Stylephoridae

Stylephoridae
Temporal range: Middle Eocene (Bartonian) to present
Stylephorus chordatus
†Parastylephorus anatoides (life restoration)
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Division: Teleostei
Order: Gadiformes
Suborder: Stylephoroidei
Family: Stylephoridae
Regan, 1924
Genera

Stylephoridae is a family of marine ray-finned fishes. It is the only family in the suborder Stylephoroidei and, depending on its classification, the order Stylephoriformes. Historically placed in the order Lampriformes, more recent analyses incorporating genetic data frequently ally it with the Gadiformes as its basalmost member. It contains two genera, commonly called tube-eyes, after the unusual, large, tubular eye morphology. These comprise the extant Stylephorus and the extinct Parastylephorus.

Both known genera exhibit a highly modified skull and jaw morphology for cranial kinesis, allowing for rapid expansion of the buccal cavity for suction feeding. Stylephorids are further characterized by a very elongate and compressed, ribbon-like body with a dorsal fin running along the entire upper margin of the body. Both genera exhibit a reduction of squamation (scale covering), with Stylephorus effectively lacking scales entirely, and Parastylephorus retaining a single row of lateral-line scales along each side of the body.

The large number of shared features between Parastylephorus and Stylephorus, despite living 40 million years apart, indicates an unexpected degree of morphological stasis within Stylephoridae. This suggests the stylephorid body plan is successful in deep sea environments, supported by the sustained stability of this region of the ocean. The stylephorid lineage had diverged from other gadiforms by at least Campanian stage of the Late Cretaceous.

Taxonomy

The cladogram below illustrates the position of Stylephoridae within the Gadiformes, in relation to other living neoteleosts:

Neoteleostei

References

  1. ↑ Fricke, R.; Eschmeyer, W. N.; Van der Laan, R. (2025). "Eschmeyer's Catalog of Fishes: Classification". California Academy of Sciences. Retrieved 2026-08-11.
  2. ↑ Miya, Masaki; Holcroft, Nancy I.; Satoh, Takashi P.; Yamaguchi, Motoomi; Nishida, Mutsumi; Wiley, E.O.; Masaki Miya; Nancy I. Holcroft; Takashi P. Satoh; Motoomi Yamaguchi; Mutsumi Nishida; E.O. Wiley (2007-11-26). "Mitochondrial genome and a nuclear gene indicate a novel phylogenetic position of deep-sea tube-eye fish (Stylephoridae)". Ichthyological Research. 54 (4): 323–332. Bibcode:2007IchtR..54..323M. doi:10.1007/s10228-007-0408-0. S2CID 38375399.
  3. ↑ Roa-Varón, Adela; Dikow, Rebecca B; Carnevale, Giorgio; Tornabene, Luke; Baldwin, Carole C; Li, Chenhong; Hilton, Eric J (2020-12-21). Ruane, Sara (ed.). "Confronting sources of systematic error to resolve historically contentious relationships: a case study using gadiform fishes (Teleostei, Paracanthopterygii, Gadiformes)". Systematic Biology. 70 (4): 739–755. doi:10.1093/sysbio/syaa095. ISSN 1063-5157. PMC 8561434. PMID 33346841.
  4. 1 2 Near, Thomas J.; Thacker, Christine E. (2024-04-18). "Phylogenetic classification of living and fossil ray-finned fishes (Actinopterygii)". Bulletin of the Peabody Museum of Natural History. 65 (1). doi:10.3374/014.065.0101. ISSN 0079-032X.
  5. 1 2 3 Ridolfi, Lorenzo; Schrøder, Ane Elise; Bahrami, Ali; Yazdi, Mehdi; Roa‐Varón, Adela; Marramà, Giuseppe; Carnevale, Giorgio (2026-08-11). "A new fossil from the Eocene of Iran provides new insights regarding the evolution of the morphologically bizarre tube‐eye fish". Papers in Palaeontology. 12 (4) e70114. doi:10.1002/spp2.70114. ISSN 2056-2799.
  6. ↑ Regan, Charles Tate (1924-04-01). "The morphology of a rare oceanic fish, Stylophorus chordatus, Shaw; based on specimens collected in the Atlantic by the "Dana" expeditions, 1920-1922". Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character. 96 (674): 193–207. doi:10.1098/rspb.1924.0021. ISSN 0950-1193.