Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Vertebrae Biology 1
| Question | Answer |
|---|---|
| Class Enteropneusta | Acorn worms |
| Vertebrates reached their peak of diversity about | 12 to 14 million years ago |
| For each living species there are about | 100 extinct species |
| The largest to smallest groups of vertebrates | fish 48 percent, amphibians 11 percent, reptiles 14 percent, birds 17 percent and mammals 8 percent |
| Phylum chordata characteristics | notochord, dorsal hollow nerve cord, post anal tail, pharyngeal slits |
| Subphylum Urochordata | Sea Squirts |
| Subphylum Cephalochordata | Lancelets |
| Jawless fish | Agnath. All other are Jawed or Gnathostomes |
| Pisces | Vertebrates that live in water |
| Tetrapods | Land vertebrates |
| Non-amniotes | Embryos enclosed in membranes produced by the reproductive tract of the female |
| Amniotes | Additional set of m embranes produced by the embryo; one of which is the amnion |
| Spiral cleavage | , the cells divide at slight angles to one another, so that the none of the four cells in one plane of the eight-cell stage is directly over a cell in the other plane |
| Radial cleavage | , the cells divide such that each cell in the top four cell plane is directly over one other cell in the bottom plane. |
| In most vertebrates the notochord becomes | the vertebral column |
| One thing that differs in the vertebra of humans and fish is | the neural (human) and hemal arch |
| Instead of vertebrata some scientists prefer to say | craniata because not all vertebrates (like hagfish)have a true vertebral column but all vertebrates have skulls |
| Telosts fish | the most abundant type of fish |
| Determinate cleavage | It results in the developmental fate of the cells being set early in the embryo development. Each cell produced by early embryonic cleavage does not have the capacity to develop into a complete embryo. |
| Indeterminate cleavage | when the original cell in a deuterostome embryo divides, the two resulting cells can be separated, and each one can individually develop into a whole organism. |
| Notochord | stiff rod; lies dorsal to coelom; hydrostatic organ: flexible, prevents telescoping of body; internal support, aids in locomotion; derived from mesoderm In mammals it becomes the intervertebral disks |
| Pharyngeal gill slits | series of slits behind the mouth into the pharynx ( muscular tube that connects the mouth to the digestive tract |
| Gill slits were originally used for | suspension feeding. Later, with addition of vascularized gills functioned in respiration |
| The nerve cord in arthropods and vertebrates differs also by | its positioning, The nerve cord is positioned dorsally in vertebrates. In invertebrates it is positioned on the ventral side |
| Endostyle or thyroid gland | Ciliated, glandular groove on the floor of pharynx that secretes mucous for trapping food particles |
| Endostyle is homologous with | thyroid gland of vertebrates (endocrine gland involved in regulating metabolism) |
| Endostyle animals | Urochordates, Cephalochordates and larval lamprey |
| Thyroid animals | adult lamprey; all other vertebrates |
| The fossil Diplodocus is an example of | the backbone that characterizes vertebrates |
| Specialized area in fish vertebral columns | trunk and caudal vertebrae |
| Specialized area in tetrapod vertebral columns | Cervical (neck), trunk, sacral and caudal (tail) regions |
| Chordate characteristics | Segmented, muscular,postanal tail, notochord |
| Each vertebrae consists of | the centrum. |
| The neural arch enclose | the nerve cord |
| Hemal arch (fish) | enclose the caudal artery and vein |
| Protostome | – cell cleavage spiral and determinant; coelom originates from split of mesoderm; mouth develops from or near blastopore |
| Deuterostomes | – cell cleavage radial and indeterminant development; coelom originates from outpocketing of gut; anus forms from, or near, blastopore |
| Placodes | epidermal thickening responsible for producing, feathers,scales,hair,teeth,etc. |
| In some lizards, birds and mammals | Trunk region is divided into thoracic (rib-bearing) and lumbar (rib-less) regions |
| The synsacrum | a skeletal structure of birds and dinosaurs, in which the sacrum is extended by incorporation of additional fused or partially fused caudal or lumbar vertebrae |
