Argyropelecus lychnus, known as the Tropical Hatchetfish or Silver Hatchetfish, is a marine fish found mainly in tropical waters. Tropical Hatchetfish are deep bodied (i.e., they are deep back to belly relative to their length) and highly compressed laterally (i.e., from side to side). The main source of food for this species is apparently copepods (Harold 1993). Tropical Hatchetfish females are oviparous, laying planktonic eggs that hatch into planktonic larvae (Harold 1993).

Tropical Hatchetfish are absent from the Atlantic Ocean and only one specimen has been found in the Indian Ocean. They are found mainly in tropical Pacific waters (Harold 1993). They are usually found between 300 m and 400 m during the day. At night, however, the fish move up in the water column to between 200 m and 350 m. Although this is the primary depth range for this species, Tropical Hatchetfish are known to occur between 200 m and 700 m (Watson 1996).

Copepods have been found in the food items consumed by this species (Ref. 6885). Oviparous, with planktonic eggs and larvae (Ref. 35838).

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.

View data on Catalog of Fishes here.

South of Cuiba Island, Panama, 6°17'N, 82°05'W, Albatross station 3360, depth 1672 fathoms.

Lectotype: USNM 57885.

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.

Dorsal-fin rays 9; anal-fin rays 12; pectoral-fin rays 10–11; total gill rakers 16–18; vertebrae 35–37. Medium to large species often exceeding 60 mm SL; body deep, depth at end of dorsal greater than 1.5 into SL; dorsal blade high, height about 2.5 times into its length; postabdominal spines of about equal size, anterior one slightly smaller, not smoothly curving but blunted or squared; upper preopercle spine long, directed posteriorly and usually ventrally; lower spine usually curved slightly anteriorly or straight down; jaws large, teeth recurved especially in lower jaw, no large canines; gill rakers medium to short, dentate; first preanal photophore usually lower than third; spiny scales present in adults below subcaudal photophores; the gap made by the anal pterygiophores contains two haemal spines lacking pterygiophores; in preservative, pigment dark dorsally, diffuse on trunk with small, light pigment spots on midline.

Western Pacific: Papua New Guinea (Ref. 6993) and New Zealand (Ref. 5755). Eastern Pacific: southern British Columbia, Canada to California, USA and farther south (Ref. 2850).

Pacific restricted species, caught SE LaHave Bank, northwest Atlantic

New Zealand Exclusive Economic Zone, North West Atlantic

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Absent from the Atlantic; represented possibly by a single sample from the Indian Ocean. Primarily restricted to the tropical Pacific; found in abundance in the eastern Pacific between 35° N and 35°S; distribution narrows across the equatorial Pacific as far as 160˚W; a moderate catch from the lesser Sunda Islands indicates a possible transequatorial distribution in the Pacific.

Eastern Pacific between 30°N and 35°S.

Dorsal spines (total): 0; Dorsal soft rays (total): 9; Analspines: 0; Analsoft rays: 12; Vertebrae: 35 - 37

Maximum size: 59 mm TL

5.9 cm TL (male/unsexed; (Ref. 2850))

Exceeds 60 mm SL.

Branchiostegal rays: 10 (Ref. 35838). Lower preopercular spine downward and curved forward, upper preopercular spine curved outward. Two postabdominal spines directed ventrally (Ref. 37473).

Two separate postabdominal spines; anal subcaudal gap fewer than 2.0 times anal-preanal gap; dorsal rays. Both postabdominal spines of about equal length and size; anterior margin of posteriormost abdominal keel scale almost vertical; greater than 3.5 times body depth. No pair of enlarged canines in lower jaw; anteriormost postabdominal spine squared or blunt (except very small individuals), not curving evenly forward; upper preopercular spine extends well beyond posterior border of preopercle; no pigment on outermost caudal rays. Dorsal blade high, blade height greater than 2.7 mm for SL 25–50 mm, greater than 3.8 mm for SL greater than 50 mm; body robust; spiny scales present below subcaudal photophores (fish greater than 30 mm SL); pigment spots minute along posterior midline; upper preopercle spine usually curved ventrally, never dorsally.

Cotype for Argyropelecus lychnus
Catalog Number: USNM 170966
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes
Year Collected: 1891
Locality: S. of Panama, Panama, Pacific
Depth (m): 2323 to 2323
Vessel: Albatross

Cotype for Argyropelecus lychnus
Catalog Number: USNM 57885
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes
Year Collected: 1891
Locality: S. of Cuiba Is. Panama, Panama, Pacific
Depth (m): 3058 to 3058
Vessel: Albatross

Cotype for Argyropelecus lychnus
Catalog Number: USNM 120239
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes
Year Collected: 1891
Locality: Off Galapagos Islands, Galapagos Islands, Pacific
Depth (m): 605 to 605
Vessel: Albatross

Cotype for Argyropelecus lychnus
Catalog Number: USNM 120240
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes
Year Collected: 1891
Locality: Off Panama, Panama, Pacific
Vessel: Albatross

Cotype for Argyropelecus lychnus
Catalog Number: USNM 120241
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes
Year Collected: 1891
Locality: Off Panama, Panama, Pacific
Depth (m): 1335 to 1335
Vessel: Albatross

bathypelagic; marine; depth range 200 - 700 m (Ref. 35838)

nektonic

Known from seamounts and knolls

Occasionally found in Canadian Atlantic waters. Mesopelagic species; found to depths of 650 m.

Depth range based on 35 specimens in 2 taxa.
Water temperature and chemistry ranges based on 32 samples.

Environmental ranges
  Depth range (m): 100 - 1900
  Temperature range (°C): 2.189 - 13.466
  Nitrate (umol/L): 14.710 - 43.935
  Salinity (PPS): 33.831 - 34.716
  Oxygen (ml/l): 0.107 - 5.177
  Phosphate (umol/l): 1.574 - 3.267
  Silicate (umol/l): 15.832 - 159.993

Graphical representation

Depth range (m): 100 - 1900

Temperature range (°C): 2.189 - 13.466

Nitrate (umol/L): 14.710 - 43.935

Salinity (PPS): 33.831 - 34.716

Oxygen (ml/l): 0.107 - 5.177

Phosphate (umol/l): 1.574 - 3.267

Silicate (umol/l): 15.832 - 159.993
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Habitat Type: Marine

Concentrated between 300 m and 400 m off California by day, with the highest concentration near 400 m; by night major concentrations occur from 200 m to 350 m, with no marked indication of geographical variation in depth.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Oviparous (Ref. 35838).

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: GNR - Not Yet Ranked

Not Evaluated