Fish pt 1 Flashcards
what’s a fish/shellfish?
aquatic animals that inhabit marine/fresh water
compare the color and texture of fish to poultry/red meat
fish have lighter colors and softer textures
true or false: all fish are a good source of protein
true - contains high quality protein (has all essential amino acids)
true or false: all fish are a good source of essential fatty acids
true
what makes fish/shellfish unique?
use gills for respiration and the gills
what structure covers the gills?
operculum
how do gills work?
as surrounding water passes over the gills, there is exchange of gases just like what happens with mammals and birds
true or false: fish/shellfish are comprised of several species and constitute the most diverse group of vertebrates and invertebrates
true
what 2 main groups are fish categorized into?
true fish, shellfish
what’s a true fish?
- lack limbs but have fins used for locomotion/turning
- tend to be torpedo shaped: rounded at head, broader and thicker in the middle, tapers toward the tail region
what categories of true fish are there?
- teleost/bony fish (has backbone/spine)
- elasmobranchs/cartilaginous fish (lack backbone)
what’s a shellfish?
some have limbs. they’re categorized into 3 groups, being crustaceans, mollusks, and echinoderms
describe and list some examples of crustaceans
decapods because they contain 10 limbs
- shrimp
- lobster
- crab
describe and list some examples of mollusks
have 8 limbs
squid, octopus, cuttlefish, sea snail
list some echinoderms
sea urchin, star fishes
what are the body temperature based categories of fish?
- poikilothermic: body temperatures is within ± 2°C of ambient water temperatures
- endothermic: keep body temperature constant ~37°C. e.g. tuna, swordfish, white shark
what vitamins are fish a good source of?
B2, B6, B12, C, A, and D
describe the scales of the fish
arranged like shingles of a roof that overlap each other; scales have concentric rings that increase in number as they age
by how much has fish/shellfish harvest increased?
400-500 times
why has fish harvest increased?
- improved and more sophisticated harvesting methods
- fish vessels are larger and better equipped to stay out on the seas for longer and better facilities for storage to keep catch from spoiling
- changes in dietary preferences (healthier source of proteins/fats)
- emergence of fish farms
- other than in N America, fish tends to be a cheaper source of animal proteins
rank countries by greatest fish/shellfish harvest
china>peru>india>indonesia>US
describe the wild fish harvest catch rate trends
remained pretty constant because of attempts to conserve species and prevent over-fishing. some countries observe this better than others
describe the aquaculture fish harvest rate
growing steadily: responsible for the 400-500 times growth
describe fish consumption
- most of the fish harvested is consumed as human food
- some obtained in fresh form
- some obtained in frozen form (more than fresh)
- salted, smoked, marinated (more common in poorer countries)
- unused parts are used as fish meal or fish oils
- small fish caught unintentionally need to be dealt with as well
compare moisture content of fish to beef
higher in fish/shellfish
why does the moisture content of fish fluctuate so much?
depends on status of the fish:
- actively feeding: deposits more fat and protein (mostly fat), leading to lower moisture content
- spawning/migrating: expend energy derived predominantly from fats, and to proteins to some extent (high moisture content)
fish with (higher/lower) moisture content tend to be more tender
higher
what are examples of fish with high moisture content?
- anchovies
- porgy
- hoki
- flounder
what are examples of fish with intermediate moisture content?
- cod
- halibut
- shrimp
- lobster
what are examples of fish with low moisture content?
- catfish
- dogfish
- sturgeon
- tuna
fish with more fat content will have (stronger/milder) flavor
stronger
list examples of fish with lower fat content
hoki, bass, cod
list examples of fish with intermediate fat content
anchovies, several shellfish like shrimp, lobster, scallops
list examples of fish with high fat content
tuna, mackerel, herring