| In hagfish and lamprey and cartilaginous fish the skull | is cartilaginous and known as the chondrocranium |
| In other vertebrates bones of dermal origin | invade the chondrocranium and obscure it |
| Two primary differences between vertebrates and other chordates | -Duplication of the Hox gene complex -New embryonic tissues, the neural crest and placodes |
| Hox genes | Regulate the expression of a hierarchical network of other genes that control the process of development from front to back along the body. Vertebrates have more HOX genes. |
| Advantages of more Hox genes | Interactions among genes modify the effects of those genes, and more genes allow more interactions that probably produce more complex structures |
| The doubling and redoubling of Hox gene sequence during vertebrate evolution is believed to have | made the structural complexity of vertebrates possible |
| Neural crest | -New tissue in embryological development -Fourth germ layer that is unique to vertebrates (along with ectoderm, endoderm and mesoderm) -Forms many novel structures especially in head region |
| the neural crest is considered | the most important innovation in the origin od the vertebrate body plan |
| Migratory neural crest-like cells have been indentified in | a larval tunicate and may represent a precursor to the vertebrate neural crest |
| Cambrium chordate Haikouella may | have eyes and muscular pharynx which would imply the presence of neural crest tissue. This would make it the oldest chordate. |
| Appearance of many microRNA’s is a genetic innovation in vertebrates that may contribute to | their anatomical complexity |
| Phylum Chordata has two new micro RNA’s. Another three are shared by | vertebrates and tunicates and -all vertebrates possess an additional 41 unique microRNA’s |
| Chordate brain | Larger than brains of primitive chordates -Three parts: Forebrain, midbrain and hindbrain |
| Amphioxus has all the genes that code for the vertebrate brain with the exception of | the forebrain |
| Vertebrates have a unique type of mineral called | hydroxyapatite. -Complex compound of calcium and phosphorus -More resistant to acid than calcite which forms shells of mollusks |
| Evolution of hydroxyapatie may be related to the fact that | vertebrates rely on anaerobic metabolism during activity which produces lactic acid that lowers blood pH |
| Skeleton of hydroxyapatite may be more resistant to | acidification than calcite. -Probably originated first in teeth (enamel and dentine), later in dermal armor (ostracoderms) and finally skeletal system |
| Protochordates | Informal assemblage of animals that share some of the five chordate characteristics -Marine -Feed by cilia and mucus -Pelagic larvae -Benthic adults |
| Phylum hemichordata (half chordates) | -Enteropneusts (acorn worm) -Pterobranchia |
| Acorn worm chordate characteristics present | -Pharyngeal gill slits (feeding and gas exchange) -Dorsal hollow nerve cord (a short length) |
| Basic Enteropneusts body plan: | Proboscis, collar, trunk |
| Acorn worm Proboscis | -Used in locomotion (burrowing) and feeding -Have a muscular wall that encloses a fluid filled coelomic space |
| The skin of the acorn worm is covered with | cilia as well as glands that secrete mucus. Acorn worms move by cilia movements and body contractions |
| Acorn worms breathe by | drawing in oxygenated water through their mouth. The water then flows out the animal's gills which are on its trunk. |
| Acorn worms are rarely seen by humans because of their benthic burrowing lifestyle | They live in u shaped burrows where they stick out their proboscis. They are either deposit or suspension feeders. |
| Deposit feeding acorn worms excrete coils of processed sediments called | casts |
| Acorn worm feeding | -Currents created by cilia on proboscis and collar move food particles toward the mouth and digestive tract -Rejected particles move toward the outside of collar -Water leaves through the gill pores, food moves through digestive tract |
| Acorn worm sexual reproduction | Fertilization is external -In some, eggs develop into free-swimming larvae that look very similar to echinoderm larvae (this suggests vertebrates and echinoderms are closely linked phylogenetically). |
| Pterobranchia lifestyle | -Sessile and colonial lifestyle -Live in secreted tubes in oceans -Small and colonial so each ‘individual’ is generally referred to as a zooid |
