anatomy - Aquarium Industries · 2015. 5. 15. · Crush 1 Drontal dog wormer tablet for 10kg dog;...
Transcript of anatomy - Aquarium Industries · 2015. 5. 15. · Crush 1 Drontal dog wormer tablet for 10kg dog;...
31T E C H N I C A L N O T E S
A N A T O M Y O F A F I S H
anatomy of a fi sh
Lateral Line
Nostril
Operculum
DorsalFin
AdiposeFin Caudal
Fin
Slime+Skin
AnalFin
CloacaPelvicFins
PectoralFins
SensoryPits
Barbel
Anterior +PosteriorKidney
Gill Filaments
Gill Arch
Brain
Swim Bladder
Gonad
CloacaSpleen
StomachGall
BladderIntestine
Liver
Heart
Internal Anatomy of a Fish
External Anatomy of a Fish
32T E C H N I C A L N O T E S
S T R E S S A N D T H E I M M U N E S Y S T E M
stress and the immune system
The Commercial Handling of FishGenerally speaking, aquarium fi sh are remarkably hardy creatures, and providing that we not only keep them in an environment
that suits them, but also that we feed them properly, they are likely to remain healthy. Conversely, if we stress them suffi ciently they are likely to become sick.
Diagrams Illustrating the Effects of Environment on Fish Health
At times we inadvertently subject fi sh to stressful conditions. Our aim must be to minimise the degree, the duration and the frequency of stress.
The following list contains a few examples of what aquarium fi sh may be subjected to before or after they reach the home aquarium.
• The shipping process/transport stress • Pollution• Crowding • Pathogens• Lowered oxygen levels • Electrical changes• High carbon dioxide levels • Aggression by other fi sh• Abrupt changes in temperature, hardness, • Excessive water velocity and conductivity • Photostress• Exposure to ammonia, nitrite and other toxins • Noise or vibration• Psychological strain • Nutritional problems• Low or High pH • Injury
Relationship Of Stress To DiseaseMost aquarists would have had the experience of severe stress on fi sh, which has lead to almost immediate death. Recent studies
have shown that an accumulation of a series of less severe stresses can cause delayed fi sh deaths, which may occur days after a non-lethal stress.
A single stress changes the fi sh’s body functions, which enable it to adapt to the stress. If the stress continues, the normal disease fi ghting function of the fi sh’s body is exhausted, resulting in disease organism invasion.
LATENT INFECTION
IMPROVING FISH HEALTH
RECOVERING ENVIRONMENT
DISEASE
DEATH
DECLINING FISH HEALTH
DECLINING ENVIRONMENT
ENVIRONMENT
HOST PATHOGEN
DISEASE
33T E C H N I C A L N O T E S
S T R E S S A N D T H E I M M U N E S Y S T E M
stress and the immune system
Host + Pathogen + Unsuitable Environment = Disease It therefore follows, that a situation free of any one of the above mentioned three components, will reduce or remove the
possibility of disease.
The Immune SystemFish live in an environment containing many bacterial, fungal, viral and other pathogenic agents. If they did not have a good
defence system, they would be swamped and consumed. We now know that fi sh have a well-developed immune system, made up of an intricate network of chemical protectors and microbiological killers.
The immune system of fi sh is able to cope with many bacteria, which are found on the surface and within the fi sh. Stress upsets this balance in favour of the harmful bacteria
Stress Scale
Skin and Mucous CoatingThe body slime and skin is the primary defence barrier. The mucus prevents invasion by continuous loss and replacement. The
skin is equipped with enzymes, antibodies and defence cells known as macrophages, which digest and destroy bacteria. Hence the importance of ensuring the skin is not damaged physically, chemically, or by parasites.
Macrophages are cells found throughout the body, which are capable of destroying bacteria by a process involving engulfment and enzymatic digestion. These cells, which are microscopic are very important in protecting the fi sh from bacterial infection. Their effi ciency is reduced by hormonal changes resulting from stress.
Specifi c Defence MechanismsFish, like humans, can be immunised against bacteria and at least one protozoan (white spot disease). This can happen by natural
exposure, or by vaccination. However, at this time, there are no vaccines commercially available to the aquarium trade in Australia.
a) Tests have shown that acquired specifi c immunity is not passed on to the offspring.b) Fishes’ immunity seems to lessen at lower temperatures.
This may explain why problems (e.g. goldfi sh ulcer disease) often develop with pond fi sh, in changing seasons, with rising temperatures. Increasing water temperatures probably increases the rate of replication of bacteria, which is not matched by the fi shes’ immune (defence) system.
