fish exam

two types of bone found in fishes and list two ways in which they differ

dermal, endochondrial
- location: skull, pectoral girdle, integument vs leg/arm bones
- formation: ossification of mesoenchyme vs cartilaginous matrix

the seven obligatory levels in Linnaean classification

Kingdom, Phylum, Class, Order, Family, Genus, Species

What are the two types of elasmoid scales? Describe them.

cycloid: round, flat, thin
ctenoid: has tiny comb-like projections on outer exposed edge of scale

rete mirabile

“wonderful net”- counter current exchage system for gas composed of a looping bundle of arteries and venous capillaries

what percentage of fish are marine and what percentage are freshwater

41.2% freshwater, 58.2% marine, 6% diadromous

apomorphic and plesiomorphic

advanced jaw type: mobile premaxilla + maxilla
primitive jaw type: immobile premaxilla + mobile maxilla

Poikilotherms, Homeotherms, Endotherms, and Ectotherms

cold-blooded, keep steady internal temp, produce their own body heat, internal temp changes with external environment

difference between a physostomous fish and a physoclistous gas bladder

physostomus: connection between gut and air/gas bladder
physoclistous: no connection between gut and gas bladder

difference between abdominal and caudal vertebrae

abdominal: makes up front of vertebral column, has ribs
caudal: makes up back of vertebral column, does not have ribs

3 functions of gas bladders in fish

• buoyancy regulation, helps amplify sounds for fish (can pick up underwater vibrations), and acts as a primitive lung or oxygen reserve in low oxygen water

purpose of glycoproteins within bloodstream of Notothenoids

prevent blood and bodily fluids from freezing in below zero waters

five main traits that define most fish

respire by means of gills, live in water, poikilotherms, have scales, have fins

typical body shape of sharks, skates, rays

sharks: pectoral fins are not especially large, skates + rays: pectoral fins greatly enlarged and connected to head

the skeletons of sharks and stingrays are composed of what

• lighter than bone: cartilage

difference between fish and fishes

fish: multiple individuals of the same species, fishes: reference to multiple diff species

characteristics of Phylum Chordata

pharyngeal opening, notochord, dorsal hollow nerve cord, post-anal tail

6 categories of fish based on shape

fusiform: torpedo: long, narrow, and pointed
compressiform: tall and skinny
depressiform: flat and wide
globiform: round and bulky
anguilliform: long, snake-like, slender
sagittiform: long, slender, arrow-like

three characteristics of Chimeras

up to 4 male claspers, no gill slits, placoid scales, lack bone

functional units of the fish cranium

neurocranium (braincase), branchiocranium (visceral skeleton or splanchnocranium)

appx # of species of vertebrates, how many are fish

appx 60,000 species in total, appx 30,000 are fish

subclasses included in class chondrichthyes, “common names”

sharks, skates, rays, chimeras, ratfish

tapetum lucidum

reflective layer of tissue located directly behind the retina in the eyes of many vertebrates that improves vision in dim light

3 possible reasons that manta rays leave the water

avoid predators, mating ritual, lose parasites, demonstrating fitness, eating surface zooplankton

diadromous fish

migrate between fresh and salt water in their life cycles

squalamine

steroid type found in sharks, which has antibiotic properties

lateralis system

a specialized sensory network found in aquatic vertebrates, such as fish and amphibians, used to detect movement, vibrations, and pressure changes in the surrounding water.

• Neuromast: sensory receptor unit- consists of a cluster of hair cells and supporting cells

• Cupula: jelly-like, dome-shaped structure that encapsulates the hair cells of a neuromast- catches fluid movements

• Canal: neuromasts are shielded inside a specialized canal

• Mucous: fluid inside the sensory canals, providing a stable, viscous medium that helps transmit external water vibrations to the cupula

intrauterine cannibalism, how it occurs in sharks

oophagy- shark embryos eat each other in the womb

oviparous, ovoviviparous, viviparous

Oviparous (Egg Retention): Animals lay fertilized or unfertilized eggs outside their bodies

Viviparous (Live Bearing): Animals give direct birth to live young

Ovoviviparous (Egg Retention/Live Birth): A middle ground where eggs form inside the mother, but she does not lay them.

3 things more likely to result in a human death than a shark attack

1. Lightning Strike

2. Hear Attack

3. Crushed by a vending machine

Where you are most likely to be bitten by a shark

Lover legs- 32% of bites

aquatic activity most likely to result in a shark attack

surfing

since the year 2000, roughly what percentage of shark attacks are fatal?

2%

threatening posture displayed by sharks

agonistic displays- lowered back, lowered pectoral fins

shark vs skate vs ray pectoral fins

sharks have smaller pectoral fins, skates and rays have larger pectoral fins, rays’ fins are attached to their head

homocercal vs heterocercal tail

homocercal tail: even distribution of net motion
heterocercal tail: uneven distribution, causes downward net motion at an angle; thrust goes into linear motion

upper jaw in sharks/lower jaw in sharks

palatoquadrate/Meckels Cartridge

male shark copulatory organ

claspers

largest shark species (max weight and length of this shark)

3 species of shark that are filter feeders

whale shark, basking shark, megamouth

issues with breathing underwater

water is very dense, less oxygen than air,

max size of a great white shark

20 ft over 7000 lbs

squalamine

anti-microbial compound in fish

how the cookie cutter shark derived its name

unique circular bite marks it leaves on prey

how to distinguish pristiformes from pristiophoriformes

placement of gill slits and presence of barbels on saw-like snouts

shark eye has more [?] (rods/cones), what is the significance?

more rods, as most species are adapted to low light

6 main characteristics of craniata

has a cranium, jaws, cardiovascular system, eyes, gills

heterocercal vs homocercal tails in fish

homocercal: symmetrical, equal upper and lower lobes
heterocercal: asymmetrical, elongated upper lobe where vertebral column extends

4 characteristics of modern chondrosteans

cartilagenous endoskeleton, heterocercal tail, reduced squamation, spiral valve intestine

3 characteristics of Actinopterygii

ray-fins, swim bladder, operculum

What division contains approximately 95% of all living fish?

bony fish (osteichthyes)

the direct connection between the gas bladder and the ear

weberian apparatus

gill arch structure labeled

light producing cells in lantern fish

photocytes

troglobitic

underground/cave-based animals that live in permanent darkness

solubility of oxygen in water varying w temp and salinity

facultative vs obligatory air breathing in fish (which can drown?)

obligatory fish can drown

4 air breathing organs other than gills found in fish

gas bladder, lung, skin, labryinth organ

one benefit and cost of ram ventilation

benefit: reduces energy expenditure
cost: forces animal to constantly swim forward to breathe

osteichthyes meaning

bony fish

evolution of lungs, relevance of dipnoi

modification of the gas bladder in order to allow fish to breathe air in oxygen-poor or stagnant freshwater habitats

• dipnoi (lungfish) share a common ancestry with land-dwelling vertebrates

4 general characteristics of Sarcopterygii

• fleshy, lobed paired fins, enamel-covered teeth, two dorsal fins, endochondral bone (bone tht develops to replace cartilage)

99% of the 30000 species of fish belong to which class?

actinopterygii

what extant species belongs to Amiiformes

bowfins

primary functions of gas bladder

regulate buoyancy without wasting energy on constant swimming