Gonorynchiformes: Milkfishes

This is technically the only order in Anotophysi, the outlier to Otophysi in the Ostariophysans. These fishes lack teeth, maybe because they wouldn't fit in their tiny mouths. These fishes have a primitive version of the Weberian apparatus, made of specialized bones to amplify sound transferred from the swimbladder to the ear; the actual Weberian apparatus is found in Otophysans.


Daiju Azuma, commons.wikipedia.org

Chanoidei: Milkfishes

There is only one family, Chanidae, with only one living species, Chanos chanos. They are an important food source in Southeast Asia, and is the national fish of the Philippines. They can grow to be about 1.8m.


By Peter Southwood (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Gonorynchoidei: Beaked Sandfishes

There is one family, Gonorynchidae, with one genus, Gonorynchus. They have an elongate body with a single barbel at the tip of the snout. They lack a swimbladder; hence they lack the primitive Weberian apparatus.


According to Nelson, some species use the swimbladder for respiration. That's pretty darn cool.


Brian Gratwicke, fishbase.org

Kneriidae: Knerias

Don't ask me what a kneria is, because I have kno idea. Some species lack scales and a lateral line. The mouth is underneath the snout.



Phractolaemidae: Snake Mudheads

There is one species, Phractolaemus ansorgii. Unlike most of the other species in this order, this l'il feller has an upturned mouth at the tip of its snout. The esophagus has numerous folds and the swimbladder has been modified to have alveoli for airbreathing.