SummaryOur role is to eliminate as much stress as possible from our fi sh, thus minimising the likelihood of disease. We are fortunate that
aquarium fi sh have an effective immune system, which is working for their well being, and indirectly, for our good at the same time. When we use medication on our fi sh, all we are doing is tipping the balance in favour of the fi sh, by hindering the disease organism.
PATHOGEN(50%)
IMMUNESYSTEM(50%)
34T E C H N I C A L N O T E S
D I S E A S E S Y M P T O M S A N D T R E A T M E N T S
disease symptoms and treatments
Illness Identifi cationThe fi rst step to determining a treatment regime is to ascertain the cause
of the problem.
Is it Environmental or Pathogenic Disease?
If it is pathogenic disease is it Parasitic or Bacterial?
These fi rst important steps require a thorough knowledge of acceptable parameters for water quality, and the ability to diagnose diseases, based on changes in behaviour, and external symptoms. Use of a microscope, for examining skin scrapings, and gill biopsies is strongly recommended.
External Signs1. Fish behaving abnormally; keeping to the top or bottom of an aquarium; erratic swimming; shimmying; poor equilibrium;
scratching or scraping on objects.2. Clamped fi ns.3. Rapid respiration.4. Abnormal colour, cloudy eyes, darkening, loss of colour.5. Loss of appetite.6. Skin abnormalities, cotton-like tufts, lesions, white spots, excessive mucus, greyish patches, haemorrhages.7. Swelling or bloating.8. Emaciation
Poor water quality can induce the same symptoms as those caused by pathogenic disease. Before applying treatments check the following:1. Is pH of water correct for the species? Is the water too acid or too alkaline?2. Is water hardness and salinity correct for the species? Is water too hard or too
soft? - Should water conditioner or extra salt be added?3. Are their own waste products, ammonia, nitrites, nitrates etc poisoning
the fi sh?4. Is the tank water too old? Insuffi cient partial water changes?5. Has water been contaminated by poisonous substances, such as fl y spray or
pest strips, cigarette tobacco, metals or toxic chemicals, including possible overdose of medications?
6. Is the temperature correct? How long since you have checked your thermometer?
7. Are fi sh too crowded, or incompatible with each other?8. Have fi sh been fed correctly - is the water polluted with uneaten particles,
or are fi sh very thin and starving?9. Is there suffi cient aeration and fi ltration to ensure adequate gas exchange?10. Is there an anaerobic condition in the fi lter, producing toxic substances?
Water Quality DiseasesRemember, many fi sh die as a direct result of unsuitable water quality. Eg.
Extremes in pH, ammonia toxicity etc. In less extreme cases, the stress of living in unsuitable water leads to the development of pathogenic disease.
35T E C H N I C A L N O T E S
D I S E A S E S Y M P T O M S A N D T R E A T M E N T S
disease symptoms and treatments
Treatment Rules1. Do not medicate aquarium until after you have eliminated environmental factors as possible cause of symptoms.2. Early action is an important factor in determining the success of treatment. Once a disease has been accurately diagnosed,
do not waste time before treating.3. Use effective medications. The wrong diagnosis may lead to improper selection of drugs, which could stress or kill fi sh.4. If you are having problems with disease diagnosis, contact Aquarium Industries Vet Services for further advice.5. Follow the manufacturer’s instructions carefully on all remedies. Many medications are highly toxic when overdosed.6. By cleaning the fi lter and doing a partial water change of about 1/3 before treating, dilutes water-born pathogens, improves water
quality, and usually makes the fi sh feel better.7. REMOVE ACTIVATED CARBON BEFORE ADDING MEDICATION: Activated carbon removes medication quickly, rendering
treatment ineffective.
Treating DiseaseThe majority of pathogenic diseases encountered in an aquarium can be grouped into two broad categories:
PARASITIC, which can be seen either with the naked eye or with the aid of a microscope.BACTERIAL - If water quality is good, and parasites are not detected, then bacterial disease can be suspected.
Most medications used with aquarium fi sh are administered via the aquarium water, as a long term, or permanent bath.
Recommended ReadingThe “T.F.H.” Handbook of Fish Diseases (TS 123) by Dieter Untergasser are highly recommended. These books should be in the
library of every aquarium and pet shop.
The Disease and Symptom Treatment Chart (on the following pages) covers the more common aquarium fi sh diseases.
