Fish Family Life History

Diadromous Fish

• General category of fish that spend one portion of their life somewhere and another portion elsewhere

• Anadromous fish are born in freshwater, then migrate to the ocean as juveniles where they grow into adults before migrating back into freshwater to spawn.

  • examples: salmon, smelt, American shad, hickory shad, striped bass, lamprey, gulf sturgeon

• Catadromous fish are born in saltwater, then migrate into freshwater as juveniles to grow into adults before migrating back to saltwater to spawn

  • eels

• Potamodromous fish are born in upstream freshwater habitats, then migrate downstream (still in freshwater) as juveniles to grow into adults before migrating back upstream to spawn.

  • examples: sickefin redhorse, lake sturgeon, robust redhorse, flathead catfish

Types of Scales

• ctenoid (bass), cycloid (salmon), ganoid (gar), placoid (shark)

• Dorsal (up), anterior (front), posterior (back), ventral (under)

• Review external anatomy of fish

• Terminal, superior (points up), inferior sub-terminal mouth

Order Acipenseriformes

• 2 families on our list

• Basal (old) ray finned fish

• Chondrostel (surgeons and paddlefish)

• Actinopterygii

Acipenseridae—sturgeons

• freshwater, brackish, and marine

• Anadromous or restricted to freshwater

• cold to temperate water

• 5 rows of scutes, ganoid scales

• inferior mouth

• 4 barrels anterior to mouth

• toothless adults—omnivorous bottom feeders

• eat anything they can suck up—invertebrates

• 25 species—most threatened/endangered

Polyodontidae—Paddlefish

• Mostly freshwater

• Snout resembling a paddle with minute barbels

• Body scaleless

• Heterocercal caudal fin

• Minute teeth

• Greatly extended operculum

• Require large free-flowing rivers

• Two species both threatened

• Extirpated from NC

Order Lepisosteiformes

Lepiososteridae—Gars

• chiefly freshwater, occasionally brackish

• elongate body

• elongated jaw, needle like teeth

• heavily armored with ganoid scales

• dorsal fin far to posterior

• shallow weedy areas

• Vascularized swim bladder allows aerial respiration

Order Amiiforms (Bowfins)

Amiidae (Bowfins)

• freshwater

• long dorsal fin (48 dorsal rays)

• cycloid scales

• large median gular plate (under mouth)

• swim bladder capable of respiratory function

• lowland rivers, swamps, backwaters

• distinguish bowfin from northern snakehead (anal fin is normal sized compared to super long)

Order Anguiliformes (Eels)

Anguillidae (freshwater eels)

• Catadromous—born in saltwater, life in fresh, return to salt to spawn and die

• no pelvic fins

• minute embedded scales don’t overlap

Eels in Sargasso sea

• they migrate there to reproduce

Clupeiformes

Clupeidae—herring and shad

• mostly anadromous or marine

• adiposa eyelids

• pelvic axillary processes

• cycloid scales—easily shed

• keeled ventral midline composed of modified scales or scutes

• usually silvery

• large schools

• grow rapidly, short life span

Order Cypriniformes

• two families from our lists

Cyprinidae—minnows, shiners, carps

• Cyprium= copper, shiny

• largest family of fishes, 2100 spp. US and Canada = 231 spp.

• Variation among species—morpholohy, diet, ecology

• Lack teeth in mouth

• up to 3 rows of pharygneal teeth deep in throat grind food against basioccipiral bone

• one dorsal fin with less than 10 rays

• No true spines in fins (carp have a dorsal “spine”)

• cycloid scales on body

• Abdominal pelvic fins

Catostomidae—Suckers

• Stoma = mouth or opening

• US and Canada = 63 spp.

• Large size and hige abundance—great biomass in streams and lakes

• large thick lips

• soft rays in fins

• no teeth in jaws

• pharyngeal teeth

• one dorsal fin

• 9 or more dorsal rays

• Abdominal pelvic fins

• Anal fin far back on body

• Cycloid scales on the body

• No scales on the head

• Robust redhorse thought extinct but rediscovered in NC in 1990’s

Order Siluriformes

Ictaluridae (N. Amer freshwater catfishes)

• - Luridus = sallow, yellow-pale brown

• US and Canada = 40 spp

• Active mainly at night

• Barbels (“whiskers”) around the mouth

• No scales

• An adipose (fat) fin — sensory? stabilize?

• Stout spines at dorsal and pectoral fin origins

• Abdominal pelvic fins

Order Salmoniformes

Salmonidae—trout and salmon

• Salmon family

• cool-cold streams and lakes

• commercially important

• some are anadromous—live in sea, migrate to freshwater to spawn

• Many small cycloid scales

• 1 dorsal fin plus an adipose fin

• Abdominal pelvic fins

• Axillary process at the base of the pelvic fin

• No spines in the fins

• Brook trout are native to NC (and require very specific conditions, requiring restoration efforts), rainbow trout are not native

Esociformes

• Pike, pickerel, muskellunge

Esocidae—pikes, pickerel, muskellunge

• fresh and brackish water

• duckbill-like snout

• many small cycloid scales

• forked caudal fin

• feed on variety of fish and other vertebrates

• common throughout northern hemisphere

Perciformes (3 families)

Centrarchidae (sunfishes and black basses)

• centrarch= ridge, dorsal fins pronounced and spiny

• 30 spp. in freshwater of N.A.

• Popular sport fishes

• males build nests and guard young

• laterally compressed

• 2 dorsal fins (so broadly jointed that they appear as 1 fin)

• 1st dorsal fin has spines

• 2nd dorsal fin has rays

• 3-8 anal spines

• Thoracic pelvic fins

• no sharp spine near the back of the gill cover

• Ctenoid scales

Moronidae (temperature basses)

• Moron = dull

• Poplar sportfish

• Compressed, deep-bodied

• 2 dorsal fins

• 1st dorsal fin with 9 spines

• 2nd dorsal fin with 1 spine and 11-14 rays

• 3 anal spines

• Large mouth

• Ctenoid scales

• Thoracic pelvic fins

• Complete lateral line

• large spine on the gill cover

• small “gill” on the underside of the gill cover (pseudobranch)

• strongly sawtoothed preopercle)

Percidae (perches, walleyes, darters)

• “perch” family

• Canada + US = 153 spp. 2nd to Cyprinidae

• most are darters

• small-most < 10 cm (Except walleye, yellow perch, sauger)

• swim bladder absent

• colorful, especially breeding males

• 2 dorsal fins