Ichthyology Lecture Notes

Flashcards about ichthyology

Ichthyology

The study of fish

FISH

The members of a single species

FISHES

More than one species of fish

Fish taxa

Cephalochordata, Hagfishes, Lampreys, Conodonts, “Ostracoderms”, Placoderms, Holocephali, Elasmobranchii, Acanthodii, Actinopterygii, Sarcopterygii

Major Fish Groups

“Cyclostomes”, Gnathostomata, “Agnathans”, Chondrichthes, Osteichthyes, Vertebrata

What are fish?

Aquatic vertebrates that have fins, scales, and gills

Examples of AGNATHA, primitive jawless fish

Lampreys and Hagfish

What are CHONDRICHTHYES?

The jawed fish with cartilaginous skeletons

What are OSTEICHTHYES?

Fish with bony skeletons

When do the earliest fish appear in the fossil record?

~540 mya

The "Age of Fishes"

The Devonian period

What accompanied the evolution of Jaws?

Formation of paired pectoral fins and pelvic fins

How do most fish exchange gases?

Using gills

What is the protective bony covering over the gill slit called?

Operculum

What do the specialized organs that serve as lungs allow lungfish to do?

Allows them to survive in oxygen poor water or areas where water dries up often

What are the 4 chambers of the fish heart?

Sinus venosus, Atrium, Ventricle, Conus arteriosus

What form do most fish rid themselves of nitrogenous wastes?

Ammonia

Which organ controls the amount of water in the bodies of fish?

Kidneys

What are the major parts of the fish brain?

Olfactory bulbs, Cerebrum, Optic Lobe, Cerebellum, Medulla oblongata

What is the function of the Cerebellum?

Coordinates body movements

What is the function of the Medulla oblongata?

Controls internal organ functions and maintains balance

What purpose do the ears serve for fish since they do not hear sounds?

Lets them feel their surroundings

What are the two sections fish ears divided into?

Pars superior (balance) and utriculus (hearing)

What is the function of the lateral line?

Receives signals stimulated in a sequence, and gives the fish much more information and short-range prey detection

What is the organ responsible for distant touch?

Neuromast

What is a neuromast?

Cluster of hair cells which have their hairs linked in a glob of jelly known as 'cupala'

What gives the fish directional input?

A free neuromast

How do fish eyes differ from humans?

They cannot dilate or contract their pupils because the lens bulges through the iris

What is the function of the Tapetum lucidum?

To amplify incoming light

Where are taste buds located on fish?

Lips, tongue, and all over their mouths

What are barbels?

Whiskers that have taste structures

Which organ detects chemicals in fish?

Olfactory rosette

What electroreceptive system do sharks and rays posses?

Ampullae of Lorenzini

What acts as a fulcrum for fish movement?

The skull

What are the muscles arranged in multiple directions that allow the fish to move in any direction called?

Myomeres

What are the different types of fins?

Caudal fin, Pectorals, Pelvic fins, Dorsal/anal

What is the function of the Caudal fin?

Provides thrust, and control the fishes direction

What is the function of the Pectorals fins?

Act mostly as rudders and hydroplanes to control yaw and pitch, also act as very important brakes by causing drag

What is the function of the Pelvic fins?

Mostly controls pitch

What is the function of the Dorsal/anal fins?

Control roll

What is the function of the gas filled swim bladder?

To adjust buoyancy and keep from sinking

What are the different body shapes of fish?

Fusiform, Attenuated, Depressed, Compressed

What are the feeding strategies of fish?

Carnivores, Herbivores, and Detritovores, Parasites, Filter feeders

What are the three modes of reproduction for fish?

Oviparous, Ovoviviparous, Viviparous

What does Oviparous reproduction entail?

Lay undeveloped eggs

Where does fertilization take place in Oviparous fish?

External fertilization (90% of bony fish), Internal fertilization (some sharks and rays)

What does Ovoviviparous reproduction entail?

Internal development- without direct maternal nourishment

What does Viviparous reproduction entail?

Internal development with direct nourishment from mother

What is a sequential hermaphrodite?

Species whose individuals may change sex at some time in their life

What is protandry?

Change from being males to females

What is protogyny?

Change from being females to males

What are the characteristics of Agnatha?

No jaws, no true teeth, cartilaginous skeleton, scaleless skin, oral sucker in place of jaws

What is an anadromous fish?

Spend lives in marine water, but migrate to fresh water to breed

What is a catadromous fish?

Live in fresh water and migrate to marine water for breeding

What are Lampreys as larvae and adults?

Filter feeders as larvae and parasites as adults

What are some characteristics of Hagfish?

Pinkish gray, wormlike bodies and four or six short tentacles around their mouths, lack eyes, feed on dead and dying fish

Examples of Chondrichthyes

Sharks, skates, rays, sawfish, chimera

What are the characteristics of Chondrichthyes?

Cartilaginous skeleton, skin covered with denticles, five to seven gill slits per side, no swim bladder, internal fertilization

What are the characteristics of Sharks?

Large curved tails, torpedo shaped bodies, rounded snouts, mouth “underneath” or on the ventral side

What are the characteristics of Skates and Rays?

Glide through the sea with large, wing-like pectoral fins, bodies are flattened from top to bottom

What environment to skates and rays typically live?

Skates live in cold seas; rays live in warm seas and in some tropical rivers

What are the skeletons of Osteichthyes made of?

Hard calcified tissue called bone

What does "Ray-finned" refer to?

Slender bony spines, or rays, that are connected by a thin layer of skin to form the fins