| Pterobranchia body plan | -Proboscis for feeding -Collar is drawn out into elaborate tentacles used for suspension feeding -Trunk is U-shaped with the anus bending back to the top of the tube -A few pharyngeal silts are usually present |
| Hemichordate biological contribution | -Tubular dorsal nerve cord (early stage of chordate nerve cord) -Gill slits in pharynx (also chordate feature) used for primarily for feeding; secondarily for respiration |
| Subphylum Urochordata | (tunicates or ascideans) -Marine organisms- most are sessile as adults few free-living -Solitary or colonial -Globular shape and enclosed by a tunic or test which serves as an exoskeleton |
| More information on tunicates: | -Made of tunicin (animal cellulose) secreted by epidermis -Contains blood vessels and other cells In some species tunic is smooth in others it may be spiny or hairy for defense; in some it is brightly colored |
| Tunic houses | distasteful chemicals (sulfuric acid, iodine) provides chemical defense |
| In the tunicate there are two projections connected to the pharynx that regulate water flow | The incurrent (oral) siphon and the excurrent (atrial) siphon. |
| Tornaria larvae | larval form of acorn worms |
| Complex body tissues lie under tunic | -epithelial tissue that give rise to tunic and lines atrium -muscles that give shape and controls siphons -gonads, nervous tissue and an open circulatory system. |
| 5 Chordate characteristics | -Notochord -Dorsal hollow nerve cord dorsal to notochord -pharangeal pouches and gill slits Animals like sea squirts are chordates because they have these characteristics in their larval stage -post anal tail -pharynx |
| Pharyngeal basket | -Sits like a huge mesh bag hanging in a protected chamber the atrium -Attached to the base of the incurrent siphon and to the opening of the esophagus |
| Gill bars are the actual structural elements of | the pharyngeal basket and spaces between them are the slits |
| Inside the pharyngeal basket | -100's of tiny ciliated gills perforate the basket -Typically organized in regular rows so that the wall of the basket looks like a piles of fabric -Lateral cilia pump water through the gill slits and frontal cilia transport the mucous net |
| Endostyle in sea squirts | -V-shaped structure running the length of the pharyngeal basket -Secretes two continuous nets of mucous that glide across both sides of the basket to the gutter Endostyle is homolgous with thyroid gland that regulates iodine levels in vertebrates |
| Sea squirt Gutter | Ciliated band opposite the endostyle Roles up the mucous net into a cord that is pushed by cilia all the way down to the esophagus |
| Sea squirt mucous net | -Very effective filter at capturing food particles -Contains iodine which helps attract certain kinds of fine particles -Resembles a very finely woven fabric perforated with many holes |
| Sea squirt gut | -U-shaped -Short esophagus leading to stomach then to Intestine -Extracellular digestion--undigested material exits into the atrium where it leaves along with the exhalent water from the pharyngeal basket |
| Sea squirt atrium | A protected internal chamber filled with water that is pumped through the basket |
| Of the four chordate characteristics adult sea squirts have only one: | pharyngeal gill slits |
| tunicate larvae posses sensory structures not present in adults including: | -Eyespot (optic organ) -Statocyst (balance) -Free swimming |
| Tunicates undergo what is referred to as retrograde metamorphosis since | soo many traits are lost. |
| Subphylum cephalochordata | (lancelets or amphioxus) |
| In lancelets food is transferred to | the midgut caecum and filtered water passes out atripore |
| Lancelets foreshadow the vertebrate body plan | -Midgut diverticulum-secretes digestive enzymes -Segmented trunk musculature -Closed circulatory pattern -Eye spot (brain) at anterior end of nerve cord |
| The study of size and its consequences is known as | scaling |
| Scaling requires more than just making parts larger or smaller. As body size changes the demands on various body parts change | disproportionately. Size and shape are necessarily linked and the consequences affect everything from metabolism to body design |
