| Family | Scientific Name | Author | Year | Common Name |
| Gonostomatidae | Cyclothone pseudopallida | Mukhacheva | 1964 | Slender Bristlemouth |
All Cyclothone Species: Anal fin rays 16-21. Dorsal fin origin not well in advance of anal fin origin. Photophores absent from isthmus; IV photophores 13-17. Anterior rays of dorsal and anal fins not elongate. Body with 2 rows of photophores or photophores inconspicuous. Pectoral fin rays 7-13. OA photophores 6-10; SO (photophore situated near anterior end or symphysis of lower jaw) photophores absent. 29-33 vertebrae. Maxillary teeth short and subequal, posteriorly increasing in length where they either remain subequal or form a repeat series of an elongate slender tooth followed by a series of smaller subequal conical teeth; palatine teeth in an anterior patch. Eyes very small.
Cyclothone pseudopallida
Unique Characteristics: Two gill rakers at angle of 1st gill arch; total gill rakers 15-20 (rarely 20); gill rakers on 1st hypobranchial 4. Snout pigment conspicuous around nares only. Branchiostegal membrane with pigment conspicuously concentrated over rays and along margins. Lateral photophores 8 or 9; ventral photophores 16 or more (very rarely (1%) 15).
Similar Species:
Cyclothone acclinidens, Benttooth Brisitlemouth
Benttooth Bristlemouth, Cyclothone acclinidens. Two gill rakers at angle of 1st gill arch; total gill rakers 23-27. Snout pigment diffuse throughout snout region. Branchiostegal membrane with pigment uniform or not heavily concentrated over rays and along margins. Posterior series of maxillary teeth sharply curved forward, enlarging uniformly caudad, without small intermediate teeth. Lateral photophores 9 or 10 (rarely (2%) 8).
Cyclothone alba, White Bristlemouth
White Bristlemouth, Cyclothone alba. One gill raker in angle of 1st gill arch; total gill rakers 14. Snout pigment absent or inconspicuous.
Cyclothone braueri, Pale Bristlemouth
Pale Bristlemouth, Cyclothone braueri. Two gill rakers at angle of 1st gill arch; total gill rakers 15-20 (rarely 20); gill rakers of 1st hypobranchial 3. Snout pigment conspicuous around nares only. Branchiostegal membrane with pigment conspicuously concentrated over rays and along margins; Lateral photophores fewer than 8; ventral photophores between pelvic fin and end of anal fin fewer than 16.
Cyclothone microdon, Smalltooth Bristlemouth
Smalltooth Bristlemouth, Cyclothone microdon. Two gill rakers at angle of 1st gill arch; total gill rakers 19-22; gill filaments fused basally in broad segment shape along hypobranchial. Snout pigment diffuse throughout snout region. Branchiostegal membrane with pigment uniform or not heavily concentrated over rays and along margins. Posterior series of maxillary teeth slightly curved forward, enlarging caudad but with long teeth separated by smaller teeth. Lateral photophores fewer than 9; 3 (rarely 4) VAV photophores anterior to genital pore.
Cyclothone pallida, Tan Bristlemouth
Tan Bristlemouth, Cyclothone pallida. Two gill rakers at angle of 1st gill arch; total gill rakers 23-27; gill filaments not fused in broad segment shape along hypobranchial. Snout pigment diffuse throughout snout region. Branchiostegal membrane with pigment uniform or not heavily concentrated over rays and along margins. Posterior series of maxillary teeth slightly curved forward, enlarging caudad but with long teeth separated by smaller teeth. Lateral photophores fewer than 9; 2 (rarely 3) VAV photophores anterior to genital pore.
References:
Goode, G.B. and T. H. Bean. 1896. Oceanic ichthyology. A treatise on the deep-sea and pelagic fishes of the world, based chiefly upon the collections made by the Steamers Blake, Albatross, and Fish Hawk in the northwestern Atlantic, with an atlas containing 417 figures. Special Bulletin. Smithsonian Institution. United States National Museum. Washington, DC. 927 pp.
Schaefer, S., R.K. Johnson, and J. Badcock. 1986. Gonostomatidae. In Smiths’ Sea Fishes, edited by M. M. Smith and P.C. Heemstra. Johannesburg, MacMillan, South Africa, pp. 247-253.