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IDENTIFICATION OF FISHES

IDENTIFICATION OF FISHES. Within the Lower Sacramento and San Joaquin Rivers, Delta and shoreline Bay habitats. USFWS Juvenile Fishes Monitoring Sites. General Anatomy. Mouth Structure. Dorsal and Anal fin ray counts. First rudimentary ray is not counted

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IDENTIFICATION OF FISHES

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  1. IDENTIFICATION OF FISHES Within the Lower Sacramento and San Joaquin Rivers, Delta and shoreline Bay habitats

  2. USFWS Juvenile Fishes Monitoring Sites

  3. General Anatomy

  4. Mouth Structure

  5. Dorsal and Anal fin ray counts • First rudimentary ray is not counted • Last ray is always treated as a double ray divided to the base of the fin

  6. Lamprey Family, PETROMYZONTIDAE • Anadromous, some freshwater • Lampreys have a notochord and a cartilaginous skeleton • Do not have jaws or paired fins • Larvae, known as ammocoetes • Brook lamprey are nonpredaceous

  7. Lamprey Ammocoete

  8. Anterior Teeth Supraoral Plate Lateral Tooth Plates Transverse Lingual Lamina Pacific Lamprey(PL)Lampetra tridentata Native • Four pairs of lateral tooth plates • Supraoral plate with 3 sharp cusps • Adult avg. TL = 400mm - 690mm

  9. Anterior Teeth Supraoral Plate Lateral Tooth Plates Transverse Lingual Lamina River Lamprey(RL)Lampetra ayresi Native • 3 pairs of lateral tooth plates • Supraoral plate with 2 sharp cusps • Center cusp on transverse lingual lamina large • Adult avg. TL 170mm, never > 320mm

  10. Sturgeon Family, ACIPENSERIDAE • Heterocercal tail • Cartilaginous skeleton • Five rows of large bony plates instead of scales • Highly protrusible, bottom-oriented mouth preceded by four barbels

  11. 38 - 48 lateral plates White Sturgeon(WST)Acipenser transmontanus Native • Barbels are closer to tip of snout than mouth • No dorsal plates behind dorsal fin • 1 row of 1 - 4 plates between pelvic and anal fins

  12. 23 - 30 lateral plates Green Sturgeon(GST)Acipenser medirostris Native • Barbels closer to mouth than to tip of snout • 1 - 2 dorsal plates behind dorsal fin • Two rows with 4 - 8 plates each between pelvic and anal fins

  13. Herring Family, CLUPEIDAE • Marine, anadromous and freshwater • Silvery deciduous scales and thin, deep bodies with a sharp keel on the belly. • Herrings have highly protractile jaws and long, fine gill rakers

  14. 39 mm FL Pacific Herring(PAH)Clupea harengus Native • No black spottingonsides • Origin of pelvic fins under midportion of dorsal fin • Teeth present on vomer (roof of mouth)

  15. American Shad(AMS)Alosa sapidissima Introduced • Row of black spots on sides • 16 - 17 ventral scutes posterior to pelvic fin base • Length to 750mm TL

  16. Threadfin Shad(TFS)Dorosoma petenense Introduced • Thread-like projection at posterior edge of dorsal fin • 8 - 12 ventral scutes posterior to pelvic fin base • One black spot posterior to operculum • Deeper bodied than American shad • Length to 220 mm TL

  17. American Shad MYOMERE COUNT ON GUT APPROXIMATELY 30-35 Threadfin Shad MYOMERE COUNT ON GUT APPROXIMATELY 18-22 AMERICAN SHAD vs. THREADFIN SHAD Photos: Rene Reyes

  18. Anchovie Family, ENGRAULIDIDAE • Mostly marine • Overhanging snout • Long upper jaw extends behind the eye

  19. Northern Anchovy(NAN)Engraulis mordax Native • Snout overhangs lower jaw • Origin of anal fin under or posterior to last few soft-rays of dorsal fin • Pectoral axillary scale more than half the length of pectoral fin

  20. Salmon and Trout Family, SALMONIDAE • Native to cooler waters of the northern hemisphere • Possess an adipose fin and an axillary scale at the base of each pelvic fin • Eleven species native to California

  21. Long black spots on back and dorsal fin Tail covered with spots 13 - 19 rays Chinook Salmon(CHN)Oncorhynchus tshawytscha Native • Numerous small black spots on both lobes of the caudal fin in adults • 6 - 12 parr marks are wider than spaces in between • Leading edge of anal fin is shorter than length of base • Adipose fin clear with dark upper edge in juveniles

  22. Spots on upper caudal 12 - 17 rays Coho Salmon(CHO)Oncorhynchus kisutch Native • Anal fin is sickle-shaped, leading edge is longer than base • Adipose fin has dark pigment on anterior and dorsal margin only • 8 - 12 parr marks are narrower than the spaces in between • Caudal, anal and adipose fins are pale orange

  23. Chinook Salmon Black on gums and base of teeth Small eye Base of teeth white Edge of gums black Coho Salmon

  24. Uniform spots on tail Square tail Rainbow Trout (Steelhead)(RBT)Oncorhynchus gairdneri Native • Spots on dorsal fin of fry • 8 - 13 parr marks are narrower than the spaces in between • Adipose fin has continuous rim of pigment in juveniles • First dorsal ray is black on fry

  25. Juvenile Salmonids of the Central Valley Coho Salmon Rainbow, Steelhead Chinook Salmon 13 - 19 rays 12 - 17 rays 8 - 12 rays • Anal fin has white leading edge and is not sickle-shaped, leading edge is shorter than base • Adipose has some black pigment on dorsal margin only • Dorsal fin has dark leading edge • Anal fin is sickle-shaped, leading edge is longer than base • Leading edges of anal and dorsal fins have white followed by black • Adipose has black pigment on anterior and dorsal margins • Fins are pale orange • Dorsal fin has black spots and black first ray, and a white tip • Adipose has continuous rim of black pigment • Anal fin has anteriormost ray about equal to the length of fin base

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