| Scaling surface tension example | Surface tension -Human exiting a bath tub (little problem) -Ant in a drop of water (hold it prisoner) Water stridder can ‘walk’ on water |
| Scaling gravity example | -Humans (slipping risk breaking limbs) -Ants (can walk across a ceiling, fall long distances without injury) |
| A change in size usually requires a change in | design to maintain overall performance - Consequently, most organisms change shape to accommodate the different relationships among length, surface area and volume |
| When an object increases in volume | its mass increases proportionately |
| To remain functionally balanced | Length, area and mass must grow at different rates. - As a result an animal ‘must’ have different shapes at different sizes |
| Changes in shape in correlation with a change in size is called | allometry |
| Isometric growth | occurs when changes in size (during growth or over evolutionary time) do not lead to changes in proportion |
| Allometric Growth--Positive allometry | - Shape changes a lot with small changes in body size - Trait ‘y’ changes a lot with changes in trait ‘x’ Examples: - Rams horns - Male lobster claw - Birds bill |
| Negative allometry | a < 1 - Trait ‘y’ grows more slowly relative to body size or to another trait ‘x’ Example: Human eye, head relative to body size |
| Metabolic rate is an example of | negative alometry in comparison to to oher traits. |
| A smaller animal has a greater energy requirement for its size than does a larger animal, although | a larger animal needs more energy in total than does a small animal |
| Consequence of small animals having a higher metabolism: | - Small animals must eat more - Breathe more oxygen |
| Saint-Hillarie 1822 | Proposed that the chordate body plan was was derived from a flipped-over version of an arthropod’s |
| Annelids and arthropods share following characteristics | - Segmented body plan - Both have similar brain regionalization (fore- and hindbrains) |
| Neoteny or Paedogenesis and Paedomorphosis | to retain juvenile characteristics in an adult body. (ie gills on adult salamanders) |
| Many of the similarities between arthropods and vertebrates result from | analogy not homology |
| In arthropods nerve cord is | solid (not hollow) and develops embryologically in a fundamentally different way |
| Garstang (1920) was the first to propose that chordate characteristics first appeared in | echinoderm larvae. - Both deuterostomes - Larvae are both bilaterally symmetrical - Both have a one way gut |
| Garstang proposed that basic chordate plan emerged in the larval echinoderm | - Elongation of body brought circumoral ciliated band to midline of body where it became the dorsal nerve cord - Lengthening of adoral band near mouth became the endostyle - elongated body and muscular tail |
| Progenesis | early development of gonads in an otherwise larval (or juvenile) body that stops growing and never attains the adult body form |
| Larger larval size is required compensating changes in locomotion and feeding because | Surface cilia used to propel larvae would not increase fast enough to keep up with expanding mass - Selection would favor an alternative method of locomotion - Segmented muscles - Stiffened notochord |
| Feeding problems with larger larvae size | As body mass increased it would outstrip the ability of surface cilia to meet nutritional needs - An adoral band expanded into an endostlye would improve food transport |
| Heterochrony | a change in the timing of events during development |
| Neotony: | development of juvenile trait is slowed |
| Garstang proposed that a larval Urochordate underwent paedogenesis and led to the | cephalochordates and ultimately the first vertebrates |
| Wormlike deuterostomes ancestor, similar to acorn worm , evolved into | hemichordates and echinoderms along one branch and into an chordates along the other - This means that, contrary to Garstangs hypothesis, chordates did not evolve from echinoderms |
| Dipleurula larvae | the supposed common ancestor between echinoderms and chordates |
| Pikaia gracilens | Chordate-like (looks like amphioxus but not a true chordate: no gills and myomeres are straight) |
| Haikouella | Most vertebrate-like chordate that resembled amphioxus - Has the chordate features of myomeres, notochord, and pharynx enclosed in an atrium |
