Electrofishing 

For the electrofishing lab we went to the Rocky River Nature Center, located between North Olmstead and the airport. There we met with members of the Cleveland Metroparks staff and learned how to use a long line electrofisher. Electrofishing is a fish sampling method which sends a controlled DC electric pulse through the water to stun fish. The fish then float to the surface and can be easily captured for identification. After identification, the fish can be returned to the water unharmed. Identifying the fish species which are present in an aquatic community enables aquatic ecologists to assess the health of the community.

Location Map

Having a ball catching some fish!

Longline Electrofisher

We sampled a total of 25 fish species in six different Families. Those families included Centrarchidae (sunfish),  Ictaluridae (catfish), Cyprinidae (minnows), Percidae (darters and perches), Gobiidae (gobies), Salmonidae (trout and salmon), and Catostomidae (suckers).

Family Centrarchidae

Largemouth Bass

Green Sunfish

Smallmouth Bass

Bluegill Sunfish

Rock Bass

Pumkinseed Sunfish

Family Centrachidae are the sunfish. This family generally prefers warm water environments. Members of this family can be distinguished from most other families by the vertical orientation of their pectoral and pelvic fins. We sampled three genera of Centrarchids; Lepomis, Micropterus, and  Ambloplites. Members of Lepomis include the bluegill sunfish (L. macrochirus),  Pumpkinseed sunfish (L. gibbosus), and green sunfish (L. cyanellus). Bluegills are extremely common and are best differentiated from other sunfish by their deep body and solid black tab at the end of the operculum. Pumkinseeds are slightly smaller than bluegills and have a small red patch at the end of their operculum. Green sunfish are very aggressive and have a large mouth. They are pollutant tolerant and have the ability to live in many different habitats.  We caught two species of Micropterus; largemouth bass (M. salmoides) and smallmouth bass (M. dolomieu). Smallmouth bass are native predators in the area. Largemouth Bass have dark lateral lines on their body. They are common predators in weedy environments but have recently moved into the stretch of stream we sampled. Rock bass (Ambloplites rupestris) represented the final genus. They live in rocky habitats where they can eat invertebrates.





Yellow Bullhead

Family Ictaluridae

Family Ictaluridae are the catfish the only member we found was Yellow Bullhead (Ameiurus natalis). They have eight barbells near their mouth for detecting prey. Four of them are a lighter color and four are a darker color. They also have poor eyesight since they feed on the bottom and at night.

Family Cyprinidae



Sand shiner and Silverjaw minnow

Rosyface minnow

Common Carp



Bluntnose minnow

Striped Shiner

Central Stoneroller

Creek Chub

Spotfin Shiner



Common shiner

 
Family Cyprinidae are the minnows. They are mostly insectivorous and are extremely diverse. We caught species from seven genera, these included Cyprinus, Notropis, Luxilis, Cyrinella, Campostoma, Semotilus, and Pinephales. Common carp (Cyprinus carpeo) are a non-native species and brought to America for food. They have barbel whiskers by their mouth that can help them sense food. We caught multiple species from the next genus, Notropis. These are the silverjaw minnow (N. buccatus), sand shiner (N. straminius), and rosyface shiner (N. rubellus). All are insectivorous and rosyfaces are intolerant of regularly turbid water. Common shiners (Luxilus cornutus) are pollution semi-tolerant and are more prevalant in upstream reaches of a river. Striped shiners (Luxilus chrysocephalus) are found more often in the main branches of the river. Spotfin Shiners (Cyrinella spiloptera) have a dorsal fin that has a black spot on it giving rise to their name. Their habitat is mostly rocky. The central stoneroller (Campostoma anomalum) is a herbivorous minnow with a sub-terminal mouth for grazing. They are very pollution tolerant. Creek chubs (Semotilus atromaculatus) have a large terminal mouth so they are able to feed on larger prey. Large creek chubs will even eat other fish! They are very pollutant tolerate native fish. Bluntnose minnows (Pinephales notatus) get their name from their bulbous nose and are the most common fish species in Ohio.

Note barbels on common carp.

                                        Family Percidae  



Rainbow Darter

Greenside Darter

Family Percidae are the perches and darters. We caught members of Genus Etheostoma.  These were the rainbow darter (E. caeruleum ) and greenside darter (E. blennoides). Darters are generally sensitive to pollution and serve as good bio-indicators.

Family Gobiidae

Family Gobiidae are the gobies. Round Goby (Neogobius melanostomus) is an invasive species in the great lakes that likely got introduced through ballast water from ships. They are a very large problem and prey on fish eggs. Interestingly, they are also now a major food source for smallmouth bass.

Round Goby

Family Salmonidae

Steelhead Trout

Family Salmonidae are the trout and salmon. Steelhead trout(Onchorhyncus mykiss) are not native, but are stocked by the Ohio Division of Wildlife for sportsmen. They don't reproduce that well in Ohio streams so they would not persist if the stocking program ended.

Family Catostomidae

White Sucker

Northern Hog Sucker (foreground)

Golden Redhorse

Family Catostomidae are the suckers with subterminal mouths. Northern hog suckers (Hypentelium nigricans) are smaller, prey on insects, and are pollution intollerant. White suckers (Catostomus commersonii) are omnivores with a more rounded head. They are pollution tolerant. Golden redhorses (Moxostoma erythrurum) are a pollution intolerant species and are mainly insectivorous.