*Excludes mobile phones
If in doubt call:
36
Dis
ease
Nam
eD
isea
se O
rgan
ism
Sym
ptom
sTr
eatm
ent
Not
es
Bact
eria
l
Col
umna
ris D
isea
se Fl
exib
acte
r col
umna
ris &
ot
her b
acte
ria &
fung
i M
outh
, fi n
s an
d bo
dy ro
t. Pr
imar
y lin
e of
infe
ctio
n is
whi
tish/
grey
. U
se a
ny te
tracy
clin
e,
aqua
rium
med
icat
ion
or
Vib
rave
t (D
oxyc
yclin
e)at
5m
g / l
itre
Afte
r 4 d
ays
chan
ge ½
the
wat
er,
then
repe
at tr
eatm
ent i
f nec
essa
ryV
ibra
vet t
reat
men
t affe
ct b
io fi
lter
Neo
n Sp
littin
g D
isea
se(F
alse
Spl
ittin
g D
isea
se)
Uni
dent
ifi ed
bac
teria
Whi
te m
ould
y pa
tch
on b
ack
or
side
, les
ion
deep
ens
rapi
dly.
If
untre
ated
hea
vy lo
sses
occ
ur
Dox
ycyc
line
(Vib
rave
t) at
5m
g pe
r litr
eD
ose
can
be d
oubl
ed fo
r sev
ere
case
sV
ibra
vet t
reat
men
t affe
ct b
io fi
lter
Gol
dfi s
h U
lcer
Dis
ease
(GU
D)
Aer
omon
as s
alm
onic
ida
var.
nova
Red
ulce
rativ
e le
sion
s on
the
body
su
rface
of g
oldfi
sh
Dox
ycyl
ine
(Vib
rave
t) 25
0mg
per 1
00 li
tres
Afte
r 4 d
ays
chan
ge ½
the
wat
er, t
hen
repe
at tr
eatm
ent i
f nec
essa
ryV
ibra
vet t
reat
men
t affe
ct b
io fi
lter
Exte
rnal
Par
asite
s
Whi
te S
pot
Icht
hyop
hthi
rius
mul
tifi ll
is Ea
rly s
tage
har
d to
det
ect,
few
sm
all w
hite
spe
cks
fi rst
see
n on
fi n
s –
fi sh
scra
pe
Use
Aqu
ason
ic Ic
hone
x or
an
y co
mm
erci
al w
hite
spo
t tre
atm
ent
Hig
her t
empe
ratu
res
appr
ox 2
8°C
sp
eeds
up
cure
tim
e
Anc
hor W
orm
Lern
aea
Stiff
rod-
like
para
site
s 5
to 1
0mm
lo
ng a
ttach
ed to
fi sh
Use
Par
a-go
ne o
r any
co
mm
erci
al a
ncho
r wor
m
treat
men
t
Follo
w m
anuf
actu
rer’s
inst
ruct
ions
. In
ver
y co
ld w
ater
anc
hor w
orm
s m
ay s
tay
dorm
ant w
ithin
gol
dfi s
h fo
r m
onth
s (s
ee p
age
on a
ncho
r wor
ms)
Fish
Lic
eA
rgul
us Ro
und
to o
val,
fl at p
aras
ite,
appr
oxim
ate
10m
m, t
rans
pare
nt
grey
/gre
en c
olou
r, ha
s 8
legs
, at
tach
es to
fi sh
Use
Par
a-go
ne o
r any
co
mm
erci
al fi
sh li
ce
treat
men
t
Follo
w m
anuf
actu
rer’s
inst
ruct
ions
.
Fung
us In
fect
ions
Fung
usSa
rpro
legn
ia Tu
fts o
f fun
gus,
rese
mbl
ing
dirty
w
hite
cot
ton
woo
l, gr
ow o
n th
e ou
tsid
e of
the
fi sh
Any
com
mer
cial
fung
us
cure
, or u
se a
cot
ton
bud
to p
aint
affe
cted
are
a w
ith
Mer
curo
chro
me
Hea
lthy
and
unda
mag
ed fi
sh d
o no
t be
com
e in
fect
ed w
ith fu
ngus
T E C H N I C A L N O T E SD I S E A S E , S Y M P T O M S A N D T R E A T M E N T C H A R T
disease, symptoms and treatment chart
37
Dis
ease
Nam
eD
isea
se O
rgan
ism
Sym
ptom
sTr
eatm
ent
Not
es
Wor
ms
Cam
alla
nus
(Too
thbr
ush
or
Pain
tbru
sh w
orm
)C
amm
alla
nus
spec
. Th
in ro
und,
red
wor
ms
prot
rudi
ng s
light
ly fr
omth
e an
us
Cru
sh 1
Dro
ntal
dog
wor
mer
ta
blet
for 1
0kg
dog;
mix
into
100
gram
s fi s
h fo
od w
ith c
od
liver
oil.
