COA 423: Anatomy

Canineiforms

large conical teeth located at the corners of the mouth:

→ useful in ripping apart exoskeltons and flesh

Villiform

small, fine teeth. Needlelike

→ pierce through skin

Molariform

pavement like crushing teeth, forms plates or individual molars

→ grinds up prey and crushes exoskelton

Cardiforms

fine, pointed teeth arranged as in a woold card

→ allows for a piercing grip when prey is swallowed whole

Incisors

Large teeth flattened cutting surfaces

→ primary prey: mollusks and crustaceous

→ can pick aparrt prey

Beaks

teeth morphed into a sharp structured

→ used for scraping plant materials off surface for consumption, or cutting into a hard shell

Flattened Triangular

teeth that are flattended and sharp

→ wide range of prey from squid, small fish, crusteceansm and marine mammals

→ pierce and hold prey in place to be consumed quickly

Pharygneal teeth

teeth located on the pharygneal arch that can exhbiti multiple types of teeth for secondary consumption

finlets

series of small doesal and anal finlets w/ a paried keel at the caudal fin

Branchicranium

consists of five series of endoskeletal arches (mandibular arch, palatine, hyoid, opercular, and branchial)

Mandibular Arch

forms upper jaw,

in bf: composed entirely of dermal bones

→palatoquadrate cartialge in Chondrichtyes

Palatoquadrate cartilage

mandibualr arch name in Chondrichtyes

Characiformes, Siluriformes, Salmoniformes, Myctophiforms, Trout Perches

orders that have adipose fins

Spines

hard and pointed

unsegmented

unbranched

solid

located in the first dorsal fin in advanced teleosts

soft rays

soft, not pointed segment

segemented

usually branched

bilateral, with left and right halves

usually found on the 2nd dorsal fin in advanced teleosts

Protocercal

caudal tail, primited, undifferentiated that extends around posterior

heterocercal tail

unequal lobed, verebral column extends to upper lobe

homocercal

equal lobed, caudal fin rays arranged symmetrically

found in most actinopterygii

leptocercal tail

caudal fin with he spinal column extending horizontally to the end of the tail, r

isocercal tail

caudal tail wehre last vertebra is modified into small plate to which caudal fin rays are attached

gephyrocercal tail

lack a true tail, modified elements of dorsal and anal fin form tail (Molidae)

Placoid Scales

Outlayer: vitrodentine, derived from the ectoderm. Largley noncellular

flattened rectangular basal plate in upper part of the dermis, from which a protruding spine projects

do not increase in size, grow in between each other

Belong to: Chondricthyes

Cosmoid Scales

Two basal layers:

→ Isopedine: dense lamellar bone

→ cancellous: spongy bone

covered in noncellular cell like structure (Cosime)

growth by addition of new lamellar bone

arose from fusion of two placoid scales

GROUP: fossilized colecanths, lungfishes

Ganoid

Rhombodial shaped scales with peg and socket joints between them

contains ganoine

coated in dentine layer

GROUP: Chondrostei, Holostei

ganonine

inorganic bone salt secreted by the dermis. Calcified noncellular

Cycloid

dermal scales with no enamel layer

circular

thin bony dermal plate replaces ganoine

lack ctenii, instead contaning breeding tubercules and contact organs

anterior portion depressed in dermis due to unequal pulling of muscles of fishes

covered by the posterior margin of preceeding scale

Layers:

→ surface bony layer containing claclium phosphate and calcium carbonate

→ Fibrillary plate: Collagen

Ctenoid

→ riunded, dermal scales with no enamal layer

→ contain ctenii

→ thin bony dermal plate replaces ganoine

anterior portion depressed in dermis due to unequal pulling of muscles of fishes

covered by the posterior margin of preceeding scale

Layers:

→ surface bony layer containing claclium phosphate and calcium carbonate

→ Fibrillary plate: Collagen

Scales can be crenate, spinoid, peripheral or transforming

made of organic protein, albuminoids(collagen)

white muscle

muscle in a fish that is used anaerobically

lacks myoglobin

fatigues quickly, mostly used in short durations

red muscle

muscle that forms a thin sheet under the skin; invovled in sustained swimming

hard to fatigue

abundant in myoglobin

1

amount of circut systems in a fish

alimentary canal

digestive system of a fish;

includes mouth, buccal cavity, foregut, intenstive, rectum

spiral

shape of Chondrichtyes and other primitive fishes intestine that increases the surface area of the stomach

gonopodium

modified anal fin for spermatophore tranfer in livebearing fish

ex: mollies

Gymnotiformes

group of fish whose anal fin is elongated and used for locomotion

Ribbon fishes

group of fish whose anal fin is reduced or lost

Gadidae

family of fish with an isocercal tail

kidneys

primary organs invovled in exrection and osmoregulation

→ FW: produced highly dilute urine

→ SW: extremely low volume of highly concentrated urine

testes

male internal organ, longitidual, and paried

→ can constitute as much as 12% body mass

ovaries

female gonad internal, usually longitudinal, and paired or fused

→ 70% of body mass

ceratotrichia

horny fin rays made of elasin and dermal cells that support fin rays in Chondrichtyes

lepidotrichia

bony supporting elements in median fins in bony fishes. replaces ceratotrichia in ontogeny. dervied from scales

Morphometric

measurable characteristics such as fin lengths, eye diameter, or ratios between such characters

Anatomical

characters of the skeleton (osetology) and characters of the soft anatomy

→ color, patterns, sexually dimoprhic stutuctures

Molecular

characters of nuclear or mitcohdonrial DNA used for classifcation

Meristic

characters that correspond to body segments(myomeres), such as number of vertbrae, fin rays; also number of scales, gill rakers, cephalic pores

→ counts are reproduced