Week 14: Body Systems - Fish & Amphibians Flashcards
What are some advantages of fish cuticle?
Makes the fish more difficult for predators to grab
Acts to reduce body friction in water
Has protective anti-pathogenic properties
Slows down water transfer across the skin
In what part of the skin are fish scales located?
Located within the stratum spongiosum and project toward (but do not pierce) the epidermis
Define: “operculum”
Flap of skin that covers the gills, supported by a series of small fin bones
What two layers is the fish dermis divided into?
(Outer) stratum spongiosum
(Inner) stratum compactum
What are “chromatophores” and where are they contained in the fish?
Pigment cells
Located within the stratum spongiosum
Where are mucous glands located in the fish skin?
The interspace between cells in the epidermis
Do the outer layers of epithelium in fish keratinise?
No - all layers of epithelium contain living cells that are capable of active division
Are chromatophores found above or below the scales in fish?
Below (or closely associated with) the scales
Describe the two different types of scales found in teleost fish
Cycloid scales: have a smooth contour
Ctenoid scales: have stiff spikes protruding from one edge
What is the function of the lateral line in fish?
Sensory system which allows fish to detect weak water motions and pressure gradients
What structures are located within the lateral line in fish?
Contains a series of pits which contain neuromast cells
Neuromast cells contain delicate hairs which are protected by a gel-like cap and are used to detect movement via vibration in the surrounding water
What fins are present on a rainbow trout and what functions do they have?
Cranial dorsal fin: stabilises the fish
Caudal dorsal fin: stabilises the fish
Anal fin: stabilises the fish
Caudal fin: propels the fish forward
Pectoral fins: turning, braking, balancing
Pelvic fins: turning, braking, propelling
How do fish smell?
Olfactory pits located on either side rostral to the eyes
Connected by a U-shaped tube containing vascular sensory epithelium
One opening is a water inlet, the other a water outlet
What structure forms the boundary between the head and the trunk in fish?
Caudal edge of the operculum
Define: “myomere”
Blocks of skeletal muscle arranged in sequence (zig-zag appearance)
Define: “myosepta”
Sheet of connective tissue which separates two myomeres (blocks of muscle)
Which muscle fibres are used for slow cruising in fish?
Lateral muscle fibres (slow)
What colour (usually) are lateral muscle fibres in fish?
Red - have a very good blood supply
Which muscle fibres are used for high speed swimming in fish?
Dorsal and ventral muscle fibres (fast)
What colour (usually) are dorsal and ventral muscle fibres in fish?
White
How does water pass over the gills in fish?
In a cranial caudal direction (and exits through the opercular opening)
When the mouth opens, water is drawn into the buccal cavity/pharynx
When the mouth closes, water is pushed out through the gills
What are the two coeloms present in fish?
Pericardial coelom: lined by pericardium and contains the heart
Peritoneal/abdominal coelom: contains all other viscera
What structures support the gills?
Skeletal/branchial arches (attach dorsally and ventrally to the walls of the pharynx)
What are “gill rakers” and what purpose do they serve?
Projections on the cranial surface of the gill arch that act as filters to protect the gills from ingested particles
