Scaly stuff: Anatomy & husbandry of fish and reptiles SDL (AHW)

how many species of fish are there

over 32000

how long ago do fossil records go for fish

500 million years

why are fish called fish even though its such a broad term for their huge variey?

t’s ecologically and culturally useful.

It works for fisheries, teaching, and everyday conversation.

So, scientists don’t mean fish aren’t real animals, only that ‘Fish’ is not a scientifically coherent evolutionary category.

what do whalesharks eat?

tiny fish, squid, plankton

how do whale sharks give birth?

to live young - not eggs

what are chondrichthyes? what are their features?

cartilaginous fish

features:

hyaline cartilage skeleton

over 700 species of shark, skate, ray

what are the bony fish characteristics?

skeleton made of bone

over 24000 species

(teleosti + osteichthyes)

term for jawless fish? how many species?

agnatha

under 100 species

how many lungfish species are there

less than 10

list 6 cartilagenous fish species

goblin shark

common skate

common stingray

great white shark

spiny dogfish

lesser spotted dogfish

list 6 bony fish species

blue tang

haddock

discus

clownfish

stickleback

neon tetra

list 3 jawless + lungfish species

spotted lungfish

sea lamprey

black hagfish

label the:

kidney, liver, spleen, ovary, stomach, anus, brain, swim bladder, lateral line, pyloric caeca, skin, ventricle, intestines, urogenital opening, bulbus arteriosis, urinary bladder

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what is the system called in the gills regarding direction of flow?

counter-current system

most difficult biological process for fish?

maintain water balance

25%-50% total energy→ osmoregulation

fresh water fish osmoregulation

hypotonic environment compared to the body

water enters passively

fish produce and excrete high urine volume with low salt conc

they extract as much salt as possible from food

marine fish for osmoregulatoin

hypertonic environment vs body

water passively leaves fish’s body

drink large salt water quantities - salt actively excrete through urine + gills + digestive tract

kidney must produce highly conc. urine with as much water reabsorption as possible

why cant a freshwater tropical fish in a tropical marine aquarium?

marine environment is hypertonic compared to the fish's body fluids, water will rapidly leave the fish’s body by osmosis, particularly across the gills.

Freshwater fish deal with excess water, not water loss. specialised kidneys → large volumes of dilute urine - not effective at conserving water.

In seawater - leads to dehydration as fish loses water cant reduce urine output/ concentrate its urine.

Freshwater fish: lack mechanisms to actively excrete large amounts of salt.

In seawater, salts diffuse into the body, freshwater fish gills are adapted for salt uptake rather than salt secretion -causes salts to accumulate in the body fluids, impacts normal cellular function.

unable to maintain internal balance → severe physiological stress and death.

label: wavemaker, hood + light, heater + thermostat, substrate + decor, protein skimmer, filter, thermometer, UV steriliser, air stones, chillers + fans

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how do you chose what species to buy to be in the same tank?

appropriate temperament

chart to help identify good species to group

social needs vs solitary

territorial behaviour: aggression and predation

how do you chose tank size + stocking density?

stocking density calculators = guideline

deduct 10% tank for decor + substrate

allow amount of space per fish depending on the breed

what cm of space should be allowed for: tropical freshwater, coldwater, marine fish?

coldwater: 0.89

tropical freshwater: 1.8

marine: 2.4

how to chose correct habitat and water parameters? (what? aims? risks?)

species must share same water requirements:

pH, salt, substrate levels, sedate/ fast flow water

aim:

different water level parameters = less competition

risks:

disease/ chronic stress

feeding fish

formulated diets:

(tablets, flakes, granules, pellets) - float, sink slowly/rapidly

how do you know where a fish will feed in water?

look for mouth position

what diet is best for omnivores?

varied diet of:

formulated feeds (pellets, flakes, granules),

fresh food ,

live food,

frozen food

what diet is best for carnivores?

live prey or frozen cubes or freeze-dried invertebrates

what diet is best for herbivores?

graze aquarium plants

algae/ seaweed tablets

aquarium plants + fresh veg

what can phosphorus deficiency cause?

screamer jaw

risk of wet fish diet?

pathogen/ parasite transfer

reptiles: label the heat sources

what are incandescent bulbs for? pros/ cons

heat + visible light

benefits:

• Provide basking areas 

• Provide a consistent environmental temperature

• Can be used alongside a UVA/UVB light so a full spectrum of heat, visible light and UVA/UVB is provided

risks:

• Risk of burns - must be fitted with a protective guard to prevent injury, epsecially for snake species

ceramic bulbs use + pros/ cons

heat not light

benefits:

• Provide basking area 

• Cheap

• Do not need changing regularly

• Long lasting 

• Useful when supplemental heat is needed over night when a light source would disrupt circadian rhythms. 

• Can be used with halogen bulbs and UVA/UVB lights so a full spectrum of heat, visible light and UVA/UVB is provided

risks:

• Significantly dries the air - may be an issue with species requiring high humidity

• No visual indication if they are working or not, must monitoring vivarium temperature closely

heat mat: uses + pros/ cons?

out of enclosure - maintain background temp (no more than 0.5 of floor)

benefits:

• Provide heat without light - does not disturb circadian rhythms

• Preserve humidity

risks:

• Significant risk of burns, even if the mat is placed outside the vivarium 

• Designed to warm surfaces not heat air - would not be a suitable choice for providing a temperature gradient

• Not suitable for providing basking areas 

heat rocks: pros/ cons?

risks:

• Not advised due to significant burns risk and difficulty maintaining a consistent temperature

