Aquatic Flashcards
ursids
polar bear is apex of marine ecosystem
feed mainly on seals and walrus
most of life is spent on sea ice
mustelids
sea, river, and marine otters
belong to the weasel family and are carnivores
marine otter
lives along Pacific coast of South America
spends time in the ocean but lives on land
prefers rocky shores and kelp forests
sea otter
the only species that lives entire life in the ocean: grooming their fur creates air bubbles that help keep them buoyant and insulate them
marine otters
more closely related to the 3 species of American river otters than to sea otters which indicates that costal/marine lifestyle evolved twice in the weasel family
pinnipeds
seals, sea lions, walruses
have front and rear flippers
sea lions
“walk” on land using large flippers
have visible ear flaps
bark like dogs and are loud
California sea lions congregate in groups called rafts
seals
have small flippers
wriggle on their bellies on land
lack visible ear flaps
many varieties: Pacific harbor seal known for spotted fur; elephant seal has huge nose that looks like elephant trunk; fur seal is closely related to sea lion, have heavy fur, hunted for pelt, spend most time far from land
walrus
both females and males have tusks that grow with age and vacuum-like mouths for sucking up shellfish from the ocean floor
have air sacs in neck that can inflate to allow them to float
largest pinnipeds
sirenias
manatees and dugong “seacow”
aka sirens: where the mermaid legend came from
evolved from 4-legged land mammals: their flippers have vestigal toenails which is a remnant of the claws they had when they lived on land (Amazonian manatee doesn’t have)
manatees
have large egg-shaped head, flippers, and flat tail
aka sea cows because of their large stature, slow movements, and lolling nature, propensity to be eaten
closely related to elephants
swim alone or in pairs
in a group = mating herd or informal meeting sharing a warm area with large food supply
herbivores: prefer sea grasses
manatee anatomy
only have 6 neck vertebrae so can’t turn head sideways
algae and photosynthetic organisms often grow on their skin
can stay under water for 15 minutes without breathing
dugong
dugong dugon
similar to manatees
part of Sirenia order but different family: Dugongidae
have a notch in their tails and tusks
cetacea
whales, dolphins, and porpoises
split up into toothed and Baleen
toothed whales
sperm whales, killer whales, belugas, narwhals, porpoises, river dolphins
have single blowhole, teeth, and use echolocation
have a layer of fatty tissue under their skin called blubber which maintains body heat, and is an important energy source
very good eyesight
orcas
large dolphins
orcas and dolphins thought to be some of the smartest animals: very curious, exhibit complex social structures living in small groups for mating and often coordinated hunting
baleen whales
great whales: blue whale, right whales, minke whales, humpbacks
right and bowhead whales lack dorsal fin
they have double blowhole and upper jaw is hung with a baleen (stiff plates of keratin with fringes inside) instead of teeth
how do baleen whales feed?
by gulping large amounts of water and prey
when the whale brings its jaws together water is forced through the baleen fringes and out the sides of the mouth
baleen whales migration
most make long-range seasonal migrations and move toward polar feeding areas in the summer and toward low-latitude (tropical) calving areas in winter
juveniles and post-reproductive adults tend to stay in protected nearshore areas
beluga whales
small toothed whale that is brown-gray at birth and bright white in adulthood
only whale species that have a movable neck: can move up and down, side to side
narwhal whales
part of the “white whales” family
males have the characteristic tusk
ectothermic
cold blooded, influenced by the environment
teleost fish
bony fish found in salt and freshwater from the tropics to the Arctic and Antarctic, and from coasts to deepest parts of the ocean
teleost anatomy
scales are flat and covered by a thin layer of skin and mucus
fish breathe through gills which absorb dissolved oxygen in the water
water comes in through the mouth, passes over gills, and leaves out of operculum
have swim bladder filled with air for buoyancy
lateral line along spine = sensory organ that detects movement and vibration
vent: waste
2-chambered heart
how do fish perform schooling behavior?
