Michigan Fishes II Powerpoint

advertisement
Michigan Fishes II
6 November 2012
Non-native species
26 total in Michigan!
• Petromyzontidae: Petromyzon marinus – sea lamprey
• Anguillidae: Anguilla rostrata – American eel
• Clupeidae: Alosa pseudoharengus - alewife
• Osmeridae: Osmerus mordax – rainbow smelt
• Gobiidae: Neogobius melanostomus – round goby
•
•
•
•
Cyprinidae: Cyprinus carpio – common carp
Salmonidae: Oncorhynchus mykiss – rainbow trout
Salmonidae: Salmo trutta – brown trout
Centrarchidae: Lepomis microlophus – redear sunfish
Threatened species
~35 threatened, endangered, or extirpated in Michigan
• Acipenseridae: Acipenser fulvescens – lake sturgeon (T)
• Hiodontidae: Hiodon tergisus – mooneye (T)
• Lepisosteus oculatus – spotted gar (SC)
• Noturus stigmosus – northern madtom (EN)
• Noturus miurus – brindled madtom (SC)
Source: http://web4.msue.msu.edu/mnfi/data/specialanimals.cfm
Commercially important fishes
• Esocidae: Esox masquinongy – muskellunge
• Salmonidae: Coregonus clupeaformis – lake whitefish
• Percidae: Stizostedion vitreum – walleye
• Centrarchidae
– Ambloplites rupestris – rock bass
– Lepomis macrochirus – bluegill
– Lepomis gibbosus – pumpkinseed
– Micropterus spp. – smallmouth and largemouth bass
Misc.
• Lepisosteidae: Lepisosteus osseus – longnose gar
Petromyzontidae
Lampreys: family characteristics
• Body eel-like
• Mouth is a sucking disc
• No jaws, no paired fins,
no scales
• Single median nostril
• Seven external gill openings on each side
Petromyzon marinus – sea lamprey
•
•
•
•
•
•
Separate dorsal fins
Teeth in radiating rows
Adults parasitic – disc as wide as body
Big – commonly 30-60 cm or more
Native to Finger Lakes of New York, introduced to Great Lakes in mid-1800s, decimated local
fish populations in 1930s and 40s
Control efforts, including electric current, chemical lampricides, and barriers, vary in success
Anguillidae
Freshwater eels: family characteristics
• Body anguilliform
• Pectoral fins present, pelvic fins absent
• Terminal mouth, jaws well toothed
• Small, embedded, linear scales
• Median fins (dorsal, caudal, anal) continuous
Anguilla rostrata – American eel
•
•
•
•
•
•
Sharp pointed head, jaws present
Only eel species in Michigan
Catadromous
Leptocephalus larval stage
Introduced to Great Lakes in 1800s – stocked in rivers in Illinois, thrown overboard from ships
carrying them as rations
Impacts in Michigan unknown, but in Texas and S. Carolina have brought Asian nematode
Clupeidae
Shads and herrings: family characteristics
• Compressed body
• Thin cycloid scales
• Head naked
• Midline of belly with spiny scutes
• No lateral line
• Gill rakers numerous and long
Alosa pseudoharengus – alewife
•
•
•
•
•
•
•
Body more elongate and streamlined than Dorosoma cepedianum
Upper margin of mandible forms strong shoulder
Invaded Lake Ontario in late 1800s, successful due to overfishing of large Salmonid predators
Distributed to Great Lakes in mid-1900s
Impact: restructures food web
May be responsible for decline of native salmonids (e.g., lake herring, arctic grayling)
Periodic large-scale die-offs in 1960s  annoying and a health hazard!
Osmeridae
Smelts: family characteristics
• Body slender and compressed
• Single soft-rayed dorsal fin
• Adipose fin
• Head naked, body scales cycloid, mod. size
• Large mouth with strong teeth
• Tongue with fangs!
Osmerus mordax – rainbow smelt
•
•
•
•
•
•
•
Only Osmerid in Michigan
Long slender body
Closely resembles Salmonids (both families in Order Salmoniformes)
Like many salmon species, spawn in streams (in this species, in early spring)
Rainbow smelt eggs were stocked in 1912 in Crystal Lake which drains into Lake Michigan
Now commercial fishery
May have contributed to loss of blue pike from Great Lakes, compete with juvenile lake trout
Gobiidae
Gobies: family characteristics
• Large head, sharp teeth, usually terminal mouth
• Two dorsal fins
• Flexible spine at beginning of anal fin and 2nd dorsal fin
• Pelvic fins fused to form disc-like cup
• Family extremely speciose
Neogobius melanostomus– round goby
•
•
•
•
•
No opercular spines – distinguish from?