Fee
d ev
ery
day
for
7 da
ys.
Trea
tmen
t sho
uld
be re
peat
edin
3-4
wee
ks
Mic
rosc
opic
Ext
erna
l Par
asite
s
Velv
et D
isea
seO
odin
ium
Dus
ty g
old
appe
aran
ce, fi
sh
listle
ss, c
lam
p fi n
s &
scr
ape
Use
any
com
mer
cial
velv
et c
ure
Follo
w m
anuf
actu
rer’s
inst
ruct
ions
Gill
& S
kin
Fluk
es D
acty
logy
rus
&
Gyr
odac
tylu
s D
ull a
ppea
ranc
e, c
lam
ped
fi ns,
scr
apin
g, re
duce
d ac
tivity
,in
crea
sed
brea
thin
g fre
quen
cy
Use
Par
a-go
ne o
r any
co
mm
erci
al fl
uke
cure
Follo
w m
anuf
actu
rer’s
inst
ruct
ions
.If
fl uke
s ar
e re
sist
ant t
o tre
atm
ent
use
diffe
rent
pro
duct
to tr
eat.
Slim
y Sk
in D
isea
se C
hilo
dene
lla,
Tric
hodi
na, C
ostia
Slim
y w
hite
ski
n, s
crap
ing,
clam
ped
fi ns,
redu
ced
activ
ity,
incr
ease
d br
eath
ing
frequ
ency
Use
a c
omm
erci
al F
orm
alin
& M
alac
hite
gre
en o
r C
hang
e 1/
3 w
ater
afte
r 12
hour
s.
Cau
tion
Form
alin
can
be
toxi
c to
som
e sp
ecie
s.
30gm
(6 te
aspo
ons)
sod
ium
ch
lorid
e (s
alt)
per 1
0 lit
res
plus
an
y tre
atm
ent t
hat c
onta
ins
acra
fl avi
ne
Afte
r fi s
h ha
ve re
cove
red
carr
y ou
t1/
3 w
ater
cha
nge
ever
y da
y fo
r 3to
4 d
ays
to d
ilute
med
icat
ion
Fung
us In
fect
ions
Whi
te S
pot
Icht
hyop
hthi
rius
mul
tifi ll
is Ea
rly s
tage
har
d to
det
ect,
few
smal
l whi
te s
peck
s fi r
st s
een
onfi n
s –
fi sh
scra
pe
Use
Aqu
ason
ic Ic
hone
x or
any
com
mer
cial
whi
te s
pot
treat
men
t
Hig
her t
empe
ratu
res
appr
ox 2
8°C
sp
eeds
up
cure
tim
e
Mar
ine
Whi
te S
pot
Cry
ptoc
aryo
n irr
tans
Pin
head
siz
e w
hite
spo
tsap
pear
on
fi sh,
redu
ced
activ
ity a
nd s
crap
ing
Use
Aqu
ason
ic O
odon
ex o
r Ve
rtone
x or
any
com
mer
cial
m
arin
e w
hite
spo
t tre
atm
ent
Follo
w m
anuf
actu
rer’s
inst
ruct
ions
disease, symptoms and treatment chart
T E C H N I C A L N O T E SD I S E A S E , S Y M P T O M S A N D T R E A T M E N T C H A R T
38T E C H N I C A L N O T E S
W H I T E S P O T D I S E A S E
white spot disease
The causative organism is Ichthyopthirius multifi liis, a single celled protozoan, which grows to 1mm in diameter and can be seen with the naked eye.
SymptomsInfected fi sh twitch their fi ns and scrape or bounce off objects in the tank. Early in the infection, only a few spots can be seen, mainly
on the fi ns. As the disease progresses the “spots” grow larger and more numerous. If left untreated the fi sh become covered in spots. Increased mucus production, as well as secondary bacterial and fungal infection, causes the fi sh to take on a slimy mouldy appearance, often with blood streaks showing on frayed fi ns. Listlessness, and hanging at the surface, are the usual fi nal symptoms before death. Small fi sh, such as neons, seldom show all these symptoms, as only a few parasites are needed to kill them. Under the microscope, the adult parasite can be seen to constantly rotate; is uniformly covered in cilia; and has a characteristic horseshoe shaped nucleus.