using the sensory organ that makes up the lateral line along their spine
this organ detects movement and vibration in the water
function of fish fins
control stability and direction with the tail fin contributing up to 40% of forward thrust
freshwater fish as pets
freshwater fish are more popular, less expensive to set up system and get fish, more hardy, can have more fish per space
coldwater fish as pets
goldfish/koi
temperature of water should be 65-68
larger species consume more oxygen so less fish options and need plants
tropical fish as pets
large variety that coexist or can do a species tank (multiple fish from only 1 species together in a tank)
require a heating element
marine fish
saltwater fish
expensive: colorful, require saltwater, need higher rates of flow in aquarium and a good filtration system
don’t use air pumps: air affects the pH and chemistry of the water
provide air agitation with pumps and filters
tropical marine temperature: 74-78
ocean pH: 8-8.2
brackish
between salt and freshwater fish
not easily obtainable, expensive
ex: puffer fish
elasmobranch
sharks, rays, skates
primitive: cartilaginous fish that predate dinosaurs
what is the largest fish in the ocean?
whale shark
sharks
shark skeleton made of cartilage and lack a swim bladder, instead they have an oily liver to control their buoyancy
slow to mature and only produce 2-10 pups per litter
scales are spiky and project through skin like sandpaper
very advanced electroreceptive system to sense electrical fields
claspers
seen in male sharks
modification of the pelvic fin to facilitate sperm transfer during reproduction
spiracle
sharks
special gill that delivers O2 directly to the eyes and brain
have separate gill slits for each gill
nurse shark
yellowish-brown color with characteristically round heads, barbels that they use to search for prey and very small eyes
able to remain perfectly still, spend most daylight hours resting in caves or under ledges, sometimes seen in groups
are active and feed during twilight and nighttime
lampreys
cartilaginous fish closely related to sharks, resemble eels
lack a jaw, suck blood
eels
teleosts
rays
thin tail and stinging tail spine or barb, has serrated ends and injects poison
skates
smaller than a ray
have 2-lobed pelvic fins, stocky tail, and dorsal fins at tail tip, thorn-like formations on back and tail which deters predators
rays and skates similarities
lack a swim bladder: can lay on ocean floor to conserve energy
very sensitive to electrical impulses
fish compatibility
aggressives go with aggressives
most ornamental marine fish don’t school in captivity
usually only 1 fish per genus should be in a tank: otherwise territory fights can occur, harassment, stealing food
exception would be mated pairs
water quality of tank
warm water dissolves less of important gases like O2 and CO2 (but very warm water may not contain enough dissolved O2 to sustain life)
increased temperature = increased O2 loss
algal blooms are related to high temperatures which increases toxins
salinity and conductivity
check electron levels
salinity = sodium chloride
fish least tolerant to salinity are in juvenile stages
pH in a fish tank
narrow pH range fir cellular metabolism
extreme ends = physical damage to gills, exoskeletons, and fins
increased pH (7+): converts nontoxic ammonium to toxic ammonia
effect of hard water in a fish tank
leads to high minerals which leads to high pH
effect of soft water in a fish tank
leads to low minerals which leads to a low pH
how can you correct the pH of your fish tank?
use a water softener or demineralized water
turbidity of fish tank
algae, sediment that is suspended, organic matter
leads to increased temperature and decreased photosynthesis
caused by overfeeding or not doing routine water changes
how long does it take to establish a tank?
can take up to a month
nitrogen cycle caused by turbidity
feces/undigested food —> broken down into ammonia (NH3) —-> broken down by nitrosomonas bacteria into nitrite NO3 — converted to nitrate NO2 by nitrobacter
how are water changes of a fish tank done and how often?
change ~20% of water every couple of weeks
is tap water okay for fish?
no!! it’s chlorinated which is toxic to fish
chlorine blocks absorption of O2 leading to suffocation
can buy dechlorinator drops or let the water sit to denature the chlorine
ammonia toxicity
CS: tachypnea, gasping at the surface, jumping, rubbing
prevention: don’t overstock or overfeed
tx: remove 25-50% of water and replace with fresh dechlorinated water, correct the primary cause
nitrite toxicity
kills nitrobacter
nitrites cause stress even at low levels
CS: gasp at the surface, sudden death, brown blood
prevention: don’t overstock or overfeed, watch temperature and give antibiotic treatment
tx: remove fish to clean, dechlorinated, well oxygenated water
oxygen depletion
a concern in outdoor ponds
photosynthesis doesn’t occur at night, plants consume oxygen, warmer temperature can cause more rapid O2 loss
tx: ensure correct number of fish/plants, use an aerator, temperature control
fish gill clip
used to check for ectoparasites
lift operculum and cut 3-5 gill filaments, view on slide with a drop of tank water
fish skin scrape
drag a slide in caudal direction across the fish, check for lesions
ich parasite CS
rubbing, scale loss, hemorrhage at attachment site