| Myllokunmingia and Haikouichthyes | - Advanced chodates - Presence of a cranium, paired ear capsules, and eye capsules at head makes them vertebrates since these structures are formed by neural-crest tissue |
| Conodonths (cone teeth) | - Resembled amphioxus - Greater cephalization, large eyes - Teeth-like in composition made of cellular bone, calcium phosphate crystals, calcified cartilage and enamel and dentin |
| Ostracoderms | - Extinct vertebrate. Jawless, lacked paired fins and had bony plates covering body. - pharynx developed muscles that replaced cilia |
| Myxini | hagfish or slime eel, hermaphrodites. |
| Parasitic lampreys secrete an anticoagulant to | promote blood flow on their host. |
| The Welland Canal is responsible for | the spread of parasitic lamprey in the great lakes |
| Control for the sea lamprey population began in | 1953. They used electrical barriers and chemicals. Later on sterile males were introduced. - Their population finally started to decrease in the late 60's |
| Placoderms | - Jaws - Paired appendages (pectoral and pelvic fins) - Largest animals of Devonian - Bony head and trunk shields, which are separated by a movable neck joint. |
| Origin of jaws | Thought to have arisen through modification of the first pair of anterior gill support bars |
| Second pair of gill support bars became | hyomandibular -a support structure and hinge of the jaw extending from the brain case to posterior end of upper jaw |
| Spiracle in sharks is | a left over gill slit |
| The quadrate bone is part of a skull in most tetrapods,and early synapsids. In these animals it connects to the | quadratojugal and squamosal in the skull, and forms part of the jaw joint . In sharks it is called the hymandibular. |
| Selachi (sharks) | Fusiform body, small pectoral fins, pelagic Batoidea (skates and rays) |
| Subclass Holocephali | Ratfish |
| Batoidea | Skates and rays |
| Class Sarcopterygii | lobe finned fish |
| Coeloacanth | - Lungfish |
| Actinopteregii (ray finnned fish) subclasses | - Chondrostei - Neopteregii > Division Teleotei |
| Fish epidermis | Non-keratinized - Exceptions: ‘teeth lining oral disc of lamprey, jaws of herbivorous minnows, belly of semi-terrestrial fish (mudskippers) |
| Mucous glands | - Resists bacterial infection - Reduces friction - Makes fish slippery to predators |
| Club cells: | secretions excite alarm or fear |
| Sacciform cells: | Secretions function as a repellent or toxins |
| Stratum compactum | Fibrous connective tissue composed of collagen fibers (sharks) - Fibers woven into layers termed piles that give the skin its shape and flexibility |
| Tubercles | - Outer layer of enamel - Inner layer of dentine |
| Placoid scales | Project through epidermis. Have enamel, dentine and pulp. Found in chondrichthyes |
| Cosmoid scales | Found in Sarcopterygii (lungfish). Also made of enamel and dentine made of cosmine. |
| Ganoid scales | Found in Chondrostei and Neopterygii fish of the class Actiopterygii. Enamel made of ganoin and dentine. |
| Circular bands in scales are used to | tell the age of fish. |
| Cycloid and Ctenoid scales | Scales seen in fish of the division teleosti. Covered in skin. |
| Mechanoreceptors | Sensory cells responsive to small changes in mechanical force. (example, hair cell) |
| Hair cell | Detect mechanical stimuli in water Transform mechanical stimuli in to electrical stimuli |
| Stimulation of hair bundle triggers | ionic changes in hair cell and is transmitted by neurons to central nervous system |
| Hair cells have a large extension called | kinocilium and a smaller ones called stereocilia. |
| Neuromast organ | A collection of hair cells covered by a fluid filled cupula that accentuates mechanical stimulation of hair cells |
| The neuromast organ is a fundamental component of | - Lateral line - Inner ear vestibular apparatus - Auditory system |
| Lateral line is present in | agnathans, fish, sharks, and aquatic amphibians. |
| Neuromasts respond directly to water currents produced by | surface feeding, distance touch,navigation,and school formation. It may also be sensitive to low frequency sounds |
| Balancing organ | keeps central nervous system informed as to whether an animal is at rest or in motion and conveys information about its orientation |
| The balancing organ is suspended in | the octic capsule of the skull which is composed of: - Semicircular canals - Sacculus - Utriculus |
