BIO 357 EXAM 2
Ganoid scale - answer-Rhomboid in shape
-Gars, sturgeons, paddlefishes
-Thick, heavy, non-overlapping
-Bone covered in ganoine
Ganoine - answer-Enamel-like inorganic salt secreted by the dermis of a ganoid scale
Placoid scale - answer-"Dermal teeth" : Homologous to teeth (denticles)
-Chondrichthys only
-Enamel-like covering over vascularized dentine cavity
-Backward orientation reduces hydrodynamic drag
-Do not grow as fish grows
Cycloid scale - answer-Lower teleosts (trouts, minnows, herrings)
-Derived from ganoid scales (no enamel)
-Thin, flexible, overlapping
-Grow with fish (form annuli)
Ctenoid scale - answer-Most derived teleosts (Acanthopterygii)
-Overlapping, thin, flexible
-Ctenii
Cteno - answer-"Comb"
Ctenii - answer-Combed part of ctenoid scale
-Reduce hydrodynamic drag impart unpalatability
Highly active - answer-Swift Water
-High amount of scales
-Small in size, low durability
-Ex: Tunas, Mackerels, Trouts
Not active - answer-Sluggish, bottom-oriented, cryptic, quiet waters
-Lower amount of scales
-Large in size, high durability
-Ex: Gars, Sturgeons
Naked Fishes - answer-Catfishes, eels, swordfish, lampreys, hagfishes
Scutes - answer-Sharp, posteriorly-directed scales
-Makes it hard for another fish to swallow it
, Development of Scales - answer-First appear on caudal peduncle (15 mm)
-Scales spread anteriorly (18-21 mm)
-Full Complement = Juvenile (30 mm)
Deciduous scales - answer-Scales that shed easily
-Makes it hard for predators to see these fishes
Uses of Scales - answer1.) Taxonomy (Species can be identified/classified based on
morphology)
2.) Systematics (Reconstruct phylogenetic relationships)
3.) Ecological Studies (Reconstruct diets from scales in stomach)
4.) Fisheries Biology (Determine individual age and growth rate)
5.) Archeological studies (obtained from pre-Columbian Indians middens)
Integument - answer-Skin of fishes
Chemical Composition of Skin - answer-Protein (collagen)
-Minerals (phosphorous, potassium, calcium)
Functions of Skin - answer-Support scales
-Mechanical protections (abrasion, predator attacks)
-Mucus production (mucin produced by glands) (barrier to bacteria, reduces drag,
decreases permeability)
-Human clothing, trinkets, and food
Photophores - answer-Found in skin
-Used for communication
Chromatophores - answer-Found in skin
-Used for crypsis
Neuromasts - answer-Found in skin
-Sensory
Venom glands - answer-Found in skin
-Used for self-defense
Epidermis - answer-Outer layer of skin
-Thin layer of living cells
-Covers scales
-Contains mucus glands
Dermis - answer-Inner layer of skin
-Vacularized and innervated
-Anchors scales and cushions muscle
Ganoid scale - answer-Rhomboid in shape
-Gars, sturgeons, paddlefishes
-Thick, heavy, non-overlapping
-Bone covered in ganoine
Ganoine - answer-Enamel-like inorganic salt secreted by the dermis of a ganoid scale
Placoid scale - answer-"Dermal teeth" : Homologous to teeth (denticles)
-Chondrichthys only
-Enamel-like covering over vascularized dentine cavity
-Backward orientation reduces hydrodynamic drag
-Do not grow as fish grows
Cycloid scale - answer-Lower teleosts (trouts, minnows, herrings)
-Derived from ganoid scales (no enamel)
-Thin, flexible, overlapping
-Grow with fish (form annuli)
Ctenoid scale - answer-Most derived teleosts (Acanthopterygii)
-Overlapping, thin, flexible
-Ctenii
Cteno - answer-"Comb"
Ctenii - answer-Combed part of ctenoid scale
-Reduce hydrodynamic drag impart unpalatability
Highly active - answer-Swift Water
-High amount of scales
-Small in size, low durability
-Ex: Tunas, Mackerels, Trouts
Not active - answer-Sluggish, bottom-oriented, cryptic, quiet waters
-Lower amount of scales
-Large in size, high durability
-Ex: Gars, Sturgeons
Naked Fishes - answer-Catfishes, eels, swordfish, lampreys, hagfishes
Scutes - answer-Sharp, posteriorly-directed scales
-Makes it hard for another fish to swallow it
, Development of Scales - answer-First appear on caudal peduncle (15 mm)
-Scales spread anteriorly (18-21 mm)
-Full Complement = Juvenile (30 mm)
Deciduous scales - answer-Scales that shed easily
-Makes it hard for predators to see these fishes
Uses of Scales - answer1.) Taxonomy (Species can be identified/classified based on
morphology)
2.) Systematics (Reconstruct phylogenetic relationships)
3.) Ecological Studies (Reconstruct diets from scales in stomach)
4.) Fisheries Biology (Determine individual age and growth rate)
5.) Archeological studies (obtained from pre-Columbian Indians middens)
Integument - answer-Skin of fishes
Chemical Composition of Skin - answer-Protein (collagen)
-Minerals (phosphorous, potassium, calcium)
Functions of Skin - answer-Support scales
-Mechanical protections (abrasion, predator attacks)
-Mucus production (mucin produced by glands) (barrier to bacteria, reduces drag,
decreases permeability)
-Human clothing, trinkets, and food
Photophores - answer-Found in skin
-Used for communication
Chromatophores - answer-Found in skin
-Used for crypsis
Neuromasts - answer-Found in skin
-Sensory
Venom glands - answer-Found in skin
-Used for self-defense
Epidermis - answer-Outer layer of skin
-Thin layer of living cells
-Covers scales
-Contains mucus glands
Dermis - answer-Inner layer of skin
-Vacularized and innervated
-Anchors scales and cushions muscle