Life Cycle1. Parasites invade the epidermis (skin) and grow within it.2. Parasites digest fi sh tissue (causing irritation) and eventually grow
to adult size (approximately pin head).3. Adult parasites leave fi sh to reproduce at bottom of aquarium.4. There they undergo a rapid division into numerous youngsters, up
to 1000.5. Young, free-swimming parasites (called tomites) burst from the cyst
after 12 to 18 hours. This is the time most medications work best.6. The complete cycle at tropical temperatures takes from 3 to 5
days, from 5 to 14 days at 15oC and even more than a monthat temperatures below 10oC.
ControlWhite spot is a common disease of tropical and goldfi sh, and can
be found in aquariums, ponds, farmed and wild fi sh. Fortunately it is easily cured using commercial preparations. It is important to remember that the medication works best on the free-swimming tomites. Therefore medication needs to be administered regularly (according to instructions on the bottle).
The white spot organism can be introduced through adding infected tap water to a tank, by introducing diseased fi sh, or by spreading the disease from an infected tank with a net or equipment. Since white spot can be easily introduced with infected tap water, it is a good practice to hold and age tap water for several days before use. The disease has been cured, experimentally, by putting fi sh in fast running water and simply washing all the free swimming tomites away before they re-infect the fi sh.
Discussion White spot is one disease that nearly all aquarists have heard of, and
as such, is often incorrectly diagnosed. Inexperienced people call any white blemish, discolouration, or fungus patch, white spot. A microscope is the best way to make a positive diagnosis, although with experience, white spot can easily be identifi ed with the naked eye. Be prepared for fi sh to look worse before they get better. This occurs because most treatments cannot reach the parasites buried deep in the fi sh’s skin. So, the parasites must mature, leave the fi sh, and turn into free-swimming tomites before the treatment has an effect. Increasing temperature is an effective way of speeding up the life cycle and therefore speeding up the cure time.
TreatmentUse Aquasonic Ichonex or any commercial white spot treatment
according to instructions.
NOTE: Turn off activated carbon fi lter, if in use, as it will remove medications on contact.
CAUTION: Scaleless fi sh may be sensitive to some white spot remedies, therefore use treatment at half dose if unsure. Example of White Spot
39T E C H N I C A L N O T E S
V E L V E T D I S E A S E O F F R E S H W A T E R F I S H
velvet disease of freshwater fi sh
Velvet disease is caused by Oodinium pillularis, a dinofl agellate parasite (or other Oodinium species) that is virtually invisible to the naked eye.
SymptomsFirst symptoms of velvet disease are usually slight variances in behaviour. Fish swim a little more stiffl y, are less active, and show
an increase in respiration rate (gill pumping). The surface of the fi sh becomes coated by thousands of parasites resulting in the classic “velvet” symptom. Fish seem coated with fi ne golden pepper and, usually, fi ns look thickened. If left untreated fi sh become more lethargic, hang at the surface, lose condition and heavy mortalities occur. Secondary fungal and bacterial infections are uncommon.
Because the velvet parasite is not quite visible to the naked eye and occasionally infections remain completely localised to gills, positive diagnoses cannot be made without the aid of a microscope. At x100 or x 200 magnifi cations, velvet can be seen as dark, oval to pear shaped cells, which do not move.
Life CycleThe life cycle of Oodinium pillularis is similar to that of white spot. Once the parasite has matured on the fi sh, it drops off and
falls to the substrate. Here it divides and produces up to several hundred offspring. Juveniles are propelled by a single fl agella and swim about in search of a host, which they must fi nd within a day or so or they perish. Successful parasites attach themselves to the host with fi laments that penetrate the skin.
ControlEnsure, as far as possible, your source of live fi sh is velvet disease free by buying from a reliable supplier.
In the event of an outbreak, quarantine the tank and take quick action with a “proven” treatment procedure (follow treatment instructions at the end of this article).
DiscussionVelvet is a relatively common disease of fresh water ornamental fi sh, and it is often mis-diagnosed. An untreated tank, in any
establishment, can become an on going source of contamination causing problems for months.
TreatmentUse any commercial velvet treatment, according to instructions.
Treatment NoteVelvet has a reputation for being diffi cult to cure and even more diffi cult to eradicate from established aquariums. Repeated
treatments are usually required.
