hermann in Der Naturforscher 1781.
Neoscopelus macrolepidotus, also known as a large-scaled lantern fish, is a species of small mesopelagic or bathypelagic fish of the family Neoscopelidae, which contains six species total along three genera. The family Neoscopelidae is one of the two families of the order Myctophiformes. Neoscopelidae can be classified by the presence of an adipose fin. The presence of photophores, or light-producing organs, further classify the species into the genus Neoscopelus. N. macrolepidotus tends to be mesopelagic until the individuals become large adults, which is when they settle down to the bathypelagic zone.
Stomias boa, also known as the boa dragonfish, scaly dragonfish, dragon-boa or boa scaly dragonfish, is a species of deep-sea fish in the family Stomiidae. It is found at great depths worldwide in tropical to temperate oceans but is absent from the northern Pacific and northwest Atlantic Oceans.