- learning objectives of lab session

- handout lists structures that must be known

- morphology

- location

- function

-Note: Function should be obtained before lab from manual, lectures, text

- watch scalpel blades, probes, pins

- wash and dry boards, pins after use

- dispose of paper towels

- place all loose specimen parts in bag, not garbage

- after removing specimen from pail, place in a secure place: don’t drip

- store valuables in a safe area

- dispose of hazards in sharps container

Responsible for male and female sharks: look at other sex)

Work in pairs (Both participate)

- review h/o on dissecting skills

Take your time, cut slowly

Scissors may be better than scalpel when there are underlying structures that shouldn’t be cut.

Spines and teeth are very sharp - can puncture gloves

Oil can stain clothing, hands.

- locate all these structures on your shark before making any cuts

- denticles : structure will be discussed in more detail in lecture

- feel surface of shark

- view thin slice under dissecting microscope

- may not see pseudobranch in spiracle at this stage of dissection

- from pectoral girdle to end, look at preserved skeleton of shark

- olfactory sac, gill filaments not visible - see gill filaments next week

- structures of vertebral column

- trunk structures, see lab manual

- caudal structures, look at tail of shark

Visceral arches = arches modified as jaw and jaw support + branchial arch

- gill arch = branchial arch

- mandibular arch - 1st visceral arch - composed of palatopterygoquadrate cartilage (upper jaw) and Meckel’s cartilage (lower jaw)

-hyoid arch - 2nd visceral arch - supports the jaw , attachment point of ligaments to the jaw

Table 2: Digestive system

locate mesenteries before dissecting the digestive system

cut open esophagus- internal papillae

stomach - longitudinal folds called rugae

intestine - spiral valve

hepatic ducts: very small, may not see

After digestive system dissection is complete, move digestive organs to one side to expose body wall but do not remove gut organs.

kidney lies on dorsal surface of body

- drained by archinephric ducts which lead to the cloaca

archinephric duct = mesonephric duct

- easily seen in caudal portion of the kidney in mature males

- convoluted tubule lying on kidney surface

- straight tube in immature male and female

see text for renal corpuscle, glomerulus, Bowman’s capsule, tubule

efferent ductules hard to see

ostium and mesotubarium may be hard to find on immature female

-cut above cloaca across to side of animal then just below the pectoral girdle

(diagram)

wash out body cavity dry with towel, pin to board

- may have oils (fats in cavity)