Oodinium pillularis in groups on the skin
40
This disease is caused by copepods within the genus Lernaea. They are not worms, even though the adult female parasites are somewhat worm like in appearance.
SymptomsInfected fi sh develop stiff, worm-like protrusions between 10 to 20mm long on the body or occasionally on fi ns. Mouthparts
of the parasite are embedded in the fi sh’s fl esh, often causing some ulceration. One pair of egg sacks are usually present at the protruding end of the female anchor worm.
Life CycleFemale anchor worms produce hundreds of eggs in each egg sack. Larvae are free swimming and about 0.3 to 0.1mm long. After
mating, only female parasites penetrate the fi sh where they stay buried for only 7 days or so at tropical temperatures, or up to 3 months if temperature is below 15°C.
ControlAnchor worm is a relatively common disease, of both pond cultured and wild fi sh in Australia. Because of this it’s best not to
introduce any fi sh from the wild. In the event of an infection, quarantine the aquarium and treat according to instruction at the end of this article.
DiscussionAnchor worm infections are more likely to occur on goldfi sh, pond cultured fi sh, and wild-caught Australian natives.
TreatmentUse Para-gone or any commercial anchor worm treatment according to instructions on the container.
Treatment NoteBecause the medication cannot reach young buried female parasites, treatment must be repeated several times depending
on temperature.
At 25°C - 30°C treat 3 or 4 times 5 days apartAt 20°C treat 2 or 3 times 12 days apartAt 15°C treat 2 or 3 times 25 days apart
NOTE: Carry out a 50% water change between treatments.
T E C H N I C A L N O T E SA N C H O R W O R M ( L E R N A E A )
anchor worm (Lernaea)
Adult female
41
skin & gill fl ukes
Skin fl ukes are common microscopic parasites of fi sh. They are often found on goldfi sh, causing many of the problems commonly encountered in aquarium and pet shops. There are two common types of fl ukes that cause disease:
SymptomsThe only sure way of diagnosing fl ukes is with the aid of a microscope. A section of tail, gill, or scraping from the body reveals
these tiny microscopic parasites. The normal response to skin parasites is for the fi sh to increase mucous secretion, in a bid to dislodge the parasites. This appears as a thickened slime coating over the body. Infected fi sh often start shimmying, develop clamped, cloudy or drooping fi ns, and scratch on the gravel and rocks.
Gill fl ukes usually attack gills, where the mucous secretion of the fi sh and the physical damage caused by fl ukes, severely interfere with the fi sh’s ability to take up oxygen from water, (to breathe). If infected fi sh are left untreated, the fl ukes cause so much damage to the protective skin coating that the fi sh eventually die.
ControlIt seems that fi sh under normal conditions usually have an adequate defence system to keep these parasites at a relatively
harmless level. When fi sh are stressed by crowding or kept in an unsuitable environment, fl ukes multiply quickly and become a major problem.
Gill fl ukes are egg layers, and skin fl ukes are live bearers. Both types of fl ukes are able to spread from fi sh to fi sh, and are easily transferred from tank to tank by use of a common net. It is quite likely some species of fl ukes are host specifi c (only parasite one species of fi sh) however it is wise to assume cross contamination can occur.
DiscussionOur investigations have shown this disease to be a major cause of goldfi sh losses in home aquariums and bowls. Infected goldfi sh
may take weeks or months to die, and many outlets unknowingly sell these fi sh. It is a major industry concern, as high failure rates of beginner goldfi sh keepers discourage the progression to serious fi sh keeping.
TreatmentSeveral commercial preparations are now available for treating fl ukes. In recent years, some fl ukes have become resistant to some
treatment chemicals. It is therefore wise to stock a few different treatments that use different chemicals as the active ingredient.
T E C H N I C A L N O T E SS K I N & G I L L F L U K E S
Gill Flukes (Dactylogyrus) Skin Flukes (Gyrodactylus)
42
Slimy skin disease is a catch all phrase used to describe a symptom usually associated with fi sh infected by a group of tiny microscopic external parasites.
SymptomsAs with skin fl ukes, the only sure way of diagnosing these parasites is with the use of a microscope. The gills, fi ns, and body,
are all usually infected when the parasites are present. Symptoms include - thickened, whitish-grey, slime coating; occasional sloughing, twitching and scraping. Fusion of gills causes increased breathing frequency. In the fi nal stages of the disease, fi sh hang at the surface, or lie at the bottom. Secondary fungal and bacterial infections are common.
