Eastern Mosquitofish

Gambusia holbrooki

Mosquito Control in Maryland

The Eastern Mosquitofish is small, only growing up to 1 1/2 inches long. It is a light olive-brown color on top, with silvery sides and a yellowish belly. It has rows of black spots on its dorsal (back) fin and caudaul (tail) fin. This fish's mouth is near the top of its head, and it has a black "tear drop" under its eye.

Eastern Mosquitofish live in ponds, lakes, marshes, and slow-moving streams. They like places with muddy bottoms, shallow water, and lots of plants.

Copyright, Florida Fish and Wildlife Conservation Commission, www.FloridaFisheries.com

Copyright, www.jjphoto.dk

Mosquitofish breed from April to August. Female mosquitofish are one of our few native livebearing fish. This means baby fish are born alive; mothers do not lay eggs. One female fish can give birth to more than 200 young each year. Fry (baby fish) are born three to four weeks after mating.

These small fish are voracious eaters. They will eat just about any living thing that fits in their mouth, including: worms, mites, small crustaceans, insects (aquatic and terrestrial), snails, tadpoles, and algae. Of course, they eat tons of mosquito larvae and pupae, which is how they get their name.

Copyright 1998, Stephen L. Doggett

Mosquitofish are very aggressive. They attack and shred the fins of larger fish. They also eat eggs and young of other fish, including Largemouth Bass and Common Carp. They sometimes even eat each other! Because they are so aggressive, Eastern Mosquitofish are almost always in competition with other fish and animals which eat insects. They can "starve out" other fish species and amphibians (frogs, toads, and salamanders).

USGS

Eastern Mosquitofish often have a parasite called "The Big Red Worm." This worm is actually a nematode, which uses the mosquitofish as part of its life cycle. Other parts of the The Big Red Worm's life cycle involve larger fish, birds, and aquatic worms. This parasite doesn't usually do much damage to the mosquitofish.

Predators of Eastern Mosquitofish include larger fish, snakes, frogs, turtles, birds, crayfish, and some large aquatic insects.

Relationships in Nature:

FOOD/PREY
PREDATORS
SHELTER
OTHER

Asian Tiger Mosquito

Bluegill

Arrow Arum

The Big Red Worm Pa

Earthworm

Crayfish

Green Algae

Stagnant Pond Snail

Green Darner

Lizard's Tail

Freshwater Leech

Large Diving Beetle

Common Duckweed

Water Flea

Northern Water Snake

Common Cattail

CommonWater Strider

Eastern Painted Turtle

Yellow Pond Lily

Black Carpenter Ant

Six-spotted Fishing Spider

Pickerelweed

Snow Flea

Yellow Perch

Long-leaf Pondweed

Green Algae

Channel Catfish

Hydrilla

Bluegill

Black Crappie

Greater Bladderwort

Largemouth Bass

Common Snapping Turtle

Common Reed

Crane Fly

Creek Chub

Buttonbush

Common Carp

Great Blue Heron

Tussock Sedge

Yellow Perch

Mallard

Black Willow

Crayfish

Belted Kingfisher

Swamp Rose Mallow

Southern Leopard Frog

Raccoon

Ebony Jewelwing

Bullfrog

American Toad

Golden Shiner

Aquatic Worm

Copepod

Northern Caddis Fly

Green Hydra

Relationship to Humans:

People have been using mosquitofish for some time to try to control mosquito populations. They have been introduced to ponds, streams, lakes, and marshes where they were not previously living, and also added to birdbaths, ditches, and other places mosquitos breed. Sometimes they help, but often this causes more problems and can lead to even more mosquitos. Since mosquitofish are aggressive, they will eat the eggs and young of other species of mosquito-killing animals, such as fish and frogs.

SCIENTIFIC CLASSIFICATION

KINGDOM
Animal
PHYLUM
Chordate
CLASS
Bony Fish
ORDER
Atheriniformes
FAMILY
Poeciliidae
GENUS
Gambusia
SPECIES
Gambusia holbrooki

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