parasites study22

8/14/2019 Parasites Study22

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A parasites lives in a close relations

another organism, its host, and cau

harm.

Dependent on its host for its life fun

Extremely common, virtually all ani

a variety of parasitic organisms fro

to helminths.



Parasites generally don't kill their hosts (parasite that kills its free lunch), but somseverely stress fish populations to the pobecoming biological and economical con

Parasites have a stake in the survival of

Sometimes, when parasites are numeroufish is stressed from another cause, the f



Destroying

tissue

Rem

and

Allowinginfection

develop

Diverting part of its nutrient

supply



Yes, in fact, parasitism is natural an

It occurs throughout the plant kingd

in every major group of the animal

Usually, fish parasites aren¶t notice

sometimes anglers will catch a fishobvious signs of infection or parasi



Type of Parasites

Cestrodes

Acanthocehalans

MolluscsIsopods

Leeches



The worm's scolex ("head") attaches tintestine of the definitive host.

suction cups

The body is composed of successivesegments ( pr oglottids).

Adults in gastrointetinal,larvae in any

Approx. 3mm up to 200 mm in length

Larvae may move within cryst,limitedmovement in adult



This group of parasites is comprised of woranterior proboscis covered with many hook

Referred to as ³thorny-headed worms´.

The body is composed of a presoma (proboassociated structures) and a cylindrical trun

The intestinal tract of the affected fish may blood-tinged fluid, and histologically, the prothese parasites will be firmly attached to the

mucosa.



Only one pair of uropods and lack stron

first thoracic legs.

The carapace is lacking which reveals thsegmented body composed of a head, a

(thorax) of 7 somites (segments) and a

(abdomen) of 6 somites.

scavengers feeding on dead fish parasitic on live fish

Greatest diversity is seen in the deep pa

ocean basins at 1000-5000 metres dept



Produce larvae (glochidia) which unde

obligatory phase in the gills, fins or sk

the fish host. The parasitic phase may last for seve

months.

The host tissue surrounds the parasit

is shed from the fish, and grows into aliving adult mollusc.



Marine leeches, 8 to 12 mm long, are

characterized by segmented bodies w

muscular body walls.

They are equipped with anterior and

posterior suckers.

Free moving;worm like movement,fixe

when feeding

Direct life cycle

Parasitic on host blood



The parasites that be present in la

numbers, typically so as to cause d

disease.



Tapeworms crawling out of the pyloric caeca of a yearling rainbow trout.

Gross

Slug

Stop

Effect o

Resul

enterit

Reduc

(interfe

absorp

Diagno

Dissec

Preven

Eliminhosts

Quick

cestod



Photomicrograpdemonstrates th(top) of an Acan

parasite which hinto the intestina(bottom) of an afish. Affected fiemaciation, lethanemia, and po

with a marked i



Observed salmonids from the Great Lakes

with marked infestation of this parasite with

literally hundreds of these parasites

embedded in the intestinal mucosa .

Gross si

Emaciat

Darkene

Effect on HNecrotic h

the intestin

Growth ret

mortality

Preventation

Quicklimethe water sup

suspected sto

quarantined.

Diagnosis

Gross examielongated and

with retractile

with spines



Inflamed and

necrotic gills

(left)

Pullus II stage

C er atothoa

oest r oides larvae

on the gills of a

sea bass



The adult isopods are haematophagus (feblood) and cause anaemia.

Adult isopods can cause considerable dammouth tissues with their biting and suckingparts, or their copulation activity.

Their large size (up to 6 cm in length) mayatrophy of the tongue, dysplasia of teeth aslackening of the cartilagenous tissues lea"bag-shaped" lower jaw. Invariably, the prelarge adult parasites in the buccal cavity inwith feeding, causes chronic stress and regrowth retardation and a predisposition toand/or endo-parasitic invasions.



Preventation

Removed m

1. Bath in 2

until the

from the

2. Dry the p

several w

liming to

adults.

3. Kill the d

by crush

physical

Diagnosis

Gross exa

microscop



G

s

f

Effect on Host

Anemia & may show

secondary bacterial infectionsact as vectors of viruses,

bacteria, and protozoan blood

parasites



Preventation

1. Leeches may b

the culture wat

2. the manual rem

leech using a w

3. A bath of 100 phr is effective.

4. Treated fish mu

to a clean, para

5. Culture facilitie

cleaned proper

intense sunligh

weeks prior to

Diagnosis

Gross examina

microscopic e



Gross sign

Attached

& Outer s

Effect on Ho

Gill tissue i

Lead to sec

and fungal i

Disruption

function

Preventation

Filter the cultu

Diagnosis

Gross exami

microscopic



It is impossible to avoid dealing witparasitic organisms that fish acquirthe normal course of their lives.

The majority of this parasites are ninfective to human or to other home

Fishes feeding heavily on parasitesintermediate hosts, probably carry

infections than will fishes that acquinfections at higher level.

parasites study22

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