Stephanoberycoidei

The Stephanoberycoidei is a suborder of marine ray-finned fishes, consisting of about 68 species, the majority (61) of which belong to the ridgehead family (Melamphaidae). They were formerly placed as their own order, the Stephanoberyciformes.<ref name=":0" /> However, more recent taxonomic sources treat them as a suborder of the Beryciformes.<ref name=":1">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

The Stephanoberyciformes are mostly uncommon deep-sea species with little, if any, importance to commercial fishery. They share many morphological similarities with the Berycoidei, their sister order. They are usually found in Australian waters.<ref name=":0">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The whalefishes, which were formerly treated as their own order, are now also placed in this group. Some families treat them as a superfamily within the group named Cetomimoidea; most taxa traditionally placed here would then be the Stephanoberycoidea.<ref>E.g. Nelson (2006)</ref>

The families are:<ref name=":1" />

• Family Stephanoberycidae Gill, 1884 (pricklefishes)
• Family Hispidoberycidae Kotlyar, 1981 (spiny-scale pricklefishes)
• Family Gibberichthyidae Parr, 1933 (gibberfishes)
• Family Rondeletiidae Goode & Bean, 1895 (redmouth whalefishes)
• Family Barbourisiidae Parr, 1945 (redvelvet whalefishes)
• Family Cetomimidae Goode & Bean, 1895 (whalefishes or flabby whalefishes)

Common characteristics include; a generally rounded body, a toothless palate, rather thin skull bones, and a missing orbitosphenoid bone (except for Hispidoberyx).

The gibberfishes on the other hand appear to be closer to whalefishes such as Rondeletia, as has been proposed time and again. These two groups have - apparently as only living fishes - the mysterious Tominaga's organ (A large mass of globular white tissue, that is present anterior to the orbit and posterior and medial to the nostrils and nasal rosette). Rondeletia, meanwhile, is suspected to be very close to the velvet whalefish, Barbourisia rufa.<ref>Paxton et al. (2001)</ref>

Despite their distinctive appearance, this clade is only thought to have diverged from the Berycoidei during the Paleocene.<ref>Template:Cite journal</ref> Potentially the earliest fossil record of the group is of a Rondeletia-like whalefish from the earliest Eocene-aged Fur Formation of Denmark.<ref>Template:Cite journal</ref>

References

• Template:Aut (2006): Fishes of the World (4th ed.). Template:ISBN
• Template:Aut (2001): Larvae and juveniles of the deepsea "whalefishes" Barbourisia and Rondeletia (Stephanoberyciformes: Barbourisiidae, Rondeletiidae), with comments on family relationships. Records of the Australian Museum 53(3): 407-425. PDF fulltext

External links

• {{#invoke:Cite taxon|main|fishbase|genus=|species=|subspecies=}}