Illinois Photo © 2010, T. Lawrence, Great Lakes Fishery Commission detail of sea lamprey's oral disc FFiisshheess detail of mooneye teeth sea lamprey attached to lake trout Salvelinus namaycush Petromyzon marinus mooneye Hiodon tergisus Photo © 2010, Great Lakes Fishery Commission Volume I Photos © 2010, Uland Thomas chestnut lamprey Ichthyomyzon castaneus goldeye Hiodon alosoides Photo © 2010, Philip Willink/The Field Museum of Natural History, Chicago Photo © 2010, Shedd Aquarium detail of silver lamprey's oral disc silver lamprey Ichthyomyzon unicuspis northern brook lamprey Ichthyomyzon fossor Photo © 2010, Shedd Aquarium Photo © 2010, Philip Willink/The Field Museum of Natural History, Chicago Alabama shad Alosa alabamae Photo © 2010, Patrick O’Neil, Geological Survey of Alabama least brook lamprey Lampetra aepyptera American brook lamprey Lampetra lamottei Photo © 2010, Julie Zimmerman Photo © 2010, Philip Willink/The Field Museum of Natural History, Chicago skipjack herring Alosa chrysochloris Photo © 2010, Patrick O’Neil, Geological Survey of Alabama alewife Alosa pseudoharengus Photo © 2010, Engbretson Underwater Photography shovelnose sturgeon Scaphirhynchus platorynchus Photo © 2010, Shedd Aquarium bowfin Amia calva Photo © 2010, Engbretson Underwater Photography gizzard shad Dorosoma cepedianum American eel Anguilla rostrata Photo © 2010, Shedd Aquarium Photo © 2010, Engbretson Underwater Photography pallid sturgeon Scaphirhynchus albus shortnose gar Lepisosteus platostomus threadfin shad Dorosoma petenense Photo © 2010, NEBRASKAland Magazine/Nebraska Game and Parks Commission Photo © 2010, Uland Thomas Photo © 2010, Uland Thomas lake sturgeon Acipenser fulvescens paddlefish Polyodon spathula Photo © 2010, Engbretson Underwater Photography Photo © 2010, Engbretson Underwater Photography longnose gar Lepisosteus osseus spotted gar Lepisosteus oculatus Photo © 2010, Engbretson Underwater Photography Photo © 2010, Uland Thomas pproximately 22,000 fish species inhabit the Species List Species are not shown in proportion to actual size. Aearth, with about 790 species found in the fresh Kingdom Animalia Phylum Chordata waters of the United States and Canada. More than This poster was made possible by: 200 fish species are known from Illinois’ aquatic habi - Family chestnut lamprey Ichthyomyzon castaneus Family bowfin Amia calva tats. The large variety of species means that fishes Petromyzontidae northern brook lamprey Ichthyomyzon fossor Amiidae silver lamprey Ichthyomyzon unicuspis Illinois Department of Natural Resources occupy almost all available aquatic habitats and have least brook lamprey Lampetra aepyptera Family goldeye Hiodon alosoides Education Section American brook lamprey Lampetra lamottei many strategies for doing so. This poster depicts 22 Hiodontidae mooneye Hiodon tergisus Division of Fisheries species from the eight families that are considered the sea lamprey Petromyzon marinus most primitive fish representatives in the state. Family American eel Anguilla rostrata Family lake sturgeon Acipenser fulvescens Anguillidae Although labeled “primitive” these vertebrates have Acipenseridae pallid sturgeon Scaphirhynchus albus complex life cycles with some living only in fresh shovelnose sturgeon Scaphirhynchus platorynchus water, some living in fresh water but migrating to salt Family Alabama shad Alosa alabamae Illinois Wildlife Preservation Fund Clupeidae skipjack herring Alosa chrysochloris Funding for this poster was made possible Family paddlefish Polyodon spathula water to reproduce and others living in salt water but alewife Alosa pseudoharengus Polyodontidae in part by contributions to the Illinois Wildlife gizzard shad Dorosoma cepedianum traveling to fresh water to spawn. Numerous adapta - Preservation Fund. tions help them to meet the challenges of living in threadfin shad Dorosoma petenense Family spotted gar Lepisosteus oculatus water. Fishes are vital components of aquatic ecosys - Lepisosteidae longnose gar Lepisosteus osseus tems and their associated food webs. shortnose gar Lepisosteus platostomus Structure Life History ishes are vertebrates that breathe through gills. They have fins, and most are covered with With about 22,000 types of fishes in the world, there is great variety in their life history. F scales. They live in water, a very demanding medium, and sometimes they live in water Some commonalities do exist, although there are always exceptions. This section will discuss that flows, requiring additional adaptations. In general, fishes are streamlined to help them the general life history of the fishes depicted on this poster with some specific examples move through the water column with the least resistance. If they live on the bottom of streams, provided. the bottom of their body may be flat, an adaptation that helps them avoid being washed away by the current. If their body is cylindrical they may be able to hide in rocks or crevices. Most fishes have external fertilization. The sperm and eggs are released at approximately