ControlThese parasites are often associated with crowding of fi sh and water with high organic loads (polluted water). Keeping fi sh in an
ideal environment is a way of avoiding this problem. The parasites can easily be spread through the use of contaminated nets. If infected fi sh are removed from an aquarium, it seems that all free swimming parasites will die off within a few days, when no host is present.
DiscussionThese three types of parasites can be found on goldfi sh as well as tropical fi sh. When examining a weakened fi sh it is not unusual
to fi nd a mixed infection of these parasites as well as skin fl ukes.
TREATMENT – Use a commercial treatmentAquasonic Formalin and Malachite green has proven to be very affective.
CAUTION: Formalin and Malachite green is toxic if overdosed.
Alternative TreatmentTry a long duration salt bath of 30gm (6 teaspoons) sodium chloride per 10 litres of water, plus a commercial fungus remedy.
When fi sh have recovered, (normally 2 or 3 days) carry out a 1/3 water change every day, for 3 to 4 days, to dilute medication.
NOTE: Salt at this concentration will kill most aquatic plants.
T E C H N I C A L N O T E SS L I M Y S K I N D I S E A S E
slimy skin disease
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Columnaris disease is usually caused by the bacteria Flexibacter columnaris, but may also be caused by a variety of bacteria.
SymptomsThis is the most common bacterial disease encountered by professional aquarium fi sh handlers. It is contagious and in its early
stage, quite diffi cult to diagnose. Some types of fi sh are particularly susceptible, e.g. female fi ghters, guppies, platys, swordtails, and to a lesser extent, mollies and rasboras. Diseased fi sh develop grey/white patches, usually at the base of the tail, at the tips of the fi ns, and on the back. Often a slimy white line appears around the mouth. The bacteria, after penetrating the protective slime coating, gain access to tissue beneath the skin where, if left untreated, they can cause enormous damage.
During the progress of the disease, fi sh become listless, lose their appetite and tend to hover at the surface near aeration. (Infected guppies in particular act this way.) The proliferation of bacteria over the gill fi laments, and the heavy production of mucus by the fi sh, contributes to impaired gill function and oxygen starvation. If appropriate treatment is not given, the entire contents of the aquarium may be lost within a few days.
Fish Showing Symptoms Of Columnaris Disease
ControlThe bacteria that cause this disease are present as normal fl ora in waters all over the world. Under normal conditions the fi sh’s
immune system prevents invasion by the bacteria. Adverse conditions such as incorrect water quality, high organic load, low oxygen levels, poor diet (e.g. lack of vitamin C), excessive handling, or shipping stress, are all conditions that may lead to the development of this disease. Care should be taken not to transfer water, nets, plants etc, from the infected tank.
DiscussionAs in human and veterinary medicine, bacterial diseases are usually treated with antibiotics, which in Australia are classifi ed by
the Department of Health as S4 drugs. This means they can only be supplied under prescription. Aquarium and pet shop owners should therefore use a veterinarian as a consultant, if they wish to acquire antibiotics for treating bacterial diseases of aquarium fi sh.
Aquarium Industries Vet Services can be contacted by calling 1800 WECARETetracycline hydrochloride has been approved for use on ornamental fi sh. This drug does not need a prescription, yet at the same
time is quite effective at preventing and treating columnaris disease.
General TreatmentColumnaris bacteria, usually start off attached to the outer surface of fi sh and therefore the disease is relatively easy to treat in the
early stages.
Preventative Measures1. Ensure water quality is right for the species of fi sh; e.g. correct pH, general hardness, and water conditioner levels for live
bearers etc.2. Use any good quality commercial antibacterial product as a preventative whenever new “columnaris disease prone fi sh”
are purchased.
Columnaris disease (body and mouth rot)
T E C H N I C A L N O T E SC O L U M N A R I S D I S E A S E ( B O D Y A N D M O U T H R O T )
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TreatmentTetracycline
There are several commercial aquarium products containing Tetracycline available now. Treated water may develop a brownish tinge after a day or two. Activated carbon fi ltration and partial water changes should be used to clear the water again after fi sh have recovered.
Alternative TreatmentThe antibiotic Doxycycline (Vibravet) at the rate of 5mg/litre is very effective but has a detrimental effect on biological fi lters.
