Bellwork: 09/03/2013

• ** Don’t forget to take pH, temperature, and salinity. Feed your fish & note general health & if they are eating, diseased, etc.

1) What three waste products are formed during the nitrogen cycle?

2) What would happen to an established system if algae and water plants were removed?

FISH:Anatomy & Disease

FISH

• cold-blooded, vertebrate that breathe w/gills and move w/fins

• most numerous vertebrates more than 30,000 species

• smallest – Philippine Island Goby –

1/3”- 1/2”

• largest – Whale Shark – 50’ and 35+

tons

EVOLUTION

• Earliest fish – Ostracoderms• fossils date to the Ordovician

Period – 425-450 Million years ago

• slow, bottom-dwelling w/thick bony plates and scales, poorly developed fins and no jaws

• believed to be first animal w/a backbone

• became extinct 250 million years ago

Parts of a Fish

Parts of a Fish

FISH ANATOMY

Most fish are covered with:• SCALES (thin, bony plates that

overlap each other and provide protection.) – Covered w/a thin layer of skin

that produces a slimy mucus to keep out bacteria.

– 4 types of scales • ctenoid – serrated edges

and rough surfaces (bass and crapie

FISH ANATOMY cycloid - smooth surfaces and edges (salmon & carp)

FISH ANATOMY ganoid – diamond shaped,

shiny, hard (gars & bichirs [ancient fish])

FISH ANATOMY Placoid – sharp, “one-way”

scales (sharks & rays)

FISH ANATOMY

• FINS – movable structures that aid the fish in swimming and maintaining balance

• May be sharp, spiny or soft • Most have: Dorsal fin

Anal fin Caudal fin(tail)

Pectoral fin Pelvic fin Adipose fin (only some, catfish, in between dorsal and caudal fin)

FISH ANATOMY

• GILLS – organs on the side of fish that allow them to breath

• Water is drawn in through the mouth and out the gills

• Dissolved oxygen in the water is taken into the blood and carbon dioxide is released

FISH ANATOMY - EYES

• similar to other vertebrates, but differ in a couple of ways: – spherical lens– no eyelids– size of the eye depends on

the amount of light reaching the eye

• Shallow water – small eyes

• Deep water – large eyes

• Dark caves – blind

FISH ANATOMY- ears, taste, smell, sensitive cells

• Have inner ears• Have taste buds in their

mouths, on their lips and on their body/fins

• Have highly developed sense of smell

• Fish react to changes in water pressure, temperature, currants and sounds w/pressure sensitive cells along a lateral line near the base of the tail

Bellwork – 08/30/2011• ** Don’t forget to take pH, temperature, and salinity. Feed your fish &

note general health & if they are eating, diseased, etc.

1) What physical characteristics would you expect to find on a fish that, on average, swims at a very high speed (55 – 65 mph)?

2) After running a full DNA comparison panel on a new species of fish, you discover that it is likely from a line of fish millions of years old. What type of scale would you expect to see on this fish?

COMMON FISH DISEASES• Parasites – organism that lives

on or within another organism and derives nourishment from the host.

1. “Ick” – White Spots one of the most common disease of aquarium fish

- caused by protozoa named Ichthyophthirius multifilis

-lives under skin and multiplies rapidly when fish is stressed

-breaks out at maturity; produces reproductive spores that infect again

- you fish will look like it has a bunch of pimples

-chemical treatment

COMMON FISH DISEASES

2. Slime Disease – parasite attacks skin causing fish to produce more mucus

- attacks the gills

- dull color

- weakens fish and

may cause death

- chemical treatment

COMMON FISH DISEASES3. Hole-in-the-head – live

under skin and in muscle tissue

- cause by protozoa that lives at low levels in most fish (2ndary infection)

- as the organisms multiply the tissues break down, the skin opens and the decayed tissue breaks away – leaving “holes” in the head

- may be caused by a vitamin deficiency; supplements may aid

COMMON FISH DISEASES

4. Fin-rot/Cloudy Eye:

- White fungus growth growths on the fins, mouth, eyes, gills

- remove fish and treat new ‘hospital aquarium” water w/medicine found at the pet stores until fungus disappears

COMMON FISH DISEASES

5. Flukes – tiny worm-like parasites that attach to the gills

- scrape to relieve irritation

- color dulls

- produce more mucus

- use “hospital aquarium” and buy treatment at pet store

- thoroughly clean both aquariums

COMMON FISH DISEASES

6. Anchor Worms- regularly found on goldfish

- have an organ on their mouth that will burrow under the scales and

attach to muscle tissue

- commercial water treatments are available

- parasite may be removed by hand w/tweezers

COMMON FISH DISEASES

7. Fish lice – fish become infected from feeding on infected plankton

- attach to the fish; pierce the skin w/a spine; discharge a poison

- may be fatal to young fish- remove w/tweezers; place

in a hospital tank and add treatment

- thoroughly clean original tank.

COMMON FISH DISEASES

8. Dropsy:- the abdomen will appear swollen/distended. - fish scales may stand out in the swollen area- fish may appear listless and lose appetite. - can be caused by bad water, viruses, or bacteria- once the damage reaches the kidneys the fish is a goner.

COMMON FISH DISEASES

9. Pop-Eye:- obvious physical symptom- can be caused by a bacterial infection- can be caused by too much dissolved oxygen (DO)- no universal cure

COMMON FISH DISEASES

10. Swim-Bladder Infection:- the fish will lose control of buoyancy regulation- fish will swim sideways or upside down- fish will lay on its side at the bottom of the tank.- no universal thought of cure or cause

COMMON FISH DISEASES

11. Nematode Worm:- a worm will protrude from the anus of the fish- the fish will become listless, bloated, and refuse to feed- nematodes are present in most fish but can become a problem as a secondary infection- can be treated by anti-worm medication

Diseases due to Chemistry

12. Ammonia (NH3):- too much waste in the water- if the pH is above 7 ammonia will become toxic to fish- gills will turn purple or red- fish gasps for breath- fish becomes listless- treat by removing waste and lowering pH

Diseases due to Chemistry

13. Nitrate/Nitrite (NO3

-/NO2-)

- fish appears too bright- fish gasps for breath and hangs just below the surface of the water

Before You Go:

Find 2 fish with each type of fish scale. Write the common name of that fish as well as drawing a small picture of the scale.

Bellwork: 08/31/2011• Change 10 to 25% of the water from your

tank. • Change more water if your tank is cloudy.• If you have a fresh water tank on side of

the room, refill your tank with water from the sink & then treat the water with dechlorinator

• Make sure to clean off the inside of the glass & filters while you change the water.

• Pick up a clicker when you’re done & sign in for a quiz.