Keywords Flashcards
Protogyny
Fish starts off as female and changes to male at a later stage.
Protandry
Fish starts off as male and changes to female at a later stage.
Monomorphic
One form, (sexes are similar in size and appearances).
Dimorphic
Two distinct forms, (sexes look different).
Sequential hermaphrodites
Changes sex at a certain point in its life
Egg Scatterers
Fish scatter their eggs onto the substrate/plants. The fry hatch very quickly. No parental care. Lay a large group of eggs to offset predation.
Egg Buriers
Usually inhabit areas of drought. Spawning takes place in the dry season. Eggs are buried in the mud, and rain stimulates eggs to hatch.
Egg depositors
Fish deposit eggs on substrate. The fish lay less eggs, but eggs are larger. Two groups;
Parental carers
Non-parental carers
Mouth brooders
Fish brood offspring in mouths, so predators will not eat the eggs/fry. Parental care is given. Female does not eat whilst brooding. Incubation takes place in the throat. Two groups;
Ovophile; eggs are laid then the female sucks them up. The male has egg shaped spots on his anal fin, the female tries to such them up but receives a mouthful of sperm (milt). Eggs are then fertilised.
Larvophile; Lay eggs on substrate, and are guarded by parents. Once hatched, the female picks the fry up and keeps them in her mouth.
Nest builders
Fish construct nests where fertilised eggs are guarded. Male tend to build the nest; either a bubble nest or a nest on the ground.
Livebearers
Two groups;
Ovoviviparous; the eggs form and hatch within the female before birth, once hatched in the body, live young is born.
Viviparous; no eggs are formed, young are nourished within the body.
Some females can store milt in the body for several months.
Anterior
Towards the head
Posterior
Towards the tail
Cranial
Head region
Caudal
Pertaining to the tail region
Dorsal
Towards the top of the animal
Ventral
Towards the belly of the animal
Placoid scales
Found in rays and sharks. Resemble small teeth like projections from skin.
Ganoid scales
Usually mosaic in arrangement with little overlaps. Seen on sturgeons and gars.
Ctenoid scales
Spiny comb or teeth-like extensions to the outer edge
Cycloid scales
Round and oval shaped
Scutes
Don’t have scales. Instead have 2 or 3 overlapping bony plates called scutes
Photoreceptors
Fish eyes that have rods and cones.
Fins
Used for stability, propulsion, steering and balance.
Dorsal fin
Located along the back of the fish between the tail and head - provides lateral stability so the fish can swim in a straight line and prevent it rolling over.
Caudal fin
Tail fin - responsible for propulsion, sudden forward movements and very fast swimming patterns
Anal fin
Located on the underside of the body between the pelvic and caudal fin - helps with stability and prevents the dish from rolling over.
pectoral fin
Paired located near the bottom of the fish directly beneath the gill openings - used for navigation and stability, provides upward lift that helps fish maintain depth, enables flight of flying fish, some species also have defensive spines.
Pelvic fin
Located in front of the anal fin on the abdomen of the fish - used for braking, stabilising their bodies and changing their direction.
Adipose fin
Some fish e.g. tetras have an extra adipose fin - located between the dorsal and caudal fins.
Ventral fin
Some fish e.g. catfish use them to hold eggs during spawning.
Lateral line
Helps detect vibrations, water pressure and currents, visible as a line of tiny perforations in a row of scales down the fish. Pressure around objects is distorted allowing fish to change direction quickly to avoid predators, catch prey and shoal.
Swim bladder
Bag-like organ filled with gas controlled by the blood. Located below the backbone. Most bony fish (except bottom-dwellers) have one. Provides buoyancy, allowing fish to remain at a certain depth in water. Lungfish use it to breathe air, and catfish use it to produce sounds and provide buoyancy.
Gills
Diffuse oxygen from the water. Take in water and expel through gills.
Respiration
Breathing process begins when the gills covers close and the mouth opens.
heart
2 chambers - atrium and ventricle.
Liver
Secrets enzymes that break down fats. Storage area for fat. Production of bile. Also involved in waste excretion.
Kidney
2 kidneys, located near the spine. Produces urine and helps regulate the salt levels.
Digestive system
Eliminates materials that are not used. This system leads from mouth to vent.
Oesophagus
A fish’s oesophagus expands easily which allows the fish to swallow its food whole.
Gizzard
Some fish have their oesophagus or stomach enlarged into a gizzard. The gizzard grinds food into smaller pieces.