Notes:1. Tetracycline has little or no ill effect on nitrifying bacteria living in the biological fi lter/gravel.2. Columnaris disease is also a disease of cold water fi sh, including medakas and goldfi sh. The resistance of the fi sh to the disease is
usually reduced as the temperature of the water increases, e.g. goldfi sh are much more prone to this disease when temperatures go above 18°C.
3. Infected fi sh usually lose their appetite and have a high oxygen requirement, so be careful not to pollute the aquarium water with uneaten food and ensure aeration is strong enough.
4. Other antibiotics such as Streptomycin and Doxycycline are often recommended in aquarium literature. These are effective but have a detrimental effect on biological fi lters, and as with virtually all antibiotics, must not be used without a prescription from a veterinarian.
T E C H N I C A L N O T E SC O L U M N A R I S D I S E A S E ( B O D Y A N D M O U T H R O T )
Columnaris disease (body and mouth rot)
45
Neon diseases are mostly diseases of Neons. They can occasionally be seen in other species, although this is quite rare.
There Are Two “Neon Diseases”Enormous confusion exists over two quite different diseases; both called Neon Disease in the industry. This is why we have called
the more economically important disease, neon splitting disease (or false neon disease). The other neon disease we prefer to call Plistophora, after the causative organism, Plistophora hyphessobryconis.
Neon Splitting Disease (False Neon Disease)The most common disease of neon tetras (Paracheirodon innesi) is bacterial neon splitting disease. The specifi c bacterium that
causes this disease is not known.
SymptomsLosses are often associated with stress of travel, or after fi sh have been moved into a new tank, especially if the water is fresh,
hard and alkaline. A slightly raised, white mouldy looking patch develops, usually on the back, around the dorsal fi n. The gills may also be infl amed and swollen, with the gill plate protruding slightly. If untreated, the patch quickly develops into a deep lesion, and death soon follows. This disease can cause high losses, and spreads within the tank’s population rapidly. Early treatment is essential.
ControlNeon splitting disease seems only to be a problem in commercial establishments. There have been very few reports of this disease
in home aquaria. Attention to water quality is the single most important factor in controlling outbreaks. Mixing batches of neons should be avoided. If an outbreak occurs, use normal quarantine precautions to avoid its spread. This disease does not seem to be contagious to many other species. We have seen it in cardinals, and occasionally in giant danios, emperor tetras, glowlights and black neons.
DiscussionNeons are very sensitive to adverse water conditions, and areas that have naturally occurring, hard, alkaline and mineral rich tap
water, are notorious for having neon problems. Shopkeepers in such areas should alter their tap water to suit their neons, especially for newly received fi sh. Once over the stress of transport, neons do acclimatize to local water conditions and one need not be as fussy. (See articles on pH, general hardness, and neons).
*Tip For Avoiding ProblemsNeons in their natural habitat live in water with a pH of about 5.0. Put newly arrived neons into a pH of between 5.5 – 6.0 and
then gradually raise it over several days to just under 7.0.
TreatmentEnsure water conditions are right for neons fi rst. Use Doxycycline (Vibravet) at 5mg per litre. After 4 days change ½ the water, than repeat treatment if necessary
Alternative TreatmentThe antibiotic Doxycycline (Vibravet) at the rate of 5mg/litre is an effective treatment but it has a detrimental effect on the
biological fi lter.
neon disease
T E C H N I C A L N O T E SN E O N D I S E A S E
46
PlistophoraPlistophora hyphessobryconis is an internal parasite that attacks muscle tissue. Pale patches develop inside fi sh, often causing part
of the green line along the Neon’s side to pale or fade. The disease is slow to progress, and fi sh may live for months showing little or no sign of ill health. In the fi nal stages, emaciation usually precedes death. This is a slow, insidious disease that usually occurs due to lack of adequate disease controls. Unfortunately, there is no practical treatment. Infected fi sh should be destroyed; as the disease spreads when healthy fi sh eat infected corpses.
Comparison Of The Two DiseasesThe common symptom of both diseases is the development of a pale patch, usually in the area of the green line.
Neon Splitting Disease Plistophora Disease
Caused by bacteriaSpreads quickly within the population (causes epidemics)Very heavy losses (within days)Responds to treatmentsCurrently a common disease
Caused by sporozoanSlow to spreadSlow to cause losses (weeks or months)Virtually incurable
Neon Splitting Disease Plistophora
Spore fi lled pansporoblasts of Plistophorahyphessibryconis in musculature
REMEMBER: As well as these two diseases, neons may also develop many others.
T E C H N I C A L N O T E SN E O N D I S E A S E
neon disease