Freshwater

Smallscale archerfish

Toxotes microlepis

The smallscale archerfish has a pointed snout and large eyes. Their back is relatively flat and …

Smelt, Rainbow

Osmerus mordax

A slender, silvery fish with a pale green or olive green back. When fresh, the sides …

Snook, Common

Centropomus undecimalis

A silvery fish with a yellow-green or olive hue, it has a streamlined and slender body …

Snook: Fat Snook, Swordspine Snook, Tarpon Snook

Centropomus parallelus, Centropomus ensiferus, Centropomus pectinatus

The fat snook has a deeper body than other snook, although it is not severely compressed. …

Southern ninespine stickleback

Pungitius platygaster

The southern ninespine stickleback can be distinguished from its European relatives by the large flaps on …

Speckled peacock bass

Cichla temensis

Speckled peacock bass has dark spots on the operculum and three distinctive vertical black stripes on …

Spined loach

Cobitis taenia

The spined loach has a long, slender body, slightly compressed laterally, which helps it move easily …

Splake

Salvelinus namaycush x Salvelinus fontinalis

Splake are difficult to identify externally as they resemble both parents. The body shape is intermediate …

Spotted lungfish

Protopterus dolloi

The spotted lungfish has a body very similar to that of an eel. It is elongated …

Squawfish, Northern

Ptychocheilus oregonensis

The mouth of the northern squawfish is terminal and large, extending backward beyond the anterior margin …

Steelhead

Oncorhynchus mykiss

Steelhead are usually slender and streamlined. The dorsal coloration is mostly blue-green with an olive hue, …

Sterba's corydoras

Corydoras sterbai

Compared to other species in the genus, Sterba's Corydoras has a relatively high body. There are …

Stonecat

Noturus flavus

Stonecats have an olive, yellowish, or slate-colored upper half of the body and are the only …

Stoneroller, Central

Campostoma anomalum

The Central Stoneroller has a thick and poorly compressed torpedo-shaped body of dull gray color with …

Striped headstander

Anostomus anostomus

The body of the striped headstander is elongated, slightly compressed laterally, resembling a torpedo. The head …

Striped snakehead

It is a bony fish with an endoskeletal thorax. Body subcylindrical, head depressed, caudal fin rounded. …

Sturgeon, Atlantic

Acipenser oxyrinchus

The Atlantic sturgeon is dark brown or olive green with a white belly. The head is …

Sturgeon, Lake

Acipenser fulvescens

Lake sturgeon are somewhat torpedo-shaped, and the upper lobe of the caudal fin is longer than …

Sturgeon, Shovelnose

Scaphirhynchus platorinchus

The shovelnose sturgeon has a broad, flat head with an elongated shovel-like snout. There are four …

Sturgeon, White

Acipenser transmontanus

The adult white sturgeon has a moderately blunt snout, spines closer to the tip of the …

Sturgeon: Green Sturgeon

Acipenser medirostris

Sturgeon and paddlefish, best known for their black caviar, belong to the order Acipenseriformes, but at …

Sucker, White

Catostomus commersoni

White suckers have inconspicuous coloration, usually sparse shades of white, yellow, and pink. Adults have almost …

Sucker: Northern Redhorse

Maxostoma macrolepidotum

Suckers are most easily distinguished by their small mouths and large fleshy lips. They have no …

Sumatra barb

Puntigrus tetrazona

These barbs have tall, strongly compressed bodies. There are no whiskers. Females are larger than males …