Fish Prac Flashcards
Scale types
Placoid
Cycloid
Ganoid
Ctenoid
Bull shark
Carcharhinus leucas
Sawfish
Pristus microdon
Lung fish
Protopteris annectus brieni
Filamentous pectoral and pelvic fins
Lungs
Aestivate during dry season
Coelacanth
Latimeria chalumnae
Paired lobe fins.
Hinged joint in the skull
Notochord - backbone
thick scales common only to extinct fish
Electro-sensory rostral organ in its snout - to detect prey.
Snout fishes
Mormyridae
• Snout extended into a proboscis
• Electricity discharge for communication and hunting
• Electric discharge – species identification
Eels
Anguillidae
Longfin eel - Anguilla mossambicus
• Elongate and sinuous
• No pelvic fins
• dorsal and anal fin joined
• Minute scales
• Diadromous life style
Cyprinidae
Red barb: Barbus fasciolatus
Largest family in SA
Barbs, yellow fish, labeos
Characins
Piscivorous
Prominent jaw and teeth
Pike, imberi, tiger fish
Tiger fish
Hydrocynus vittatus
Imberi
Brycinus imberi
African pike genus
Hepsetus
Catfishes characteristics
Large adipose fin
3-4 pairs of barbels around mouth
No scales
Sharp dorsal fin
Rock catfishes
Barnard`s rock catfish
Austroglanididae
Austroglanis barnardi
Threatened
Catfish threats
Threats: • Introduced predators – basses -Habitat modification • Stream channeling • Water extraction • Sedimentation
Mountain catfishes
Catlets
Butter catfish
Shilbeidae
Unusual body form – depressed head, large mouth, short deep abdomen and compressed, tapered body with long anal fin
* sharp dorsal and pectoral spines with chemical irritant
Air breathing catfish
Clariidae
Electric catfishes
Malapteruridae
Can generate 400 volts for defense and predation
Killifishes
• Habitat – temporary pools in savanna
• Brightly colored
• Eggs can withstand desiccation
• Model species for age research
* threatened – habitat destruction and insecticide spraying
Vertebrate with shortest lifespan
Nothobranchius furzeri
Killifish
Cichlids
- One of the largest and most widely distributed freshwater fish families
- Over 70% of known cichlids are found in Africa (> 900 species).
- 8 genera and 42 species in southern Africa
- Important food fishes
- Attractive aquarium species
Mozambique tilapia
Oreochromis mossambicus
• Tolerant to wide temperature and salinity ranges
• live and breed in both fresh and seawater
• Opportunistic and versatile feeding behaviour
• High fecundity and fast growth rate
• Ability to utilize a wide range of habitats for spawning and nursery purposes
Labyrinth fish
Well developed breathing organ (Labyrinth)
Found in temperature and oxygen harsh areas
Terrestrial movements in search of suitable habitat
Many spined climbing perch
Labyrinth fish (Anabantidae) Ctenopoma multispine
Conservation concerns
- Habitat alteration
- Erosion and sedimentation
- Excessive abstraction of water for irrigation purposes
- Pollution
- Invasive fish and plants e.g. basses, trout, water hyacinth and Kariba weed.
Water hyacinth
Eichhornia crassipes
Blocks waterways, impeding both navigation and drainage.
High rates of evapotranspiration
Displacement of indigenous flora and fauna by habitat modification. Provides suitable breeding sites for vectors of human and animal diseases
Introduce species
Basses Carps Chinese carps Trout Mosquito fish
Basses (large mouth)
Micropterus salmoides
Trouts (rainbow)
Salmonidae
Oncorhynchus mykiss
Common carp
Cyprinus carpio
Destructive feeding habits
Mosquito fish
Gambia affinis
Types of fins
Diphycercal
Heterocercal
Homocercal
