Fish Disease

Answer 1

Opportunistic infection Spp: Channel Catfish, Japanese eels, Occurs at high temp and organic pollution Uncommon zoonosis 3-5mm red cutaneous foci on flanks and peduncle (Catfish); supparative coelomic infection (Jap. eels).

Answer 2

Obligate pathogen Spp. Channel catfish Open ulcer on frontal bone (encephalitic form), peritoneal effusion (Acute septicemic form)

Question 3

Answer 3

“red sore disease” aeromonas hydrophilum

Pathogenesis: Opportunistic pathogen, polluted water, high temps, overcrowding; found with water molds, and epistylis protozoan

Zoonotic (low risk) -exposure of wounds, ingestion of infected fish

CS: White or hemorrhagic masses on skin, mouth, or gills

Assoc. with GN infection

Dx: Isiolation from the kidneys.

Tx: formalin (), Pot. permanganate, Salt water, antibiotics

Question 4

Leech “Myzodbella”

Answer 4

tx: Organophosphate

Answer 5

“Cyclops” Free living

“Ergasalid” FW and MAR- cephalothorax and abdomen “Lernaeidae”- Anchored female- Koi, goldfish Tx: Organophosphate prolonged immersion( x amount q 7d for 28 days) Or Diflubenzuron prolonged immersion

Question 6

Answer 6

“Argulus” Focal red lesions, erratic behavior Cyprinids, centrarchids, salmonids 2 month life-cycle Tx: Organophosphate prolonged immersion; Formalin bath; Potassium permanganate May serve as intermediate host for fish nematodes

Question 7

Isopods

Answer 7

“Flabellifera-Cymothoids”- 6cm “Gnathiidae”- larvae are infected, live in anemones Tx: Organophosphate, biologic control (cleaner fish),

Question 8

Monogeneans

Answer 8

Monopisthocotlea (dactogyrids (ovip), gyrodactylids (Vivip), capsalids “benedenia- 2 pairs of anchors”, “Neopenedeia-3 pairs anchors” (Ovip))- centralized hooks -Oviparous- free swimming stage is infective Polypisthocotyleans-Sucking clamps CS: Mucus production, pruritis, anemia Tx: FW bath (for small species) - 1 hour Formalin (25ppm prolonged immersion EOD x 3tx) Organophosphate bath (resistance in some monogeneans)-2-5ppm trichlorfon for 60 minutes) Reduce crowding (for viviparous monos which transmit fish to fish) Potassium Permanganate (5ppm x 1 hour) Copper (Prolonged immersion) 0.15-0.2mg/L Chloramine T

Question 9

Answer 9

“Ergasalid”

• similar to free- living but with antennae for grasping
• ~2mm long
• cephalothorax and abdomen

Species: FW >MAR

-Life-cylce- 1-5 free living nauplius stages, 105 free living copepod statges, 1 pre-adult, then adult

Question 10

Answer 10

Lernaeids “Anchor worms”- Lernae

Dx- Scope, wet mount

Locaton- gill arches, oral cavity

Species: common in Koi, but can affect any fish

Life-cycle: lay larvae every 2weeks for 16 weeks, hundred of larvae

Female penetrates skin

Can cause hemorrhage or secondary bacterial infection at att. site

Tx: Manual removal, Potssium permanganate

*Organophosphates* “Diflubenzuron” q 7 d x for 4 weeks- not legal in farmed fish

*Sodium chlorite (20-40ppm) prolonged immersion with EOD water changes for 2 weeks.

Question 11

Answer 11

Found on skin and gills

Viviparous- Feeds for 6 days on host, falls off, continues growing T

x: Formalin (Except lookdown turbs); Organophosphate

Question 12

Answer 12

Monopisthocotlea

Oviparous “Live bearer”

Tx:

Question 13

Answer 13

Monopisthocotlea

Viviparous

Infx skin and gill in MAR and FW species

Tx: FW bath (for small species) - 1 hour Formalin (25ppm prolonged immersion EOD x 3tx) Organophosphate bath (resistance in some monogeneans)-2-5ppm trichlorfon for 60 minutes) Reduce crowding (for viviparous monos which transmit fish to fish) Potassium Permanganate (5ppm x 1 hour) Copper (Prolonged immersion) 0.15-0.2mg/L Chloramine T

Answer 14

Monopisthocotlea

“benedenia- 2 pairs of anchors”

“Neopenedeia-3 pairs anchors”

Oviparous, centralized hooks, free swimming stage is infective CS: Mucus production, pruritis, anemia Tx: FW bath (for small species) - 1 hour Formalin (25ppm prolonged immersion EOD x 3tx) Organophosphate bath (resistance in some monogeneans)-2-5ppm trichlorfon for 60 minutes) Reduce crowding (for viviparous monos which transmit fish to fish) Potassium Permanganate (5ppm x 1 hour) Copper (Prolonged immersion) 0.15-0.2mg/L Chloramine T

Answer 15

Polypisthocotyleans-Sucking clamps

Question 16

Answer 16

CS: Salt dusting

Tx: Formalin- 25ppm q EOD for 2 weeks with a water change on alternate days- variable success (most effective if administered late at night as this is when Tomites excyst)

Leteux-Meyer-25ppm formalin and 0.1ppm

Hyposaliity- < 16ppt for 14d, or <10ppt for 3h q 3d x 4 tx

Question 17

Answer 17

MW or FW fish

Location: S/G, somtimes repro or GI

CS: Skin erosions, anorexia

Tx:

Water change- correction of water quality abnormalities

Formalin Bath or prolonged immersion

Potassium permanganate prolonged immersion

Acetic acid bath (FW only)

SW bath (FW only) vs. FW bath (SW only)