Gallbladder
Produces bile which neutralises acid in the stomach. Helps digest fat.
Spinal Cord
Spine connects the skull and the tail. Relays sensory information.
Pyloric Caeca
Fringelike projections. Located near the junction of the stomach and intestines. Secretes enzymes that aid digestion and absorb digested food.
Vent
Acts as a urinary digestive and reproductive opening
Top feeder
Aquatic organisms that feed from the surface/ top section of the water.
Superior feeder
Mouths are turned upwards, on top of the head. Commonly seen in top feeders
Mid feeder
Aquatic organisms that feed from the middle section of the water.
Terminal feeder
Mouths are positioned in the middle of the head, facing forwards. Commonly seen in mid feeders.
Bottom dweller
Aquatics organisms that feed from the bottom section of the water. Often rummage through the substrate for nutrients
Inferior mouth
Mouths are downward facing, on the underside of the head. Commonly seen in bottom/ substrate feeders.
Filter feeder
Aquatic organisms that pass water over specialised filtering structures in their mouth (e.g. baleen in whales), extracting the nutrients and tiny organisms.
Carnivore
Meat eater
Herbivore
Vegetation eater
Omnivore
Eats both meats and veg
Insectivore
specialist eater - insects
Browser
Aquatic herbivores that eat specific aquatic plants and spend much of their time searching for them
Chondrichthyes
Group of cartilaginous fish including sharks, skates, rays, and chimaeras. They have:
Flexible skeletons made of cartilage
Paired fins
Hard scales
Two-chambered heart
5-7 gill slits each side
1 pair of nostrils
Some produce eggs and some give birth.
Osteichthyes
They are the largest class of vertebrates, they are also known as bony fish because they have a bone skeleton instead of cartilage.
They have a swim bladder
Paired pectoral and pelvic fins
Most have bones in their fins
They have dorsal, anal, and cordal fins
They have an operculum and also have scales.
Most have a fusiform body design which means their bodies are tapered on both sides.
They have a lateral line that runs across one side of the body
Agnathas
They are jawless fish, this includes lampreys and hagfish, they are also probably the earliest vertebrates.
They don’t have paired fins or stomachs
They have a chord that provides the main support for the body during the embryonic stage
Most have a cartilage skeleton and 7 paired gills or more
They have a light sensitive pineal eye and egg fertilization takes place outside the body.
two chamberd hearts
An organ that pumps blood for animals with gills and single circulation
embryonic stage
Impregnation of the fish.
Cartilaginous
Skeleton made out of cartilage instead of bone.
Fusiform
Osteichthyes species that have a rounded body at both ends to make them more streamlined
Bony fish
Part of the Osteichthyes class of vertebrates.
Operculum
A series of bones found in bony fish and chimaeras. It serves as a facial support structure as well as covering the gills.
Costia
Signs/Symptoms; The fish may show signs of flashing, which is rubbing their body on rocks
They will also get clamped fins and also lose their appetite
They could also get red patches across their scales
Cause;
This is caused by a parasite that attaches to the gills
Treatment; Effective methods of treatment include the use of salt, as well as heat treatment
Trichodina
Signs/Symptoms; Ulcers, Irritated skin and lack of appetite are common symptoms
Cause; Poor water quality can be a good cause. Overcrowding and the introduction of a new fish are the most common
Treatment; Quarantining new fish. All infected fish should be isolated and good water quality must be maintained
White spot
Signs/Symptoms; Large quantity of white spots, the fish will also scratch itself on the substrate of the
Cause; This Parasite once grown will detach from fish and rest on the floor waiting for other fish to come close. It can also be found on new fish that have not gone through quarantining.
Treatment;
Camellanus
Signs/Symptoms; This can be spotted by a reddish coloured worm protruding from the skin of the fish. Sudden weight loss and loss of appetite can be another symptom
Cause; Fish can pick up this worm from infested copepods in the water, as well as free swimming worm larvae
Treatment; Wormer medication are useful as well as quarantining. The supply of live food should only be from trusted suppliers
Ethical
Buying animals to be kept in captivity in an ethical way. This means they are not harmed. Can be bred in captivity are considered ethical.
Unethical
Unethical sourcing usually means wild caught fish. The fish can be put through stress and illness when sourced from unethical places / methods.
Specialist Breeders
Breed certain species (limited range) to a high quality - well cared for. May be wild caught or captive bred. Fish kept in correct conditions for high breeding rates. Often supply wholesalers and shops.
Hobbysist
Someone who breeds captive bred fish as a hobby. They find caring homes for them. Stock is generally high quality - health checked and well looked after.