| The lateral line consists of | long recessed canals that run through the head, along sides of body, and tail. - Neuromast organs occur in the bottom of the canals |
| Number of semicircular canals in chordates and vertebrtes | - 1 in hagfish - 2 in lamprey - 3 in all other vertebrates |
| Cristae | - Sensory receptors within the semicircular canals - Each cristae is an expanded neuromast organ - Located in an ampullae at base of each semicirular canal |
| Fluid in semicircular canals moves as | head is rotated or turns (angular acceleration) which stimulates hair cells in cristae |
| Macula | - Sensory receptor found within the sacculus and utriculus - Neuromast organ with tiny calcium carbonate mineral crystals (otoconia or otoliths) imbedded in surface |
| Otoliths, or "earstones", are found in the head of | all fishes other than sharks, rays and lampreys. - They are white and about the size of a pea, found in the skull just below the rear of brain. 3 in each fish. The largest is used to determine age in fish. |
| Hearing in fish generally involves two organs called | sacculus and lagena - Maculae within the sacculus and lagena are the sound receptors |
| Differences in size & shape of otoconia are thought to lead to | slight differences in hair cell stimulation and thus allow the perception of different frequencies of sound |
| Weberian Ossicles | Structure that connects the swim bladder to the auditory system in fishes - sound waves are transferred to between swim bladder and sacculus and lagena by this structure |
| Weberian osccilces are found in a group of teleost fish called the | Ostariophsi - include catfish, minnows and knifefish |
| Two types of electroreceptors | Ampullary and Tuberous receptors |
| Ampullary receptors | Detect steady, low level electric currents given off by active respiration and muscles of living organisms |
| Tuberous Receptors | Detect phase or rapidly changing discharges of electricity |
| Ampullae of Lorenzini | jelly filled canals that sense electricity emitted by muscle contractions of living organisms |
| Sharks use their electroreceptor ampullae for | - navigation Electromagnetic field of Earth’s surface produces tiny voltage gradients - detecting prey |
| Electrocytes | Muscles that have lost the ability to contract. Specialized for generating an ion current. |
| Chemoreceptors | Receptors sensitive to chemical stimuli - Taste and smell |
| Olfactory epithelium | Contains chemoreceptors |
| Olfactory tract | Long axons connecting olfactory bulb to rest of brain |
| Molecules (scents) captured in mucous lining of olfactory epithelium attach to | receptors inside the lining of nasal cavities - Each receptor is tuned to a different kind of odor molecule |
| The olfactory epithelium | All of the genes that are involved in smelling are active in tissues involved in smelling |
| Tidal flow | water carrying chemicals flows in and out of sacs through same opening (lamprey) |
| Unidirection | one-way flow - Enters through incurrent apeture - Exits through excurrent apeture |
| Two types of smelling genes | Water base receptors and air based. Jawless fish have a combination of both. Mammals have most odor receptors. |
| 3% of human genome is devoted to odor genes however only about 300 are functional because | Humans (and other primates) traded smell for sight |
| Median or Parietal Eye | - Simplest of all vert. eyes - Located near the middle of the top of head - Found in a few fishes (also frogs and lizards) |
| Three layers of eye | sclera,uvea and retina |
| Sclera | outer layer, white of eye - helps maintain shape and rotate eye |
| Uvea | - middle region of eye composed of three regions * Choroid * Ciliary body * Iris |
| Choroid | lies next to retina. Pigmented - Provides nutritional support to ocular tissue |
| Tapetum lucidum - | part of choroid in nocturnal animals that reflects light back to retina increasing vision in low light Conditions (eye shine) |
| Ciliary body | Tiny circle of smooth muscle around the interior of the eyeball - Attached to the flexible lens by the suspensory ligament |
| Iris | A thin continuation of the uvea across the front of the eyeball |
| Retina | - inner most layer of eye, composed of three layers - Composed of rods and cones (color)(some fish and all other vertebrates) |