Copper prolonged immersion

Question 18

Answer 18

Chilodonella piscicola and hexasticha

Cilliate (cilia on ventral surface)

30-80 x 20-60um

Location: SG

CS: tattered skin, blue sheen on body

Tx: Formalin bath or prolonged formalin immersion

Question 19

Answer 19

“Marine velvet disease”

Marine analogue of cholodonellosis

causes acute mortalities in troical fish

Oval shape wiht numerous ciliary rows

56-86 x 32-50um

Tx: Formalin Bath 50ppm

Question 20

Answer 20

Free living ciliate that can be lethal

causes mucus production and epithelial damage

30-60 x 50-100um

Tx: Formalin

Question 21

Answer 21

Scuticociliatosis

Uronema marinum

MAR fish

Found on skin, gills

CS: ulceration/depigmentation of skin, Dyspnea

Tx: FW bath followed by a 24 hr formalin prolonged immersion

Question 22

Answer 22

Amyloodinium “Marine velvet disease”

Dinoflagellate

Warm water, MAR fish

CS: Golden/dust sheen on scales, flashing

Tx: Tx free swimming dinospore (trophonts and tomonts are resistant)

Copper - 0.15mg/L (using 1mg/ml Copper stock solution)

FW dip- removes

Question 23

Answer 23

Found on skin and gills

Very small (5-8 x 10-15um)

two forms: detached mobile form (2-4 flagella) or adhered pyriform

Tx: Formalin tx; saltwater (for FW fish only)

Question 24

Answer 24

FW Ciliate

C- shaped maconucleus seen in trophonts

Catfish and loaches particularly susceptible

Tx: Formalin 25-50ppm x 3tx with water change on alternate days; Copper (pond fish), Formalin and Malachite green

Question 25

Answer 25

Found on gills of FW or MAR fish Found in polluted FW or MW Attaches to gills via recurrent flagellum Tx: Formalin bath or prolonged immersion

Question 26

Answer 26

Gills Found in salmonids Tx: 2-6hr FW bath

Question 27

Answer 27

Found on wet mount of F or G Sessile/solitary = Apisoma, Ambiphyra, Riboscphidia Caprinana- tentacles that emanate- can cause mechanical blockage of the gills reproduce by binary fision Tx: Formalin bath, prolonged immersion; Copper prolonged immersion

Question 28

Answer 28

"Red sore disease" "Epistylis" Often assoc. with a mixed Gram negative bacteria known as "Red-sore disease" Common in pond-raised fish Reproduce by binary fision Can be free-living , colonizing debilitated fish Produces wite or hemorrhagic lesions on the flanks or tips of bony prominences such as the fins, jaws or gill operculum May also become invaded by water molds Spp. Centrarchids, ictalurids Dx: wet mount of S/G CS: amorphous masses on skin or mouth Tx: Formalin bath or prolonged immersion K permanganate Salt bath 3 x weekly Salt prolonged immersion

Question 29

Answer 29

"Saproleniosis, oomycete infection" CS: Cottony proliferations Class: oomycetes Orders: Saprolegnia, Letomitale, peronosporales Opportunistic, called "winterkill" during cold months Tx: Prolonged salt immersion; Copper prolonged immersion; Malachite green (Leutex Meyer)

Question 30

Answer 30

* Aphoanomyces invadans* "Epizootic Ulcerative Syndrome" - Atypical water mold infection- containing broad Aseptate hyphae CS: Causes deep penetrating ulcers Issue in estuarine fish in the w atlantic and astralo-pacific and S. Asia Dx: Culture with Glucose-yeast medium Tx: NO known treatment. Can try malachite green or leteux meyer.

Question 31

Answer 31

Effects skin and gills "saddleback" disease FW fish Dx: wet mounts (long, thin rods ~0.5-1.0 C 5-10um, gliding motions CS: EPithelial disease--\> erosive, necrotic skin and gill lesions (witish plaques with red periphery), or fins (especially caudal fin) Gill infection less common but more serious pathogenesis: Opportunistic; Found at increasing temperatures Mineral content is important (less pathogenic in soft water) Tx: Potassium permanganate Copper sulfate 3ppt salinity can preven tdisease

Question 32

Answer 32

"Bacterial Cold water disease" Dx: Wet mounts of skin , with long, thin rods Opportunistic CS: spring, temps \< 50F; subacute to acute infection in young fish (distended abdomen, exophthalmia, severe anemia); scoliosis, lordosis in older fish Associated with erythrocyte includion syndrom Spp: FW salmonids (problem in hateries), esp. Coho salmon; cyprinids, and eels, Rainbow trout Tx: Quaternary ammonium, chloramine-T or copper sulfate;often fish require systemic antibiotics

Question 33

Answer 33

Virus of MW antd FW fish CS: salt-like dusting on the body, may coallesce to masses Spp: does not effect salmonids, catfish or cyprinidsTx/Pathogenisis: Chronic (usually many weeks)- self limiting, no tx.

Question 34

Answer 34

Glochidia-producing FW bivalve molluscs Pathogenesis- Infective larvae are released by adult clams and dispersed passively to gills and skin of fish using sharp hooks

Answer 35

Mycoplasma

Answer 36

Goldfish furunculosis Obligate pathogen Common bacterial disease in FW fish- Atlantic salmon, carp, goldfish, koi, japanese eels (rainbow trout resistant) Dx: Skin or internal lesions Acute to chronic morbidity/mortality CS: ulcers, exophthalmos, swollen abdomen Pathogenesis- shed in the feces via horizontal transmission

Question 37

Answer 37

Photobacterium Damselae ssp piscida Causes chronic mortalities. Small hemorrhages on operculum or base of skin.

Question 38

Answer 38

Causes anemia, skin ulcers Tx: TFM (3-trifluoromethyl-4-nitrophenol