unit 2 Flashcards

Question

shark food detection experiment

Answer 1

sharks prefer electical over chemical (smell) signal to find food

Answer 2

Elasmobranchii: elasma = plate & branchia = gills – Between 5 and 7 gill openings on each side of the head • Includes extant sharks, skates & rays • Hyostylic upper jaw suspension- upper jaw not fused to the chondrocranium, permits it to be projected and retracted (SUUUUCK) 2. Holocephali holo = whole; cephalo = head – Includes ratfishes/chimaerans – Single gill opening – Holostylic upper jaw suspension- upper jaw fused to the chondrocranium

Answer 3

1. Placoid scales – Composed of dentine and enamel with a pulp cavity -tooth like structure -also called denticle -reduce friction as they move through the water -rough and tough -grow more scales as they grow in size (the scales do not get larger) 2. Cartilaginous skeleton * Ancestral condition of vertebrates * Mineralized with hydroxyapatite. Bone from osteichthyans are also mineralized with hydroxyapatite but deposited differently. * Not necessarily weaker than bone * More buoyant than bone -more flexible 3. Teeth whorls of sharks * dentine, enameloid & traces of bone * Not embedded in the jaw (sit on jaw bone) * Constantly being shed and replaced 4. Internal fertilization * Males have pelvic claspers for internal fertilization -associated with pelvic fins 5. Lipid-filled liver * Less dense than other body tissues and may be large to Facilitate buoyancy * Skates & bottom dwelling species have smaller livers so they Sink to sea floor

Answer 4

Clade Selachii • Highly diverse group • Marine apex predators • Many derived locomotor, sensory and behavioral adaptations

Answer 5

Well developed vision permits vision at low light * Rod rich retina with platelike crystals of guanine : tapetum lucidum -eye shine -acts like mirror and reflects light -adaptation that concentrates even low light

Answer 6

* Smell (chemoreception): - extremely acute * Electroreception: to weak electric fields via the ampullae of Lorenzini

Answer 7

* Internal fertilization * Produce few offspring as a result * Males have a clasper that deposits sperm into the female’s cloaca during copulation * many speices are Oviparous some are viviparous * Nourisment of embryo is either via a egg yolk (lecithotrophy and oviparous) or via the reproductive tract (matrotrophy and viviparous) -lecithotrophy means "yolk of the egg" "acquisition of energy" -matrotrophy means "mother" "acquisition of energy"

Answer 8

have large eggs that have projections that help it attach to vegetation/substrates for protection

Answer 9

Eggs are produced and retained inside the mother * Young hatch in the female and stay until they are fully developed - may eat other eggs or each other or fluids inside mother -can be Non placental or placental

Answer 10

• Clade Batoidea • Dorsoventrally compressed with mouth and gill slits on ventral surface (flat bois) • Enlarged pectoral fin • Fewer placoid scales • Durophagous (flat teeth used to crush hard things) • Some rays are venomous • Skates are oviparous, rays viviparous

Answer 11

* Widely distributed in deep water (500+m) * cartilaginous skeleton, oil filled liver * Feed on invertebrates and small fish * Extant chimaerans are oviparous -take 10-12 yrs puberty because of slow metabolism once/year with few resulting young vulnerable to extinction Evidence for oviparity being ancestral in chondrichyhes

Answer 12

• Four gill openings that are covered so it looks like one opening • Teeth reduced to tooth plates • Specialized sensory receptors on head

Answer 13

1. Ossified endoskeleton with endochondral bone, in addition to the dermal and perichondral bone. 2. Enamel -highly mineralized -hardest mineral in body -made of hydroxyapatite -originates from epidermis 3. Gas containing structure (either gas bladder or lungs) -some have both -believed to be homologous -lungs came first that turned into gas bladder

Answer 14

Very diverse group consisting of > 66,000 species in 2 classes:

Answer 15

1. Actinopterygii: ray-finned fishes 2. Sarcopterygii: lobe-finned fishes

Answer 16

The fins of Actinopterygian have lost the basals and the radials attach to the limb girdles -can collapse fin against the body -less turbulence -more streamlined

Answer 17

have a row of basals that interact with the limb girdle, followed radials and then fin rays that support the web of the fins

Answer 18

have a single basal that articulates with the limb girdles

Answer 19

1. Non-teleosts 2. Teleosts

Answer 20

Jaw mobility: (greater in teleosts) Tail shape : HOMOcercal (teleosts) vs HETEROcercal (non-teleosts).