perculum the same time in close proximity. The water keeps the eggs moist and allows sperm to Water provides support for aquatic o dorsal fin organisms, so large, complex limbs (gill cover) Illinois swim to them. Mating in fishes is known as spawning. Most Illinois fishes spawn in are not needed to overcome the eye spring and summer. Spawning may be accompanied by a migration. Depending on the effects of gravity. Fishes use fins to species, eggs may sink or be carried by the current, attach to vegetation, gravel or rocks, help them move, steer the body, mouth be deposited in a hollow log or be placed in a “nest” that has been cleared on the bottom. pro vide stability, function as brakes pectoral Parental care varies from none to defending the eggs and newly hatched young for a short fin anal fin caudal and maintain position in the water. pelvic fin (tail) fin time. Generally, the greatest numbers of eggs are produced by the species with the least There are single (dorsal, caudal, parental care. Eggs hatch within a few days. Newly hatched young feed on a supply of adi pose, anal) and paired fins (pectoral, pelvic). The swim bladder is a gas-filled internal stored yolk until they can obtain food on their own. Fishes have the potential to grow organ that can be adjusted so that the fish’s density is equal to that of the water, in effect throughout their life and to live for many years. allowing it to suspend itself effortlessly in the water column. Fishes that live on the bottom may not have a swim bladder. The examples below provide details of some specific life cycles of fishes represented on this poster. Most fishes have scales. Some primitive fishes, like sturgeons and gars, have hard scales that do not overlap. The majority of fish species have thin scales that overlap. Other fishes Lampreys – Lampreys have both a larval and an adult stage. The ammocoete is the blind, have no scales but have a tough, leathery skin for protection. A film of mucus is secreted FFiisshheess larval form that hatches from the fertilized egg. It burrows tail first into the bottom of the by the skin of all fishes. The mucus helps decrease resistance with the water column as the small stream where it hatched leaving only the head sticking out to filter microscopic fish swims and helps to maintain the internal salt balance of the fish. organ isms that pass by. It transforms to the adult after several years. There are two types of Gills are located on each side of and behind the head. The gills of most fishes are covered adult lampreys. Some species are parasitic on fishes. Other species do not feed as adults. The by a bony flap, the gill cover. A gill has a hard gill arch with many fleshy gill filaments, parasitic lamprey adult leaves the small stream and swims to a larger river or lake. It uses its each loaded with blood vessels. As water is forced over the gills, oxygen is removed from oral disc to attach to a fish and scrape a hole in the body through which it sucks blood and the water at the filaments, and carbon dioxide is released into the water. Gill filaments are Volume I tissue fluids. After feeding in this manner for several days, the lamprey drops off. The host very fragile and can be easily damaged. fish is generally not killed directly but may die due to infections that invade through the Fishes can see, but depending on the clarity of the water, the sense of sight may not be of wound. Parasitic lampreys feed in this manner for one to two years before migrating to much value to them. They have an inner ear for hearing and for aiding with equilibrium small streams to spawn. Spawning usually involves many lampreys at the same location. In in the water. The sense of smell is acute and used for finding food, recognition of locations, those species that are not parasitic, the adults remain in the small stream after transforming homing, migration and finding a mate. Most fishes have a lateral line, a series of open-ended from the larval stage. They do not feed and die soon after spawning the next spring. tubes along the sides. The lateral line system detects moving and fixed objects in the water American eel Anguilla rostrata American eel adults spend five to 20 years in fresh water and helps supplement the other senses. before migrating to the sea to breed. Males tend to stay near the coast, while females travel far inland until their movement is blocked by a dam or other object. Any eel found natu rally in Illinois is a female. The eggs are laid in the Sargasso Sea of the Atlantic Ocean near Cuba. Larval eels live in the ocean for about a year before transforming to the elver stage and traveling to fresh water. Alabama shad Alosa alabamae The Alabama shad lives most of its adult life in salt water, Species Descriptions spotted gar Lepisosteus oculatus coming to fresh water only to reproduce. Adults are present in the Mississippi River drainage system from April through July but at no other time. Young are present only The spotted gar may grow to about three feet in length.