| Fovea | Point at back of eye where light converges Composed entirely of cones |
| To focus an image, light rays must be bent so they | converge on the retina |
| In terrestrial vertebrates the cornea | does most of the focusing. In aquatic animals the cornea contributes little. |
| Elasmobranchs | Gills lie lateral to branchial arch |
| Dual Pump mechanism | Creates alternating negative and positive pressure to draw water in and then drive it across gills |
| Dual pump involves two chambers | - Branchial pouch (area of gills) - Parabranchial pouch (area between gills and flaps) |
| Tropical catfish are able to diffuse oxygen through | their digestive tract because of their highlu vascularized gut. Most air breathing fish live in tropical water where oxygen in water is poor. |
| lungs in fish derive from the outpocketing of | the esophagus |
| Single Circulation | - heart to gills to systemic tissue back to heart - characteristic of fish |
| Double Circulation | - Birds and Mammals - tissue to heart to lungs, no mixing of oxygenated and deoxigenated blood |
| Anterior cardinal veins (jugular) drain the head and posterior cardinal veins drain | the body; these unite on each side in a common cardinal vein that enters the atrium of the heart |
| Ammonotelism | Direct excretion of ammonia. Converting to urea and uric acid requires more energy |
| Some verts. switch between ammonia and urea like | The African lungfish: - Aquatic phase- ammonia During aestivation- ammonia is converted to urea which can accumulate without the need for large amounts of water |
| Regional Heterothermy | - some fish have the ability to maintain different temp. in different parts of their bodies (sharks and tuna) |
| fish lacks the tendinous system connecting muscle bundles to | the skeleton of the animal |
| Fish have trunk muscles, consisting of a series of block muscles called | myotomes, separated by connective tissue called myosepta which are anchored to the skeleton |
| Vertical septum separates muscles into right and left halves.On each side of body, a horizontal septum divides the myotomes into | epaxial (upper) and hypaxial (lower) muscles |
| Red (slow) muscles | - require oxygen - contain myoglobin for O2 transport, a higher fat content, more mitochondria - Highly vascularized - good for prolonged activity |
| White (fast) muscles | - Most fish muscle, particularly in benthic, slow moving fish - Larger diameter, no myoglobin, little lipid, few mitochondria, little vascularization - Function anaerobically producing lactic acid |
| Anguilliform | eels and some sharks - entire body involved in swimming |
| Fish need to overcome 4 effects to swim | gravity, thrust, lift, drag |
| High viscous drag: | Thin bodies- large surface area relative to its muscle mass |
| High inertial drag | Thick body- because it displaces a large volume of water as it moves forward |
| Physostomic (stoma = mouth) | Open, duct connects to gut - Herring, carp, catfish - gulp air |
| Physoclistic (clistic = closed) | Closed, duct lost - 2/3 teleost fish - use gasses |
| Bones of Jaw | - Palatoquadrate (upper jaw) - Meckels cartilage (lower jaw) - Hyomandibular (jaw suspension |
| Hyolistic jaw | Some fish and sharks have this jaw - plataquadrate separate from skull, jaws attached to it |
| Modified hyolistic jaw | teleosts have this jaw - premaxilla fixed to jaw |
| Amphiphistic | primitive jaws of primitive fish - plataquadrate strongly attached |
| autostylistic | lingfish and chimeras - plataquadrate becomes part of skull |
| In modern fish premaxilla and maxilla are movable. Movement of maxilla and premaxilla creates | a strong suction—tube |
| Acrodont | -- rootless teeth; attached to the rim of the jawbone (e.g., most bony fish, some lizards, tuatara) |
| Pleurodont | -rootless teeth; attached to lingual side of jaw (e.g., some lizards, snakes) |
| Thecodont | having teeth rooted in sockets (e.g., mammals, crocodilians, toothed birds) |
| Polyphodont | - teeth are continuously replaced throughout life |
| Pyloric caeca | - Junction of intestine and stomach - Fat absorption, secrete digestive enzymes - Unique to teleost fish |
| Spiral valves | - Sharks, chimaeras, lungfish, sturgeon - Located in intestine - Aids digestion by increasing absorptive area and reducing rate of food passage |
Created by:
awahay
Popular Biology sets