Aquatic habitats. warmwatercool water cold water LOTIC benthicdarters, dace, sculpin, darters sculpin stonerollers, bullhead water bluegill, esocidsyellow.

Aquatic habitats

warmwater cool water cold waterLOTIC benthic darters, dace, sculpin, darters sculpin

stonerollers, bullhead

water bluegill, esocids yellow perch trout, salmon column smallmouth bass,

fallfish, channel cats

LENTIC benthic dace sculpin, darters burbot, sculpin

demersal bass, centrarchids yellow perch

pelagic walleye clupeids salmonids, coregonids, lamprey

Freshwater environments

Estuarine environments

Estuarine environment - challenging 1. Freshwater; usually temporary residents

2. Diadromous a. Found in large numbers as they travel through estuary b. Staging area (before moving upstream) e.g. salmon c. Nursery (e.g. shad)

3. True residents (entire life cycle in estuary)Few species in this category, e.g. white perch

4. Non-dependent marineCommonly found in lower reaches of estuary e.g. sculpins, flounders, surfperch

5. Dependent marine (a least 1 life-cycle stage)Spawning grounds or nurseries or feeding grounds for adults

Intertidal environment – very harsh Crashing surf Strong currents/tides Daily exposure to air But, great spatial heterogeneity, abundance of food

Intertidal (littoral) environment Residential status of the ichthyofauna: 1. True residents: (dominant)

e.g. sculpins, blennies, clingfishes, gobies, gunnels

2. Partial residents (juveniles): (dominant)e.g. blennies, surfperches, labrids, some cottids, pholids

3. Tidal (= feeders) many species

4. Seasonal (= spawners) few species

Neritic zone (to ~200 m)Neritic zone

Neritic zone terratogenic sources of nutrients within the photic zone, highly productive energy from waves, tides, for mixing

coral reefs, kelp forestshighly complex physical habitat, diverse physical nicheshighly speciose - about 40% of fish fauna - 6000-8000 spp

many species, few members, mostly smallmany specialized adaptations, particularly for feeding

continental shelfarea out to 200 m deep - average 700 km widemud/silt substrate, not complex, little structural complexitymostly ground feeders - gadids, pleuronectidsfew species, very abundant, mostly large (up to 1m)

(euphotic)

(disphotic)

(aphotic)

Depth (m)

closed ~ 3.7 mya

saline, cold

saline, cold

hot

23°C

2.5°C

14°C

2.5°C

225 MYA180 MYA

130 MYA 70 MYA

Barriers to marine dispersal

continental drift – separated continental shelf areas

continents – absolute barriersisthmus of Panama, Suez, closed ~ 3.7mya

submerged geographic features – mountains, sills

temperature – tropics vs. temperate, currents

salinity barriers – polar regions

Freshwater fishes

Paleozoic MYACambrian 570Ordovician 505 first fishesSilurian 38Devonian 408 placoderms; age of fishesCarboniferous 360 hagfishes and lampreysPermian 286

MesozoicTriassic 245 Pangea convergence – paddlefish, sturgeonJurassic 208 Pangea split bowfins, gars, lungishes Cretaceous 144 Esocidae, Umbridae, Salmonidae

Cenozoic Tertiary

Paleocene 65 Cyrpinidae, Percidae, CatasomidaeEocene 58 Centrarchidae, Ictaluridae, Oligocene 38Miocene 24Pliocene 5

QuaternaryPleistocene 1.8 period of glaciationRecent

225 MYA180 MYA

130 MYA 70 MYA

Freshwater fishes

no FWfishes

Holarctic

950 spp

2200

2501500-3000

1800

230

Ethiopian

Native ichthyofauna: Atlantic salmon European eel Sea lamprey Brown trout Sturgeon Shad

Six ichthyofaunal groups based on origin (Gilbert, 1976):

EurasianEsocidae, Umbridae, Cyprinidae, Catostomidae, Percidae

North American (endemics)Ictaluridae, Centrarchidae, Goodeidae, Amblyopsidae, Hiodontidae, Percopsidae, Aphredoderidae

Marine originCottidae, Sciaenidae, Atherinidae, Cyprinodontidae, Petromyzontidae, Anguillidae

Central AmericanPoeciliidae

South AmericanCharacidae, Pimelodidae, Cichlidae

Archaic Old-World (Laurasian)Amiidae, Lepisosteidae, Polyodontidae, Acipenseridae