TroutWalter Salzburger:

brown trout

Salmo trutta (forma fario)

Occurrence: Europe (part. Asia)

habitat: rivers, lakes

Max. size: 140 cm (f. lacustris)

Max. weight: 50 kg

Max. age: 38 years

Note: there are various forms, e.g. lake trout (f. lacustris) or marmorated trout (f. marmorata)

rainbow trout

Oncorhynchus mykiss

Occurrence: N-America (pacific)

habitat: rivers, lakes

Max. size: 120 cm

Max. weight: 25,4 kg

Max. age: 11 yeras

Note: since 1880 introduced in Europe and later also elsewhere

Exercise:1. How many fins are there in the trout? Which are paired/unpaired?

2. How many fin-rays are in the dorsal and caudal fin, respectively?

3. How many scales are along the lateral line? What are the rings in a scale?

Drawing I:

‣ Draw the trout

‣ mark the following features: mouth, nose, eye, operculum, lateral line, after, fins. mouth

eye

pectoral finventral fin

anal fin

dorsal fin

gill slit

operculum adipose fin

caudal fin

after

kidney

Drawing II:

heartlivergills

stomachgut

gonad

adipose fincaudal fin

dorsal fin

nose

swim bladder

after

anal fin

ventral finurinary bladder

lateral line

Exercise:1. Which is the organ next to the liver?

2. Is there a connection between kidney and urinary bladder?

3. Find the abdominal membrane (Septum transversum)

Heart and circulation

Exercise:1. Check the thickness of the wall of atrium and ventricle

2. Where is the ventral aorta?

‣ dissect the heart

‣ find the dorsal aorta

‣ longitudinal section through the heart

heart (A), atrium (1), ventricle (2), Bulbus arteriosus, Truncus arteriosus (3)

Drawing III: Brain

‣ 1. open the neurocranium (e.g. with a scalpel) and dissect the brain

‣ 2. draw the brain

Exercise

1. find the labyrinth with the semicircular canals

2. preparation of otoliths

Otolith

lateral line

‣ raise a scale with along the lateral line (with the forceps)

‣ lift the skin with a small cut

‣ the channels of the lateral line lie below the whitish skin layer...

Exercise:1. Find the Nervus lateralis. It is a side branch of the Nervus vagus and runs

below the later line

NV

CuEpP

S

De

Cupula (Cu), Dermis (De), Epidermis (Ep), nervous filament (N), Pore (P), scale (S), Nervus vagus (V)

Drawing IV: Cross section

Exercise:1. Where is the vein and the artery?

2. Which structures are paired/unpaired?

PeritoneumCoelomgutgonadkidneyribvertebra

muscle

dorsal fin

spinal cord

‣ make a cross section through the trout

‣ draw the cross section

skeleton