Answer 21

1. Polypteriformes (Bichirs and Reedfishes) 2. Acipenseriformes (Sturgeons and Paddlefishes) 3. Lepisosteiformes (Gars) 4. Amiiformes (Bowfin)

Answer 22

* Live in stagnant freshwater * Have 2 lungs which supplement gill respiration and spiral intestine (increases surface area) with a pulmonary circulatory route

Answer 23

* Have dermal head bones that are formed of cartilage (lost endochondral bone) * Upper jaw is not fused to cranium * Lung has been modified into non-respiratory gas bladder

Answer 24

* Large, benthic fish with heterocercal tail * Rows of armorlike scales: scutes (5 rows) * Found in Northern Hemisphere * Both freshwater & marine – Marine forms go to freshwater to breed

Answer 25

Two extant species of paddlefish – Chinese paddlefish * Yangtze River * Bottom-feeding * Not recorded since 2002 -long flat rostrum which is rich in ampules – North American paddlefish: * Mississippi River drainage * Filter feeding * Classified as vulnerable

Answer 26

* Live in fresh water and estuarine water of North & Central America & Cuba * Vascularized gas bladder (can be used as a lung) * Move slowly but have a very fast strike to capture prey -7 extant species -interlocking multilayer scales that are very good armour

Answer 27

Generalist predator live in weed filled lakes thin layer of scales have an eye spot on tail to confuse predators

Answer 28

1. Osteoglossomorpha (e.g., elephant nose fish) 2. Elopomorpha (e.g., eel) 3. Otocephala (e.g., herring, catfish) 4. Euteleostei (e.g., salmon, etc. etc. etc.)

Answer 29

Bony Tongue * Most primitive of the teleosts * Some communicate and sense their environment via electric discharges

Answer 30

* Include bonefishes, tarpons and true eels – Most live in marine environments but some are freshwater * Unique in that they have leptocephalus (small head) larvae freshwater or marine environments

Answer 31

* migrates from freshwater to sea to breed: catadromous * Leptocephalus larvae float and drift to the coast where they morph into glass eels -15-20 years until sexual maturity

Answer 32

* Very diverse – Includes marine schooling fish (important in food web) and carnivorous freshwater fish * Many of the marine fish are anadromous * Have two distinctive features 1. Weberian apparatus: Small bones that connect the swim bladder to the inner ear 2. Have a flight reaction due to release of pheromones from other fish

Answer 33

• Includes thousands of species • Diverse life history and morphology

Answer 34

Anterior to posterior sequential contractions of muscle segments on one side of body and simultaneous relaxation on the other

Answer 35

1. Anguilliform: Typical of highly flexible fish – Typical of true eels: Anguilliformes - lots of movement in the body 2. Carangiform: undulations limited to the caudal region * Typical of Jacks (Caranx spp.) 3. Ostraciiform: only caudal fin undulation – Inflexible body – Boxfishes, cowfishes, trunkfish 4. Labriform: Rapid undulation of the pectoral fins – e.g. sticklebacks & wrasses 5. Rajiform: use elongated pectoral fins -rays 6. Amiiform: use dorsal fin -long dorsal fin -undulates 7. Gymnotiform :use anal fin -similar to amiiform but with anal tail 8. Balistiform: use dorsal and anal fins