• Do not provide a temperature gradient - poor heat distribution

substrate requirements for reptiles

• Non-irritant, non-toxic

• Easy to clean, obtain and replace

• Suitable for species

• Provide enrichment

risk of inappropriate substrate

microbe + parasite build up

high humidity species substrates reptiles:

mulch + husk substrate

• retain moisture + no mould

low humidity species substrates reptiles:

shavings

• absorbent + can dig

what shavings are not good?

pine + cedar → contain irritating oils to skin, mucous membranes + resp. tract

wood shavings → toxicity, impaction, mould growth, dust + splinters

what substrate is good for desert reptiles? examples of reptiles?

sand

• leopard geckos

• collared lizards

• sand boas

inappropriate ingestion

anecdotal tissue - reason why reptiles are fed in separate feeding containers

large amounts = impaction (blockage)

(sand, bark, wood chips)

what does current research recommend regarding substrates?

mix of types - mimics natural habitat

What is a disadvantage of peat moss as a substrate? reptiles

organic waste hard to detect

What is a major clinical risk associated with sand as a substrate? reptiles

gut impaction

Which substrate is associated with lead exposure risk from ink? reptiles

newspaper

Which general principle best explains why multiple substrates may be used in vivaria? reptiles

provide humidity gradient

Which substrate is particularly associated with harbouring mites and chiggers and is NOT recommended? reptiles

corn cobs

Why are wood shavings generally not recommended? reptiles

They retain humdity and promote mould

Why is Astroturf unsuitable for some reptile species?

It is unsuitable for burrowing species

Cat litter is not recommended for reptiles primarily because:

Its dust is a respiratory irritant

carnivore diet needs - reptiles

whole defrosted prey - live prey = illegal

Prey should be no larger than the widest part of the snake as a general rule.

regurgitation if handled within 24-48 hrs of feeding

juvenile snakes: 5-7 days

adult snakes: 1-3 weeks

herbivore and omnivore reptile diets

leafy weeds + vegetables

chopped = reduce selective feeding

hay - added for some species

herbivore and omnivore reptile diets - what to avoid

fruit and image

omnivore reptile species diets

appropriate meat source - range of insects (mealworms + crickets)

range = reduced nutritional imbalance

what insects are advised for omnivore reptile species

Insects that are gut loaded are advised → the insects have been given nutrient rich food - passed on to the reptile.

issues with gut loaded insects

Insects may not consume enough of the nutrients to pass them on

Rapid nutrient loss: Insects cannot retain nutrients for long and often "off-load" them rapidly, meaning the benefits may be lost if not fed to the reptile quickly

Incorrect diets: Feeding insects high-fat/protein items rather than high-nutrient greens (e.g., leafy greens) causes dietary imbalances 

method of feeding reptiles

live prey → separate handling box = best

(monitor feeding)

(less ingested substrate)

live insects should be removed after 30 mins if uneaten

vegetables and plant material:

the wheel method → content is systematically rotated to ensure a balanced intake of nutrients, mimic natural browsing and reduce unwanted feeding behaviours - e.g. selective feeding 

how should snakes be fed?

use tongs when feeding snakes → creates distance between your fingers and a snake in full feeding response.

snakes have poor vision - rely on other senses (smell and heat) to locate prey

the risk of bites increases if we offer food via our hands.

can present the prey at a natural angle and create movement to encourage interest

supplementation

Ca deficiency - supplement 2:1 (Ca:P)

Vit D3 to obtain Ca from food/ UVB for basking animals

methods:

dust over food or gut loading

based on life stage: reptoboost dissolved in drinking water = glucose + electrolytes + vitamins + probiotics → for debilitated reptiles/ tortoises post hibernation

what does a bearded dragon eat

live insects and veg

what does leopard gecko eat?

live insects only

what does corn snake eat?

frozen mice

what does hermanns tortoise eat?

leafy greens and weeds

sexing bearded dragons

 hemipene bulges+ phemoral pores = male

s3xing snakes

probing the cloaca (further in males as entering inverted hemipene spaces)

s3xing tortoises

tail length + shape + cloaca positions

longer tail with spur + cloaca (more slit shaped) further to tail tip = male

what s3x?

male

what s3x?

female

which is male?

right

what s3x?

male

what s3x?

female

In freshwater fish, what is the main osmoregulatory challenge?

Losing too much salt

Losing too much water

Producing highly concentrated urine

Gaining excess water

gaining excess water

Why should heat mats not cover more than half of a reptile enclosure floor?

 

They reduce availiable UVB 

The inhibit temperature gradients

They decrease humidity

They interact with water

inhibit temp gradients

Why is stocking density guidance used when setting up an aquarium?

To prevent aggression between big and small fish

To maximise the number of occupants

To reduce competition for food

To prevent overloading the biofilter

prevent overloading biofilter

Which factor is MOST important when creating a community fish tank?

Ensuring all the fish are the same size

Choosing fish which eat the same diet

Choosing fish which share water parameters

Choosing fish which swim at different levels

choose fish that share water parameters

Which of the following substrates is MOST appropriate for a high-humidity species like a ball python?

Mulch or husk

Sand

Pine shavings

Gravel

mulch/ husk

What is the main functional advantage of countercurrent exchange in fish gills?

It reduces water flow over the gills

It prevents nitrogenous waste excretion

It allows oxygen to diffuse continuously into the blood

It increases carbon dioxide excretion

allows oxygen to diffuse continuously into the blood

Why is feeding whole prey important for carnivorous reptiles?

It prevents dehydration

It prevents nutritional imbalace

It reduces feeding frequency

It improves digestive tract health

It prevents nutritional imbalace

What is a key risk of feeding reptiles vegetables high in oxalates (e.g. spinach)?

Increased fat absorption

Increased protein digestion

Reduced calcium availability

Reduced thyroid secretion

reduced Ca availability