Black spot at posterior of first dorsal fin
Native to Eurasia
Compete with native species for food
Feed on eggs and fry of sculpin and darters
Non-native review species
• Cyprinidae: Cyprinus carpio – common carp
– Native to Eurasia
– Records in all states but Alaska
– Deteriorates habitat by eating vegetation, increasing turbidity
• Salmonidae: Salmo trutta (brown trout) and Oncorhynchus mykiss
(rainbow trout)
– Both stocked for fisheries
• Centrarchidae: Lepomis microlophus – redear sunfish
– Native to Southeast/lower Midwest
– Intentionally stocked for sportfishing
– Molluscivorous, so may compete with L. gibbosus
Acipenseridae
Sturgeons: family characteristics
• Body with five rows of bony plates
• Caudal fin heterocercal
• Mouth ventral and protrusible
• Conical snout with two pairs of elongate
barbels
• Partly cartilaginous skeleton
Acipenser fulvescens – lake sturgeon
•
•
•
Juveniles with long, pointed nose and large bony plates
Barbels (usually 4) surround mouth
Threatened due to:
– Overharvesting
– Pollution
– Closing of migratory channels
Hiodontidae
Mooneyes: family characteristics
• Body compressed and herring-like
• Midline of belly keeled but without spiny scutes
• Large eye, no adipose fin, single short dorsal fin
Hiodon tergisus – mooneye
•
•
•
•
•
Silvery body
Lateral line distinct
Moth strongly toothed, including
toothed plate on tongue
One of only two Osteoglossomorph spp in N America
Impact factors:
– Isolated populations
– Intolerant to silt and turbidity
– Agriculture and industrialization
Review threatened species
• Ictaluridae: Noturus miurus & N. stigmosus
– Intolerant to pollutants
– Sensitive to increased turbidity, siltation, and stream flow
alterations
– Are in decline all across range
– N. miurus competes for spawning ground and cover with
round goby
• Lepisosteidae: Lepisosteus oculatus
– Requires clear vegetated water  these habitats in decline
across range
– Sensitive to siltation, dredging, and harbor improvements
Esocidae
Pikes: family characteristics
• Body elongate, terete
• Single dorsal, opposed to anal, far back on body
• Snout duck-like with canine teeth
• Caudal fin forked
Esox musquinongy – muskellunge
• Scales on only upper half
of cheek and opercle
• Dorsal, caudal, and anal
fins with dusky spots
• Dark bars on light
background (not always
visible in large specimens)
• “Legendary for its size” – record 65” and 70 lb
Salmonidae
Trouts: family characteristics
•
•
•
Body terete to moderately compressed
Single soft-rayed dorsal fin, adipose fin present
Cycloid scales on body, head naked
Coregonus clupeaformis – lake whitefish
•
•
•
•
•
Mouth subterminal
Snout rounded
Axillary scale present
Two flaps between nostrils
Most important commercial fish in lakes Ontario and Huron
–
•
•
More than $5mill in catches from these two lakes in 1 yr
Critical component in Lake Michigan commercial fishery
Popular sport fish in all of the Great Lakes
Percidae
Perches: family characteristics
• Body usually elongate
• Two dorsal fins that may be
contiguous or separate
• Anal fin with 1 or 2 spines
• Lateral line usually complete
Stizostedion vitreum - walleye
•
•
•
•
Dusky blotch on webbing between last 3
dorsal spines (1st dorsal)
Tip of lower lobe of caudal fin and anal fin
white
Grow to 25” and 5 lb
In peak years, make up half the value of
Lake Erie fishery
Lepisosteidae
Gars: family characteristics
• Body elongate with ganoid (rhombic) scales
• Snout and jaws extended into strong flattened
beak with conical teeth
• Caudal fin abbreviate heterocercal
Lepisosteus osseus – longnose gar
•
•
•
•
Snout beak-like, long and narrow
Head not spotted
Black streak across body
Grows to 72” in length
Download