Hatchetfish

View data on Catalog of Fishes here.

Dorsal-fin rays 10–11; anal-fin rays 14–16; pectoral-fin rays10–11; total gill rakers 7–9; vertebrae 29. Largest species in genus, often exceeds 55 mm SL; trunk broad, its depth greater than length; dorsal spine long, its length about equal to, or less than, length of dorsal fin; posterior anal pterygiophores long, extend behind and at same level as anal photophores; supra-anal photophore very high, its height more than one-half the distance from ventral body margin to midline (often raised to midline); no body margin extension in front of anal photophores; jaws large; teeth well developed and recurved; gill-raker tooth plates with long spines; usually one longer than others; anterior dorsal surface of tongue with small nodules; postabdominal and anal pterygiophore spines long; in preservative, pigment dark over most of body except lighter in trunk region; if present, pigment band very narrow at base of caudal rays.

Differs from S. obscura in its longer dorsal spine and longer dorsal fin; shorter, wider trunk, absence of a broad pigment band on base of caudal rays, and generally lighter pigment; differs from S. diaphana by its larger mouth, longer teeth and gill-raker tooth plate spines; markedly higher supra-anal photophore; extension of long anal pterygiophores behind and at same level with anal photophores.

This species occurs in the South Atlantic off Brazil, and in the Gulf of Guinea off Africa with widely scattered occurrences in the tropical Atlantic; it is abundant in the northern Gulf of Mexico and the straits of Florida; scattered catches indicate its presence in the southern Caribbean; it has not been reported from the western North Atlantic, but occurs in numbers off the northwest coast of Africa and near the Azores; small catches indicate its presence in the southwestern Indian Ocean from 5°S to 40°S latitude; isolated small to moderate catches south of Java, near the Marshall Islands, in the North Pacific, off California, and in the southeast Pacific indicate a broad range in the Pacific which future collecting should better define.

The deepest-living species in the genus; data indicate a depth distribution from 500 m to 1500 m; greatest concentrations recorded occur between 800 m and 1500 m; overall small rates of captures plus relatively few deep stations may be indicative of a depth preference below 1000 m; no diurnal movement is indicated.

Baird RC. 1971. The Systematics, Distribution, and Zoogeography of the Marine Hatchetfishes (family Sternoptychidae). Bulletin of the Museum of Comparative Zooology 142(1):1–128.

Baird RC. 1971. The Systematics, Distribution, and Zoogeography of the Marine Hatchetfishes (family Sternoptychidae). Bulletin of the Museum of Comparative Zooology 142(1):1–128.

Often exceed 55 mm SL.

Western Atlantic, 1°20'S, 27°37'W to 1°26'S, 27°33'W.

Holotype: MCZ 46400.

Oceanic (Ref. 4739). Does not exhibit vertical migration (Ref. 4462). Feed on copepods, ostracods, euphausiids, amphipods, decapods (Ref. 4739). Photophores develop in adults over 16-18 mm SL (Ref. 4739).

Triangular transparent membrane above anal fin (Ref. 13608).

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 0; Dorsal soft rays (total): 9 - 12; Analspines: 0; Analsoft rays: 13 - 15; Vertebrae: 27 - 30

Oceanic (Ref. 4739). Meso- and bathypelagic (Ref. 58302). Does not exhibits vertical migration (Ref. 4462). Feeds on copepods, ostracods, euphausiids, amphipods, decapods (Ref. 4739). Photophores develop in adults over 16-18 mm SL (Ref. 4739). Minimum depth from Ref. 004054.

fisheries: of no interest

Sternoptyx pseudobscura

This is the largest member of the genus, often exceeding 55 mm SL (Baird, 1971). S. pseudobscura was rare in the Ocean Acre area and was completely absent from discrete-depth samples.

Three specimens were taken in open nets, all in late summer. A 36 mm male was taken in an Engel trawl towed at 0–1025 m. The remaining two specimens were IKMT captures. One, a 14 mm juvenile, was captured in a tow from 0–1003 m, while the other, a juvenile 16 mm SL, was taken at 0–1435 m.

Both the rarity and capture depths of S. pseudobscura in our study area agree with the findings of Badcock and Baird (1980), who showed that this species is uncommon in the western North Atlantic, where S. diaphana is abundant, and that S. pseudobscura is consistently deeper wherever the two species are sympatric.

全球性的種類。分布範圍廣，通常發現於熱帶和亞熱帶海域、但並未發現於地中海。臺灣分布於東北、西南、東南部及東沙群島附近海域。

一般以底拖網捕獲，不具食用經濟價值，通常做為下雜魚用。

為此屬中大型的種類，通常超過55mm SL。D 10-11﹔P 10﹔V 5-7﹔A 12-14﹔GR 6-7﹔脊椎骨29。軀幹寬，它的高度稍微大於其長度。背棘長，它的長度小於或等於背鰭長。臀鰭支鰭骨長。臀上發光器明顯較高，它的高大於身體腹緣到中線的一半(通常升高至中線)。前頜骨短、上頜骨長，齒發達向內彎，為多列。較前面的鰓弓上的鰓耙齒板有較長的棘狀脊。4後腹棘和臀鰭支鰭骨棘長。銀色體表黑色色素比例較低，主要集中於頭部及背側形成側色素條，軀幹較亮；另外，尾鰭基部邊緣有色素寬帶。

大洋性中層魚類，成體無明顯的垂直迴游。以橈腳類、端足類、介形蟲、磷蝦和小魚等為食。

Feeds on copepods, ostracods, euphausiids, amphipods, decapods

widely distributed in the Atlantic

oceanic

nektonic

Known from seamounts and knolls