Sternoptyx diaphana

Sternoptyx diaphana, Longspine Hatchetfish. Source: Baird 1971.
Sternoptyx diaphana, Longspine Hatchetfish.
Source: Baird 1971.
FamilyScientific NameAuthorYearCommon Name
SternoptychidaeSternoptyx diaphanaHerman1781Longspine Hatchetfish
Sternoptychidae, Marine Hatchetfishes. Source: FAO 2002
Sternoptychidae, Marine Hatchetfishes.
Source: FAO 2002

All Sternoptyx Species: Body laterally compressed, deep, greatest body depth 0.8 to 2.0 in Standard Length Exposed bony dorsal blade ahead of dorsal fin; iliac or postabdominal spines present. Eyes not tubular, directed laterally. PV photophores 10. Dorsal blade a single median flattened spine and prominent. BR photophores 3, IP 5.

Sternoptyx sp. Source: FAO 2002.
Sternoptyx sp. Source: FAO 2002.

Sternoptyx diaphana

Unique Characteristics: Posterior AN photophore adjoining A base; SAN photophore raised V2 or less distance to mid trunk-line; little pigment in region of mid trunk-line.

Sternoptyx diaphana, Longspine Hatchetfish. Source: Weitzman 1986.
Sternoptyx diaphana, Longspine Hatchetfish.
Source: Weitzman 1986.

Similar Species:

Sternoptyx pseudobscura – Highlight Hatchetfish

Sternoptyx pseudobscura, Highlight Hatchetfish. Source: Baird 1971.
Sternoptyx pseudobscura, Highlight Hatchetfish.
Source: Baird 1971.
Sternoptyx pseudobscura, Highlight Hatchetfish. Source: Weitzman 1986
Sternoptyx pseudobscura, Highlight Hatchetfish.
Source: Weitzman 1986

Highlight Hatchetfish, Sternoptyx pseudobscura. Posterior AN photophore separated from A base; SAN photophore height 1.5-2.5 in trunk depth, often raised to mid trunk-line; non-uniform dark pigment on trunk.

References:

Baird, R.C. 1971. The systematics, distribution and zoogeography of the marine hatchetfishes (family Sternoptychidae). Bull. Mus. Comp. Zool., Harvard Univ., 142:1-128.

Weitzman, S.H. 1986. Family No. 75: Sternoptychidae. In Smith’s sea fishes, edited by M.M. Smith and P.C. Heemstra. Johannesburg, Macmillan South Africa, pp. 253-259.