food/feeding & reproduction

function of carnassials

shearing of soft or tough food

function of molars in monivore

rolling and crushing of turgid or brittle food

function of cheek teeth in ungulate

shredding and grinding of tough, fibrous food

know muscles and functions

• temporalis (T): holds jaws closed and aid in vertical chewing action (in carnivores); maintains horizontal movement of molars for grinding fibrous food (in herbivores)

• masseter (M): stabilizes the articulation of jaw

• digastric (D):

• pterygoid (P): helps to position carnassials

name muscle

temporalis: holds jaw closed and aid in vertical chewing action in carnivores; maintains horizontal movement of molars for grinding fibrous food in herbivores

name muscle

masseter: stabilizes articulation of jaw

name muscle

digastric:

name muscle

pterygoids: helps to position carnassials

what type of eater does this belong to

insectivore - primitive condition of eutherians

• short intestine

• no cecum

• alimentary canal short

what type of eater does this belong to

carnivore

• short intestine and colon

• small cecum

which eater does this belong to

nonruminant herbivore

• simple stomach

• large cecum

which eater does this belong to

ruminant herbivore

• four-chambered stomach with large rumen

• small and large intestine

carnivory

• arboreal, terrestrial, marine

• sharp cutting teeth, some with homodont dentition

• sanguinivorous (blood-eating)

• piscivorous (fish-eating)

herbivory types

• browsers and grazers

  • hooved mammals

  • aquatic grazers

• gnawing mammals

  • rodents and lagomorphs

  • coprophagy

herbivore dentition

• selenodont in ruminant artiodactyls

• canines reduced or absent

• broad molars for crushing, shredding, grinding

foregut fermentation

• also called rumination

• four chambered process

  • rumen: first and largest

  • reticulum: second chamber; fermentation continues

  • regurgitation and chewing

  • omasum: third chamber; muscular walls knead food further

  • abomasum: fourth chamber; true stomach; digestion complete

• digested materials move to small intestines' for absorption

hindgut fermentation

• food masticated during eating, and digestion begins with salivary enzymes

• digestion continues in a simple stomach

• finely ground particles pass into cecum

• colon acts as principal fermentation chamber for larger species

hindgut fermenter traits

• efficiency of nutrient extraction not as high

• microorganisms in cecum can’t be absorbed

• toxins absorbed in blood, liver must detoxify

• faster processing

• can work with low quality but abundant food

• 2x volume needed than what ruminants eat

foregut fermenter traits

• efficiency very high

• microorganisms absorbed

• microorganisms can detoxify alkaloids in rumen

• benefit from high quality, limited food

• doesn’t need as much volume of food

coprophagy

• feeding on feces

• in lagomorphs, rodents, shrews, and some marsupials

• evolved to optimize update of essential vitamins and minerals and enhance assimilation of energy

specializations in herbivory

• granivory: seed-eating

• folivory: leaf-eating

• frugivory: fruit-eating (bats; phalangerids; tupaiids; some primates)

• nectarivory: nectar-eating (bats; marsupial honey possums)

• gummivory: gum-eating

• mycophagy: fungus-eating

ovaries

produce ova (female gamete) and estrogen/progesterone (female hormones)

gonadotropins

• control the development of follicles

  • follicle-stimulating hormone (FSH)

  • luteinizing hormone (LH)

monotreme reproductive system

• cloaca used for urinary, defecatory, and reproductive systems

• only left ovary is functional

• mammary glands but lack nipples

• altricial newborns

marsupial reproductive system

• cloaca for urinary and defecatory systems, but reproductive system has separate opening

• choriovitelline placenta

• brief gestation

• altricial young

• long period spent in pouch

• two uteri; conception alters between two

placental reproductive system

• no cloaca

• true placenta

• relatively precocial when born

metatherian placental traits

• vascular yolk-sac chorion

• yolk sac

• relatively little attachment to developing fetus

eutherian placental traits

• chorion

• allantois

• chorionic villi extend deeply into the endometrium and form a very tight connection between mother and fetuses

estrous

period of receptivity shortly before and after ovulation

spontaneous ovulation

happens without copulation; seen in majority of mammals (sometimes seasonal)

induced ovulation

happens with copulation; seen in several species of carnivores, rodents, lagomorphs, and insectivores

semelparity