Wholesalers/ Importers
They provide livestock to pet shops and garden centres. Shipments arrive regularly from countries all over the world and they also source from local uk breeders. They will support serious hobbyists with stock that’s hard to find.
There are welfare issues:
The animals have to travel long distances and conditions aren’t ideal (many fish die)
Often not quarantined and have parasites.
They experience bad handling resulting in stress or injury
Farms
Normally many species are farmed in fresh and saltwater. They are produced in closed systems where the water is recirculated and open systems which are more natural bodies of water.
Welfare issues:
Methods of slaughter are unethical like using carbon dioxide or suffocating them on air.
Percussive stunning is considered the most ethical way of slaughter
Welfare issues
Transport - can be stressful and can cause illness due to the water conditions that first stay in during transportation.
Handling - can cause stress and damage the fish.
Wild caught fish - may not cope with captivity, destruction of natural habitats, crime (illegal wildlife trade)
Filtration
Removes organic particles from the aquarium including fish waste.
Mechanical filtration
Draws aquarium water through filter media and expels it quickly afterwards. Small debris and waste products are trapped in the filter media, which is rinsed clean on a regular basis to remove waste. Removes particulate waste.
Biological filtration
Works similar to mechanical, but also has media with a large surface area in which bacteria can multiply on and colonate. As water enters over the media, bacteria break down and convert toxic substances into less toxic ones. Only cleaned with aquarium water to prevent killing bacteria off.
Chemical filtration
Usually done with activated carbon as it has a positive charge which attracts the negatively charged chemical impurities e.g. chlorine. Filter media and products can clarify water, eliminate odor, remove chlorine, eliminate medications after disease treatments, neutralize heavy metal ions and effect changes in hardness and pH levels
underwater filters
Simplest filtration to use and install. All types of filtrations - mechanical, biological and chemical. Removes large and small particles out the water. Suitable for larger aquariums, but there are mini filters for smaller tanks. Suitable for marine and fresh water.
External canisters
Water is pumped through from the aquarium into canisters, then water will be oxygenated and cleaned. Tank is outside of the tank, so there is more space inside the tank.
Under gravel filtration
These work by drawing water through the aquarium gravel to where good bacteria colonise. As the water and fish waste passes through the gravel, the bacteria will break down the toxic substances.
Sump tanks
Large filtration system. Located below the aquarium where overflow water is passed down a tube from the main aquarium. Faltered water will return to main tank. Can be mechanical, biological and chemical filtration.
UV sterilsers
Ultraviolet or UV sterilisers are used in fish tanks to remove unwanted free floating algae, parasites or bacteria from marine and freshwater. Will prevent the bacteria and algae from reproducing and will kill them off.
Temperature
Relative heat of aquarium water. Measured in degrees Fahrenheit or Celsius. Measured with a thermometer.
pH
Measure of hydrogen ion levels in the water on a scale of 0-14. Tells you whether the water is acidic or alkaline. Neutral is pH7 (preferred for aquariums).
Water Hardness
The amount of dissolved minerals in the water. Measured in parts per million (ppm).
General Hardness
The amount of dissolved calcium, magnesium and trace amounts of other minerals.
Carbonate Hardness
The amount of carbonate or bicarbonate in the water.
Salinity
Amount of salt in the water. Measured with a hydrometer, in specific gravity (the ratio of saltwater to pure water).
Zoo licencing
Requires all zoos in Great Britain to be licensed and inspected by local authorities, zoos are defined as ‘an establishment where wild animals are kept for exhibition’. The act ensures that animals are provided with a suitable environment. Violation of this legislation can lead to a £2,500 fine.
Animal Welfare Act 2006
This piece of legislation describes the five animal welfare needs. This includes:
The need for a correct diet
The need for a suitable environment
The need to be able to exhibit natural behaviour,
The need to be housed with or apart from other animals
The need to be protected from pain, injury and disease
CITES
(Convention on International Trade in Endangered Species) This aims to ban international trade of species under threat of extinction. All wild plants and animals are included. Violating this legislation can lead to a max of 7 years in prison, and an unlimited fine.
Pet animal act 1951
This piece of legislation is in place to protect animals sold as pets. It ensures that pet shop owners are licenced and keep animals in clean conditions where their needs are being met. To be allowed a licence, an inspector from the council will ensure that animals are being kept in clean and suitable accommodation, that they are supplied with appropriate food and drink, and that they are adequately protected from disease and fire.