Answer 36

1. Most species lay eggs. * Most are oviparous, but some are viviparous 2. Nutrition varies from lecithotrophy to matrotrophy 3. Varying degrees of parental care 4. Sex determination may be fixed for life, change sexes at some point, hermaphroditic or completely female (no males) -this varies on genetics and environment -maximizes number of offspring produced

Answer 37

freshwater vs. marine reproduction: Freshwater: small number of demersal (bury in gravel, place in nest, or attach to substrate) eggs Marine:large number of eggs that are transparent and buoyant

Answer 38

Many lay eggs at high tide, and eggs develop over about 2 weeks, before the next high tide

Answer 39

- 3% but Seen in 12 lineages of teleosts -seahorses, guppys, etc

Answer 40

Challenges of life in the deep sea include: 1. Absence of light 2. Little food * Despite this there is diversity in the deep-sea fishes that live in the mesopelagic and bathypelagic zones * Typically, species are: * Small with sparse populations * Resulting selection pressures include predator avoidance & finding a mate -Many deep sea fish have large mouths and stomachs (need to be able to eat any prey you may encounter at those depths) * Many contain photophores, which are organs that produce light via a symbiosis with Photobacterium species * May attract prey or be used to find potential mates

Answer 41

-eggs float to top of water -larvae develop and swim down -female fully develops -male only eats as a larvae -once male is no longer a larvae, only purpose is to find a mate -once mate is found the male will fuse to the female, connecting the circulatory systems

Answer 42

1. Actinistians (Coelacanths) (1 extant) 2. Dipnoans (Lungfishes) (3 extant) 3. Tetrapodomorph fishes (the ancestors of tetrapods)

Answer 43

Coelacanths arose in the Early Devonian (~408 mybp) – Thought to be extinct until ~70 years ago when one found in Indian Ocean * Latimeria chalumnae ranges from 75cm-2m * Another species was found in 1998 near Borneo (Latimeria menadoensis) -Nocturnal * Have a fat-filled “lung” that has ossified walls (vestigial organ) * Viviparous fish * Must have internal fertilization but copulation is not understood

Answer 44

-More related to tetrapods than coelacanths * Australian lungfish have one lung, the others have 2 lungs. * Lungs have subdivisions to increase surface area for gas exchange

Answer 45

-South American lungfish (Lepidosiren paradoxa): little is known about it -the males have a highly vascularized extensions under the pelvic fins to deliver oxygen to eggs * Austrailian lungfish (Neoceratodus forsteri) has lobelike fins & heavy scales * Inhabits permanent water bodies * No parental care of offspring * Does not depend on air to breathe * African lungfish (Protopterus): four species * Can “walk” underwater. * Obligate air breathers * Estivate in a U-shape in burrows during dry periods (covered in mucus with an opening for the mouth) -water recedes sometimes and they burrow in the mud

Answer 46

1. Air is less viscous & less dense (less resistance) * Need to overcome gravity 2. Gills collapse in air 3. Heat capacity and conductivity

Answer 47

* Fish are essentially ‘weightless’ in water * Terrestrial tetrapods must have adaptations for support and locomotion – Skeleton must be rigid – and as light as possible -survival of the fittest -must use energy effectively -heavy bones are good for gravity but not for running

Answer 48

* Made up of cartilage (more elastic than bone) and bone * Bones are dynamic so that its internal structure can adjust to its changing demand * In amniotes, bones are arranged in concentric layers around blood vessels * The cylindrical units are called Haversian systems * External layers of bone are dense/compact. * Internal layers are spongy: cancellous bone

Answer 49

* Joints are covered by articular cartilage which covers cancellous bone * Entire joint is enclosed in a joint capsule which contains synovial fluid

Answer 50

Axial (skull, vertebral column, and sternum) -cervical vertebra -thoracic vertebra (connect to ribs) -lumbar vertebra (do not connect to ribs but to ilium) -sacral vertebra (pelvic girdle) -caudal vertebra Appendicular (pectoral and pelvic girdle, and limbs)