Otocephala families

Clupeidae is a family of clupeiform ray-finned fishes, comprising, for instance, the herrings and sprats. Many members of the family have a body protected with shiny cycloid (very smooth and uniform) scales, a single dorsal fin, and a fusiform body for quick, evasive swimming and pursuit of prey composed of small planktonic animals. Due to their small size and position in the lower trophic level of many marine food webs, the levels of methylmercury they bioaccumulate are very low, reducing the risk of mercury poisoning when consumed.

Slickheads, also known as nakedheads or smoothheads, are deep water fishes that belong to the family Alepocephalidae. They are most commonly found in the bathypelagic layer, which is approximately 3000m below the surface. They get their name from the lack of scales on their heads. Similarly, the scientific name is from the Greek ᾰ̓- (a-, "not"); λέπος (lepos, "scale"); and κεφαλή (kephalē, "head"). It has about 22 genera with ca. 96 species.

Pristigasteridae is a family of ray-finned fish related to the herrings, including the genera Ilisha, Pellona, and Pristigaster. One common name for the taxon is longfin herring. The taxonomic classification of this family is in doubt; it was traditionally divided into two subfamilies, Pelloninae and Pristigasterinae, but molecu|lar data indicates these families aren't monophyletic.

The tubeshoulders are a family, Platytroctidae, of ray-finned fish belonging to the order Alepocephaliformes. They are found throughout the world, except for the Mediterranean Sea. Tubeshoulders live at moderate depths of , and some have light-producing organs. They are generally small to medium fish, ranging from in length.

The Hypopomidae are a family of fishes in the order Gymnotiformes known as the bluntnose knifefish. They may also be called grass or leaf knifefishes. These electric fish are not often eaten, of little commercial importance, rarely kept as aquarium fish, and poorly studied; however, species in this family may constitute a significant fraction of the biomass in the areas they inhabit.

Sand knifefish are freshwater electric fish of the family Rhamphichthyidae, from freshwater habitats in South America.

The Kneriidae are a small family of freshwater gonorhynchiform fishes native to sub-Saharan Africa.

The Alosidae, or the shads, are a family of clupeiform fishes. The family currently comprises four genera worldwide, and about 32 species.

Dussumieriidae is a family of clupeiform fishes popularly called the "round herrings". It is now recognized by FishBase as a family in its own right; it had been considered to be a subfamily of Clupeidae. It contains two extant genera, and some potential fossil genera. Possibly the earliest record of the group is Nardoclupea from the Campanian of Italy.

REDIRECT Wolf herring

Chanidae is a family of fishes which has a number of fossil genera and one monotypic extant genus which contains the milkfish (Chanos chanos).

Dorosomatidae is a family of clupeiform fishes. It is now recognized by FishBase as a family in its own right; it had been considered to be a subfamily of Clupeidae. It contains 31 extant genera.

Gonorynchidae is a family of ray-finned fish in the order Gonorynchiformes, which has a number of fossil taxa and one extant genus, Gonorynchus, the beaked salmons. They are an ancient group, with fossils known from as far back as the Albian stage of the Early Cretaceous. The family name comes from Ancient Greek γωνία (gōnía), meaning "angle", and ῥύγχος (rhúnkhos), meaning "snout", referring to the angular snout that the type species use to dig themselves into the sand.

Spratelloididae is a small family of marine ray-finned fishes belonging to the suborder Clupeoidei of the order Clupeiformes, which also includes the anchovies and herrings. The taxa in this family were previously classified within the family Clupeidae but are now considered to be a valid family. One genus, Jenkinsia is found in the Western Atlantic, the other, Spratelloides, in the Indian and Pacific Oceans.